Merge branch 'main' into libjpeg-turbo

.appveyor.yml

@@ -6,6 +6,7 @@ init:
 # Uncomment previous line to get RDP access during the build.
 
 environment:
+  COVERAGE_CORE: sysmon
   EXECUTABLE: python.exe
   TEST_OPTIONS:
   DEPLOY: YES

.ci/requirements-cibw.txt

@@ -1 +1 @@
-cibuildwheel==2.16.2
+cibuildwheel==2.16.5

.ci/requirements-mypy.txt

@@ -0,0 +1 @@
+mypy==1.7.1

.coveragerc

@@ -10,6 +10,11 @@ exclude_also =
     if DEBUG:
     # Don't complain about compatibility code for missing optional dependencies
     except ImportError
+    if TYPE_CHECKING:
+    @abc.abstractmethod
+    # Empty bodies in protocols or abstract methods
+    ^\s*def [a-zA-Z0-9_]+\(.*\)(\s*->.*)?:\s*\.\.\.(\s*#.*)?$
+    ^\s*\.\.\.(\s*#.*)?$
 
 [run]
 omit =

.github/FUNDING.yml

@@ -1 +1 @@
-tidelift: "pypi/Pillow"
+tidelift: "pypi/pillow"

.github/workflows/docs.yml

@@ -7,10 +7,12 @@ on:
     paths:
       - ".github/workflows/docs.yml"
       - "docs/**"
+      - "src/PIL/**"
   pull_request:
     paths:
       - ".github/workflows/docs.yml"
       - "docs/**"
+      - "src/PIL/**"
   workflow_dispatch:
 
 permissions:
@@ -37,16 +39,26 @@ jobs:
       with:
         python-version: "3.x"
         cache: pip
-        cache-dependency-path: ".ci/*.sh"
+        cache-dependency-path: |
+          ".ci/*.sh"
+          "pyproject.toml"
 
     - name: Build system information
       run: python3 .github/workflows/system-info.py
 
+    - name: Cache libimagequant
+      uses: actions/cache@v4
+      id: cache-libimagequant
+      with:
+        path: ~/cache-libimagequant
+        key: ${{ runner.os }}-libimagequant-${{ hashFiles('depends/install_imagequant.sh') }}
+
     - name: Install Linux dependencies
       run: |
         .ci/install.sh
       env:
         GHA_PYTHON_VERSION: "3.x"
+        GHA_LIBIMAGEQUANT_CACHE_HIT: ${{ steps.cache-libimagequant.outputs.cache-hit }}
 
     - name: Build
       run: |

.github/workflows/macos-install.sh

@@ -2,7 +2,16 @@
 
 set -e
 
-brew install libtiff libjpeg openjpeg libimagequant webp little-cms2 freetype libraqm
+brew install \
+    freetype \
+    ghostscript \
+    libimagequant \
+    libjpeg \
+    libraqm \
+    libtiff \
+    little-cms2 \
+    openjpeg \
+    webp
 export PKG_CONFIG_PATH="/usr/local/opt/openblas/lib/pkgconfig"
 
 # TODO Update condition when cffi supports 3.13

.github/workflows/release-drafter.yml

@@ -23,6 +23,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       # Drafts your next release notes as pull requests are merged into "main"
-      - uses: release-drafter/release-drafter@v5
+      - uses: release-drafter/release-drafter@v6
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/system-info.py

@@ -6,6 +6,7 @@ This sort of info is missing from GitHub Actions.
 Requested here:
 https://github.com/actions/virtual-environments/issues/79
 """
+
 from __future__ import annotations
 
 import os

.github/workflows/test-cygwin.yml

@@ -26,6 +26,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+env:
+  COVERAGE_CORE: sysmon
+
 jobs:
   build:
     runs-on: windows-latest
@@ -47,9 +50,8 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install Cygwin
-        uses: cygwin/cygwin-install-action@v4
+        uses: egor-tensin/setup-cygwin@v4
         with:
-          platform: x86_64
           packages: >
             gcc-g++
             ghostscript
@@ -69,6 +71,7 @@ jobs:
             make
             netpbm
             perl
+            python39=3.9.16-1
             python3${{ matrix.python-minor-version }}-cffi
             python3${{ matrix.python-minor-version }}-cython
             python3${{ matrix.python-minor-version }}-devel
@@ -80,13 +83,13 @@ jobs:
             zlib-devel
 
       - name: Add Lapack to PATH
-        uses: egor-tensin/cleanup-path@v3
+        uses: egor-tensin/cleanup-path@v4
         with:
           dirs: 'C:\cygwin\bin;C:\cygwin\lib\lapack'
 
       - name: Select Python version
         run: |
-          ln -sf c:/cygwin/bin/python3.${{ matrix.python-minor-version }} c:/cygwin/bin/python3
+          ln -sf c:/tools/cygwin/bin/python3.${{ matrix.python-minor-version }} c:/tools/cygwin/bin/python3
 
       - name: Get latest NumPy version
         id: latest-numpy
@@ -141,7 +144,7 @@ jobs:
           bash.exe .ci/after_success.sh
 
       - name: Upload coverage
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v3.1.5
         with:
           file: ./coverage.xml
           flags: GHA_Cygwin

.github/workflows/test-docker.yml

@@ -101,7 +101,7 @@ jobs:
         MATRIX_DOCKER: ${{ matrix.docker }}
 
     - name: Upload coverage
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v3.1.5
       with:
         flags: GHA_Docker
         name: ${{ matrix.docker }}

.github/workflows/test-mingw.yml

@@ -26,6 +26,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+env:
+  COVERAGE_CORE: sysmon
+
 jobs:
   build:
     runs-on: windows-latest
@@ -82,7 +85,7 @@ jobs:
           python3 -m pytest -vx --cov PIL --cov Tests --cov-report term --cov-report xml Tests
 
       - name: Upload coverage
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v3.1.5
         with:
           file: ./coverage.xml
           flags: GHA_Windows

.github/workflows/test-windows.yml

@@ -26,13 +26,16 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+env:
+  COVERAGE_CORE: sysmon
+
 jobs:
   build:
     runs-on: windows-latest
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["pypy3.10", "pypy3.9", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
+        python-version: ["pypy3.10", "pypy3.9", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13.0-alpha.3"]
 
     timeout-minutes: 30
 
@@ -66,8 +69,16 @@ jobs:
     - name: Print build system information
       run: python3 .github/workflows/system-info.py
 
-    - name: python3 -m pip install pytest pytest-cov pytest-timeout defusedxml olefile pyroma
+    - name: Install Python dependencies
-      run: python3 -m pip install pytest pytest-cov pytest-timeout defusedxml olefile pyroma
+      run: >
+        python3 -m pip install
+        coverage>=7.4.2
+        defusedxml
+        olefile
+        pyroma
+        pytest
+        pytest-cov
+        pytest-timeout
 
     - name: Install dependencies
       id: install
@@ -202,7 +213,7 @@ jobs:
       shell: pwsh
 
     - name: Upload coverage
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v3.1.5
       with:
         file: ./coverage.xml
         flags: GHA_Windows

.github/workflows/test.yml

@@ -26,6 +26,10 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+env:
+  COVERAGE_CORE: sysmon
+  FORCE_COLOR: 1
+
 jobs:
   build:
 
@@ -33,7 +37,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [
-          "macos-latest",
+          "macos-14",
           "ubuntu-latest",
         ]
         python-version: [
@@ -47,11 +51,21 @@ jobs:
           "3.8",
         ]
         include:
-        - python-version: "3.9"
+        - python-version: "3.11"
           PYTHONOPTIMIZE: 1
           REVERSE: "--reverse"
-        - python-version: "3.8"
+        - python-version: "3.10"
           PYTHONOPTIMIZE: 2
+        # M1 only available for 3.10+
+        - os: "macos-latest"
+          python-version: "3.9"
+        - os: "macos-latest"
+          python-version: "3.8"
+        exclude:
+        - os: "macos-14"
+          python-version: "3.9"
+        - os: "macos-14"
+          python-version: "3.8"
 
     runs-on: ${{ matrix.os }}
     name: ${{ matrix.os }} Python ${{ matrix.python-version }}
@@ -65,17 +79,28 @@ jobs:
         python-version: ${{ matrix.python-version }}
         allow-prereleases: true
         cache: pip
-        cache-dependency-path: ".ci/*.sh"
+        cache-dependency-path: |
+          ".ci/*.sh"
+          "pyproject.toml"
 
     - name: Build system information
       run: python3 .github/workflows/system-info.py
 
+    - name: Cache libimagequant
+      if: startsWith(matrix.os, 'ubuntu')
+      uses: actions/cache@v4
+      id: cache-libimagequant
+      with:
+        path: ~/cache-libimagequant
+        key: ${{ runner.os }}-libimagequant-${{ hashFiles('depends/install_imagequant.sh') }}
+
     - name: Install Linux dependencies
       if: startsWith(matrix.os, 'ubuntu')
       run: |
         .ci/install.sh
       env:
         GHA_PYTHON_VERSION: ${{ matrix.python-version }}
+        GHA_LIBIMAGEQUANT_CACHE_HIT: ${{ steps.cache-libimagequant.outputs.cache-hit }}
 
     - name: Install macOS dependencies
       if: startsWith(matrix.os, 'macOS')
@@ -125,9 +150,9 @@ jobs:
         .ci/after_success.sh
 
     - name: Upload coverage
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v3.1.5
       with:
-        flags: ${{ matrix.os == 'macos-latest' && 'GHA_macOS' || 'GHA_Ubuntu' }}
+        flags: ${{ matrix.os == 'ubuntu-latest' && 'GHA_Ubuntu' || 'GHA_macOS' }}
         name: ${{ matrix.os }} Python ${{ matrix.python-version }}
         gcov: true
 

.github/workflows/wheels-dependencies.sh

@@ -19,7 +19,7 @@ FREETYPE_VERSION=2.13.2
 HARFBUZZ_VERSION=8.3.0
 LIBPNG_VERSION=1.6.40
 JPEGTURBO_VERSION=3.0.2
-OPENJPEG_VERSION=2.5.0
+OPENJPEG_VERSION=2.5.2
 XZ_VERSION=5.4.5
 TIFF_VERSION=4.6.0
 LCMS2_VERSION=2.16
@@ -40,7 +40,7 @@ BROTLI_VERSION=1.1.0
 
 if [[ -n "$IS_MACOS" ]] && [[ "$CIBW_ARCHS" == "x86_64" ]]; then
     function build_openjpeg {
-        local out_dir=$(fetch_unpack https://github.com/uclouvain/openjpeg/archive/v${OPENJPEG_VERSION}.tar.gz openjpeg-2.5.0.tar.gz)
+        local out_dir=$(fetch_unpack https://github.com/uclouvain/openjpeg/archive/v${OPENJPEG_VERSION}.tar.gz openjpeg-${OPENJPEG_VERSION}.tar.gz)
         (cd $out_dir \
             && cmake -DCMAKE_INSTALL_PREFIX=$BUILD_PREFIX -DCMAKE_INSTALL_NAME_DIR=$BUILD_PREFIX/lib . \
             && make install)
@@ -72,14 +72,12 @@ function build {
 
     build_simple xcb-proto 1.16.0 https://xorg.freedesktop.org/archive/individual/proto
     if [ -n "$IS_MACOS" ]; then
-        if [[ "$CIBW_ARCHS" == "arm64" ]]; then
         build_simple xorgproto 2023.2 https://www.x.org/pub/individual/proto
         build_simple libXau 1.0.11 https://www.x.org/pub/individual/lib
         build_simple libpthread-stubs 0.5 https://xcb.freedesktop.org/dist
         if [ -f /Library/Frameworks/Python.framework/Versions/Current/share/pkgconfig/xcb-proto.pc ]; then
             cp /Library/Frameworks/Python.framework/Versions/Current/share/pkgconfig/xcb-proto.pc /Library/Frameworks/Python.framework/Versions/Current/lib/pkgconfig/xcb-proto.pc
         fi
-        fi
     else
         sed s/\${pc_sysrootdir\}// /usr/local/share/pkgconfig/xcb-proto.pc > /usr/local/lib/pkgconfig/xcb-proto.pc
     fi
@@ -95,6 +93,9 @@ function build {
         done
     fi
     build_openjpeg
+    if [ -f /usr/local/lib64/libopenjp2.so ]; then
+        cp /usr/local/lib64/libopenjp2.so /usr/local/lib
+    fi
 
     ORIGINAL_CFLAGS=$CFLAGS
     CFLAGS="$CFLAGS -O3 -DNDEBUG"
@@ -131,13 +132,13 @@ untar pillow-depends-main.zip
 
 if [[ -n "$IS_MACOS" ]]; then
   # webp, libtiff, libxcb cause a conflict with building webp, libtiff, libxcb
-  # libxdmcp causes an issue on macOS < 11
+  # libxau and libxdmcp cause an issue on macOS < 11
   # if php is installed, brew tries to reinstall these after installing openblas
   # remove cairo to fix building harfbuzz on arm64
   # remove lcms2 and libpng to fix building openjpeg on arm64
   # remove zstd to avoid inclusion on x86_64
   # curl from brew requires zstd, use system curl
-  brew remove --ignore-dependencies webp libpng libtiff libxcb libxdmcp curl php cairo lcms2 ghostscript zstd
+  brew remove --ignore-dependencies webp libpng libtiff libxcb libxau libxdmcp curl php cairo lcms2 ghostscript zstd
 
   brew install pkg-config
 fi

.pre-commit-config.yaml

@@ -1,17 +1,17 @@
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.1.9
+    rev: v0.2.0
     hooks:
       - id: ruff
         args: [--fix, --exit-non-zero-on-fix]
 
   - repo: https://github.com/psf/black-pre-commit-mirror
-    rev: 23.12.1
+    rev: 24.1.1
     hooks:
       - id: black
 
   - repo: https://github.com/PyCQA/bandit
-    rev: 1.7.6
+    rev: 1.7.7
     hooks:
     - id: bandit
       args: [--severity-level=high]
@@ -32,6 +32,7 @@ repos:
     rev: v4.5.0
     hooks:
       - id: check-executables-have-shebangs
+      - id: check-shebang-scripts-are-executable
       - id: check-merge-conflict
       - id: check-json
       - id: check-toml
@@ -47,12 +48,12 @@ repos:
       - id: sphinx-lint
 
   - repo: https://github.com/tox-dev/pyproject-fmt
-    rev: 1.5.3
+    rev: 1.7.0
     hooks:
       - id: pyproject-fmt
 
   - repo: https://github.com/abravalheri/validate-pyproject
-    rev: v0.15
+    rev: v0.16
     hooks:
       - id: validate-pyproject
 

CHANGES.rst

@@ -5,6 +5,18 @@ Changelog (Pillow)
 10.3.0 (unreleased)
 -------------------
 
+- Release GIL while calling ``WebPAnimDecoderGetNext`` #7782
+  [evanmiller, radarhere]
+
+- Fixed reading FLI/FLC images with a prefix chunk #7804
+  [twolife]
+
+- Update wl-paste handling and return None for some errors in grabclipboard() on Linux #7745
+  [nik012003, radarhere]
+
+- Remove execute bit from ``setup.py`` #7760
+  [hugovk]
+
 - Do not support using test-image-results to upload images after test failures #7739
   [radarhere]
 

README.md

@@ -64,7 +64,7 @@ As of 2019, Pillow development is
                 src="https://zenodo.org/badge/17549/python-pillow/Pillow.svg"></a>
             <a href="https://tidelift.com/subscription/pkg/pypi-pillow?utm_source=pypi-pillow&utm_medium=badge"><img
                 alt="Tidelift"
-                src="https://tidelift.com/badges/package/pypi/Pillow?style=flat"></a>
+                src="https://tidelift.com/badges/package/pypi/pillow?style=flat"></a>
             <a href="https://pypi.org/project/pillow/"><img
                 alt="Newest PyPI version"
                 src="https://img.shields.io/pypi/v/pillow.svg"></a>
@@ -82,9 +82,6 @@ As of 2019, Pillow development is
             <a href="https://gitter.im/python-pillow/Pillow?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge"><img
                 alt="Join the chat at https://gitter.im/python-pillow/Pillow"
                 src="https://badges.gitter.im/python-pillow/Pillow.svg"></a>
-            <a href="https://twitter.com/PythonPillow"><img
-                alt="Follow on https://twitter.com/PythonPillow"
-                src="https://img.shields.io/badge/tweet-on%20Twitter-00aced.svg"></a>
             <a href="https://fosstodon.org/@pillow"><img
                 alt="Follow on https://fosstodon.org/@pillow"
                 src="https://img.shields.io/badge/publish-on%20Mastodon-595aff.svg"

RELEASING.md

@@ -86,7 +86,7 @@ Released as needed privately to individual vendors for critical security-related
 
 ## Publicize Release
 
-* [ ] Announce release availability via [Twitter](https://twitter.com/pythonpillow) and [Mastodon](https://fosstodon.org/@pillow) e.g. https://twitter.com/PythonPillow/status/1013789184354603010
+* [ ] Announce release availability via [Mastodon](https://fosstodon.org/@pillow) e.g. https://fosstodon.org/@pillow/110639450470725321
 
 ## Documentation
 

Tests/bench_cffi_access.py

@@ -9,21 +9,21 @@ from .helper import hopper
 # Not running this test by default. No DOS against CI.
 
 
-def iterate_get(size, access):
+def iterate_get(size, access) -> None:
     (w, h) = size
     for x in range(w):
         for y in range(h):
             access[(x, y)]
 
 
-def iterate_set(size, access):
+def iterate_set(size, access) -> None:
     (w, h) = size
     for x in range(w):
         for y in range(h):
             access[(x, y)] = (x % 256, y % 256, 0)
 
 
-def timer(func, label, *args):
+def timer(func, label, *args) -> None:
     iterations = 5000
     starttime = time.time()
     for x in range(iterations):
@@ -38,7 +38,7 @@ def timer(func, label, *args):
     )
 
 
-def test_direct():
+def test_direct() -> None:
     im = hopper()
     im.load()
     # im = Image.new("RGB", (2000, 2000), (1, 3, 2))

Tests/check_fli_oob.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python3
 from __future__ import annotations
 
 from PIL import Image

Tests/check_jp2_overflow.py

@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 # Reproductions/tests for OOB read errors in FliDecode.c
 
 # When run in python, all of these images should fail for

Tests/helper.py

@@ -1,6 +1,7 @@
 """
 Helper functions.
 """
+
 from __future__ import annotations
 
 import logging
@@ -243,7 +244,7 @@ def fromstring(data: bytes) -> Image.Image:
     return Image.open(BytesIO(data))
 
 
-def tostring(im: Image.Image, string_format: str, **options: dict[str, Any]) -> bytes:
+def tostring(im: Image.Image, string_format: str, **options: Any) -> bytes:
     out = BytesIO()
     im.save(out, string_format, **options)
     return out.getvalue()

Tests/images/create_eps.gnuplot

@@ -1,5 +1,3 @@
-#!/usr/bin/gnuplot
-
 #This is the script that was used to create our sample EPS files
 #We used the following version of the gnuplot program
 #G N U P L O T

Tests/oss-fuzz/fuzz_pillow.py

@@ -1,5 +1,3 @@
-#!/usr/bin/python3
-
 # Copyright 2020 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");

Tests/test_000_sanity.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 from PIL import Image
 
 
-def test_sanity():
+def test_sanity() -> None:
     # Make sure we have the binary extension
     Image.core.new("L", (100, 100))
 

Tests/test_binary.py

@@ -3,12 +3,12 @@ from __future__ import annotations
 from PIL import _binary
 
 
-def test_standard():
+def test_standard() -> None:
     assert _binary.i8(b"*") == 42
     assert _binary.o8(42) == b"*"
 
 
-def test_little_endian():
+def test_little_endian() -> None:
     assert _binary.i16le(b"\xff\xff\x00\x00") == 65535
     assert _binary.i32le(b"\xff\xff\x00\x00") == 65535
 
@@ -16,7 +16,7 @@ def test_little_endian():
     assert _binary.o32le(65535) == b"\xff\xff\x00\x00"
 
 
-def test_big_endian():
+def test_big_endian() -> None:
     assert _binary.i16be(b"\x00\x00\xff\xff") == 0
     assert _binary.i32be(b"\x00\x00\xff\xff") == 65535
 

Tests/test_bmp_reference.py

@@ -10,13 +10,13 @@ from .helper import assert_image_similar
 base = os.path.join("Tests", "images", "bmp")
 
 
-def get_files(d, ext=".bmp"):
+def get_files(d: str, ext: str = ".bmp") -> list[str]:
     return [
         os.path.join(base, d, f) for f in os.listdir(os.path.join(base, d)) if ext in f
     ]
 
 
-def test_bad():
+def test_bad() -> None:
     """These shouldn't crash/dos, but they shouldn't return anything
     either"""
     for f in get_files("b"):
@@ -29,7 +29,7 @@ def test_bad():
                 pass
 
 
-def test_questionable():
+def test_questionable() -> None:
     """These shouldn't crash/dos, but it's not well defined that these
     are in spec"""
     supported = [
@@ -56,7 +56,7 @@ def test_questionable():
                 raise
 
 
-def test_good():
+def test_good() -> None:
     """These should all work. There's a set of target files in the
     html directory that we can compare against."""
 
@@ -80,7 +80,7 @@ def test_good():
         "rgb32bf.bmp": "rgb24.png",
     }
 
-    def get_compare(f):
+    def get_compare(f: str) -> str:
         name = os.path.split(f)[1]
         if name in file_map:
             return os.path.join(base, "html", file_map[name])

Tests/test_box_blur.py

@@ -16,18 +16,18 @@ sample.putdata(sum([
 # fmt: on
 
 
-def test_imageops_box_blur():
+def test_imageops_box_blur() -> None:
     i = sample.filter(ImageFilter.BoxBlur(1))
     assert i.mode == sample.mode
     assert i.size == sample.size
     assert isinstance(i, Image.Image)
 
 
-def box_blur(image, radius=1, n=1):
+def box_blur(image: Image.Image, radius: float = 1, n: int = 1) -> Image.Image:
     return image._new(image.im.box_blur((radius, radius), n))
 
 
-def assert_image(im, data, delta=0):
+def assert_image(im: Image.Image, data: list[list[int]], delta: int = 0) -> None:
     it = iter(im.getdata())
     for data_row in data:
         im_row = [next(it) for _ in range(im.size[0])]
@@ -37,7 +37,13 @@ def assert_image(im, data, delta=0):
         next(it)
 
 
-def assert_blur(im, radius, data, passes=1, delta=0):
+def assert_blur(
+    im: Image.Image,
+    radius: float,
+    data: list[list[int]],
+    passes: int = 1,
+    delta: int = 0,
+) -> None:
     # check grayscale image
     assert_image(box_blur(im, radius, passes), data, delta)
     rgba = Image.merge("RGBA", (im, im, im, im))
@@ -45,7 +51,7 @@ def assert_blur(im, radius, data, passes=1, delta=0):
         assert_image(band, data, delta)
 
 
-def test_color_modes():
+def test_color_modes() -> None:
     with pytest.raises(ValueError):
         box_blur(sample.convert("1"))
     with pytest.raises(ValueError):
@@ -65,7 +71,7 @@ def test_color_modes():
         box_blur(sample.convert("YCbCr"))
 
 
-def test_radius_0():
+def test_radius_0() -> None:
     assert_blur(
         sample,
         0,
@@ -81,7 +87,7 @@ def test_radius_0():
     )
 
 
-def test_radius_0_02():
+def test_radius_0_02() -> None:
     assert_blur(
         sample,
         0.02,
@@ -98,7 +104,7 @@ def test_radius_0_02():
     )
 
 
-def test_radius_0_05():
+def test_radius_0_05() -> None:
     assert_blur(
         sample,
         0.05,
@@ -115,7 +121,7 @@ def test_radius_0_05():
     )
 
 
-def test_radius_0_1():
+def test_radius_0_1() -> None:
     assert_blur(
         sample,
         0.1,
@@ -132,7 +138,7 @@ def test_radius_0_1():
     )
 
 
-def test_radius_0_5():
+def test_radius_0_5() -> None:
     assert_blur(
         sample,
         0.5,
@@ -149,7 +155,7 @@ def test_radius_0_5():
     )
 
 
-def test_radius_1():
+def test_radius_1() -> None:
     assert_blur(
         sample,
         1,
@@ -166,7 +172,7 @@ def test_radius_1():
     )
 
 
-def test_radius_1_5():
+def test_radius_1_5() -> None:
     assert_blur(
         sample,
         1.5,
@@ -183,7 +189,7 @@ def test_radius_1_5():
     )
 
 
-def test_radius_bigger_then_half():
+def test_radius_bigger_then_half() -> None:
     assert_blur(
         sample,
         3,
@@ -200,7 +206,7 @@ def test_radius_bigger_then_half():
     )
 
 
-def test_radius_bigger_then_width():
+def test_radius_bigger_then_width() -> None:
     assert_blur(
         sample,
         10,
@@ -215,7 +221,7 @@ def test_radius_bigger_then_width():
     )
 
 
-def test_extreme_large_radius():
+def test_extreme_large_radius() -> None:
     assert_blur(
         sample,
         600,
@@ -230,7 +236,7 @@ def test_extreme_large_radius():
     )
 
 
-def test_two_passes():
+def test_two_passes() -> None:
     assert_blur(
         sample,
         1,
@@ -248,7 +254,7 @@ def test_two_passes():
     )
 
 
-def test_three_passes():
+def test_three_passes() -> None:
     assert_blur(
         sample,
         1,

Tests/test_color_lut.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from array import array
+from types import ModuleType
 
 import pytest
 
@@ -8,6 +9,7 @@ from PIL import Image, ImageFilter
 
 from .helper import assert_image_equal
 
+numpy: ModuleType | None
 try:
     import numpy
 except ImportError:
@@ -15,7 +17,9 @@ except ImportError:
 
 
 class TestColorLut3DCoreAPI:
-    def generate_identity_table(self, channels, size):
+    def generate_identity_table(
+        self, channels: int, size: int | tuple[int, int, int]
+    ) -> tuple[int, int, int, int, list[float]]:
         if isinstance(size, tuple):
             size_1d, size_2d, size_3d = size
         else:
@@ -41,7 +45,7 @@ class TestColorLut3DCoreAPI:
             [item for sublist in table for item in sublist],
         )
 
-    def test_wrong_args(self):
+    def test_wrong_args(self) -> None:
         im = Image.new("RGB", (10, 10), 0)
 
         with pytest.raises(ValueError, match="filter"):
@@ -101,7 +105,7 @@ class TestColorLut3DCoreAPI:
         with pytest.raises(TypeError):
             im.im.color_lut_3d("RGB", Image.Resampling.BILINEAR, 3, 2, 2, 2, 16)
 
-    def test_correct_args(self):
+    def test_correct_args(self) -> None:
         im = Image.new("RGB", (10, 10), 0)
 
         im.im.color_lut_3d(
@@ -136,7 +140,7 @@ class TestColorLut3DCoreAPI:
             *self.generate_identity_table(3, (3, 3, 65)),
         )
 
-    def test_wrong_mode(self):
+    def test_wrong_mode(self) -> None:
         with pytest.raises(ValueError, match="wrong mode"):
             im = Image.new("L", (10, 10), 0)
             im.im.color_lut_3d(
@@ -167,7 +171,7 @@ class TestColorLut3DCoreAPI:
                 "RGB", Image.Resampling.BILINEAR, *self.generate_identity_table(4, 3)
             )
 
-    def test_correct_mode(self):
+    def test_correct_mode(self) -> None:
         im = Image.new("RGBA", (10, 10), 0)
         im.im.color_lut_3d(
             "RGBA", Image.Resampling.BILINEAR, *self.generate_identity_table(3, 3)
@@ -188,7 +192,7 @@ class TestColorLut3DCoreAPI:
             "RGBA", Image.Resampling.BILINEAR, *self.generate_identity_table(4, 3)
         )
 
-    def test_identities(self):
+    def test_identities(self) -> None:
         g = Image.linear_gradient("L")
         im = Image.merge(
             "RGB",
@@ -224,7 +228,7 @@ class TestColorLut3DCoreAPI:
             ),
         )
 
-    def test_identities_4_channels(self):
+    def test_identities_4_channels(self) -> None:
         g = Image.linear_gradient("L")
         im = Image.merge(
             "RGB",
@@ -247,7 +251,7 @@ class TestColorLut3DCoreAPI:
             ),
         )
 
-    def test_copy_alpha_channel(self):
+    def test_copy_alpha_channel(self) -> None:
         g = Image.linear_gradient("L")
         im = Image.merge(
             "RGBA",
@@ -270,7 +274,7 @@ class TestColorLut3DCoreAPI:
             ),
         )
 
-    def test_channels_order(self):
+    def test_channels_order(self) -> None:
         g = Image.linear_gradient("L")
         im = Image.merge(
             "RGB",
@@ -295,7 +299,7 @@ class TestColorLut3DCoreAPI:
                     ])))
         # fmt: on
 
-    def test_overflow(self):
+    def test_overflow(self) -> None:
         g = Image.linear_gradient("L")
         im = Image.merge(
             "RGB",
@@ -348,7 +352,7 @@ class TestColorLut3DCoreAPI:
 
 
 class TestColorLut3DFilter:
-    def test_wrong_args(self):
+    def test_wrong_args(self) -> None:
         with pytest.raises(ValueError, match="should be either an integer"):
             ImageFilter.Color3DLUT("small", [1])
 
@@ -376,7 +380,7 @@ class TestColorLut3DFilter:
         with pytest.raises(ValueError, match="Only 3 or 4 output"):
             ImageFilter.Color3DLUT((2, 2, 2), [[1, 1]] * 8, channels=2)
 
-    def test_convert_table(self):
+    def test_convert_table(self) -> None:
         lut = ImageFilter.Color3DLUT(2, [0, 1, 2] * 8)
         assert tuple(lut.size) == (2, 2, 2)
         assert lut.name == "Color 3D LUT"
@@ -394,7 +398,8 @@ class TestColorLut3DFilter:
         assert lut.table == list(range(4)) * 8
 
     @pytest.mark.skipif(numpy is None, reason="NumPy not installed")
-    def test_numpy_sources(self):
+    def test_numpy_sources(self) -> None:
+        assert numpy is not None
         table = numpy.ones((5, 6, 7, 3), dtype=numpy.float16)
         with pytest.raises(ValueError, match="should have either channels"):
             lut = ImageFilter.Color3DLUT((5, 6, 7), table)
@@ -427,7 +432,8 @@ class TestColorLut3DFilter:
         assert lut.table[0] == 33
 
     @pytest.mark.skipif(numpy is None, reason="NumPy not installed")
-    def test_numpy_formats(self):
+    def test_numpy_formats(self) -> None:
+        assert numpy is not None
         g = Image.linear_gradient("L")
         im = Image.merge(
             "RGB",
@@ -466,7 +472,7 @@ class TestColorLut3DFilter:
         lut.table = numpy.array(lut.table, dtype=numpy.int8)
         im.filter(lut)
 
-    def test_repr(self):
+    def test_repr(self) -> None:
         lut = ImageFilter.Color3DLUT(2, [0, 1, 2] * 8)
         assert repr(lut) == "<Color3DLUT from list size=2x2x2 channels=3>"
 
@@ -484,7 +490,7 @@ class TestColorLut3DFilter:
 
 
 class TestGenerateColorLut3D:
-    def test_wrong_channels_count(self):
+    def test_wrong_channels_count(self) -> None:
         with pytest.raises(ValueError, match="3 or 4 output channels"):
             ImageFilter.Color3DLUT.generate(
                 5, channels=2, callback=lambda r, g, b: (r, g, b)
@@ -498,7 +504,7 @@ class TestGenerateColorLut3D:
                 5, channels=4, callback=lambda r, g, b: (r, g, b)
             )
 
-    def test_3_channels(self):
+    def test_3_channels(self) -> None:
         lut = ImageFilter.Color3DLUT.generate(5, lambda r, g, b: (r, g, b))
         assert tuple(lut.size) == (5, 5, 5)
         assert lut.name == "Color 3D LUT"
@@ -508,7 +514,7 @@ class TestGenerateColorLut3D:
             1.0, 0.0, 0.0,  0.0, 0.25, 0.0,  0.25, 0.25, 0.0,  0.5, 0.25, 0.0]
         # fmt: on
 
-    def test_4_channels(self):
+    def test_4_channels(self) -> None:
         lut = ImageFilter.Color3DLUT.generate(
             5, channels=4, callback=lambda r, g, b: (b, r, g, (r + g + b) / 2)
         )
@@ -521,7 +527,7 @@ class TestGenerateColorLut3D:
         ]
         # fmt: on
 
-    def test_apply(self):
+    def test_apply(self) -> None:
         lut = ImageFilter.Color3DLUT.generate(5, lambda r, g, b: (r, g, b))
 
         g = Image.linear_gradient("L")
@@ -537,7 +543,7 @@ class TestGenerateColorLut3D:
 
 
 class TestTransformColorLut3D:
-    def test_wrong_args(self):
+    def test_wrong_args(self) -> None:
         source = ImageFilter.Color3DLUT.generate(5, lambda r, g, b: (r, g, b))
 
         with pytest.raises(ValueError, match="Only 3 or 4 output"):
@@ -552,7 +558,7 @@ class TestTransformColorLut3D:
         with pytest.raises(TypeError):
             source.transform(lambda r, g, b, a: (r, g, b))
 
-    def test_target_mode(self):
+    def test_target_mode(self) -> None:
         source = ImageFilter.Color3DLUT.generate(
             2, lambda r, g, b: (r, g, b), target_mode="HSV"
         )
@@ -563,7 +569,7 @@ class TestTransformColorLut3D:
         lut = source.transform(lambda r, g, b: (r, g, b), target_mode="RGB")
         assert lut.mode == "RGB"
 
-    def test_3_to_3_channels(self):
+    def test_3_to_3_channels(self) -> None:
         source = ImageFilter.Color3DLUT.generate((3, 4, 5), lambda r, g, b: (r, g, b))
         lut = source.transform(lambda r, g, b: (r * r, g * g, b * b))
         assert tuple(lut.size) == tuple(source.size)
@@ -571,7 +577,7 @@ class TestTransformColorLut3D:
         assert lut.table != source.table
         assert lut.table[:10] == [0.0, 0.0, 0.0, 0.25, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0]
 
-    def test_3_to_4_channels(self):
+    def test_3_to_4_channels(self) -> None:
         source = ImageFilter.Color3DLUT.generate((6, 5, 4), lambda r, g, b: (r, g, b))
         lut = source.transform(lambda r, g, b: (r * r, g * g, b * b, 1), channels=4)
         assert tuple(lut.size) == tuple(source.size)
@@ -583,7 +589,7 @@ class TestTransformColorLut3D:
             0.4**2, 0.0, 0.0, 1,  0.6**2, 0.0, 0.0, 1]
         # fmt: on
 
-    def test_4_to_3_channels(self):
+    def test_4_to_3_channels(self) -> None:
         source = ImageFilter.Color3DLUT.generate(
             (3, 6, 5), lambda r, g, b: (r, g, b, 1), channels=4
         )
@@ -599,7 +605,7 @@ class TestTransformColorLut3D:
             1.0, 0.96, 1.0,  0.75, 0.96, 1.0,  0.0, 0.96, 1.0]
         # fmt: on
 
-    def test_4_to_4_channels(self):
+    def test_4_to_4_channels(self) -> None:
         source = ImageFilter.Color3DLUT.generate(
             (6, 5, 4), lambda r, g, b: (r, g, b, 1), channels=4
         )
@@ -613,7 +619,7 @@ class TestTransformColorLut3D:
             0.4**2, 0.0, 0.0, 0.5,  0.6**2, 0.0, 0.0, 0.5]
         # fmt: on
 
-    def test_with_normals_3_channels(self):
+    def test_with_normals_3_channels(self) -> None:
         source = ImageFilter.Color3DLUT.generate(
             (6, 5, 4), lambda r, g, b: (r * r, g * g, b * b)
         )
@@ -629,7 +635,7 @@ class TestTransformColorLut3D:
             0.24, 0.0, 0.0,  0.8 - (0.8**2), 0, 0,  0, 0, 0]
         # fmt: on
 
-    def test_with_normals_4_channels(self):
+    def test_with_normals_4_channels(self) -> None:
         source = ImageFilter.Color3DLUT.generate(
             (3, 6, 5), lambda r, g, b: (r * r, g * g, b * b, 1), channels=4
         )

Tests/test_core_resources.py

@@ -9,7 +9,7 @@ from PIL import Image
 from .helper import is_pypy
 
 
-def test_get_stats():
+def test_get_stats() -> None:
     # Create at least one image
     Image.new("RGB", (10, 10))
 
@@ -22,7 +22,7 @@ def test_get_stats():
     assert "blocks_cached" in stats
 
 
-def test_reset_stats():
+def test_reset_stats() -> None:
     Image.core.reset_stats()
 
     stats = Image.core.get_stats()
@@ -35,19 +35,19 @@ def test_reset_stats():
 
 
 class TestCoreMemory:
-    def teardown_method(self):
+    def teardown_method(self) -> None:
         # Restore default values
         Image.core.set_alignment(1)
         Image.core.set_block_size(1024 * 1024)
         Image.core.set_blocks_max(0)
         Image.core.clear_cache()
 
-    def test_get_alignment(self):
+    def test_get_alignment(self) -> None:
         alignment = Image.core.get_alignment()
 
         assert alignment > 0
 
-    def test_set_alignment(self):
+    def test_set_alignment(self) -> None:
         for i in [1, 2, 4, 8, 16, 32]:
             Image.core.set_alignment(i)
             alignment = Image.core.get_alignment()
@@ -63,12 +63,12 @@ class TestCoreMemory:
         with pytest.raises(ValueError):
             Image.core.set_alignment(3)
 
-    def test_get_block_size(self):
+    def test_get_block_size(self) -> None:
         block_size = Image.core.get_block_size()
 
         assert block_size >= 4096
 
-    def test_set_block_size(self):
+    def test_set_block_size(self) -> None:
         for i in [4096, 2 * 4096, 3 * 4096]:
             Image.core.set_block_size(i)
             block_size = Image.core.get_block_size()
@@ -84,7 +84,7 @@ class TestCoreMemory:
         with pytest.raises(ValueError):
             Image.core.set_block_size(4000)
 
-    def test_set_block_size_stats(self):
+    def test_set_block_size_stats(self) -> None:
         Image.core.reset_stats()
         Image.core.set_blocks_max(0)
         Image.core.set_block_size(4096)
@@ -96,12 +96,12 @@ class TestCoreMemory:
         if not is_pypy():
             assert stats["freed_blocks"] >= 64
 
-    def test_get_blocks_max(self):
+    def test_get_blocks_max(self) -> None:
         blocks_max = Image.core.get_blocks_max()
 
         assert blocks_max >= 0
 
-    def test_set_blocks_max(self):
+    def test_set_blocks_max(self) -> None:
         for i in [0, 1, 10]:
             Image.core.set_blocks_max(i)
             blocks_max = Image.core.get_blocks_max()
@@ -117,7 +117,7 @@ class TestCoreMemory:
                 Image.core.set_blocks_max(2**29)
 
     @pytest.mark.skipif(is_pypy(), reason="Images not collected")
-    def test_set_blocks_max_stats(self):
+    def test_set_blocks_max_stats(self) -> None:
         Image.core.reset_stats()
         Image.core.set_blocks_max(128)
         Image.core.set_block_size(4096)
@@ -132,7 +132,7 @@ class TestCoreMemory:
         assert stats["blocks_cached"] == 64
 
     @pytest.mark.skipif(is_pypy(), reason="Images not collected")
-    def test_clear_cache_stats(self):
+    def test_clear_cache_stats(self) -> None:
         Image.core.reset_stats()
         Image.core.clear_cache()
         Image.core.set_blocks_max(128)
@@ -149,7 +149,7 @@ class TestCoreMemory:
         assert stats["freed_blocks"] >= 48
         assert stats["blocks_cached"] == 16
 
-    def test_large_images(self):
+    def test_large_images(self) -> None:
         Image.core.reset_stats()
         Image.core.set_blocks_max(0)
         Image.core.set_block_size(4096)
@@ -166,14 +166,14 @@ class TestCoreMemory:
 
 
 class TestEnvVars:
-    def teardown_method(self):
+    def teardown_method(self) -> None:
         # Restore default values
         Image.core.set_alignment(1)
         Image.core.set_block_size(1024 * 1024)
         Image.core.set_blocks_max(0)
         Image.core.clear_cache()
 
-    def test_units(self):
+    def test_units(self) -> None:
         Image._apply_env_variables({"PILLOW_BLOCKS_MAX": "2K"})
         assert Image.core.get_blocks_max() == 2 * 1024
         Image._apply_env_variables({"PILLOW_BLOCK_SIZE": "2m"})
@@ -187,6 +187,6 @@ class TestEnvVars:
             {"PILLOW_BLOCKS_MAX": "wat"},
         ),
     )
-    def test_warnings(self, var):
+    def test_warnings(self, var: dict[str, str]) -> None:
         with pytest.warns(UserWarning):
             Image._apply_env_variables(var)

Tests/test_decompression_bomb.py

@@ -12,16 +12,16 @@ ORIGINAL_LIMIT = Image.MAX_IMAGE_PIXELS
 
 
 class TestDecompressionBomb:
-    def teardown_method(self, method):
+    def teardown_method(self, method) -> None:
         Image.MAX_IMAGE_PIXELS = ORIGINAL_LIMIT
 
-    def test_no_warning_small_file(self):
+    def test_no_warning_small_file(self) -> None:
         # Implicit assert: no warning.
         # A warning would cause a failure.
         with Image.open(TEST_FILE):
             pass
 
-    def test_no_warning_no_limit(self):
+    def test_no_warning_no_limit(self) -> None:
         # Arrange
         # Turn limit off
         Image.MAX_IMAGE_PIXELS = None
@@ -33,7 +33,7 @@ class TestDecompressionBomb:
         with Image.open(TEST_FILE):
             pass
 
-    def test_warning(self):
+    def test_warning(self) -> None:
         # Set limit to trigger warning on the test file
         Image.MAX_IMAGE_PIXELS = 128 * 128 - 1
         assert Image.MAX_IMAGE_PIXELS == 128 * 128 - 1
@@ -42,7 +42,7 @@ class TestDecompressionBomb:
             with Image.open(TEST_FILE):
                 pass
 
-    def test_exception(self):
+    def test_exception(self) -> None:
         # Set limit to trigger exception on the test file
         Image.MAX_IMAGE_PIXELS = 64 * 128 - 1
         assert Image.MAX_IMAGE_PIXELS == 64 * 128 - 1
@@ -51,22 +51,22 @@ class TestDecompressionBomb:
             with Image.open(TEST_FILE):
                 pass
 
-    def test_exception_ico(self):
+    def test_exception_ico(self) -> None:
         with pytest.raises(Image.DecompressionBombError):
             with Image.open("Tests/images/decompression_bomb.ico"):
                 pass
 
-    def test_exception_gif(self):
+    def test_exception_gif(self) -> None:
         with pytest.raises(Image.DecompressionBombError):
             with Image.open("Tests/images/decompression_bomb.gif"):
                 pass
 
-    def test_exception_gif_extents(self):
+    def test_exception_gif_extents(self) -> None:
         with Image.open("Tests/images/decompression_bomb_extents.gif") as im:
             with pytest.raises(Image.DecompressionBombError):
                 im.seek(1)
 
-    def test_exception_gif_zero_width(self):
+    def test_exception_gif_zero_width(self) -> None:
         # Set limit to trigger exception on the test file
         Image.MAX_IMAGE_PIXELS = 4 * 64 * 128
         assert Image.MAX_IMAGE_PIXELS == 4 * 64 * 128
@@ -75,7 +75,7 @@ class TestDecompressionBomb:
             with Image.open("Tests/images/zero_width.gif"):
                 pass
 
-    def test_exception_bmp(self):
+    def test_exception_bmp(self) -> None:
         with pytest.raises(Image.DecompressionBombError):
             with Image.open("Tests/images/bmp/b/reallybig.bmp"):
                 pass
@@ -83,15 +83,15 @@ class TestDecompressionBomb:
 
 class TestDecompressionCrop:
     @classmethod
-    def setup_class(cls):
+    def setup_class(cls) -> None:
         width, height = 128, 128
         Image.MAX_IMAGE_PIXELS = height * width * 4 - 1
 
     @classmethod
-    def teardown_class(cls):
+    def teardown_class(cls) -> None:
         Image.MAX_IMAGE_PIXELS = ORIGINAL_LIMIT
 
-    def test_enlarge_crop(self):
+    def test_enlarge_crop(self) -> None:
         # Crops can extend the extents, therefore we should have the
         # same decompression bomb warnings on them.
         with hopper() as src:
@@ -99,7 +99,7 @@ class TestDecompressionCrop:
             with pytest.warns(Image.DecompressionBombWarning):
                 src.crop(box)
 
-    def test_crop_decompression_checks(self):
+    def test_crop_decompression_checks(self) -> None:
         im = Image.new("RGB", (100, 100))
 
         for value in ((-9999, -9999, -9990, -9990), (-999, -999, -990, -990)):

Tests/test_deprecate.py

@@ -20,12 +20,12 @@ from PIL import _deprecate
         ),
     ],
 )
-def test_version(version, expected):
+def test_version(version: int | None, expected: str) -> None:
     with pytest.warns(DeprecationWarning, match=expected):
         _deprecate.deprecate("Old thing", version, "new thing")
 
 
-def test_unknown_version():
+def test_unknown_version() -> None:
     expected = r"Unknown removal version: 12345. Update PIL\._deprecate\?"
     with pytest.raises(ValueError, match=expected):
         _deprecate.deprecate("Old thing", 12345, "new thing")
@@ -46,13 +46,13 @@ def test_unknown_version():
         ),
     ],
 )
-def test_old_version(deprecated, plural, expected):
+def test_old_version(deprecated: str, plural: bool, expected: str) -> None:
     expected = r""
     with pytest.raises(RuntimeError, match=expected):
         _deprecate.deprecate(deprecated, 1, plural=plural)
 
 
-def test_plural():
+def test_plural() -> None:
     expected = (
         r"Old things are deprecated and will be removed in Pillow 11 \(2024-10-15\)\. "
         r"Use new thing instead\."
@@ -61,7 +61,7 @@ def test_plural():
         _deprecate.deprecate("Old things", 11, "new thing", plural=True)
 
 
-def test_replacement_and_action():
+def test_replacement_and_action() -> None:
     expected = "Use only one of 'replacement' and 'action'"
     with pytest.raises(ValueError, match=expected):
         _deprecate.deprecate(
@@ -76,7 +76,7 @@ def test_replacement_and_action():
         "Upgrade to new thing.",
     ],
 )
-def test_action(action):
+def test_action(action: str) -> None:
     expected = (
         r"Old thing is deprecated and will be removed in Pillow 11 \(2024-10-15\)\. "
         r"Upgrade to new thing\."
@@ -85,7 +85,7 @@ def test_action(action):
         _deprecate.deprecate("Old thing", 11, action=action)
 
 
-def test_no_replacement_or_action():
+def test_no_replacement_or_action() -> None:
     expected = (
         r"Old thing is deprecated and will be removed in Pillow 11 \(2024-10-15\)"
     )

Tests/test_features.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import io
 import re
+from typing import Callable
 
 import pytest
 
@@ -15,7 +16,7 @@ except ImportError:
     pass
 
 
-def test_check():
+def test_check() -> None:
     # Check the correctness of the convenience function
     for module in features.modules:
         assert features.check_module(module) == features.check(module)
@@ -25,11 +26,11 @@ def test_check():
         assert features.check_feature(feature) == features.check(feature)
 
 
-def test_version():
+def test_version() -> None:
     # Check the correctness of the convenience function
     # and the format of version numbers
 
-    def test(name, function):
+    def test(name: str, function: Callable[[str], bool]) -> None:
         version = features.version(name)
         if not features.check(name):
             assert version is None
@@ -47,56 +48,56 @@ def test_version():
 
 
 @skip_unless_feature("webp")
-def test_webp_transparency():
+def test_webp_transparency() -> None:
     assert features.check("transp_webp") != _webp.WebPDecoderBuggyAlpha()
     assert features.check("transp_webp") == _webp.HAVE_TRANSPARENCY
 
 
 @skip_unless_feature("webp")
-def test_webp_mux():
+def test_webp_mux() -> None:
     assert features.check("webp_mux") == _webp.HAVE_WEBPMUX
 
 
 @skip_unless_feature("webp")
-def test_webp_anim():
+def test_webp_anim() -> None:
     assert features.check("webp_anim") == _webp.HAVE_WEBPANIM
 
 
 @skip_unless_feature("libjpeg_turbo")
-def test_libjpeg_turbo_version():
+def test_libjpeg_turbo_version() -> None:
     assert re.search(r"\d+\.\d+\.\d+$", features.version("libjpeg_turbo"))
 
 
 @skip_unless_feature("libimagequant")
-def test_libimagequant_version():
+def test_libimagequant_version() -> None:
     assert re.search(r"\d+\.\d+\.\d+$", features.version("libimagequant"))
 
 
 @pytest.mark.parametrize("feature", features.modules)
-def test_check_modules(feature):
+def test_check_modules(feature: str) -> None:
     assert features.check_module(feature) in [True, False]
 
 
 @pytest.mark.parametrize("feature", features.codecs)
-def test_check_codecs(feature):
+def test_check_codecs(feature: str) -> None:
     assert features.check_codec(feature) in [True, False]
 
 
-def test_check_warns_on_nonexistent():
+def test_check_warns_on_nonexistent() -> None:
     with pytest.warns(UserWarning) as cm:
         has_feature = features.check("typo")
     assert has_feature is False
     assert str(cm[-1].message) == "Unknown feature 'typo'."
 
 
-def test_supported_modules():
+def test_supported_modules() -> None:
     assert isinstance(features.get_supported_modules(), list)
     assert isinstance(features.get_supported_codecs(), list)
     assert isinstance(features.get_supported_features(), list)
     assert isinstance(features.get_supported(), list)
 
 
-def test_unsupported_codec():
+def test_unsupported_codec() -> None:
     # Arrange
     codec = "unsupported_codec"
     # Act / Assert
@@ -106,7 +107,7 @@ def test_unsupported_codec():
         features.version_codec(codec)
 
 
-def test_unsupported_module():
+def test_unsupported_module() -> None:
     # Arrange
     module = "unsupported_module"
     # Act / Assert
@@ -116,7 +117,7 @@ def test_unsupported_module():
         features.version_module(module)
 
 
-def test_pilinfo():
+def test_pilinfo() -> None:
     buf = io.StringIO()
     features.pilinfo(buf)
     out = buf.getvalue()

Tests/test_file_apng.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 
 from PIL import Image, ImageSequence, PngImagePlugin
@@ -8,7 +10,7 @@ from PIL import Image, ImageSequence, PngImagePlugin
 # APNG browser support tests and fixtures via:
 # https://philip.html5.org/tests/apng/tests.html
 # (referenced from https://wiki.mozilla.org/APNG_Specification)
-def test_apng_basic():
+def test_apng_basic() -> None:
     with Image.open("Tests/images/apng/single_frame.png") as im:
         assert not im.is_animated
         assert im.n_frames == 1
@@ -45,14 +47,14 @@ def test_apng_basic():
     "filename",
     ("Tests/images/apng/split_fdat.png", "Tests/images/apng/split_fdat_zero_chunk.png"),
 )
-def test_apng_fdat(filename):
+def test_apng_fdat(filename: str) -> None:
     with Image.open(filename) as im:
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
 
-def test_apng_dispose():
+def test_apng_dispose() -> None:
     with Image.open("Tests/images/apng/dispose_op_none.png") as im:
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
@@ -84,7 +86,7 @@ def test_apng_dispose():
         assert im.getpixel((64, 32)) == (0, 0, 0, 0)
 
 
-def test_apng_dispose_region():
+def test_apng_dispose_region() -> None:
     with Image.open("Tests/images/apng/dispose_op_none_region.png") as im:
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
@@ -106,7 +108,7 @@ def test_apng_dispose_region():
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
 
-def test_apng_dispose_op_previous_frame():
+def test_apng_dispose_op_previous_frame() -> None:
     # Test that the dispose settings being used are from the previous frame
     #
     # Image created with:
@@ -131,14 +133,14 @@ def test_apng_dispose_op_previous_frame():
         assert im.getpixel((0, 0)) == (255, 0, 0, 255)
 
 
-def test_apng_dispose_op_background_p_mode():
+def test_apng_dispose_op_background_p_mode() -> None:
     with Image.open("Tests/images/apng/dispose_op_background_p_mode.png") as im:
         im.seek(1)
         im.load()
         assert im.size == (128, 64)
 
 
-def test_apng_blend():
+def test_apng_blend() -> None:
     with Image.open("Tests/images/apng/blend_op_source_solid.png") as im:
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
@@ -165,20 +167,20 @@ def test_apng_blend():
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
 
-def test_apng_blend_transparency():
+def test_apng_blend_transparency() -> None:
     with Image.open("Tests/images/blend_transparency.png") as im:
         im.seek(1)
         assert im.getpixel((0, 0)) == (255, 0, 0)
 
 
-def test_apng_chunk_order():
+def test_apng_chunk_order() -> None:
     with Image.open("Tests/images/apng/fctl_actl.png") as im:
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
 
-def test_apng_delay():
+def test_apng_delay() -> None:
     with Image.open("Tests/images/apng/delay.png") as im:
         im.seek(1)
         assert im.info.get("duration") == 500.0
@@ -218,7 +220,7 @@ def test_apng_delay():
         assert im.info.get("duration") == 1000.0
 
 
-def test_apng_num_plays():
+def test_apng_num_plays() -> None:
     with Image.open("Tests/images/apng/num_plays.png") as im:
         assert im.info.get("loop") == 0
 
@@ -226,7 +228,7 @@ def test_apng_num_plays():
         assert im.info.get("loop") == 1
 
 
-def test_apng_mode():
+def test_apng_mode() -> None:
     with Image.open("Tests/images/apng/mode_16bit.png") as im:
         assert im.mode == "RGBA"
         im.seek(im.n_frames - 1)
@@ -267,7 +269,7 @@ def test_apng_mode():
         assert im.getpixel((64, 32)) == (0, 0, 255, 128)
 
 
-def test_apng_chunk_errors():
+def test_apng_chunk_errors() -> None:
     with Image.open("Tests/images/apng/chunk_no_actl.png") as im:
         assert not im.is_animated
 
@@ -292,7 +294,7 @@ def test_apng_chunk_errors():
             im.seek(im.n_frames - 1)
 
 
-def test_apng_syntax_errors():
+def test_apng_syntax_errors() -> None:
     with pytest.warns(UserWarning):
         with Image.open("Tests/images/apng/syntax_num_frames_zero.png") as im:
             assert not im.is_animated
@@ -336,14 +338,14 @@ def test_apng_syntax_errors():
         "sequence_fdat_fctl.png",
     ),
 )
-def test_apng_sequence_errors(test_file):
+def test_apng_sequence_errors(test_file: str) -> None:
     with pytest.raises(SyntaxError):
         with Image.open(f"Tests/images/apng/{test_file}") as im:
             im.seek(im.n_frames - 1)
             im.load()
 
 
-def test_apng_save(tmp_path):
+def test_apng_save(tmp_path: Path) -> None:
     with Image.open("Tests/images/apng/single_frame.png") as im:
         test_file = str(tmp_path / "temp.png")
         im.save(test_file, save_all=True)
@@ -374,7 +376,7 @@ def test_apng_save(tmp_path):
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
 
-def test_apng_save_alpha(tmp_path):
+def test_apng_save_alpha(tmp_path: Path) -> None:
     test_file = str(tmp_path / "temp.png")
 
     im = Image.new("RGBA", (1, 1), (255, 0, 0, 255))
@@ -388,7 +390,7 @@ def test_apng_save_alpha(tmp_path):
         assert reloaded.getpixel((0, 0)) == (255, 0, 0, 127)
 
 
-def test_apng_save_split_fdat(tmp_path):
+def test_apng_save_split_fdat(tmp_path: Path) -> None:
     # test to make sure we do not generate sequence errors when writing
     # frames with image data spanning multiple fdAT chunks (in this case
     # both the default image and first animation frame will span multiple
@@ -412,7 +414,7 @@ def test_apng_save_split_fdat(tmp_path):
         assert exception is None
 
 
-def test_apng_save_duration_loop(tmp_path):
+def test_apng_save_duration_loop(tmp_path: Path) -> None:
     test_file = str(tmp_path / "temp.png")
     with Image.open("Tests/images/apng/delay.png") as im:
         frames = []
@@ -475,7 +477,7 @@ def test_apng_save_duration_loop(tmp_path):
         assert im.info["duration"] == 600
 
 
-def test_apng_save_disposal(tmp_path):
+def test_apng_save_disposal(tmp_path: Path) -> None:
     test_file = str(tmp_path / "temp.png")
     size = (128, 64)
     red = Image.new("RGBA", size, (255, 0, 0, 255))
@@ -576,7 +578,7 @@ def test_apng_save_disposal(tmp_path):
         assert im.getpixel((64, 32)) == (0, 0, 0, 0)
 
 
-def test_apng_save_disposal_previous(tmp_path):
+def test_apng_save_disposal_previous(tmp_path: Path) -> None:
     test_file = str(tmp_path / "temp.png")
     size = (128, 64)
     blue = Image.new("RGBA", size, (0, 0, 255, 255))
@@ -598,7 +600,7 @@ def test_apng_save_disposal_previous(tmp_path):
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
 
-def test_apng_save_blend(tmp_path):
+def test_apng_save_blend(tmp_path: Path) -> None:
     test_file = str(tmp_path / "temp.png")
     size = (128, 64)
     red = Image.new("RGBA", size, (255, 0, 0, 255))
@@ -666,7 +668,7 @@ def test_apng_save_blend(tmp_path):
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
 
 
-def test_seek_after_close():
+def test_seek_after_close() -> None:
     im = Image.open("Tests/images/apng/delay.png")
     im.seek(1)
     im.close()
@@ -678,7 +680,9 @@ def test_seek_after_close():
 @pytest.mark.parametrize("mode", ("RGBA", "RGB", "P"))
 @pytest.mark.parametrize("default_image", (True, False))
 @pytest.mark.parametrize("duplicate", (True, False))
-def test_different_modes_in_later_frames(mode, default_image, duplicate, tmp_path):
+def test_different_modes_in_later_frames(
+    mode: str, default_image: bool, duplicate: bool, tmp_path: Path
+) -> None:
     test_file = str(tmp_path / "temp.png")
 
     im = Image.new("L", (1, 1))

Tests/test_file_blp.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 
 from PIL import Image
@@ -12,7 +14,7 @@ from .helper import (
 )
 
 
-def test_load_blp1():
+def test_load_blp1() -> None:
     with Image.open("Tests/images/blp/blp1_jpeg.blp") as im:
         assert_image_equal_tofile(im, "Tests/images/blp/blp1_jpeg.png")
 
@@ -20,22 +22,22 @@ def test_load_blp1():
         im.load()
 
 
-def test_load_blp2_raw():
+def test_load_blp2_raw() -> None:
     with Image.open("Tests/images/blp/blp2_raw.blp") as im:
         assert_image_equal_tofile(im, "Tests/images/blp/blp2_raw.png")
 
 
-def test_load_blp2_dxt1():
+def test_load_blp2_dxt1() -> None:
     with Image.open("Tests/images/blp/blp2_dxt1.blp") as im:
         assert_image_equal_tofile(im, "Tests/images/blp/blp2_dxt1.png")
 
 
-def test_load_blp2_dxt1a():
+def test_load_blp2_dxt1a() -> None:
     with Image.open("Tests/images/blp/blp2_dxt1a.blp") as im:
         assert_image_equal_tofile(im, "Tests/images/blp/blp2_dxt1a.png")
 
 
-def test_save(tmp_path):
+def test_save(tmp_path: Path) -> None:
     f = str(tmp_path / "temp.blp")
 
     for version in ("BLP1", "BLP2"):
@@ -69,7 +71,7 @@ def test_save(tmp_path):
         "Tests/images/timeout-ef9112a065e7183fa7faa2e18929b03e44ee16bf.blp",
     ],
 )
-def test_crashes(test_file):
+def test_crashes(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
             with pytest.raises(OSError):

Tests/test_file_bmp.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import io
+from pathlib import Path
 
 import pytest
 
@@ -14,8 +15,8 @@ from .helper import (
 )
 
 
-def test_sanity(tmp_path):
+def test_sanity(tmp_path: Path) -> None:
-    def roundtrip(im):
+    def roundtrip(im: Image.Image) -> None:
         outfile = str(tmp_path / "temp.bmp")
 
         im.save(outfile, "BMP")
@@ -35,20 +36,20 @@ def test_sanity(tmp_path):
     roundtrip(hopper("RGB"))
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     with open("Tests/images/flower.jpg", "rb") as fp:
         with pytest.raises(SyntaxError):
             BmpImagePlugin.BmpImageFile(fp)
 
 
-def test_fallback_if_mmap_errors():
+def test_fallback_if_mmap_errors() -> None:
     # This image has been truncated,
     # so that the buffer is not large enough when using mmap
     with Image.open("Tests/images/mmap_error.bmp") as im:
         assert_image_equal_tofile(im, "Tests/images/pal8_offset.bmp")
 
 
-def test_save_to_bytes():
+def test_save_to_bytes() -> None:
     output = io.BytesIO()
     im = hopper()
     im.save(output, "BMP")
@@ -60,7 +61,7 @@ def test_save_to_bytes():
         assert reloaded.format == "BMP"
 
 
-def test_small_palette(tmp_path):
+def test_small_palette(tmp_path: Path) -> None:
     im = Image.new("P", (1, 1))
     colors = [0, 0, 0, 125, 125, 125, 255, 255, 255]
     im.putpalette(colors)
@@ -72,7 +73,7 @@ def test_small_palette(tmp_path):
         assert reloaded.getpalette() == colors
 
 
-def test_save_too_large(tmp_path):
+def test_save_too_large(tmp_path: Path) -> None:
     outfile = str(tmp_path / "temp.bmp")
     with Image.new("RGB", (1, 1)) as im:
         im._size = (37838, 37838)
@@ -80,7 +81,7 @@ def test_save_too_large(tmp_path):
             im.save(outfile)
 
 
-def test_dpi():
+def test_dpi() -> None:
     dpi = (72, 72)
 
     output = io.BytesIO()
@@ -92,7 +93,7 @@ def test_dpi():
         assert reloaded.info["dpi"] == (72.008961115161, 72.008961115161)
 
 
-def test_save_bmp_with_dpi(tmp_path):
+def test_save_bmp_with_dpi(tmp_path: Path) -> None:
     # Test for #1301
     # Arrange
     outfile = str(tmp_path / "temp.jpg")
@@ -110,7 +111,7 @@ def test_save_bmp_with_dpi(tmp_path):
             assert reloaded.format == "JPEG"
 
 
-def test_save_float_dpi(tmp_path):
+def test_save_float_dpi(tmp_path: Path) -> None:
     outfile = str(tmp_path / "temp.bmp")
     with Image.open("Tests/images/hopper.bmp") as im:
         im.save(outfile, dpi=(72.21216100543306, 72.21216100543306))
@@ -118,7 +119,7 @@ def test_save_float_dpi(tmp_path):
             assert reloaded.info["dpi"] == (72.21216100543306, 72.21216100543306)
 
 
-def test_load_dib():
+def test_load_dib() -> None:
     # test for #1293, Imagegrab returning Unsupported Bitfields Format
     with Image.open("Tests/images/clipboard.dib") as im:
         assert im.format == "DIB"
@@ -127,7 +128,7 @@ def test_load_dib():
         assert_image_equal_tofile(im, "Tests/images/clipboard_target.png")
 
 
-def test_save_dib(tmp_path):
+def test_save_dib(tmp_path: Path) -> None:
     outfile = str(tmp_path / "temp.dib")
 
     with Image.open("Tests/images/clipboard.dib") as im:
@@ -139,7 +140,7 @@ def test_save_dib(tmp_path):
             assert_image_equal(im, reloaded)
 
 
-def test_rgba_bitfields():
+def test_rgba_bitfields() -> None:
     # This test image has been manually hexedited
     # to change the bitfield compression in the header from XBGR to RGBA
     with Image.open("Tests/images/rgb32bf-rgba.bmp") as im:
@@ -157,7 +158,7 @@ def test_rgba_bitfields():
         )
 
 
-def test_rle8():
+def test_rle8() -> None:
     with Image.open("Tests/images/hopper_rle8.bmp") as im:
         assert_image_similar_tofile(im.convert("RGB"), "Tests/images/hopper.bmp", 12)
 
@@ -177,7 +178,7 @@ def test_rle8():
                 im.load()
 
 
-def test_rle4():
+def test_rle4() -> None:
     with Image.open("Tests/images/bmp/g/pal4rle.bmp") as im:
         assert_image_similar_tofile(im, "Tests/images/bmp/g/pal4.bmp", 12)
 
@@ -193,7 +194,7 @@ def test_rle4():
         ("Tests/images/bmp/g/pal8rle.bmp", 1064),
     ),
 )
-def test_rle8_eof(file_name, length):
+def test_rle8_eof(file_name: str, length: int) -> None:
     with open(file_name, "rb") as fp:
         data = fp.read(length)
         with Image.open(io.BytesIO(data)) as im:
@@ -201,7 +202,7 @@ def test_rle8_eof(file_name, length):
                 im.load()
 
 
-def test_offset():
+def test_offset() -> None:
     # This image has been hexedited
     # to exclude the palette size from the pixel data offset
     with Image.open("Tests/images/pal8_offset.bmp") as im:

Tests/test_file_bufrstub.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 
 from PIL import BufrStubImagePlugin, Image
@@ -9,7 +11,7 @@ from .helper import hopper
 TEST_FILE = "Tests/images/gfs.t06z.rassda.tm00.bufr_d"
 
 
-def test_open():
+def test_open() -> None:
     # Act
     with Image.open(TEST_FILE) as im:
         # Assert
@@ -20,7 +22,7 @@ def test_open():
         assert im.size == (1, 1)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     # Arrange
     invalid_file = "Tests/images/flower.jpg"
 
@@ -29,7 +31,7 @@ def test_invalid_file():
         BufrStubImagePlugin.BufrStubImageFile(invalid_file)
 
 
-def test_load():
+def test_load() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         # Act / Assert: stub cannot load without an implemented handler
@@ -37,7 +39,7 @@ def test_load():
             im.load()
 
 
-def test_save(tmp_path):
+def test_save(tmp_path: Path) -> None:
     # Arrange
     im = hopper()
     tmpfile = str(tmp_path / "temp.bufr")
@@ -47,13 +49,13 @@ def test_save(tmp_path):
         im.save(tmpfile)
 
 
-def test_handler(tmp_path):
+def test_handler(tmp_path: Path) -> None:
     class TestHandler:
         opened = False
         loaded = False
         saved = False
 
-        def open(self, im):
+        def open(self, im) -> None:
             self.opened = True
 
         def load(self, im):
@@ -61,7 +63,7 @@ def test_handler(tmp_path):
             im.fp.close()
             return Image.new("RGB", (1, 1))
 
-        def save(self, im, fp, filename):
+        def save(self, im, fp, filename) -> None:
             self.saved = True
 
     handler = TestHandler()

Tests/test_file_container.py

@@ -9,19 +9,19 @@ from .helper import hopper
 TEST_FILE = "Tests/images/dummy.container"
 
 
-def test_sanity():
+def test_sanity() -> None:
     dir(Image)
     dir(ContainerIO)
 
 
-def test_isatty():
+def test_isatty() -> None:
     with hopper() as im:
         container = ContainerIO.ContainerIO(im, 0, 0)
 
     assert container.isatty() is False
 
 
-def test_seek_mode_0():
+def test_seek_mode_0() -> None:
     # Arrange
     mode = 0
     with open(TEST_FILE, "rb") as fh:
@@ -35,7 +35,7 @@ def test_seek_mode_0():
         assert container.tell() == 33
 
 
-def test_seek_mode_1():
+def test_seek_mode_1() -> None:
     # Arrange
     mode = 1
     with open(TEST_FILE, "rb") as fh:
@@ -49,7 +49,7 @@ def test_seek_mode_1():
         assert container.tell() == 66
 
 
-def test_seek_mode_2():
+def test_seek_mode_2() -> None:
     # Arrange
     mode = 2
     with open(TEST_FILE, "rb") as fh:
@@ -64,7 +64,7 @@ def test_seek_mode_2():
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_read_n0(bytesmode):
+def test_read_n0(bytesmode: bool) -> None:
     # Arrange
     with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
         container = ContainerIO.ContainerIO(fh, 22, 100)
@@ -80,7 +80,7 @@ def test_read_n0(bytesmode):
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_read_n(bytesmode):
+def test_read_n(bytesmode: bool) -> None:
     # Arrange
     with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
         container = ContainerIO.ContainerIO(fh, 22, 100)
@@ -96,7 +96,7 @@ def test_read_n(bytesmode):
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_read_eof(bytesmode):
+def test_read_eof(bytesmode: bool) -> None:
     # Arrange
     with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
         container = ContainerIO.ContainerIO(fh, 22, 100)
@@ -112,7 +112,7 @@ def test_read_eof(bytesmode):
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_readline(bytesmode):
+def test_readline(bytesmode: bool) -> None:
     # Arrange
     with open(TEST_FILE, "rb" if bytesmode else "r") as fh:
         container = ContainerIO.ContainerIO(fh, 0, 120)
@@ -127,7 +127,7 @@ def test_readline(bytesmode):
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))
-def test_readlines(bytesmode):
+def test_readlines(bytesmode: bool) -> None:
     # Arrange
     expected = [
         "This is line 1\n",

Tests/test_file_cur.py

@@ -7,7 +7,7 @@ from PIL import CurImagePlugin, Image
 TEST_FILE = "Tests/images/deerstalker.cur"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(TEST_FILE) as im:
         assert im.size == (32, 32)
         assert isinstance(im, CurImagePlugin.CurImageFile)
@@ -17,7 +17,7 @@ def test_sanity():
         assert im.getpixel((16, 16)) == (84, 87, 86, 255)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):

Tests/test_file_dcx.py

@@ -12,7 +12,7 @@ from .helper import assert_image_equal, hopper, is_pypy
 TEST_FILE = "Tests/images/hopper.dcx"
 
 
-def test_sanity():
+def test_sanity() -> None:
     # Arrange
 
     # Act
@@ -25,8 +25,8 @@ def test_sanity():
 
 
 @pytest.mark.skipif(is_pypy(), reason="Requires CPython")
-def test_unclosed_file():
+def test_unclosed_file() -> None:
-    def open():
+    def open() -> None:
         im = Image.open(TEST_FILE)
         im.load()
 
@@ -34,26 +34,26 @@ def test_unclosed_file():
         open()
 
 
-def test_closed_file():
+def test_closed_file() -> None:
     with warnings.catch_warnings():
         im = Image.open(TEST_FILE)
         im.load()
         im.close()
 
 
-def test_context_manager():
+def test_context_manager() -> None:
     with warnings.catch_warnings():
         with Image.open(TEST_FILE) as im:
             im.load()
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     with open("Tests/images/flower.jpg", "rb") as fp:
         with pytest.raises(SyntaxError):
             DcxImagePlugin.DcxImageFile(fp)
 
 
-def test_tell():
+def test_tell() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         # Act
@@ -63,13 +63,13 @@ def test_tell():
         assert frame == 0
 
 
-def test_n_frames():
+def test_n_frames() -> None:
     with Image.open(TEST_FILE) as im:
         assert im.n_frames == 1
         assert not im.is_animated
 
 
-def test_eoferror():
+def test_eoferror() -> None:
     with Image.open(TEST_FILE) as im:
         n_frames = im.n_frames
 
@@ -82,7 +82,7 @@ def test_eoferror():
         im.seek(n_frames - 1)
 
 
-def test_seek_too_far():
+def test_seek_too_far() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         frame = 999  # too big on purpose

Tests/test_file_dds.py

@@ -1,7 +1,9 @@
 """Test DdsImagePlugin"""
+
 from __future__ import annotations
 
 from io import BytesIO
+from pathlib import Path
 
 import pytest
 
@@ -46,7 +48,7 @@ TEST_FILE_UNCOMPRESSED_RGB_WITH_ALPHA = "Tests/images/uncompressed_rgb.dds"
         TEST_FILE_DX10_BC1_TYPELESS,
     ),
 )
-def test_sanity_dxt1_bc1(image_path):
+def test_sanity_dxt1_bc1(image_path: str) -> None:
     """Check DXT1 and BC1 images can be opened"""
     with Image.open(TEST_FILE_DXT1.replace(".dds", ".png")) as target:
         target = target.convert("RGBA")
@@ -60,7 +62,7 @@ def test_sanity_dxt1_bc1(image_path):
         assert_image_equal(im, target)
 
 
-def test_sanity_dxt3():
+def test_sanity_dxt3() -> None:
     """Check DXT3 images can be opened"""
 
     with Image.open(TEST_FILE_DXT3) as im:
@@ -73,7 +75,7 @@ def test_sanity_dxt3():
         assert_image_equal_tofile(im, TEST_FILE_DXT3.replace(".dds", ".png"))
 
 
-def test_sanity_dxt5():
+def test_sanity_dxt5() -> None:
     """Check DXT5 images can be opened"""
 
     with Image.open(TEST_FILE_DXT5) as im:
@@ -94,7 +96,7 @@ def test_sanity_dxt5():
         TEST_FILE_BC4U,
     ),
 )
-def test_sanity_ati1_bc4u(image_path):
+def test_sanity_ati1_bc4u(image_path: str) -> None:
     """Check ATI1 and BC4U images can be opened"""
 
     with Image.open(image_path) as im:
@@ -115,7 +117,7 @@ def test_sanity_ati1_bc4u(image_path):
         TEST_FILE_DX10_BC4_TYPELESS,
     ),
 )
-def test_dx10_bc4(image_path):
+def test_dx10_bc4(image_path: str) -> None:
     """Check DX10 BC4 images can be opened"""
 
     with Image.open(image_path) as im:
@@ -136,7 +138,7 @@ def test_dx10_bc4(image_path):
         TEST_FILE_BC5U,
     ),
 )
-def test_sanity_ati2_bc5u(image_path):
+def test_sanity_ati2_bc5u(image_path: str) -> None:
     """Check ATI2 and BC5U images can be opened"""
 
     with Image.open(image_path) as im:
@@ -160,7 +162,7 @@ def test_sanity_ati2_bc5u(image_path):
         (TEST_FILE_BC5S, TEST_FILE_BC5S),
     ),
 )
-def test_dx10_bc5(image_path, expected_path):
+def test_dx10_bc5(image_path: str, expected_path: str) -> None:
     """Check DX10 BC5 images can be opened"""
 
     with Image.open(image_path) as im:
@@ -174,7 +176,7 @@ def test_dx10_bc5(image_path, expected_path):
 
 
 @pytest.mark.parametrize("image_path", (TEST_FILE_BC6H, TEST_FILE_BC6HS))
-def test_dx10_bc6h(image_path):
+def test_dx10_bc6h(image_path: str) -> None:
     """Check DX10 BC6H/BC6HS images can be opened"""
 
     with Image.open(image_path) as im:
@@ -187,7 +189,7 @@ def test_dx10_bc6h(image_path):
         assert_image_equal_tofile(im, image_path.replace(".dds", ".png"))
 
 
-def test_dx10_bc7():
+def test_dx10_bc7() -> None:
     """Check DX10 images can be opened"""
 
     with Image.open(TEST_FILE_DX10_BC7) as im:
@@ -200,7 +202,7 @@ def test_dx10_bc7():
         assert_image_equal_tofile(im, TEST_FILE_DX10_BC7.replace(".dds", ".png"))
 
 
-def test_dx10_bc7_unorm_srgb():
+def test_dx10_bc7_unorm_srgb() -> None:
     """Check DX10 unsigned normalized integer images can be opened"""
 
     with Image.open(TEST_FILE_DX10_BC7_UNORM_SRGB) as im:
@@ -216,7 +218,7 @@ def test_dx10_bc7_unorm_srgb():
         )
 
 
-def test_dx10_r8g8b8a8():
+def test_dx10_r8g8b8a8() -> None:
     """Check DX10 images can be opened"""
 
     with Image.open(TEST_FILE_DX10_R8G8B8A8) as im:
@@ -229,7 +231,7 @@ def test_dx10_r8g8b8a8():
         assert_image_equal_tofile(im, TEST_FILE_DX10_R8G8B8A8.replace(".dds", ".png"))
 
 
-def test_dx10_r8g8b8a8_unorm_srgb():
+def test_dx10_r8g8b8a8_unorm_srgb() -> None:
     """Check DX10 unsigned normalized integer images can be opened"""
 
     with Image.open(TEST_FILE_DX10_R8G8B8A8_UNORM_SRGB) as im:
@@ -255,7 +257,7 @@ def test_dx10_r8g8b8a8_unorm_srgb():
         ("RGBA", (800, 600), TEST_FILE_UNCOMPRESSED_RGB_WITH_ALPHA),
     ],
 )
-def test_uncompressed(mode, size, test_file):
+def test_uncompressed(mode: str, size: tuple[int, int], test_file: str) -> None:
     """Check uncompressed images can be opened"""
 
     with Image.open(test_file) as im:
@@ -266,7 +268,7 @@ def test_uncompressed(mode, size, test_file):
         assert_image_equal_tofile(im, test_file.replace(".dds", ".png"))
 
 
-def test__accept_true():
+def test__accept_true() -> None:
     """Check valid prefix"""
     # Arrange
     prefix = b"DDS etc"
@@ -278,7 +280,7 @@ def test__accept_true():
     assert output
 
 
-def test__accept_false():
+def test__accept_false() -> None:
     """Check invalid prefix"""
     # Arrange
     prefix = b"something invalid"
@@ -290,19 +292,19 @@ def test__accept_false():
     assert not output
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         DdsImagePlugin.DdsImageFile(invalid_file)
 
 
-def test_short_header():
+def test_short_header() -> None:
     """Check a short header"""
     with open(TEST_FILE_DXT5, "rb") as f:
         img_file = f.read()
 
-    def short_header():
+    def short_header() -> None:
         with Image.open(BytesIO(img_file[:119])):
             pass  # pragma: no cover
 
@@ -310,13 +312,13 @@ def test_short_header():
         short_header()
 
 
-def test_short_file():
+def test_short_file() -> None:
     """Check that the appropriate error is thrown for a short file"""
 
     with open(TEST_FILE_DXT5, "rb") as f:
         img_file = f.read()
 
-    def short_file():
+    def short_file() -> None:
         with Image.open(BytesIO(img_file[:-100])) as im:
             im.load()
 
@@ -324,7 +326,7 @@ def test_short_file():
         short_file()
 
 
-def test_dxt5_colorblock_alpha_issue_4142():
+def test_dxt5_colorblock_alpha_issue_4142() -> None:
     """Check that colorblocks are decoded correctly in DXT5"""
 
     with Image.open("Tests/images/dxt5-colorblock-alpha-issue-4142.dds") as im:
@@ -339,12 +341,12 @@ def test_dxt5_colorblock_alpha_issue_4142():
         assert px[2] != 0
 
 
-def test_palette():
+def test_palette() -> None:
     with Image.open("Tests/images/palette.dds") as im:
         assert_image_equal_tofile(im, "Tests/images/transparent.gif")
 
 
-def test_unsupported_bitcount():
+def test_unsupported_bitcount() -> None:
     with pytest.raises(OSError):
         with Image.open("Tests/images/unsupported_bitcount.dds"):
             pass
@@ -357,13 +359,13 @@ def test_unsupported_bitcount():
         "Tests/images/unimplemented_pfflags.dds",
     ),
 )
-def test_not_implemented(test_file):
+def test_not_implemented(test_file: str) -> None:
     with pytest.raises(NotImplementedError):
         with Image.open(test_file):
             pass
 
 
-def test_save_unsupported_mode(tmp_path):
+def test_save_unsupported_mode(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.dds")
     im = hopper("HSV")
     with pytest.raises(OSError):
@@ -379,7 +381,7 @@ def test_save_unsupported_mode(tmp_path):
         ("RGBA", "Tests/images/pil123rgba.png"),
     ],
 )
-def test_save(mode, test_file, tmp_path):
+def test_save(mode: str, test_file: str, tmp_path: Path) -> None:
     out = str(tmp_path / "temp.dds")
     with Image.open(test_file) as im:
         assert im.mode == mode

Tests/test_file_eps.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import io
+from pathlib import Path
 
 import pytest
 
@@ -83,7 +84,7 @@ simple_eps_file_with_long_binary_data = (
     ("filename", "size"), ((FILE1, (460, 352)), (FILE2, (360, 252)))
 )
 @pytest.mark.parametrize("scale", (1, 2))
-def test_sanity(filename, size, scale):
+def test_sanity(filename: str, size: tuple[int, int], scale: int) -> None:
     expected_size = tuple(s * scale for s in size)
     with Image.open(filename) as image:
         image.load(scale=scale)
@@ -93,7 +94,7 @@ def test_sanity(filename, size, scale):
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
-def test_load():
+def test_load() -> None:
     with Image.open(FILE1) as im:
         assert im.load()[0, 0] == (255, 255, 255)
 
@@ -101,7 +102,7 @@ def test_load():
         assert im.load()[0, 0] == (255, 255, 255)
 
 
-def test_binary():
+def test_binary() -> None:
     if HAS_GHOSTSCRIPT:
         assert EpsImagePlugin.gs_binary is not None
     else:
@@ -115,41 +116,41 @@ def test_binary():
         assert EpsImagePlugin.gs_windows_binary is not None
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
     with pytest.raises(SyntaxError):
         EpsImagePlugin.EpsImageFile(invalid_file)
 
 
-def test_binary_header_only():
+def test_binary_header_only() -> None:
     data = io.BytesIO(simple_binary_header)
     with pytest.raises(SyntaxError, match='EPS header missing "%!PS-Adobe" comment'):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_missing_version_comment(prefix):
+def test_missing_version_comment(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_without_version))
     with pytest.raises(SyntaxError):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_missing_boundingbox_comment(prefix):
+def test_missing_boundingbox_comment(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_without_boundingbox))
     with pytest.raises(SyntaxError, match='EPS header missing "%%BoundingBox" comment'):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_invalid_boundingbox_comment(prefix):
+def test_invalid_boundingbox_comment(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_invalid_boundingbox))
     with pytest.raises(OSError, match="cannot determine EPS bounding box"):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_invalid_boundingbox_comment_valid_imagedata_comment(prefix):
+def test_invalid_boundingbox_comment_valid_imagedata_comment(prefix: bytes) -> None:
     data = io.BytesIO(
         prefix + b"\n".join(simple_eps_file_with_invalid_boundingbox_valid_imagedata)
     )
@@ -160,21 +161,21 @@ def test_invalid_boundingbox_comment_valid_imagedata_comment(prefix):
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_ascii_comment_too_long(prefix):
+def test_ascii_comment_too_long(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_long_ascii_comment))
     with pytest.raises(SyntaxError, match="not an EPS file"):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_long_binary_data(prefix):
+def test_long_binary_data(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_long_binary_data))
     EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_load_long_binary_data(prefix):
+def test_load_long_binary_data(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_long_binary_data))
     with Image.open(data) as img:
         img.load()
@@ -187,7 +188,7 @@ def test_load_long_binary_data(prefix):
     pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
 )
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
-def test_cmyk():
+def test_cmyk() -> None:
     with Image.open("Tests/images/pil_sample_cmyk.eps") as cmyk_image:
         assert cmyk_image.mode == "CMYK"
         assert cmyk_image.size == (100, 100)
@@ -203,7 +204,7 @@ def test_cmyk():
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
-def test_showpage():
+def test_showpage() -> None:
     # See https://github.com/python-pillow/Pillow/issues/2615
     with Image.open("Tests/images/reqd_showpage.eps") as plot_image:
         with Image.open("Tests/images/reqd_showpage.png") as target:
@@ -214,7 +215,7 @@ def test_showpage():
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
-def test_transparency():
+def test_transparency() -> None:
     with Image.open("Tests/images/reqd_showpage.eps") as plot_image:
         plot_image.load(transparency=True)
         assert plot_image.mode == "RGBA"
@@ -225,7 +226,7 @@ def test_transparency():
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
-def test_file_object(tmp_path):
+def test_file_object(tmp_path: Path) -> None:
     # issue 479
     with Image.open(FILE1) as image1:
         with open(str(tmp_path / "temp.eps"), "wb") as fh:
@@ -233,7 +234,7 @@ def test_file_object(tmp_path):
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
-def test_bytesio_object():
+def test_bytesio_object() -> None:
     with open(FILE1, "rb") as f:
         img_bytes = io.BytesIO(f.read())
 
@@ -246,12 +247,12 @@ def test_bytesio_object():
         assert_image_similar(img, image1_scale1_compare, 5)
 
 
-def test_1_mode():
+def test_1_mode() -> None:
     with Image.open("Tests/images/1.eps") as im:
         assert im.mode == "1"
 
 
-def test_image_mode_not_supported(tmp_path):
+def test_image_mode_not_supported(tmp_path: Path) -> None:
     im = hopper("RGBA")
     tmpfile = str(tmp_path / "temp.eps")
     with pytest.raises(ValueError):
@@ -260,7 +261,7 @@ def test_image_mode_not_supported(tmp_path):
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @skip_unless_feature("zlib")
-def test_render_scale1():
+def test_render_scale1() -> None:
     # We need png support for these render test
 
     # Zero bounding box
@@ -282,7 +283,7 @@ def test_render_scale1():
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @skip_unless_feature("zlib")
-def test_render_scale2():
+def test_render_scale2() -> None:
     # We need png support for these render test
 
     # Zero bounding box
@@ -304,7 +305,7 @@ def test_render_scale2():
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @pytest.mark.parametrize("filename", (FILE1, FILE2, "Tests/images/illu10_preview.eps"))
-def test_resize(filename):
+def test_resize(filename: str) -> None:
     with Image.open(filename) as im:
         new_size = (100, 100)
         im = im.resize(new_size)
@@ -313,7 +314,7 @@ def test_resize(filename):
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @pytest.mark.parametrize("filename", (FILE1, FILE2))
-def test_thumbnail(filename):
+def test_thumbnail(filename: str) -> None:
     # Issue #619
     with Image.open(filename) as im:
         new_size = (100, 100)
@@ -321,20 +322,20 @@ def test_thumbnail(filename):
         assert max(im.size) == max(new_size)
 
 
-def test_read_binary_preview():
+def test_read_binary_preview() -> None:
     # Issue 302
     # open image with binary preview
     with Image.open(FILE3):
         pass
 
 
-def test_readline_psfile(tmp_path):
+def test_readline_psfile(tmp_path: Path) -> None:
     # check all the freaking line endings possible from the spec
     # test_string = u'something\r\nelse\n\rbaz\rbif\n'
     line_endings = ["\r\n", "\n", "\n\r", "\r"]
     strings = ["something", "else", "baz", "bif"]
 
-    def _test_readline(t, ending):
+    def _test_readline(t: EpsImagePlugin.PSFile, ending: str) -> None:
         ending = "Failure with line ending: %s" % (
             "".join("%s" % ord(s) for s in ending)
         )
@@ -343,13 +344,13 @@ def test_readline_psfile(tmp_path):
         assert t.readline().strip("\r\n") == "baz", ending
         assert t.readline().strip("\r\n") == "bif", ending
 
-    def _test_readline_io_psfile(test_string, ending):
+    def _test_readline_io_psfile(test_string: str, ending: str) -> None:
         f = io.BytesIO(test_string.encode("latin-1"))
         with pytest.warns(DeprecationWarning):
             t = EpsImagePlugin.PSFile(f)
         _test_readline(t, ending)
 
-    def _test_readline_file_psfile(test_string, ending):
+    def _test_readline_file_psfile(test_string: str, ending: str) -> None:
         f = str(tmp_path / "temp.txt")
         with open(f, "wb") as w:
             w.write(test_string.encode("latin-1"))
@@ -365,7 +366,7 @@ def test_readline_psfile(tmp_path):
         _test_readline_file_psfile(s, ending)
 
 
-def test_psfile_deprecation():
+def test_psfile_deprecation() -> None:
     with pytest.warns(DeprecationWarning):
         EpsImagePlugin.PSFile(None)
 
@@ -375,7 +376,7 @@ def test_psfile_deprecation():
     "line_ending",
     (b"\r\n", b"\n", b"\n\r", b"\r"),
 )
-def test_readline(prefix, line_ending):
+def test_readline(prefix: bytes, line_ending: bytes) -> None:
     simple_file = prefix + line_ending.join(simple_eps_file_with_comments)
     data = io.BytesIO(simple_file)
     test_file = EpsImagePlugin.EpsImageFile(data)
@@ -393,14 +394,14 @@ def test_readline(prefix, line_ending):
         "Tests/images/illuCS6_preview.eps",
     ),
 )
-def test_open_eps(filename):
+def test_open_eps(filename: str) -> None:
     # https://github.com/python-pillow/Pillow/issues/1104
     with Image.open(filename) as img:
         assert img.mode == "RGB"
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
-def test_emptyline():
+def test_emptyline() -> None:
     # Test file includes an empty line in the header data
     emptyline_file = "Tests/images/zero_bb_emptyline.eps"
 
@@ -416,14 +417,14 @@ def test_emptyline():
     "test_file",
     ["Tests/images/timeout-d675703545fee17acab56e5fec644c19979175de.eps"],
 )
-def test_timeout(test_file):
+def test_timeout(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with pytest.raises(Image.UnidentifiedImageError):
             with Image.open(f):
                 pass
 
 
-def test_bounding_box_in_trailer():
+def test_bounding_box_in_trailer() -> None:
     # Check bounding boxes are parsed in the same way
     # when specified in the header and the trailer
     with Image.open("Tests/images/zero_bb_trailer.eps") as trailer_image, Image.open(
@@ -432,7 +433,7 @@ def test_bounding_box_in_trailer():
         assert trailer_image.size == header_image.size
 
 
-def test_eof_before_bounding_box():
+def test_eof_before_bounding_box() -> None:
     with pytest.raises(OSError):
         with Image.open("Tests/images/zero_bb_eof_before_boundingbox.eps"):
             pass

Tests/test_file_fits.py

@@ -11,7 +11,7 @@ from .helper import assert_image_equal, hopper
 TEST_FILE = "Tests/images/hopper.fits"
 
 
-def test_open():
+def test_open() -> None:
     # Act
     with Image.open(TEST_FILE) as im:
         # Assert
@@ -22,7 +22,7 @@ def test_open():
         assert_image_equal(im, hopper("L"))
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     # Arrange
     invalid_file = "Tests/images/flower.jpg"
 
@@ -31,14 +31,14 @@ def test_invalid_file():
         FitsImagePlugin.FitsImageFile(invalid_file)
 
 
-def test_truncated_fits():
+def test_truncated_fits() -> None:
     # No END to headers
     image_data = b"SIMPLE  =                    T" + b" " * 50 + b"TRUNCATE"
     with pytest.raises(OSError):
         FitsImagePlugin.FitsImageFile(BytesIO(image_data))
 
 
-def test_naxis_zero():
+def test_naxis_zero() -> None:
     # This test image has been manually hexedited
     # to set the number of data axes to zero
     with pytest.raises(ValueError):
@@ -46,7 +46,7 @@ def test_naxis_zero():
             pass
 
 
-def test_comment():
+def test_comment() -> None:
     image_data = b"SIMPLE  =                    T / comment string"
     with pytest.raises(OSError):
         FitsImagePlugin.FitsImageFile(BytesIO(image_data))

Tests/test_file_fli.py

@@ -4,7 +4,7 @@ import warnings
 
 import pytest
 
-from PIL import FliImagePlugin, Image
+from PIL import FliImagePlugin, Image, ImageFile
 
 from .helper import assert_image_equal, assert_image_equal_tofile, is_pypy
 
@@ -12,11 +12,14 @@ from .helper import assert_image_equal, assert_image_equal_tofile, is_pypy
 # save as...-> hopper.fli, default options.
 static_test_file = "Tests/images/hopper.fli"
 
-# From https://samples.libav.org/fli-flc/
+# From https://samples.ffmpeg.org/fli-flc/
 animated_test_file = "Tests/images/a.fli"
 
+# From https://samples.ffmpeg.org/fli-flc/
+animated_test_file_with_prefix_chunk = "Tests/images/2422.flc"
 
-def test_sanity():
+
+def test_sanity() -> None:
     with Image.open(static_test_file) as im:
         im.load()
         assert im.mode == "P"
@@ -32,9 +35,27 @@ def test_sanity():
         assert im.is_animated
 
 
+def test_prefix_chunk() -> None:
+    ImageFile.LOAD_TRUNCATED_IMAGES = True
+    try:
+        with Image.open(animated_test_file_with_prefix_chunk) as im:
+            assert im.mode == "P"
+            assert im.size == (320, 200)
+            assert im.format == "FLI"
+            assert im.info["duration"] == 171
+            assert im.is_animated
+
+            palette = im.getpalette()
+            assert palette[3:6] == [255, 255, 255]
+            assert palette[381:384] == [204, 204, 12]
+            assert palette[765:] == [252, 0, 0]
+    finally:
+        ImageFile.LOAD_TRUNCATED_IMAGES = False
+
+
 @pytest.mark.skipif(is_pypy(), reason="Requires CPython")
-def test_unclosed_file():
+def test_unclosed_file() -> None:
-    def open():
+    def open() -> None:
         im = Image.open(static_test_file)
         im.load()
 
@@ -42,14 +63,14 @@ def test_unclosed_file():
         open()
 
 
-def test_closed_file():
+def test_closed_file() -> None:
     with warnings.catch_warnings():
         im = Image.open(static_test_file)
         im.load()
         im.close()
 
 
-def test_seek_after_close():
+def test_seek_after_close() -> None:
     im = Image.open(animated_test_file)
     im.seek(1)
     im.close()
@@ -58,13 +79,13 @@ def test_seek_after_close():
         im.seek(0)
 
 
-def test_context_manager():
+def test_context_manager() -> None:
     with warnings.catch_warnings():
         with Image.open(static_test_file) as im:
             im.load()
 
 
-def test_tell():
+def test_tell() -> None:
     # Arrange
     with Image.open(static_test_file) as im:
         # Act
@@ -74,20 +95,20 @@ def test_tell():
         assert frame == 0
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         FliImagePlugin.FliImageFile(invalid_file)
 
 
-def test_palette_chunk_second():
+def test_palette_chunk_second() -> None:
     with Image.open("Tests/images/hopper_palette_chunk_second.fli") as im:
         with Image.open(static_test_file) as expected:
             assert_image_equal(im.convert("RGB"), expected.convert("RGB"))
 
 
-def test_n_frames():
+def test_n_frames() -> None:
     with Image.open(static_test_file) as im:
         assert im.n_frames == 1
         assert not im.is_animated
@@ -97,7 +118,7 @@ def test_n_frames():
         assert im.is_animated
 
 
-def test_eoferror():
+def test_eoferror() -> None:
     with Image.open(animated_test_file) as im:
         n_frames = im.n_frames
 
@@ -110,7 +131,7 @@ def test_eoferror():
         im.seek(n_frames - 1)
 
 
-def test_seek_tell():
+def test_seek_tell() -> None:
     with Image.open(animated_test_file) as im:
         layer_number = im.tell()
         assert layer_number == 0
@@ -132,7 +153,7 @@ def test_seek_tell():
         assert layer_number == 1
 
 
-def test_seek():
+def test_seek() -> None:
     with Image.open(animated_test_file) as im:
         im.seek(50)
 
@@ -147,7 +168,7 @@ def test_seek():
     ],
 )
 @pytest.mark.timeout(timeout=3)
-def test_timeouts(test_file):
+def test_timeouts(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
             with pytest.raises(OSError):
@@ -160,7 +181,7 @@ def test_timeouts(test_file):
         "Tests/images/crash-5762152299364352.fli",
     ],
 )
-def test_crash(test_file):
+def test_crash(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
             with pytest.raises(OSError):

Tests/test_file_fpx.py

@@ -11,7 +11,7 @@ FpxImagePlugin = pytest.importorskip(
 )
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open("Tests/images/input_bw_one_band.fpx") as im:
         assert im.mode == "L"
         assert im.size == (70, 46)
@@ -20,7 +20,7 @@ def test_sanity():
         assert_image_equal_tofile(im, "Tests/images/input_bw_one_band.png")
 
 
-def test_close():
+def test_close() -> None:
     with Image.open("Tests/images/input_bw_one_band.fpx") as im:
         pass
     assert im.ole.fp.closed
@@ -30,7 +30,7 @@ def test_close():
     assert im.ole.fp.closed
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     # Test an invalid OLE file
     invalid_file = "Tests/images/flower.jpg"
     with pytest.raises(SyntaxError):
@@ -42,7 +42,7 @@ def test_invalid_file():
         FpxImagePlugin.FpxImageFile(ole_file)
 
 
-def test_fpx_invalid_number_of_bands():
+def test_fpx_invalid_number_of_bands() -> None:
     with pytest.raises(OSError, match="Invalid number of bands"):
         with Image.open("Tests/images/input_bw_five_bands.fpx"):
             pass

Tests/test_file_ftex.py

@@ -7,18 +7,18 @@ from PIL import FtexImagePlugin, Image
 from .helper import assert_image_equal_tofile, assert_image_similar
 
 
-def test_load_raw():
+def test_load_raw() -> None:
     with Image.open("Tests/images/ftex_uncompressed.ftu") as im:
         assert_image_equal_tofile(im, "Tests/images/ftex_uncompressed.png")
 
 
-def test_load_dxt1():
+def test_load_dxt1() -> None:
     with Image.open("Tests/images/ftex_dxt1.ftc") as im:
         with Image.open("Tests/images/ftex_dxt1.png") as target:
             assert_image_similar(im, target.convert("RGBA"), 15)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):

Tests/test_file_gbr.py

@@ -7,12 +7,12 @@ from PIL import GbrImagePlugin, Image
 from .helper import assert_image_equal_tofile
 
 
-def test_gbr_file():
+def test_gbr_file() -> None:
     with Image.open("Tests/images/gbr.gbr") as im:
         assert_image_equal_tofile(im, "Tests/images/gbr.png")
 
 
-def test_load():
+def test_load() -> None:
     with Image.open("Tests/images/gbr.gbr") as im:
         assert im.load()[0, 0] == (0, 0, 0, 0)
 
@@ -20,14 +20,14 @@ def test_load():
         assert im.load()[0, 0] == (0, 0, 0, 0)
 
 
-def test_multiple_load_operations():
+def test_multiple_load_operations() -> None:
     with Image.open("Tests/images/gbr.gbr") as im:
         im.load()
         im.load()
         assert_image_equal_tofile(im, "Tests/images/gbr.png")
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):

Tests/test_file_gd.py

@@ -7,18 +7,18 @@ from PIL import GdImageFile, UnidentifiedImageError
 TEST_GD_FILE = "Tests/images/hopper.gd"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with GdImageFile.open(TEST_GD_FILE) as im:
         assert im.size == (128, 128)
         assert im.format == "GD"
 
 
-def test_bad_mode():
+def test_bad_mode() -> None:
     with pytest.raises(ValueError):
         GdImageFile.open(TEST_GD_FILE, "bad mode")
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(UnidentifiedImageError):

Tests/test_file_gif.py

@@ -2,6 +2,8 @@ from __future__ import annotations
 
 import warnings
 from io import BytesIO
+from pathlib import Path
+from typing import Generator
 
 import pytest
 
@@ -23,7 +25,7 @@ with open(TEST_GIF, "rb") as f:
     data = f.read()
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(TEST_GIF) as im:
         im.load()
         assert im.mode == "P"
@@ -33,8 +35,8 @@ def test_sanity():
 
 
 @pytest.mark.skipif(is_pypy(), reason="Requires CPython")
-def test_unclosed_file():
+def test_unclosed_file() -> None:
-    def open():
+    def open() -> None:
         im = Image.open(TEST_GIF)
         im.load()
 
@@ -42,14 +44,14 @@ def test_unclosed_file():
         open()
 
 
-def test_closed_file():
+def test_closed_file() -> None:
     with warnings.catch_warnings():
         im = Image.open(TEST_GIF)
         im.load()
         im.close()
 
 
-def test_seek_after_close():
+def test_seek_after_close() -> None:
     im = Image.open("Tests/images/iss634.gif")
     im.load()
     im.close()
@@ -62,20 +64,20 @@ def test_seek_after_close():
         im.seek(1)
 
 
-def test_context_manager():
+def test_context_manager() -> None:
     with warnings.catch_warnings():
         with Image.open(TEST_GIF) as im:
             im.load()
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         GifImagePlugin.GifImageFile(invalid_file)
 
 
-def test_l_mode_transparency():
+def test_l_mode_transparency() -> None:
     with Image.open("Tests/images/no_palette_with_transparency.gif") as im:
         assert im.mode == "L"
         assert im.load()[0, 0] == 128
@@ -86,7 +88,7 @@ def test_l_mode_transparency():
         assert im.load()[0, 0] == 128
 
 
-def test_l_mode_after_rgb():
+def test_l_mode_after_rgb() -> None:
     with Image.open("Tests/images/no_palette_after_rgb.gif") as im:
         im.seek(1)
         assert im.mode == "RGB"
@@ -95,13 +97,13 @@ def test_l_mode_after_rgb():
         assert im.mode == "RGB"
 
 
-def test_palette_not_needed_for_second_frame():
+def test_palette_not_needed_for_second_frame() -> None:
     with Image.open("Tests/images/palette_not_needed_for_second_frame.gif") as im:
         im.seek(1)
         assert_image_similar(im, hopper("L").convert("RGB"), 8)
 
 
-def test_strategy():
+def test_strategy() -> None:
     with Image.open("Tests/images/iss634.gif") as im:
         expected_rgb_always = im.convert("RGB")
 
@@ -142,14 +144,14 @@ def test_strategy():
         GifImagePlugin.LOADING_STRATEGY = GifImagePlugin.LoadingStrategy.RGB_AFTER_FIRST
 
 
-def test_optimize():
+def test_optimize() -> None:
-    def test_grayscale(optimize):
+    def test_grayscale(optimize: int) -> int:
         im = Image.new("L", (1, 1), 0)
         filename = BytesIO()
         im.save(filename, "GIF", optimize=optimize)
         return len(filename.getvalue())
 
-    def test_bilevel(optimize):
+    def test_bilevel(optimize: int) -> int:
         im = Image.new("1", (1, 1), 0)
         test_file = BytesIO()
         im.save(test_file, "GIF", optimize=optimize)
@@ -177,7 +179,9 @@ def test_optimize():
         (4, 513, 256),
     ),
 )
-def test_optimize_correctness(colors, size, expected_palette_length):
+def test_optimize_correctness(
+    colors: int, size: int, expected_palette_length: int
+) -> None:
     # 256 color Palette image, posterize to > 128 and < 128 levels.
     # Size bigger and smaller than 512x512.
     # Check the palette for number of colors allocated.
@@ -199,14 +203,14 @@ def test_optimize_correctness(colors, size, expected_palette_length):
         assert_image_equal(im.convert("RGB"), reloaded.convert("RGB"))
 
 
-def test_optimize_full_l():
+def test_optimize_full_l() -> None:
     im = Image.frombytes("L", (16, 16), bytes(range(256)))
     test_file = BytesIO()
     im.save(test_file, "GIF", optimize=True)
     assert im.mode == "L"
 
 
-def test_optimize_if_palette_can_be_reduced_by_half():
+def test_optimize_if_palette_can_be_reduced_by_half() -> None:
     im = Image.new("P", (8, 1))
     im.palette = ImagePalette.raw("RGB", bytes((0, 0, 0) * 150))
     for i in range(8):
@@ -219,7 +223,7 @@ def test_optimize_if_palette_can_be_reduced_by_half():
             assert len(reloaded.palette.palette) // 3 == colors
 
 
-def test_full_palette_second_frame(tmp_path):
+def test_full_palette_second_frame(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     im = Image.new("P", (1, 256))
 
@@ -240,7 +244,7 @@ def test_full_palette_second_frame(tmp_path):
             reloaded.getpixel((0, i)) == i
 
 
-def test_roundtrip(tmp_path):
+def test_roundtrip(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     im = hopper()
     im.save(out)
@@ -248,7 +252,7 @@ def test_roundtrip(tmp_path):
         assert_image_similar(reread.convert("RGB"), im, 50)
 
 
-def test_roundtrip2(tmp_path):
+def test_roundtrip2(tmp_path: Path) -> None:
     # see https://github.com/python-pillow/Pillow/issues/403
     out = str(tmp_path / "temp.gif")
     with Image.open(TEST_GIF) as im:
@@ -258,7 +262,7 @@ def test_roundtrip2(tmp_path):
         assert_image_similar(reread.convert("RGB"), hopper(), 50)
 
 
-def test_roundtrip_save_all(tmp_path):
+def test_roundtrip_save_all(tmp_path: Path) -> None:
     # Single frame image
     out = str(tmp_path / "temp.gif")
     im = hopper()
@@ -275,7 +279,7 @@ def test_roundtrip_save_all(tmp_path):
         assert reread.n_frames == 5
 
 
-def test_roundtrip_save_all_1(tmp_path):
+def test_roundtrip_save_all_1(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     im = Image.new("1", (1, 1))
     im2 = Image.new("1", (1, 1), 1)
@@ -296,7 +300,7 @@ def test_roundtrip_save_all_1(tmp_path):
         ("Tests/images/dispose_bgnd_rgba.gif", "RGBA"),
     ),
 )
-def test_loading_multiple_palettes(path, mode):
+def test_loading_multiple_palettes(path: str, mode: str) -> None:
     with Image.open(path) as im:
         assert im.mode == "P"
         first_frame_colors = im.palette.colors.keys()
@@ -314,7 +318,7 @@ def test_loading_multiple_palettes(path, mode):
         assert im.load()[24, 24] not in first_frame_colors
 
 
-def test_headers_saving_for_animated_gifs(tmp_path):
+def test_headers_saving_for_animated_gifs(tmp_path: Path) -> None:
     important_headers = ["background", "version", "duration", "loop"]
     # Multiframe image
     with Image.open("Tests/images/dispose_bgnd.gif") as im:
@@ -327,7 +331,7 @@ def test_headers_saving_for_animated_gifs(tmp_path):
             assert info[header] == reread.info[header]
 
 
-def test_palette_handling(tmp_path):
+def test_palette_handling(tmp_path: Path) -> None:
     # see https://github.com/python-pillow/Pillow/issues/513
 
     with Image.open(TEST_GIF) as im:
@@ -343,12 +347,12 @@ def test_palette_handling(tmp_path):
         assert_image_similar(im, reloaded.convert("RGB"), 10)
 
 
-def test_palette_434(tmp_path):
+def test_palette_434(tmp_path: Path) -> None:
     # see https://github.com/python-pillow/Pillow/issues/434
 
-    def roundtrip(im, *args, **kwargs):
+    def roundtrip(im: Image.Image, **kwargs: bool) -> Image.Image:
         out = str(tmp_path / "temp.gif")
-        im.copy().save(out, *args, **kwargs)
+        im.copy().save(out, **kwargs)
         reloaded = Image.open(out)
 
         return reloaded
@@ -368,7 +372,7 @@ def test_palette_434(tmp_path):
 
 
 @pytest.mark.skipif(not netpbm_available(), reason="Netpbm not available")
-def test_save_netpbm_bmp_mode(tmp_path):
+def test_save_netpbm_bmp_mode(tmp_path: Path) -> None:
     with Image.open(TEST_GIF) as img:
         img = img.convert("RGB")
 
@@ -379,7 +383,7 @@ def test_save_netpbm_bmp_mode(tmp_path):
 
 
 @pytest.mark.skipif(not netpbm_available(), reason="Netpbm not available")
-def test_save_netpbm_l_mode(tmp_path):
+def test_save_netpbm_l_mode(tmp_path: Path) -> None:
     with Image.open(TEST_GIF) as img:
         img = img.convert("L")
 
@@ -389,7 +393,7 @@ def test_save_netpbm_l_mode(tmp_path):
             assert_image_similar(img, reloaded.convert("L"), 0)
 
 
-def test_seek():
+def test_seek() -> None:
     with Image.open("Tests/images/dispose_none.gif") as img:
         frame_count = 0
         try:
@@ -400,7 +404,7 @@ def test_seek():
             assert frame_count == 5
 
 
-def test_seek_info():
+def test_seek_info() -> None:
     with Image.open("Tests/images/iss634.gif") as im:
         info = im.info.copy()
 
@@ -410,7 +414,7 @@ def test_seek_info():
         assert im.info == info
 
 
-def test_seek_rewind():
+def test_seek_rewind() -> None:
     with Image.open("Tests/images/iss634.gif") as im:
         im.seek(2)
         im.seek(1)
@@ -428,7 +432,7 @@ def test_seek_rewind():
         ("Tests/images/iss634.gif", 42),
     ),
 )
-def test_n_frames(path, n_frames):
+def test_n_frames(path: str, n_frames: int) -> None:
     # Test is_animated before n_frames
     with Image.open(path) as im:
         assert im.is_animated == (n_frames != 1)
@@ -439,7 +443,7 @@ def test_n_frames(path, n_frames):
         assert im.is_animated == (n_frames != 1)
 
 
-def test_no_change():
+def test_no_change() -> None:
     # Test n_frames does not change the image
     with Image.open("Tests/images/dispose_bgnd.gif") as im:
         im.seek(1)
@@ -460,7 +464,7 @@ def test_no_change():
         assert_image_equal(im, expected)
 
 
-def test_eoferror():
+def test_eoferror() -> None:
     with Image.open(TEST_GIF) as im:
         n_frames = im.n_frames
 
@@ -473,13 +477,13 @@ def test_eoferror():
         im.seek(n_frames - 1)
 
 
-def test_first_frame_transparency():
+def test_first_frame_transparency() -> None:
     with Image.open("Tests/images/first_frame_transparency.gif") as im:
         px = im.load()
         assert px[0, 0] == im.info["transparency"]
 
 
-def test_dispose_none():
+def test_dispose_none() -> None:
     with Image.open("Tests/images/dispose_none.gif") as img:
         try:
             while True:
@@ -489,7 +493,7 @@ def test_dispose_none():
             pass
 
 
-def test_dispose_none_load_end():
+def test_dispose_none_load_end() -> None:
     # Test image created with:
     #
     # im = Image.open("transparent.gif")
@@ -502,7 +506,7 @@ def test_dispose_none_load_end():
         assert_image_equal_tofile(img, "Tests/images/dispose_none_load_end_second.png")
 
 
-def test_dispose_background():
+def test_dispose_background() -> None:
     with Image.open("Tests/images/dispose_bgnd.gif") as img:
         try:
             while True:
@@ -512,7 +516,7 @@ def test_dispose_background():
             pass
 
 
-def test_dispose_background_transparency():
+def test_dispose_background_transparency() -> None:
     with Image.open("Tests/images/dispose_bgnd_transparency.gif") as img:
         img.seek(2)
         px = img.load()
@@ -540,7 +544,10 @@ def test_dispose_background_transparency():
         ),
     ),
 )
-def test_transparent_dispose(loading_strategy, expected_colors):
+def test_transparent_dispose(
+    loading_strategy: GifImagePlugin.LoadingStrategy,
+    expected_colors: tuple[tuple[int | tuple[int, int, int, int], ...]],
+) -> None:
     GifImagePlugin.LOADING_STRATEGY = loading_strategy
     try:
         with Image.open("Tests/images/transparent_dispose.gif") as img:
@@ -553,7 +560,7 @@ def test_transparent_dispose(loading_strategy, expected_colors):
         GifImagePlugin.LOADING_STRATEGY = GifImagePlugin.LoadingStrategy.RGB_AFTER_FIRST
 
 
-def test_dispose_previous():
+def test_dispose_previous() -> None:
     with Image.open("Tests/images/dispose_prev.gif") as img:
         try:
             while True:
@@ -563,7 +570,7 @@ def test_dispose_previous():
             pass
 
 
-def test_dispose_previous_first_frame():
+def test_dispose_previous_first_frame() -> None:
     with Image.open("Tests/images/dispose_prev_first_frame.gif") as im:
         im.seek(1)
         assert_image_equal_tofile(
@@ -571,7 +578,7 @@ def test_dispose_previous_first_frame():
         )
 
 
-def test_previous_frame_loaded():
+def test_previous_frame_loaded() -> None:
     with Image.open("Tests/images/dispose_none.gif") as img:
         img.load()
         img.seek(1)
@@ -582,7 +589,7 @@ def test_previous_frame_loaded():
             assert_image_equal(img_skipped, img)
 
 
-def test_save_dispose(tmp_path):
+def test_save_dispose(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     im_list = [
         Image.new("L", (100, 100), "#000"),
@@ -610,7 +617,7 @@ def test_save_dispose(tmp_path):
             assert img.disposal_method == i + 1
 
 
-def test_dispose2_palette(tmp_path):
+def test_dispose2_palette(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     # Four colors: white, gray, black, red
@@ -641,7 +648,7 @@ def test_dispose2_palette(tmp_path):
             assert rgb_img.getpixel((50, 50)) == circle
 
 
-def test_dispose2_diff(tmp_path):
+def test_dispose2_diff(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     # 4 frames: red/blue, red/red, blue/blue, red/blue
@@ -683,7 +690,7 @@ def test_dispose2_diff(tmp_path):
             assert rgb_img.getpixel((1, 1)) == (255, 255, 255, 0)
 
 
-def test_dispose2_background(tmp_path):
+def test_dispose2_background(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     im_list = []
@@ -709,7 +716,7 @@ def test_dispose2_background(tmp_path):
         assert im.getpixel((0, 0)) == (255, 0, 0)
 
 
-def test_dispose2_background_frame(tmp_path):
+def test_dispose2_background_frame(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     im_list = [Image.new("RGBA", (1, 20))]
@@ -727,7 +734,7 @@ def test_dispose2_background_frame(tmp_path):
         assert im.n_frames == 3
 
 
-def test_transparency_in_second_frame(tmp_path):
+def test_transparency_in_second_frame(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     with Image.open("Tests/images/different_transparency.gif") as im:
         assert im.info["transparency"] == 0
@@ -747,7 +754,7 @@ def test_transparency_in_second_frame(tmp_path):
         )
 
 
-def test_no_transparency_in_second_frame():
+def test_no_transparency_in_second_frame() -> None:
     with Image.open("Tests/images/iss634.gif") as img:
         # Seek to the second frame
         img.seek(img.tell() + 1)
@@ -757,7 +764,7 @@ def test_no_transparency_in_second_frame():
         assert img.histogram()[255] == 0
 
 
-def test_remapped_transparency(tmp_path):
+def test_remapped_transparency(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     im = Image.new("P", (1, 2))
@@ -773,7 +780,7 @@ def test_remapped_transparency(tmp_path):
         assert reloaded.info["transparency"] == reloaded.getpixel((0, 1))
 
 
-def test_duration(tmp_path):
+def test_duration(tmp_path: Path) -> None:
     duration = 1000
 
     out = str(tmp_path / "temp.gif")
@@ -787,7 +794,7 @@ def test_duration(tmp_path):
         assert reread.info["duration"] == duration
 
 
-def test_multiple_duration(tmp_path):
+def test_multiple_duration(tmp_path: Path) -> None:
     duration_list = [1000, 2000, 3000]
 
     out = str(tmp_path / "temp.gif")
@@ -822,7 +829,7 @@ def test_multiple_duration(tmp_path):
                 pass
 
 
-def test_roundtrip_info_duration(tmp_path):
+def test_roundtrip_info_duration(tmp_path: Path) -> None:
     duration_list = [100, 500, 500]
 
     out = str(tmp_path / "temp.gif")
@@ -839,7 +846,7 @@ def test_roundtrip_info_duration(tmp_path):
         ] == duration_list
 
 
-def test_roundtrip_info_duration_combined(tmp_path):
+def test_roundtrip_info_duration_combined(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     with Image.open("Tests/images/duplicate_frame.gif") as im:
         assert [frame.info["duration"] for frame in ImageSequence.Iterator(im)] == [
@@ -855,7 +862,7 @@ def test_roundtrip_info_duration_combined(tmp_path):
         ] == [1000, 2000]
 
 
-def test_identical_frames(tmp_path):
+def test_identical_frames(tmp_path: Path) -> None:
     duration_list = [1000, 1500, 2000, 4000]
 
     out = str(tmp_path / "temp.gif")
@@ -888,7 +895,9 @@ def test_identical_frames(tmp_path):
         1500,
     ),
 )
-def test_identical_frames_to_single_frame(duration, tmp_path):
+def test_identical_frames_to_single_frame(
+    duration: int | list[int], tmp_path: Path
+) -> None:
     out = str(tmp_path / "temp.gif")
     im_list = [
         Image.new("L", (100, 100), "#000"),
@@ -905,7 +914,7 @@ def test_identical_frames_to_single_frame(duration, tmp_path):
         assert reread.info["duration"] == 4500
 
 
-def test_loop_none(tmp_path):
+def test_loop_none(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     im = Image.new("L", (100, 100), "#000")
     im.save(out, loop=None)
@@ -913,7 +922,7 @@ def test_loop_none(tmp_path):
         assert "loop" not in reread.info
 
 
-def test_number_of_loops(tmp_path):
+def test_number_of_loops(tmp_path: Path) -> None:
     number_of_loops = 2
 
     out = str(tmp_path / "temp.gif")
@@ -931,7 +940,7 @@ def test_number_of_loops(tmp_path):
         assert im.info["loop"] == 2
 
 
-def test_background(tmp_path):
+def test_background(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     im = Image.new("L", (100, 100), "#000")
     im.info["background"] = 1
@@ -940,7 +949,7 @@ def test_background(tmp_path):
         assert reread.info["background"] == im.info["background"]
 
 
-def test_webp_background(tmp_path):
+def test_webp_background(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     # Test opaque WebP background
@@ -955,7 +964,7 @@ def test_webp_background(tmp_path):
     im.save(out)
 
 
-def test_comment(tmp_path):
+def test_comment(tmp_path: Path) -> None:
     with Image.open(TEST_GIF) as im:
         assert im.info["comment"] == b"File written by Adobe Photoshop\xa8 4.0"
 
@@ -975,7 +984,7 @@ def test_comment(tmp_path):
         assert reread.info["version"] == b"GIF89a"
 
 
-def test_comment_over_255(tmp_path):
+def test_comment_over_255(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     im = Image.new("L", (100, 100), "#000")
     comment = b"Test comment text"
@@ -990,18 +999,18 @@ def test_comment_over_255(tmp_path):
         assert reread.info["version"] == b"GIF89a"
 
 
-def test_zero_comment_subblocks():
+def test_zero_comment_subblocks() -> None:
     with Image.open("Tests/images/hopper_zero_comment_subblocks.gif") as im:
         assert_image_equal_tofile(im, TEST_GIF)
 
 
-def test_read_multiple_comment_blocks():
+def test_read_multiple_comment_blocks() -> None:
     with Image.open("Tests/images/multiple_comments.gif") as im:
         # Multiple comment blocks in a frame are separated not concatenated
         assert im.info["comment"] == b"Test comment 1\nTest comment 2"
 
 
-def test_empty_string_comment(tmp_path):
+def test_empty_string_comment(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     with Image.open("Tests/images/chi.gif") as im:
         assert "comment" in im.info
@@ -1014,7 +1023,7 @@ def test_empty_string_comment(tmp_path):
             assert "comment" not in frame.info
 
 
-def test_retain_comment_in_subsequent_frames(tmp_path):
+def test_retain_comment_in_subsequent_frames(tmp_path: Path) -> None:
     # Test that a comment block at the beginning is kept
     with Image.open("Tests/images/chi.gif") as im:
         for frame in ImageSequence.Iterator(im):
@@ -1045,10 +1054,10 @@ def test_retain_comment_in_subsequent_frames(tmp_path):
             assert frame.info["comment"] == b"Test"
 
 
-def test_version(tmp_path):
+def test_version(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
-    def assert_version_after_save(im, version):
+    def assert_version_after_save(im: Image.Image, version: bytes) -> None:
         im.save(out)
         with Image.open(out) as reread:
             assert reread.info["version"] == version
@@ -1075,7 +1084,7 @@ def test_version(tmp_path):
         assert_version_after_save(im, b"GIF87a")
 
 
-def test_append_images(tmp_path):
+def test_append_images(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     # Test appending single frame images
@@ -1087,7 +1096,7 @@ def test_append_images(tmp_path):
         assert reread.n_frames == 3
 
     # Tests appending using a generator
-    def im_generator(ims):
+    def im_generator(ims: list[Image.Image]) -> Generator[Image.Image, None, None]:
         yield from ims
 
     im.save(out, save_all=True, append_images=im_generator(ims))
@@ -1104,7 +1113,7 @@ def test_append_images(tmp_path):
         assert reread.n_frames == 10
 
 
-def test_transparent_optimize(tmp_path):
+def test_transparent_optimize(tmp_path: Path) -> None:
     # From issue #2195, if the transparent color is incorrectly optimized out, GIF loses
     # transparency.
     # Need a palette that isn't using the 0 color,
@@ -1124,7 +1133,7 @@ def test_transparent_optimize(tmp_path):
         assert reloaded.info["transparency"] == reloaded.getpixel((252, 0))
 
 
-def test_removed_transparency(tmp_path):
+def test_removed_transparency(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     im = Image.new("RGB", (256, 1))
 
@@ -1139,7 +1148,7 @@ def test_removed_transparency(tmp_path):
         assert "transparency" not in reloaded.info
 
 
-def test_rgb_transparency(tmp_path):
+def test_rgb_transparency(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     # Single frame
@@ -1161,7 +1170,7 @@ def test_rgb_transparency(tmp_path):
         assert "transparency" not in reloaded.info
 
 
-def test_rgba_transparency(tmp_path):
+def test_rgba_transparency(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     im = hopper("P")
@@ -1172,13 +1181,13 @@ def test_rgba_transparency(tmp_path):
         assert_image_equal(hopper("P").convert("RGB"), reloaded)
 
 
-def test_background_outside_palettte(tmp_path):
+def test_background_outside_palettte(tmp_path: Path) -> None:
     with Image.open("Tests/images/background_outside_palette.gif") as im:
         im.seek(1)
         assert im.info["background"] == 255
 
 
-def test_bbox(tmp_path):
+def test_bbox(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     im = Image.new("RGB", (100, 100), "#fff")
@@ -1189,7 +1198,7 @@ def test_bbox(tmp_path):
         assert reread.n_frames == 2
 
 
-def test_bbox_alpha(tmp_path):
+def test_bbox_alpha(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
 
     im = Image.new("RGBA", (1, 2), (255, 0, 0, 255))
@@ -1201,7 +1210,7 @@ def test_bbox_alpha(tmp_path):
         assert reread.n_frames == 2
 
 
-def test_palette_save_L(tmp_path):
+def test_palette_save_L(tmp_path: Path) -> None:
     # Generate an L mode image with a separate palette
 
     im = hopper("P")
@@ -1215,7 +1224,7 @@ def test_palette_save_L(tmp_path):
         assert_image_equal(reloaded.convert("RGB"), im.convert("RGB"))
 
 
-def test_palette_save_P(tmp_path):
+def test_palette_save_P(tmp_path: Path) -> None:
     im = Image.new("P", (1, 2))
     im.putpixel((0, 1), 1)
 
@@ -1229,7 +1238,7 @@ def test_palette_save_P(tmp_path):
         assert reloaded_rgb.getpixel((0, 1)) == (4, 5, 6)
 
 
-def test_palette_save_duplicate_entries(tmp_path):
+def test_palette_save_duplicate_entries(tmp_path: Path) -> None:
     im = Image.new("P", (1, 2))
     im.putpixel((0, 1), 1)
 
@@ -1242,7 +1251,7 @@ def test_palette_save_duplicate_entries(tmp_path):
         assert reloaded.convert("RGB").getpixel((0, 1)) == (0, 0, 0)
 
 
-def test_palette_save_all_P(tmp_path):
+def test_palette_save_all_P(tmp_path: Path) -> None:
     frames = []
     colors = ((255, 0, 0), (0, 255, 0))
     for color in colors:
@@ -1265,7 +1274,7 @@ def test_palette_save_all_P(tmp_path):
         assert im.palette.palette == im.global_palette.palette
 
 
-def test_palette_save_ImagePalette(tmp_path):
+def test_palette_save_ImagePalette(tmp_path: Path) -> None:
     # Pass in a different palette, as an ImagePalette.ImagePalette
     # effectively the same as test_palette_save_P
 
@@ -1280,7 +1289,7 @@ def test_palette_save_ImagePalette(tmp_path):
         assert_image_equal(reloaded.convert("RGB"), im.convert("RGB"))
 
 
-def test_save_I(tmp_path):
+def test_save_I(tmp_path: Path) -> None:
     # Test saving something that would trigger the auto-convert to 'L'
 
     im = hopper("I")
@@ -1292,7 +1301,7 @@ def test_save_I(tmp_path):
         assert_image_equal(reloaded.convert("L"), im.convert("L"))
 
 
-def test_getdata():
+def test_getdata() -> None:
     # Test getheader/getdata against legacy values.
     # Create a 'P' image with holes in the palette.
     im = Image._wedge().resize((16, 16), Image.Resampling.NEAREST)
@@ -1320,7 +1329,7 @@ def test_getdata():
         GifImagePlugin._FORCE_OPTIMIZE = False
 
 
-def test_lzw_bits():
+def test_lzw_bits() -> None:
     # see https://github.com/python-pillow/Pillow/issues/2811
     with Image.open("Tests/images/issue_2811.gif") as im:
         assert im.tile[0][3][0] == 11  # LZW bits
@@ -1328,7 +1337,7 @@ def test_lzw_bits():
         im.load()
 
 
-def test_extents():
+def test_extents() -> None:
     with Image.open("Tests/images/test_extents.gif") as im:
         assert im.size == (100, 100)
 
@@ -1340,7 +1349,7 @@ def test_extents():
         assert im.size == (150, 150)
 
 
-def test_missing_background():
+def test_missing_background() -> None:
     # The Global Color Table Flag isn't set, so there is no background color index,
     # but the disposal method is "Restore to background color"
     with Image.open("Tests/images/missing_background.gif") as im:
@@ -1348,7 +1357,7 @@ def test_missing_background():
         assert_image_equal_tofile(im, "Tests/images/missing_background_first_frame.png")
 
 
-def test_saving_rgba(tmp_path):
+def test_saving_rgba(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.gif")
     with Image.open("Tests/images/transparent.png") as im:
         im.save(out)

Tests/test_file_gimpgradient.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 from PIL import GimpGradientFile, ImagePalette
 
 
-def test_linear_pos_le_middle():
+def test_linear_pos_le_middle() -> None:
     # Arrange
     middle = 0.5
     pos = 0.25
@@ -15,7 +15,7 @@ def test_linear_pos_le_middle():
     assert ret == 0.25
 
 
-def test_linear_pos_le_small_middle():
+def test_linear_pos_le_small_middle() -> None:
     # Arrange
     middle = 1e-11
     pos = 1e-12
@@ -27,7 +27,7 @@ def test_linear_pos_le_small_middle():
     assert ret == 0.0
 
 
-def test_linear_pos_gt_middle():
+def test_linear_pos_gt_middle() -> None:
     # Arrange
     middle = 0.5
     pos = 0.75
@@ -39,7 +39,7 @@ def test_linear_pos_gt_middle():
     assert ret == 0.75
 
 
-def test_linear_pos_gt_small_middle():
+def test_linear_pos_gt_small_middle() -> None:
     # Arrange
     middle = 1 - 1e-11
     pos = 1 - 1e-12
@@ -51,7 +51,7 @@ def test_linear_pos_gt_small_middle():
     assert ret == 1.0
 
 
-def test_curved():
+def test_curved() -> None:
     # Arrange
     middle = 0.5
     pos = 0.75
@@ -63,7 +63,7 @@ def test_curved():
     assert ret == 0.75
 
 
-def test_sine():
+def test_sine() -> None:
     # Arrange
     middle = 0.5
     pos = 0.75
@@ -75,7 +75,7 @@ def test_sine():
     assert ret == 0.8535533905932737
 
 
-def test_sphere_increasing():
+def test_sphere_increasing() -> None:
     # Arrange
     middle = 0.5
     pos = 0.75
@@ -87,7 +87,7 @@ def test_sphere_increasing():
     assert round(abs(ret - 0.9682458365518543), 7) == 0
 
 
-def test_sphere_decreasing():
+def test_sphere_decreasing() -> None:
     # Arrange
     middle = 0.5
     pos = 0.75
@@ -99,7 +99,7 @@ def test_sphere_decreasing():
     assert ret == 0.3385621722338523
 
 
-def test_load_via_imagepalette():
+def test_load_via_imagepalette() -> None:
     # Arrange
     test_file = "Tests/images/gimp_gradient.ggr"
 
@@ -112,7 +112,7 @@ def test_load_via_imagepalette():
     assert palette[1] == "RGBA"
 
 
-def test_load_1_3_via_imagepalette():
+def test_load_1_3_via_imagepalette() -> None:
     # Arrange
     # GIMP 1.3 gradient files contain a name field
     test_file = "Tests/images/gimp_gradient_with_name.ggr"

Tests/test_file_gimppalette.py

@@ -5,7 +5,7 @@ import pytest
 from PIL.GimpPaletteFile import GimpPaletteFile
 
 
-def test_sanity():
+def test_sanity() -> None:
     with open("Tests/images/test.gpl", "rb") as fp:
         GimpPaletteFile(fp)
 
@@ -22,7 +22,7 @@ def test_sanity():
             GimpPaletteFile(fp)
 
 
-def test_get_palette():
+def test_get_palette() -> None:
     # Arrange
     with open("Tests/images/custom_gimp_palette.gpl", "rb") as fp:
         palette_file = GimpPaletteFile(fp)

Tests/test_file_gribstub.py

@@ -1,5 +1,8 @@
 from __future__ import annotations
 
+from pathlib import Path
+from typing import IO
+
 import pytest
 
 from PIL import GribStubImagePlugin, Image
@@ -9,7 +12,7 @@ from .helper import hopper
 TEST_FILE = "Tests/images/WAlaska.wind.7days.grb"
 
 
-def test_open():
+def test_open() -> None:
     # Act
     with Image.open(TEST_FILE) as im:
         # Assert
@@ -20,7 +23,7 @@ def test_open():
         assert im.size == (1, 1)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     # Arrange
     invalid_file = "Tests/images/flower.jpg"
 
@@ -29,7 +32,7 @@ def test_invalid_file():
         GribStubImagePlugin.GribStubImageFile(invalid_file)
 
 
-def test_load():
+def test_load() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         # Act / Assert: stub cannot load without an implemented handler
@@ -37,7 +40,7 @@ def test_load():
             im.load()
 
 
-def test_save(tmp_path):
+def test_save(tmp_path: Path) -> None:
     # Arrange
     im = hopper()
     tmpfile = str(tmp_path / "temp.grib")
@@ -47,21 +50,21 @@ def test_save(tmp_path):
         im.save(tmpfile)
 
 
-def test_handler(tmp_path):
+def test_handler(tmp_path: Path) -> None:
     class TestHandler:
         opened = False
         loaded = False
         saved = False
 
-        def open(self, im):
+        def open(self, im: Image.Image) -> None:
             self.opened = True
 
-        def load(self, im):
+        def load(self, im: Image.Image) -> Image.Image:
             self.loaded = True
             im.fp.close()
             return Image.new("RGB", (1, 1))
 
-        def save(self, im, fp, filename):
+        def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
             self.saved = True
 
     handler = TestHandler()

Tests/test_file_hdf5stub.py

@@ -1,5 +1,8 @@
 from __future__ import annotations
 
+from pathlib import Path
+from typing import IO
+
 import pytest
 
 from PIL import Hdf5StubImagePlugin, Image
@@ -7,7 +10,7 @@ from PIL import Hdf5StubImagePlugin, Image
 TEST_FILE = "Tests/images/hdf5.h5"
 
 
-def test_open():
+def test_open() -> None:
     # Act
     with Image.open(TEST_FILE) as im:
         # Assert
@@ -18,7 +21,7 @@ def test_open():
         assert im.size == (1, 1)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     # Arrange
     invalid_file = "Tests/images/flower.jpg"
 
@@ -27,7 +30,7 @@ def test_invalid_file():
         Hdf5StubImagePlugin.HDF5StubImageFile(invalid_file)
 
 
-def test_load():
+def test_load() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         # Act / Assert: stub cannot load without an implemented handler
@@ -35,7 +38,7 @@ def test_load():
             im.load()
 
 
-def test_save():
+def test_save() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         dummy_fp = None
@@ -48,21 +51,21 @@ def test_save():
             Hdf5StubImagePlugin._save(im, dummy_fp, dummy_filename)
 
 
-def test_handler(tmp_path):
+def test_handler(tmp_path: Path) -> None:
     class TestHandler:
         opened = False
         loaded = False
         saved = False
 
-        def open(self, im):
+        def open(self, im: Image.Image) -> None:
             self.opened = True
 
-        def load(self, im):
+        def load(self, im: Image.Image) -> Image.Image:
             self.loaded = True
             im.fp.close()
             return Image.new("RGB", (1, 1))
 
-        def save(self, im, fp, filename):
+        def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
             self.saved = True
 
     handler = TestHandler()

Tests/test_file_icns.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import io
 import os
 import warnings
+from pathlib import Path
 
 import pytest
 
@@ -14,7 +15,7 @@ from .helper import assert_image_equal, assert_image_similar_tofile, skip_unless
 TEST_FILE = "Tests/images/pillow.icns"
 
 
-def test_sanity():
+def test_sanity() -> None:
     # Loading this icon by default should result in the largest size
     # (512x512@2x) being loaded
     with Image.open(TEST_FILE) as im:
@@ -27,7 +28,7 @@ def test_sanity():
         assert im.format == "ICNS"
 
 
-def test_load():
+def test_load() -> None:
     with Image.open(TEST_FILE) as im:
         assert im.load()[0, 0] == (0, 0, 0, 0)
 
@@ -35,7 +36,7 @@ def test_load():
         assert im.load()[0, 0] == (0, 0, 0, 0)
 
 
-def test_save(tmp_path):
+def test_save(tmp_path: Path) -> None:
     temp_file = str(tmp_path / "temp.icns")
 
     with Image.open(TEST_FILE) as im:
@@ -52,7 +53,7 @@ def test_save(tmp_path):
         assert _binary.i32be(fp.read(4)) == file_length
 
 
-def test_save_append_images(tmp_path):
+def test_save_append_images(tmp_path: Path) -> None:
     temp_file = str(tmp_path / "temp.icns")
     provided_im = Image.new("RGBA", (32, 32), (255, 0, 0, 128))
 
@@ -67,7 +68,7 @@ def test_save_append_images(tmp_path):
             assert_image_equal(reread, provided_im)
 
 
-def test_save_fp():
+def test_save_fp() -> None:
     fp = io.BytesIO()
 
     with Image.open(TEST_FILE) as im:
@@ -79,7 +80,7 @@ def test_save_fp():
         assert reread.format == "ICNS"
 
 
-def test_sizes():
+def test_sizes() -> None:
     # Check that we can load all of the sizes, and that the final pixel
     # dimensions are as expected
     with Image.open(TEST_FILE) as im:
@@ -96,7 +97,7 @@ def test_sizes():
             im.size = (1, 1)
 
 
-def test_older_icon():
+def test_older_icon() -> None:
     # This icon was made with Icon Composer rather than iconutil; it still
     # uses PNG rather than JP2, however (since it was made on 10.9).
     with Image.open("Tests/images/pillow2.icns") as im:
@@ -111,7 +112,7 @@ def test_older_icon():
 
 
 @skip_unless_feature("jpg_2000")
-def test_jp2_icon():
+def test_jp2_icon() -> None:
     # This icon uses JPEG 2000 images instead of the PNG images.
     # The advantage of doing this is that OS X 10.5 supports JPEG 2000
     # but not PNG; some commercial software therefore does just this.
@@ -127,7 +128,7 @@ def test_jp2_icon():
                 assert im2.size == (wr, hr)
 
 
-def test_getimage():
+def test_getimage() -> None:
     with open(TEST_FILE, "rb") as fp:
         icns_file = IcnsImagePlugin.IcnsFile(fp)
 
@@ -140,14 +141,14 @@ def test_getimage():
         assert im.size == (512, 512)
 
 
-def test_not_an_icns_file():
+def test_not_an_icns_file() -> None:
     with io.BytesIO(b"invalid\n") as fp:
         with pytest.raises(SyntaxError):
             IcnsImagePlugin.IcnsFile(fp)
 
 
 @skip_unless_feature("jpg_2000")
-def test_icns_decompression_bomb():
+def test_icns_decompression_bomb() -> None:
     with Image.open(
         "Tests/images/oom-8ed3316a4109213ca96fb8a256a0bfefdece1461.icns"
     ) as im:

Tests/test_file_ico.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import io
 import os
+from pathlib import Path
 
 import pytest
 
@@ -12,7 +13,7 @@ from .helper import assert_image_equal, assert_image_equal_tofile, hopper
 TEST_ICO_FILE = "Tests/images/hopper.ico"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(TEST_ICO_FILE) as im:
         im.load()
     assert im.mode == "RGBA"
@@ -21,29 +22,29 @@ def test_sanity():
     assert im.get_format_mimetype() == "image/x-icon"
 
 
-def test_load():
+def test_load() -> None:
     with Image.open(TEST_ICO_FILE) as im:
         assert im.load()[0, 0] == (1, 1, 9, 255)
 
 
-def test_mask():
+def test_mask() -> None:
     with Image.open("Tests/images/hopper_mask.ico") as im:
         assert_image_equal_tofile(im, "Tests/images/hopper_mask.png")
 
 
-def test_black_and_white():
+def test_black_and_white() -> None:
     with Image.open("Tests/images/black_and_white.ico") as im:
         assert im.mode == "RGBA"
         assert im.size == (16, 16)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     with open("Tests/images/flower.jpg", "rb") as fp:
         with pytest.raises(SyntaxError):
             IcoImagePlugin.IcoImageFile(fp)
 
 
-def test_save_to_bytes():
+def test_save_to_bytes() -> None:
     output = io.BytesIO()
     im = hopper()
     im.save(output, "ico", sizes=[(32, 32), (64, 64)])
@@ -73,7 +74,7 @@ def test_save_to_bytes():
         )
 
 
-def test_getpixel(tmp_path):
+def test_getpixel(tmp_path: Path) -> None:
     temp_file = str(tmp_path / "temp.ico")
 
     im = hopper()
@@ -86,7 +87,7 @@ def test_getpixel(tmp_path):
         assert reloaded.getpixel((0, 0)) == (18, 20, 62)
 
 
-def test_no_duplicates(tmp_path):
+def test_no_duplicates(tmp_path: Path) -> None:
     temp_file = str(tmp_path / "temp.ico")
     temp_file2 = str(tmp_path / "temp2.ico")
 
@@ -100,7 +101,7 @@ def test_no_duplicates(tmp_path):
     assert os.path.getsize(temp_file) == os.path.getsize(temp_file2)
 
 
-def test_different_bit_depths(tmp_path):
+def test_different_bit_depths(tmp_path: Path) -> None:
     temp_file = str(tmp_path / "temp.ico")
     temp_file2 = str(tmp_path / "temp2.ico")
 
@@ -134,7 +135,7 @@ def test_different_bit_depths(tmp_path):
 
 
 @pytest.mark.parametrize("mode", ("1", "L", "P", "RGB", "RGBA"))
-def test_save_to_bytes_bmp(mode):
+def test_save_to_bytes_bmp(mode: str) -> None:
     output = io.BytesIO()
     im = hopper(mode)
     im.save(output, "ico", bitmap_format="bmp", sizes=[(32, 32), (64, 64)])
@@ -162,13 +163,13 @@ def test_save_to_bytes_bmp(mode):
         assert_image_equal(reloaded, im)
 
 
-def test_incorrect_size():
+def test_incorrect_size() -> None:
     with Image.open(TEST_ICO_FILE) as im:
         with pytest.raises(ValueError):
             im.size = (1, 1)
 
 
-def test_save_256x256(tmp_path):
+def test_save_256x256(tmp_path: Path) -> None:
     """Issue #2264 https://github.com/python-pillow/Pillow/issues/2264"""
     # Arrange
     with Image.open("Tests/images/hopper_256x256.ico") as im:
@@ -181,7 +182,7 @@ def test_save_256x256(tmp_path):
         assert im_saved.size == (256, 256)
 
 
-def test_only_save_relevant_sizes(tmp_path):
+def test_only_save_relevant_sizes(tmp_path: Path) -> None:
     """Issue #2266 https://github.com/python-pillow/Pillow/issues/2266
     Should save in 16x16, 24x24, 32x32, 48x48 sizes
     and not in 16x16, 24x24, 32x32, 48x48, 48x48, 48x48, 48x48 sizes
@@ -197,7 +198,7 @@ def test_only_save_relevant_sizes(tmp_path):
         assert im_saved.info["sizes"] == {(16, 16), (24, 24), (32, 32), (48, 48)}
 
 
-def test_save_append_images(tmp_path):
+def test_save_append_images(tmp_path: Path) -> None:
     # append_images should be used for scaled down versions of the image
     im = hopper("RGBA")
     provided_im = Image.new("RGBA", (32, 32), (255, 0, 0))
@@ -211,7 +212,7 @@ def test_save_append_images(tmp_path):
         assert_image_equal(reread, provided_im)
 
 
-def test_unexpected_size():
+def test_unexpected_size() -> None:
     # This image has been manually hexedited to state that it is 16x32
     # while the image within is still 16x16
     with pytest.warns(UserWarning):
@@ -219,7 +220,7 @@ def test_unexpected_size():
             assert im.size == (16, 16)
 
 
-def test_draw_reloaded(tmp_path):
+def test_draw_reloaded(tmp_path: Path) -> None:
     with Image.open(TEST_ICO_FILE) as im:
         outfile = str(tmp_path / "temp_saved_hopper_draw.ico")
 

Tests/test_file_im.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import filecmp
 import warnings
+from pathlib import Path
 
 import pytest
 
@@ -13,7 +14,7 @@ from .helper import assert_image_equal_tofile, hopper, is_pypy
 TEST_IM = "Tests/images/hopper.im"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(TEST_IM) as im:
         im.load()
         assert im.mode == "RGB"
@@ -21,7 +22,7 @@ def test_sanity():
         assert im.format == "IM"
 
 
-def test_name_limit(tmp_path):
+def test_name_limit(tmp_path: Path) -> None:
     out = str(tmp_path / ("name_limit_test" * 7 + ".im"))
     with Image.open(TEST_IM) as im:
         im.save(out)
@@ -29,8 +30,8 @@ def test_name_limit(tmp_path):
 
 
 @pytest.mark.skipif(is_pypy(), reason="Requires CPython")
-def test_unclosed_file():
+def test_unclosed_file() -> None:
-    def open():
+    def open() -> None:
         im = Image.open(TEST_IM)
         im.load()
 
@@ -38,20 +39,20 @@ def test_unclosed_file():
         open()
 
 
-def test_closed_file():
+def test_closed_file() -> None:
     with warnings.catch_warnings():
         im = Image.open(TEST_IM)
         im.load()
         im.close()
 
 
-def test_context_manager():
+def test_context_manager() -> None:
     with warnings.catch_warnings():
         with Image.open(TEST_IM) as im:
             im.load()
 
 
-def test_tell():
+def test_tell() -> None:
     # Arrange
     with Image.open(TEST_IM) as im:
         # Act
@@ -61,13 +62,13 @@ def test_tell():
     assert frame == 0
 
 
-def test_n_frames():
+def test_n_frames() -> None:
     with Image.open(TEST_IM) as im:
         assert im.n_frames == 1
         assert not im.is_animated
 
 
-def test_eoferror():
+def test_eoferror() -> None:
     with Image.open(TEST_IM) as im:
         n_frames = im.n_frames
 
@@ -81,14 +82,14 @@ def test_eoferror():
 
 
 @pytest.mark.parametrize("mode", ("RGB", "P", "PA"))
-def test_roundtrip(mode, tmp_path):
+def test_roundtrip(mode: str, tmp_path: Path) -> None:
     out = str(tmp_path / "temp.im")
     im = hopper(mode)
     im.save(out)
     assert_image_equal_tofile(im, out)
 
 
-def test_small_palette(tmp_path):
+def test_small_palette(tmp_path: Path) -> None:
     im = Image.new("P", (1, 1))
     colors = [0, 1, 2]
     im.putpalette(colors)
@@ -100,19 +101,19 @@ def test_small_palette(tmp_path):
         assert reloaded.getpalette() == colors + [0] * 765
 
 
-def test_save_unsupported_mode(tmp_path):
+def test_save_unsupported_mode(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.im")
     im = hopper("HSV")
     with pytest.raises(ValueError):
         im.save(out)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         ImImagePlugin.ImImageFile(invalid_file)
 
 
-def test_number():
+def test_number() -> None:
     assert ImImagePlugin.number("1.2") == 1.2

Tests/test_file_imt.py

@@ -9,13 +9,13 @@ from PIL import Image, ImtImagePlugin
 from .helper import assert_image_equal_tofile
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open("Tests/images/bw_gradient.imt") as im:
         assert_image_equal_tofile(im, "Tests/images/bw_gradient.png")
 
 
 @pytest.mark.parametrize("data", (b"\n", b"\n-", b"width 1\n"))
-def test_invalid_file(data):
+def test_invalid_file(data: bytes) -> None:
     with io.BytesIO(data) as fp:
         with pytest.raises(SyntaxError):
             ImtImagePlugin.ImtImageFile(fp)

Tests/test_file_iptc.py

@@ -12,7 +12,7 @@ from .helper import assert_image_equal, hopper
 TEST_FILE = "Tests/images/iptc.jpg"
 
 
-def test_open():
+def test_open() -> None:
     expected = Image.new("L", (1, 1))
 
     f = BytesIO(
@@ -24,7 +24,7 @@ def test_open():
         assert_image_equal(im, expected)
 
 
-def test_getiptcinfo_jpg_none():
+def test_getiptcinfo_jpg_none() -> None:
     # Arrange
     with hopper() as im:
         # Act
@@ -34,7 +34,7 @@ def test_getiptcinfo_jpg_none():
     assert iptc is None
 
 
-def test_getiptcinfo_jpg_found():
+def test_getiptcinfo_jpg_found() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         # Act
@@ -46,7 +46,7 @@ def test_getiptcinfo_jpg_found():
     assert iptc[(2, 101)] == b"Hungary"
 
 
-def test_getiptcinfo_fotostation():
+def test_getiptcinfo_fotostation() -> None:
     # Arrange
     with open(TEST_FILE, "rb") as fp:
         data = bytearray(fp.read())
@@ -63,7 +63,7 @@ def test_getiptcinfo_fotostation():
     pytest.fail("FotoStation tag not found")
 
 
-def test_getiptcinfo_zero_padding():
+def test_getiptcinfo_zero_padding() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         im.info["photoshop"][0x0404] += b"\x00\x00\x00"
@@ -76,7 +76,7 @@ def test_getiptcinfo_zero_padding():
     assert len(iptc) == 3
 
 
-def test_getiptcinfo_tiff_none():
+def test_getiptcinfo_tiff_none() -> None:
     # Arrange
     with Image.open("Tests/images/hopper.tif") as im:
         # Act
@@ -86,7 +86,7 @@ def test_getiptcinfo_tiff_none():
     assert iptc is None
 
 
-def test_i():
+def test_i() -> None:
     # Arrange
     c = b"a"
 
@@ -98,7 +98,7 @@ def test_i():
     assert ret == 97
 
 
-def test_dump(monkeypatch):
+def test_dump(monkeypatch: pytest.MonkeyPatch) -> None:
     # Arrange
     c = b"abc"
     # Temporarily redirect stdout
@@ -113,6 +113,6 @@ def test_dump(monkeypatch):
     assert mystdout.getvalue() == "61 62 63 \n"
 
 
-def test_pad_deprecation():
+def test_pad_deprecation() -> None:
     with pytest.warns(DeprecationWarning):
         assert IptcImagePlugin.PAD == b"\0\0\0\0"

Tests/test_file_jpeg.py

@@ -4,6 +4,9 @@ import os
 import re
 import warnings
 from io import BytesIO
+from pathlib import Path
+from types import ModuleType
+from typing import Any
 
 import pytest
 
@@ -31,6 +34,7 @@ from .helper import (
     skip_unless_feature,
 )
 
+ElementTree: ModuleType | None
 try:
     from defusedxml import ElementTree
 except ImportError:
@@ -41,7 +45,7 @@ TEST_FILE = "Tests/images/hopper.jpg"
 
 @skip_unless_feature("jpg")
 class TestFileJpeg:
-    def roundtrip(self, im, **options):
+    def roundtrip(self, im: Image.Image, **options: Any) -> Image.Image:
         out = BytesIO()
         im.save(out, "JPEG", **options)
         test_bytes = out.tell()
@@ -50,7 +54,7 @@ class TestFileJpeg:
         im.bytes = test_bytes  # for testing only
         return im
 
-    def gen_random_image(self, size, mode="RGB"):
+    def gen_random_image(self, size: tuple[int, int], mode: str = "RGB") -> Image.Image:
         """Generates a very hard to compress file
         :param size: tuple
         :param mode: optional image mode
@@ -58,7 +62,7 @@ class TestFileJpeg:
         """
         return Image.frombytes(mode, size, os.urandom(size[0] * size[1] * len(mode)))
 
-    def test_sanity(self):
+    def test_sanity(self) -> None:
         # internal version number
         assert re.search(r"\d+\.\d+$", features.version_codec("jpg"))
 
@@ -70,13 +74,13 @@ class TestFileJpeg:
             assert im.get_format_mimetype() == "image/jpeg"
 
     @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
-    def test_zero(self, size, tmp_path):
+    def test_zero(self, size: tuple[int, int], tmp_path: Path) -> None:
         f = str(tmp_path / "temp.jpg")
         im = Image.new("RGB", size)
         with pytest.raises(ValueError):
             im.save(f)
 
-    def test_app(self):
+    def test_app(self) -> None:
         # Test APP/COM reader (@PIL135)
         with Image.open(TEST_FILE) as im:
             assert im.applist[0] == ("APP0", b"JFIF\x00\x01\x01\x01\x00`\x00`\x00\x00")
@@ -89,7 +93,7 @@ class TestFileJpeg:
             assert im.info["comment"] == b"File written by Adobe Photoshop\xa8 4.0\x00"
             assert im.app["COM"] == im.info["comment"]
 
-    def test_comment_write(self):
+    def test_comment_write(self) -> None:
         with Image.open(TEST_FILE) as im:
             assert im.info["comment"] == b"File written by Adobe Photoshop\xa8 4.0\x00"
 
@@ -107,15 +111,13 @@ class TestFileJpeg:
                     assert "comment" not in reloaded.info
 
             # Test that a comment argument overrides the default comment
-            for comment in ("Test comment text", b"Text comment text"):
+            for comment in ("Test comment text", b"Test comment text"):
                 out = BytesIO()
                 im.save(out, format="JPEG", comment=comment)
                 with Image.open(out) as reloaded:
-                    if not isinstance(comment, bytes):
+                    assert reloaded.info["comment"] == b"Test comment text"
-                        comment = comment.encode()
-                    assert reloaded.info["comment"] == comment
 
-    def test_cmyk(self):
+    def test_cmyk(self) -> None:
         # Test CMYK handling.  Thanks to Tim and Charlie for test data,
         # Michael for getting me to look one more time.
         f = "Tests/images/pil_sample_cmyk.jpg"
@@ -143,8 +145,8 @@ class TestFileJpeg:
             )
             assert k > 0.9
 
-    def test_rgb(self):
+    def test_rgb(self) -> None:
-        def getchannels(im):
+        def getchannels(im: Image.Image) -> tuple[int, int, int]:
             return tuple(v[0] for v in im.layer)
 
         im = hopper()
@@ -160,8 +162,8 @@ class TestFileJpeg:
         "test_image_path",
         [TEST_FILE, "Tests/images/pil_sample_cmyk.jpg"],
     )
-    def test_dpi(self, test_image_path):
+    def test_dpi(self, test_image_path: str) -> None:
-        def test(xdpi, ydpi=None):
+        def test(xdpi: int, ydpi: int | None = None):
             with Image.open(test_image_path) as im:
                 im = self.roundtrip(im, dpi=(xdpi, ydpi or xdpi))
             return im.info.get("dpi")
@@ -174,7 +176,7 @@ class TestFileJpeg:
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_icc(self, tmp_path):
+    def test_icc(self, tmp_path: Path) -> None:
         # Test ICC support
         with Image.open("Tests/images/rgb.jpg") as im1:
             icc_profile = im1.info["icc_profile"]
@@ -206,7 +208,7 @@ class TestFileJpeg:
             ImageFile.MAXBLOCK * 4 + 3,  # large block
         ),
     )
-    def test_icc_big(self, n):
+    def test_icc_big(self, n: int) -> None:
         # Make sure that the "extra" support handles large blocks
         # The ICC APP marker can store 65519 bytes per marker, so
         # using a 4-byte test code should allow us to detect out of
@@ -219,7 +221,7 @@ class TestFileJpeg:
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_large_icc_meta(self, tmp_path):
+    def test_large_icc_meta(self, tmp_path: Path) -> None:
         # https://github.com/python-pillow/Pillow/issues/148
         # Sometimes the meta data on the icc_profile block is bigger than
         # Image.MAXBLOCK or the image size.
@@ -243,7 +245,7 @@ class TestFileJpeg:
             f = str(tmp_path / "temp3.jpg")
             im.save(f, progressive=True, quality=94, exif=b" " * 43668)
 
-    def test_optimize(self):
+    def test_optimize(self) -> None:
         im1 = self.roundtrip(hopper())
         im2 = self.roundtrip(hopper(), optimize=0)
         im3 = self.roundtrip(hopper(), optimize=1)
@@ -252,14 +254,14 @@ class TestFileJpeg:
         assert im1.bytes >= im2.bytes
         assert im1.bytes >= im3.bytes
 
-    def test_optimize_large_buffer(self, tmp_path):
+    def test_optimize_large_buffer(self, tmp_path: Path) -> None:
         # https://github.com/python-pillow/Pillow/issues/148
         f = str(tmp_path / "temp.jpg")
         # this requires ~ 1.5x Image.MAXBLOCK
         im = Image.new("RGB", (4096, 4096), 0xFF3333)
         im.save(f, format="JPEG", optimize=True)
 
-    def test_progressive(self):
+    def test_progressive(self) -> None:
         im1 = self.roundtrip(hopper())
         im2 = self.roundtrip(hopper(), progressive=False)
         im3 = self.roundtrip(hopper(), progressive=True)
@@ -270,25 +272,25 @@ class TestFileJpeg:
         assert_image_equal(im1, im3)
         assert im1.bytes >= im3.bytes
 
-    def test_progressive_large_buffer(self, tmp_path):
+    def test_progressive_large_buffer(self, tmp_path: Path) -> None:
         f = str(tmp_path / "temp.jpg")
         # this requires ~ 1.5x Image.MAXBLOCK
         im = Image.new("RGB", (4096, 4096), 0xFF3333)
         im.save(f, format="JPEG", progressive=True)
 
-    def test_progressive_large_buffer_highest_quality(self, tmp_path):
+    def test_progressive_large_buffer_highest_quality(self, tmp_path: Path) -> None:
         f = str(tmp_path / "temp.jpg")
         im = self.gen_random_image((255, 255))
         # this requires more bytes than pixels in the image
         im.save(f, format="JPEG", progressive=True, quality=100)
 
-    def test_progressive_cmyk_buffer(self):
+    def test_progressive_cmyk_buffer(self) -> None:
         # Issue 2272, quality 90 cmyk image is tripping the large buffer bug.
         f = BytesIO()
         im = self.gen_random_image((256, 256), "CMYK")
         im.save(f, format="JPEG", progressive=True, quality=94)
 
-    def test_large_exif(self, tmp_path):
+    def test_large_exif(self, tmp_path: Path) -> None:
         # https://github.com/python-pillow/Pillow/issues/148
         f = str(tmp_path / "temp.jpg")
         im = hopper()
@@ -297,12 +299,12 @@ class TestFileJpeg:
         with pytest.raises(ValueError):
             im.save(f, "JPEG", quality=90, exif=b"1" * 65534)
 
-    def test_exif_typeerror(self):
+    def test_exif_typeerror(self) -> None:
         with Image.open("Tests/images/exif_typeerror.jpg") as im:
             # Should not raise a TypeError
             im._getexif()
 
-    def test_exif_gps(self, tmp_path):
+    def test_exif_gps(self, tmp_path: Path) -> None:
         expected_exif_gps = {
             0: b"\x00\x00\x00\x01",
             2: 4294967295,
@@ -327,7 +329,7 @@ class TestFileJpeg:
             exif = reloaded._getexif()
             assert exif[gps_index] == expected_exif_gps
 
-    def test_empty_exif_gps(self):
+    def test_empty_exif_gps(self) -> None:
         with Image.open("Tests/images/empty_gps_ifd.jpg") as im:
             exif = im.getexif()
             del exif[0x8769]
@@ -345,7 +347,7 @@ class TestFileJpeg:
         # Assert that it was transposed
         assert 0x0112 not in exif
 
-    def test_exif_equality(self):
+    def test_exif_equality(self) -> None:
         # In 7.2.0, Exif rationals were changed to be read as
         # TiffImagePlugin.IFDRational. This class had a bug in __eq__,
         # breaking the self-equality of Exif data
@@ -355,7 +357,7 @@ class TestFileJpeg:
                 exifs.append(im._getexif())
         assert exifs[0] == exifs[1]
 
-    def test_exif_rollback(self):
+    def test_exif_rollback(self) -> None:
         # rolling back exif support in 3.1 to pre-3.0 formatting.
         # expected from 2.9, with b/u qualifiers switched for 3.2 compatibility
         # this test passes on 2.9 and 3.1, but not 3.0
@@ -390,12 +392,12 @@ class TestFileJpeg:
         for tag, value in expected_exif.items():
             assert value == exif[tag]
 
-    def test_exif_gps_typeerror(self):
+    def test_exif_gps_typeerror(self) -> None:
         with Image.open("Tests/images/exif_gps_typeerror.jpg") as im:
             # Should not raise a TypeError
             im._getexif()
 
-    def test_progressive_compat(self):
+    def test_progressive_compat(self) -> None:
         im1 = self.roundtrip(hopper())
         assert not im1.info.get("progressive")
         assert not im1.info.get("progression")
@@ -416,7 +418,7 @@ class TestFileJpeg:
         assert im3.info.get("progressive")
         assert im3.info.get("progression")
 
-    def test_quality(self):
+    def test_quality(self) -> None:
         im1 = self.roundtrip(hopper())
         im2 = self.roundtrip(hopper(), quality=50)
         assert_image(im1, im2.mode, im2.size)
@@ -426,13 +428,13 @@ class TestFileJpeg:
         assert_image(im1, im3.mode, im3.size)
         assert im2.bytes > im3.bytes
 
-    def test_smooth(self):
+    def test_smooth(self) -> None:
         im1 = self.roundtrip(hopper())
         im2 = self.roundtrip(hopper(), smooth=100)
         assert_image(im1, im2.mode, im2.size)
 
-    def test_subsampling(self):
+    def test_subsampling(self) -> None:
-        def getsampling(im):
+        def getsampling(im: Image.Image):
             layer = im.layer
             return layer[0][1:3] + layer[1][1:3] + layer[2][1:3]
 
@@ -440,46 +442,46 @@ class TestFileJpeg:
         for subsampling in (-1, 3):  # (default, invalid)
             im = self.roundtrip(hopper(), subsampling=subsampling)
             assert getsampling(im) == (2, 2, 1, 1, 1, 1)
-        for subsampling in (0, "4:4:4"):
+        for subsampling1 in (0, "4:4:4"):
-            im = self.roundtrip(hopper(), subsampling=subsampling)
+            im = self.roundtrip(hopper(), subsampling=subsampling1)
             assert getsampling(im) == (1, 1, 1, 1, 1, 1)
-        for subsampling in (1, "4:2:2"):
+        for subsampling1 in (1, "4:2:2"):
-            im = self.roundtrip(hopper(), subsampling=subsampling)
+            im = self.roundtrip(hopper(), subsampling=subsampling1)
             assert getsampling(im) == (2, 1, 1, 1, 1, 1)
-        for subsampling in (2, "4:2:0", "4:1:1"):
+        for subsampling1 in (2, "4:2:0", "4:1:1"):
-            im = self.roundtrip(hopper(), subsampling=subsampling)
+            im = self.roundtrip(hopper(), subsampling=subsampling1)
             assert getsampling(im) == (2, 2, 1, 1, 1, 1)
 
         # RGB colorspace
-        for subsampling in (-1, 0, "4:4:4"):
+        for subsampling1 in (-1, 0, "4:4:4"):
             # "4:4:4" doesn't really make sense for RGB, but the conversion
             # to an integer happens at a higher level
-            im = self.roundtrip(hopper(), keep_rgb=True, subsampling=subsampling)
+            im = self.roundtrip(hopper(), keep_rgb=True, subsampling=subsampling1)
             assert getsampling(im) == (1, 1, 1, 1, 1, 1)
-        for subsampling in (1, "4:2:2", 2, "4:2:0", 3):
+        for subsampling1 in (1, "4:2:2", 2, "4:2:0", 3):
             with pytest.raises(OSError):
-                self.roundtrip(hopper(), keep_rgb=True, subsampling=subsampling)
+                self.roundtrip(hopper(), keep_rgb=True, subsampling=subsampling1)
 
         with pytest.raises(TypeError):
             self.roundtrip(hopper(), subsampling="1:1:1")
 
-    def test_exif(self):
+    def test_exif(self) -> None:
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
             info = im._getexif()
             assert info[305] == "Adobe Photoshop CS Macintosh"
 
-    def test_get_child_images(self):
+    def test_get_child_images(self) -> None:
         with Image.open("Tests/images/flower.jpg") as im:
             ims = im.get_child_images()
 
         assert len(ims) == 1
         assert_image_similar_tofile(ims[0], "Tests/images/flower_thumbnail.png", 2.1)
 
-    def test_mp(self):
+    def test_mp(self) -> None:
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
             assert im._getmp() is None
 
-    def test_quality_keep(self, tmp_path):
+    def test_quality_keep(self, tmp_path: Path) -> None:
         # RGB
         with Image.open("Tests/images/hopper.jpg") as im:
             f = str(tmp_path / "temp.jpg")
@@ -493,13 +495,13 @@ class TestFileJpeg:
             f = str(tmp_path / "temp.jpg")
             im.save(f, quality="keep")
 
-    def test_junk_jpeg_header(self):
+    def test_junk_jpeg_header(self) -> None:
         # https://github.com/python-pillow/Pillow/issues/630
         filename = "Tests/images/junk_jpeg_header.jpg"
         with Image.open(filename):
             pass
 
-    def test_ff00_jpeg_header(self):
+    def test_ff00_jpeg_header(self) -> None:
         filename = "Tests/images/jpeg_ff00_header.jpg"
         with Image.open(filename):
             pass
@@ -507,7 +509,7 @@ class TestFileJpeg:
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_truncated_jpeg_should_read_all_the_data(self):
+    def test_truncated_jpeg_should_read_all_the_data(self) -> None:
         filename = "Tests/images/truncated_jpeg.jpg"
         ImageFile.LOAD_TRUNCATED_IMAGES = True
         with Image.open(filename) as im:
@@ -515,7 +517,7 @@ class TestFileJpeg:
             ImageFile.LOAD_TRUNCATED_IMAGES = False
             assert im.getbbox() is not None
 
-    def test_truncated_jpeg_throws_oserror(self):
+    def test_truncated_jpeg_throws_oserror(self) -> None:
         filename = "Tests/images/truncated_jpeg.jpg"
         with Image.open(filename) as im:
             with pytest.raises(OSError):
@@ -528,8 +530,8 @@ class TestFileJpeg:
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_qtables(self, tmp_path):
+    def test_qtables(self, tmp_path: Path) -> None:
-        def _n_qtables_helper(n, test_file):
+        def _n_qtables_helper(n: int, test_file: str) -> None:
             with Image.open(test_file) as im:
                 f = str(tmp_path / "temp.jpg")
                 im.save(f, qtables=[[n] * 64] * n)
@@ -637,24 +639,24 @@ class TestFileJpeg:
             with pytest.raises(ValueError):
                 self.roundtrip(im, qtables=[[1, 2, 3, 4]])
 
-    def test_load_16bit_qtables(self):
+    def test_load_16bit_qtables(self) -> None:
         with Image.open("Tests/images/hopper_16bit_qtables.jpg") as im:
             assert len(im.quantization) == 2
             assert len(im.quantization[0]) == 64
             assert max(im.quantization[0]) > 255
 
-    def test_save_multiple_16bit_qtables(self):
+    def test_save_multiple_16bit_qtables(self) -> None:
         with Image.open("Tests/images/hopper_16bit_qtables.jpg") as im:
             im2 = self.roundtrip(im, qtables="keep")
             assert im.quantization == im2.quantization
 
-    def test_save_single_16bit_qtable(self):
+    def test_save_single_16bit_qtable(self) -> None:
         with Image.open("Tests/images/hopper_16bit_qtables.jpg") as im:
             im2 = self.roundtrip(im, qtables={0: im.quantization[0]})
             assert len(im2.quantization) == 1
             assert im2.quantization[0] == im.quantization[0]
 
-    def test_save_low_quality_baseline_qtables(self):
+    def test_save_low_quality_baseline_qtables(self) -> None:
         with Image.open(TEST_FILE) as im:
             im2 = self.roundtrip(im, quality=10)
             assert len(im2.quantization) == 2
@@ -665,7 +667,7 @@ class TestFileJpeg:
         "blocks, rows, markers",
         ((0, 0, 0), (1, 0, 15), (3, 0, 5), (8, 0, 1), (0, 1, 3), (0, 2, 1)),
     )
-    def test_restart_markers(self, blocks, rows, markers):
+    def test_restart_markers(self, blocks: int, rows: int, markers: int) -> None:
         im = Image.new("RGB", (32, 32))  # 16 MCUs
         out = BytesIO()
         im.save(
@@ -679,20 +681,20 @@ class TestFileJpeg:
         assert len(re.findall(b"\xff[\xd0-\xd7]", out.getvalue())) == markers
 
     @pytest.mark.skipif(not djpeg_available(), reason="djpeg not available")
-    def test_load_djpeg(self):
+    def test_load_djpeg(self) -> None:
         with Image.open(TEST_FILE) as img:
             img.load_djpeg()
             assert_image_similar_tofile(img, TEST_FILE, 5)
 
     @pytest.mark.skipif(not cjpeg_available(), reason="cjpeg not available")
-    def test_save_cjpeg(self, tmp_path):
+    def test_save_cjpeg(self, tmp_path: Path) -> None:
         with Image.open(TEST_FILE) as img:
             tempfile = str(tmp_path / "temp.jpg")
             JpegImagePlugin._save_cjpeg(img, 0, tempfile)
             # Default save quality is 75%, so a tiny bit of difference is alright
             assert_image_similar_tofile(img, tempfile, 17)
 
-    def test_no_duplicate_0x1001_tag(self):
+    def test_no_duplicate_0x1001_tag(self) -> None:
         # Arrange
         tag_ids = {v: k for k, v in ExifTags.TAGS.items()}
 
@@ -700,7 +702,7 @@ class TestFileJpeg:
         assert tag_ids["RelatedImageWidth"] == 0x1001
         assert tag_ids["RelatedImageLength"] == 0x1002
 
-    def test_MAXBLOCK_scaling(self, tmp_path):
+    def test_MAXBLOCK_scaling(self, tmp_path: Path) -> None:
         im = self.gen_random_image((512, 512))
         f = str(tmp_path / "temp.jpeg")
         im.save(f, quality=100, optimize=True)
@@ -711,7 +713,7 @@ class TestFileJpeg:
             reloaded.save(f, quality="keep", progressive=True)
             reloaded.save(f, quality="keep", optimize=True)
 
-    def test_bad_mpo_header(self):
+    def test_bad_mpo_header(self) -> None:
         """Treat unknown MPO as JPEG"""
         # Arrange
 
@@ -723,20 +725,20 @@ class TestFileJpeg:
             assert im.format == "JPEG"
 
     @pytest.mark.parametrize("mode", ("1", "L", "RGB", "RGBX", "CMYK", "YCbCr"))
-    def test_save_correct_modes(self, mode):
+    def test_save_correct_modes(self, mode: str) -> None:
         out = BytesIO()
         img = Image.new(mode, (20, 20))
         img.save(out, "JPEG")
 
     @pytest.mark.parametrize("mode", ("LA", "La", "RGBA", "RGBa", "P"))
-    def test_save_wrong_modes(self, mode):
+    def test_save_wrong_modes(self, mode: str) -> None:
         # ref https://github.com/python-pillow/Pillow/issues/2005
         out = BytesIO()
         img = Image.new(mode, (20, 20))
         with pytest.raises(OSError):
             img.save(out, "JPEG")
 
-    def test_save_tiff_with_dpi(self, tmp_path):
+    def test_save_tiff_with_dpi(self, tmp_path: Path) -> None:
         # Arrange
         outfile = str(tmp_path / "temp.tif")
         with Image.open("Tests/images/hopper.tif") as im:
@@ -748,7 +750,7 @@ class TestFileJpeg:
                 reloaded.load()
                 assert im.info["dpi"] == reloaded.info["dpi"]
 
-    def test_save_dpi_rounding(self, tmp_path):
+    def test_save_dpi_rounding(self, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.jpg")
         with Image.open("Tests/images/hopper.jpg") as im:
             im.save(outfile, dpi=(72.2, 72.2))
@@ -761,7 +763,7 @@ class TestFileJpeg:
         with Image.open(outfile) as reloaded:
             assert reloaded.info["dpi"] == (73, 73)
 
-    def test_dpi_tuple_from_exif(self):
+    def test_dpi_tuple_from_exif(self) -> None:
         # Arrange
         # This Photoshop CC 2017 image has DPI in EXIF not metadata
         # EXIF XResolution is (2000000, 10000)
@@ -769,7 +771,7 @@ class TestFileJpeg:
             # Act / Assert
             assert im.info.get("dpi") == (200, 200)
 
-    def test_dpi_int_from_exif(self):
+    def test_dpi_int_from_exif(self) -> None:
         # Arrange
         # This image has DPI in EXIF not metadata
         # EXIF XResolution is 72
@@ -777,7 +779,7 @@ class TestFileJpeg:
             # Act / Assert
             assert im.info.get("dpi") == (72, 72)
 
-    def test_dpi_from_dpcm_exif(self):
+    def test_dpi_from_dpcm_exif(self) -> None:
         # Arrange
         # This is photoshop-200dpi.jpg with EXIF resolution unit set to cm:
         # exiftool -exif:ResolutionUnit=cm photoshop-200dpi.jpg
@@ -785,7 +787,7 @@ class TestFileJpeg:
             # Act / Assert
             assert im.info.get("dpi") == (508, 508)
 
-    def test_dpi_exif_zero_division(self):
+    def test_dpi_exif_zero_division(self) -> None:
         # Arrange
         # This is photoshop-200dpi.jpg with EXIF resolution set to 0/0:
         # exiftool -XResolution=0/0 -YResolution=0/0 photoshop-200dpi.jpg
@@ -794,7 +796,7 @@ class TestFileJpeg:
             # This should return the default, and not raise a ZeroDivisionError
             assert im.info.get("dpi") == (72, 72)
 
-    def test_dpi_exif_string(self):
+    def test_dpi_exif_string(self) -> None:
         # Arrange
         # 0x011A tag in this exif contains string '300300\x02'
         with Image.open("Tests/images/broken_exif_dpi.jpg") as im:
@@ -802,14 +804,14 @@ class TestFileJpeg:
             # This should return the default
             assert im.info.get("dpi") == (72, 72)
 
-    def test_dpi_exif_truncated(self):
+    def test_dpi_exif_truncated(self) -> None:
         # Arrange
         with Image.open("Tests/images/truncated_exif_dpi.jpg") as im:
             # Act / Assert
             # This should return the default
             assert im.info.get("dpi") == (72, 72)
 
-    def test_no_dpi_in_exif(self):
+    def test_no_dpi_in_exif(self) -> None:
         # Arrange
         # This is photoshop-200dpi.jpg with resolution removed from EXIF:
         # exiftool "-*resolution*"= photoshop-200dpi.jpg
@@ -819,7 +821,7 @@ class TestFileJpeg:
             # https://exiv2.org/tags.html
             assert im.info.get("dpi") == (72, 72)
 
-    def test_invalid_exif(self):
+    def test_invalid_exif(self) -> None:
         # This is no-dpi-in-exif with the tiff header of the exif block
         # hexedited from MM * to FF FF FF FF
         with Image.open("Tests/images/invalid-exif.jpg") as im:
@@ -830,7 +832,7 @@ class TestFileJpeg:
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_exif_x_resolution(self, tmp_path):
+    def test_exif_x_resolution(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/flower.jpg") as im:
             exif = im.getexif()
             assert exif[282] == 180
@@ -842,14 +844,14 @@ class TestFileJpeg:
         with Image.open(out) as reloaded:
             assert reloaded.getexif()[282] == 180
 
-    def test_invalid_exif_x_resolution(self):
+    def test_invalid_exif_x_resolution(self) -> None:
         # When no x or y resolution is defined in EXIF
         with Image.open("Tests/images/invalid-exif-without-x-resolution.jpg") as im:
             # This should return the default, and not a ValueError or
             # OSError for an unidentified image.
             assert im.info.get("dpi") == (72, 72)
 
-    def test_ifd_offset_exif(self):
+    def test_ifd_offset_exif(self) -> None:
         # Arrange
         # This image has been manually hexedited to have an IFD offset of 10,
         # in contrast to normal 8
@@ -857,14 +859,14 @@ class TestFileJpeg:
             # Act / Assert
             assert im._getexif()[306] == "2017:03:13 23:03:09"
 
-    def test_multiple_exif(self):
+    def test_multiple_exif(self) -> None:
         with Image.open("Tests/images/multiple_exif.jpg") as im:
             assert im.info["exif"] == b"Exif\x00\x00firstsecond"
 
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_photoshop(self):
+    def test_photoshop(self) -> None:
         with Image.open("Tests/images/photoshop-200dpi.jpg") as im:
             assert im.info["photoshop"][0x03ED] == {
                 "XResolution": 200.0,
@@ -881,14 +883,14 @@ class TestFileJpeg:
         with Image.open("Tests/images/app13.jpg") as im:
             assert "photoshop" not in im.info
 
-    def test_photoshop_malformed_and_multiple(self):
+    def test_photoshop_malformed_and_multiple(self) -> None:
         with Image.open("Tests/images/app13-multiple.jpg") as im:
             assert "photoshop" in im.info
             assert 24 == len(im.info["photoshop"])
             apps_13_lengths = [len(v) for k, v in im.applist if k == "APP13"]
             assert [65504, 24] == apps_13_lengths
 
-    def test_adobe_transform(self):
+    def test_adobe_transform(self) -> None:
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
             assert im.info["adobe_transform"] == 1
 
@@ -902,11 +904,11 @@ class TestFileJpeg:
             assert "adobe" in im.info
             assert "adobe_transform" not in im.info
 
-    def test_icc_after_SOF(self):
+    def test_icc_after_SOF(self) -> None:
         with Image.open("Tests/images/icc-after-SOF.jpg") as im:
             assert im.info["icc_profile"] == b"profile"
 
-    def test_jpeg_magic_number(self):
+    def test_jpeg_magic_number(self) -> None:
         size = 4097
         buffer = BytesIO(b"\xFF" * size)  # Many xFF bytes
         buffer.max_pos = 0
@@ -925,7 +927,7 @@ class TestFileJpeg:
         # Assert the entire file has not been read
         assert 0 < buffer.max_pos < size
 
-    def test_getxmp(self):
+    def test_getxmp(self) -> None:
         with Image.open("Tests/images/xmp_test.jpg") as im:
             if ElementTree is None:
                 with pytest.warns(
@@ -954,7 +956,7 @@ class TestFileJpeg:
             with Image.open("Tests/images/hopper.jpg") as im:
                 assert im.getxmp() == {}
 
-    def test_getxmp_no_prefix(self):
+    def test_getxmp_no_prefix(self) -> None:
         with Image.open("Tests/images/xmp_no_prefix.jpg") as im:
             if ElementTree is None:
                 with pytest.warns(
@@ -965,7 +967,7 @@ class TestFileJpeg:
             else:
                 assert im.getxmp() == {"xmpmeta": {"key": "value"}}
 
-    def test_getxmp_padded(self):
+    def test_getxmp_padded(self) -> None:
         with Image.open("Tests/images/xmp_padded.jpg") as im:
             if ElementTree is None:
                 with pytest.warns(
@@ -977,16 +979,16 @@ class TestFileJpeg:
                 assert im.getxmp() == {"xmpmeta": None}
 
     @pytest.mark.timeout(timeout=1)
-    def test_eof(self):
+    def test_eof(self) -> None:
         # Even though this decoder never says that it is finished
         # the image should still end when there is no new data
         class InfiniteMockPyDecoder(ImageFile.PyDecoder):
-            def decode(self, buffer):
+            def decode(self, buffer: bytes) -> tuple[int, int]:
                 return 0, 0
 
         decoder = InfiniteMockPyDecoder(None)
 
-        def closure(mode, *args):
+        def closure(mode: str, *args) -> InfiniteMockPyDecoder:
             decoder.__init__(mode, *args)
             return decoder
 
@@ -1000,7 +1002,7 @@ class TestFileJpeg:
             im.load()
             ImageFile.LOAD_TRUNCATED_IMAGES = False
 
-    def test_separate_tables(self):
+    def test_separate_tables(self) -> None:
         im = hopper()
         data = []  # [interchange, tables-only, image-only]
         for streamtype in range(3):
@@ -1022,14 +1024,14 @@ class TestFileJpeg:
             with Image.open(BytesIO(data[1] + data[2])) as combined_im:
                 assert_image_equal(interchange_im, combined_im)
 
-    def test_repr_jpeg(self):
+    def test_repr_jpeg(self) -> None:
         im = hopper()
 
         with Image.open(BytesIO(im._repr_jpeg_())) as repr_jpeg:
             assert repr_jpeg.format == "JPEG"
             assert_image_similar(im, repr_jpeg, 17)
 
-    def test_repr_jpeg_error_returns_none(self):
+    def test_repr_jpeg_error_returns_none(self) -> None:
         im = hopper("F")
 
         assert im._repr_jpeg_() is None
@@ -1038,7 +1040,7 @@ class TestFileJpeg:
 @pytest.mark.skipif(not is_win32(), reason="Windows only")
 @skip_unless_feature("jpg")
 class TestFileCloseW32:
-    def test_fd_leak(self, tmp_path):
+    def test_fd_leak(self, tmp_path: Path) -> None:
         tmpfile = str(tmp_path / "temp.jpg")
 
         with Image.open("Tests/images/hopper.jpg") as im:

Tests/test_file_jpeg2k.py

@@ -3,6 +3,8 @@ from __future__ import annotations
 import os
 import re
 from io import BytesIO
+from pathlib import Path
+from typing import Any
 
 import pytest
 
@@ -35,7 +37,7 @@ test_card.load()
 # 'Not enough memory to handle tile data'
 
 
-def roundtrip(im, **options):
+def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
     out = BytesIO()
     im.save(out, "JPEG2000", **options)
     test_bytes = out.tell()
@@ -46,7 +48,7 @@ def roundtrip(im, **options):
     return im
 
 
-def test_sanity():
+def test_sanity() -> None:
     # Internal version number
     assert re.search(r"\d+\.\d+\.\d+$", features.version_codec("jpg_2000"))
 
@@ -59,20 +61,20 @@ def test_sanity():
         assert im.get_format_mimetype() == "image/jp2"
 
 
-def test_jpf():
+def test_jpf() -> None:
     with Image.open("Tests/images/balloon.jpf") as im:
         assert im.format == "JPEG2000"
         assert im.get_format_mimetype() == "image/jpx"
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         Jpeg2KImagePlugin.Jpeg2KImageFile(invalid_file)
 
 
-def test_bytesio():
+def test_bytesio() -> None:
     with open("Tests/images/test-card-lossless.jp2", "rb") as f:
         data = BytesIO(f.read())
     assert_image_similar_tofile(test_card, data, 1.0e-3)
@@ -82,7 +84,7 @@ def test_bytesio():
 # PIL (they were made using Adobe Photoshop)
 
 
-def test_lossless(tmp_path):
+def test_lossless(tmp_path: Path) -> None:
     with Image.open("Tests/images/test-card-lossless.jp2") as im:
         im.load()
         outfile = str(tmp_path / "temp_test-card.png")
@@ -90,54 +92,54 @@ def test_lossless(tmp_path):
     assert_image_similar(im, test_card, 1.0e-3)
 
 
-def test_lossy_tiled():
+def test_lossy_tiled() -> None:
     assert_image_similar_tofile(
         test_card, "Tests/images/test-card-lossy-tiled.jp2", 2.0
     )
 
 
-def test_lossless_rt():
+def test_lossless_rt() -> None:
     im = roundtrip(test_card)
     assert_image_equal(im, test_card)
 
 
-def test_lossy_rt():
+def test_lossy_rt() -> None:
     im = roundtrip(test_card, quality_layers=[20])
     assert_image_similar(im, test_card, 2.0)
 
 
-def test_tiled_rt():
+def test_tiled_rt() -> None:
     im = roundtrip(test_card, tile_size=(128, 128))
     assert_image_equal(im, test_card)
 
 
-def test_tiled_offset_rt():
+def test_tiled_offset_rt() -> None:
     im = roundtrip(test_card, tile_size=(128, 128), tile_offset=(0, 0), offset=(32, 32))
     assert_image_equal(im, test_card)
 
 
-def test_tiled_offset_too_small():
+def test_tiled_offset_too_small() -> None:
     with pytest.raises(ValueError):
         roundtrip(test_card, tile_size=(128, 128), tile_offset=(0, 0), offset=(128, 32))
 
 
-def test_irreversible_rt():
+def test_irreversible_rt() -> None:
     im = roundtrip(test_card, irreversible=True, quality_layers=[20])
     assert_image_similar(im, test_card, 2.0)
 
 
-def test_prog_qual_rt():
+def test_prog_qual_rt() -> None:
     im = roundtrip(test_card, quality_layers=[60, 40, 20], progression="LRCP")
     assert_image_similar(im, test_card, 2.0)
 
 
-def test_prog_res_rt():
+def test_prog_res_rt() -> None:
     im = roundtrip(test_card, num_resolutions=8, progression="RLCP")
     assert_image_equal(im, test_card)
 
 
 @pytest.mark.parametrize("num_resolutions", range(2, 6))
-def test_default_num_resolutions(num_resolutions):
+def test_default_num_resolutions(num_resolutions: int) -> None:
     d = 1 << (num_resolutions - 1)
     im = test_card.resize((d - 1, d - 1))
     with pytest.raises(OSError):
@@ -146,7 +148,7 @@ def test_default_num_resolutions(num_resolutions):
     assert_image_equal(im, reloaded)
 
 
-def test_reduce():
+def test_reduce() -> None:
     with Image.open("Tests/images/test-card-lossless.jp2") as im:
         assert callable(im.reduce)
 
@@ -160,7 +162,7 @@ def test_reduce():
         assert im.size == (40, 30)
 
 
-def test_load_dpi():
+def test_load_dpi() -> None:
     with Image.open("Tests/images/test-card-lossless.jp2") as im:
         assert im.info["dpi"] == (71.9836, 71.9836)
 
@@ -168,7 +170,7 @@ def test_load_dpi():
         assert "dpi" not in im.info
 
 
-def test_restricted_icc_profile():
+def test_restricted_icc_profile() -> None:
     ImageFile.LOAD_TRUNCATED_IMAGES = True
     try:
         # JPEG2000 image with a restricted ICC profile and a known colorspace
@@ -178,7 +180,7 @@ def test_restricted_icc_profile():
         ImageFile.LOAD_TRUNCATED_IMAGES = False
 
 
-def test_header_errors():
+def test_header_errors() -> None:
     for path in (
         "Tests/images/invalid_header_length.jp2",
         "Tests/images/not_enough_data.jp2",
@@ -192,17 +194,17 @@ def test_header_errors():
             pass
 
 
-def test_layers_type(tmp_path):
+def test_layers_type(tmp_path: Path) -> None:
     outfile = str(tmp_path / "temp_layers.jp2")
     for quality_layers in [[100, 50, 10], (100, 50, 10), None]:
         test_card.save(outfile, quality_layers=quality_layers)
 
-    for quality_layers in ["quality_layers", ("100", "50", "10")]:
+    for quality_layers_str in ["quality_layers", ("100", "50", "10")]:
         with pytest.raises(ValueError):
-            test_card.save(outfile, quality_layers=quality_layers)
+            test_card.save(outfile, quality_layers=quality_layers_str)
 
 
-def test_layers():
+def test_layers() -> None:
     out = BytesIO()
     test_card.save(out, "JPEG2000", quality_layers=[100, 50, 10], progression="LRCP")
     out.seek(0)
@@ -232,7 +234,7 @@ def test_layers():
         ("foo.jp2", {"no_jp2": False}, 4, b"jP"),
     ),
 )
-def test_no_jp2(name, args, offset, data):
+def test_no_jp2(name: str, args: dict[str, bool], offset: int, data: bytes) -> None:
     out = BytesIO()
     if name:
         out.name = name
@@ -241,7 +243,7 @@ def test_no_jp2(name, args, offset, data):
     assert out.read(2) == data
 
 
-def test_mct():
+def test_mct() -> None:
     # Three component
     for val in (0, 1):
         out = BytesIO()
@@ -262,7 +264,7 @@ def test_mct():
             assert_image_similar(im, jp2, 1.0e-3)
 
 
-def test_sgnd(tmp_path):
+def test_sgnd(tmp_path: Path) -> None:
     outfile = str(tmp_path / "temp.jp2")
 
     im = Image.new("L", (1, 1))
@@ -277,7 +279,7 @@ def test_sgnd(tmp_path):
 
 
 @pytest.mark.parametrize("ext", (".j2k", ".jp2"))
-def test_rgba(ext):
+def test_rgba(ext: str) -> None:
     # Arrange
     with Image.open("Tests/images/rgb_trns_ycbc" + ext) as im:
         # Act
@@ -288,47 +290,47 @@ def test_rgba(ext):
 
 
 @pytest.mark.parametrize("ext", (".j2k", ".jp2"))
-def test_16bit_monochrome_has_correct_mode(ext):
+def test_16bit_monochrome_has_correct_mode(ext: str) -> None:
     with Image.open("Tests/images/16bit.cropped" + ext) as im:
         im.load()
         assert im.mode == "I;16"
 
 
-def test_16bit_monochrome_jp2_like_tiff():
+def test_16bit_monochrome_jp2_like_tiff() -> None:
     with Image.open("Tests/images/16bit.cropped.tif") as tiff_16bit:
         assert_image_similar_tofile(tiff_16bit, "Tests/images/16bit.cropped.jp2", 1e-3)
 
 
-def test_16bit_monochrome_j2k_like_tiff():
+def test_16bit_monochrome_j2k_like_tiff() -> None:
     with Image.open("Tests/images/16bit.cropped.tif") as tiff_16bit:
         assert_image_similar_tofile(tiff_16bit, "Tests/images/16bit.cropped.j2k", 1e-3)
 
 
-def test_16bit_j2k_roundtrips():
+def test_16bit_j2k_roundtrips() -> None:
     with Image.open("Tests/images/16bit.cropped.j2k") as j2k:
         im = roundtrip(j2k)
         assert_image_equal(im, j2k)
 
 
-def test_16bit_jp2_roundtrips():
+def test_16bit_jp2_roundtrips() -> None:
     with Image.open("Tests/images/16bit.cropped.jp2") as jp2:
         im = roundtrip(jp2)
         assert_image_equal(im, jp2)
 
 
-def test_issue_6194():
+def test_issue_6194() -> None:
     with Image.open("Tests/images/issue_6194.j2k") as im:
         assert im.getpixel((5, 5)) == 31
 
 
-def test_unbound_local():
+def test_unbound_local() -> None:
     # prepatch, a malformed jp2 file could cause an UnboundLocalError exception.
     with pytest.raises(OSError):
         with Image.open("Tests/images/unbound_variable.jp2"):
             pass
 
 
-def test_parser_feed():
+def test_parser_feed() -> None:
     # Arrange
     with open("Tests/images/test-card-lossless.jp2", "rb") as f:
         data = f.read()
@@ -345,12 +347,12 @@ def test_parser_feed():
     not os.path.exists(EXTRA_DIR), reason="Extra image files not installed"
 )
 @pytest.mark.parametrize("name", ("subsampling_1", "subsampling_2", "zoo1", "zoo2"))
-def test_subsampling_decode(name):
+def test_subsampling_decode(name: str) -> None:
     test = f"{EXTRA_DIR}/{name}.jp2"
     reference = f"{EXTRA_DIR}/{name}.ppm"
 
     with Image.open(test) as im:
-        epsilon = 3  # for YCbCr images
+        epsilon = 3.0  # for YCbCr images
         with Image.open(reference) as im2:
             width, height = im2.size
             if name[-1] == "2":
@@ -361,7 +363,7 @@ def test_subsampling_decode(name):
         assert_image_similar(im, expected, epsilon)
 
 
-def test_comment():
+def test_comment() -> None:
     with Image.open("Tests/images/comment.jp2") as im:
         assert im.info["comment"] == b"Created by OpenJPEG version 2.5.0"
 
@@ -372,7 +374,7 @@ def test_comment():
             pass
 
 
-def test_save_comment():
+def test_save_comment() -> None:
     for comment in ("Created by Pillow", b"Created by Pillow"):
         out = BytesIO()
         test_card.save(out, "JPEG2000", comment=comment)
@@ -399,7 +401,7 @@ def test_save_comment():
         "Tests/images/crash-d2c93af851d3ab9a19e34503626368b2ecde9c03.j2k",
     ],
 )
-def test_crashes(test_file):
+def test_crashes(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
             # Valgrind should not complain here
@@ -410,7 +412,7 @@ def test_crashes(test_file):
 
 
 @skip_unless_feature_version("jpg_2000", "2.4.0")
-def test_plt_marker():
+def test_plt_marker() -> None:
     # Search the start of the codesteam for PLT
     out = BytesIO()
     test_card.save(out, "JPEG2000", no_jp2=True, plt=True)

Tests/test_file_libtiff.py

@@ -7,6 +7,7 @@ import os
 import re
 import sys
 from collections import namedtuple
+from pathlib import Path
 
 import pytest
 
@@ -26,7 +27,7 @@ from .helper import (
 
 @skip_unless_feature("libtiff")
 class LibTiffTestCase:
-    def _assert_noerr(self, tmp_path, im):
+    def _assert_noerr(self, tmp_path: Path, im: Image.Image) -> None:
         """Helper tests that assert basic sanity about the g4 tiff reading"""
         # 1 bit
         assert im.mode == "1"
@@ -50,10 +51,10 @@ class LibTiffTestCase:
 
 
 class TestFileLibTiff(LibTiffTestCase):
-    def test_version(self):
+    def test_version(self) -> None:
         assert re.search(r"\d+\.\d+\.\d+$", features.version_codec("libtiff"))
 
-    def test_g4_tiff(self, tmp_path):
+    def test_g4_tiff(self, tmp_path: Path) -> None:
         """Test the ordinary file path load path"""
 
         test_file = "Tests/images/hopper_g4_500.tif"
@@ -61,12 +62,12 @@ class TestFileLibTiff(LibTiffTestCase):
             assert im.size == (500, 500)
             self._assert_noerr(tmp_path, im)
 
-    def test_g4_large(self, tmp_path):
+    def test_g4_large(self, tmp_path: Path) -> None:
         test_file = "Tests/images/pport_g4.tif"
         with Image.open(test_file) as im:
             self._assert_noerr(tmp_path, im)
 
-    def test_g4_tiff_file(self, tmp_path):
+    def test_g4_tiff_file(self, tmp_path: Path) -> None:
         """Testing the string load path"""
 
         test_file = "Tests/images/hopper_g4_500.tif"
@@ -75,7 +76,7 @@ class TestFileLibTiff(LibTiffTestCase):
                 assert im.size == (500, 500)
                 self._assert_noerr(tmp_path, im)
 
-    def test_g4_tiff_bytesio(self, tmp_path):
+    def test_g4_tiff_bytesio(self, tmp_path: Path) -> None:
         """Testing the stringio loading code path"""
         test_file = "Tests/images/hopper_g4_500.tif"
         s = io.BytesIO()
@@ -86,7 +87,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert im.size == (500, 500)
             self._assert_noerr(tmp_path, im)
 
-    def test_g4_non_disk_file_object(self, tmp_path):
+    def test_g4_non_disk_file_object(self, tmp_path: Path) -> None:
         """Testing loading from non-disk non-BytesIO file object"""
         test_file = "Tests/images/hopper_g4_500.tif"
         s = io.BytesIO()
@@ -98,18 +99,18 @@ class TestFileLibTiff(LibTiffTestCase):
             assert im.size == (500, 500)
             self._assert_noerr(tmp_path, im)
 
-    def test_g4_eq_png(self):
+    def test_g4_eq_png(self) -> None:
         """Checking that we're actually getting the data that we expect"""
         with Image.open("Tests/images/hopper_bw_500.png") as png:
             assert_image_equal_tofile(png, "Tests/images/hopper_g4_500.tif")
 
     # see https://github.com/python-pillow/Pillow/issues/279
-    def test_g4_fillorder_eq_png(self):
+    def test_g4_fillorder_eq_png(self) -> None:
         """Checking that we're actually getting the data that we expect"""
         with Image.open("Tests/images/g4-fillorder-test.tif") as g4:
             assert_image_equal_tofile(g4, "Tests/images/g4-fillorder-test.png")
 
-    def test_g4_write(self, tmp_path):
+    def test_g4_write(self, tmp_path: Path) -> None:
         """Checking to see that the saved image is the same as what we wrote"""
         test_file = "Tests/images/hopper_g4_500.tif"
         with Image.open(test_file) as orig:
@@ -128,7 +129,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
                 assert orig.tobytes() != reread.tobytes()
 
-    def test_adobe_deflate_tiff(self):
+    def test_adobe_deflate_tiff(self) -> None:
         test_file = "Tests/images/tiff_adobe_deflate.tif"
         with Image.open(test_file) as im:
             assert im.mode == "RGB"
@@ -139,7 +140,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
 
     @pytest.mark.parametrize("legacy_api", (False, True))
-    def test_write_metadata(self, legacy_api, tmp_path):
+    def test_write_metadata(self, legacy_api: bool, tmp_path: Path) -> None:
         """Test metadata writing through libtiff"""
         f = str(tmp_path / "temp.tiff")
         with Image.open("Tests/images/hopper_g4.tif") as img:
@@ -184,7 +185,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert field in reloaded, f"{field} not in metadata"
 
     @pytest.mark.valgrind_known_error(reason="Known invalid metadata")
-    def test_additional_metadata(self, tmp_path):
+    def test_additional_metadata(self, tmp_path: Path) -> None:
         # these should not crash. Seriously dummy data, most of it doesn't make
         # any sense, so we're running up against limits where we're asking
         # libtiff to do stupid things.
@@ -241,8 +242,8 @@ class TestFileLibTiff(LibTiffTestCase):
 
         TiffImagePlugin.WRITE_LIBTIFF = False
 
-    def test_custom_metadata(self, tmp_path):
+    def test_custom_metadata(self, tmp_path: Path) -> None:
-        tc = namedtuple("test_case", "value,type,supported_by_default")
+        tc = namedtuple("tc", "value,type,supported_by_default")
         custom = {
             37000 + k: v
             for k, v in enumerate(
@@ -283,7 +284,9 @@ class TestFileLibTiff(LibTiffTestCase):
         for libtiff in libtiffs:
             TiffImagePlugin.WRITE_LIBTIFF = libtiff
 
-            def check_tags(tiffinfo):
+            def check_tags(
+                tiffinfo: TiffImagePlugin.ImageFileDirectory_v2 | dict[int, str]
+            ) -> None:
                 im = hopper()
 
                 out = str(tmp_path / "temp.tif")
@@ -322,7 +325,7 @@ class TestFileLibTiff(LibTiffTestCase):
             )
         TiffImagePlugin.WRITE_LIBTIFF = False
 
-    def test_subifd(self, tmp_path):
+    def test_subifd(self, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.tif")
         with Image.open("Tests/images/g4_orientation_6.tif") as im:
             im.tag_v2[SUBIFD] = 10000
@@ -330,7 +333,7 @@ class TestFileLibTiff(LibTiffTestCase):
             # Should not segfault
             im.save(outfile)
 
-    def test_xmlpacket_tag(self, tmp_path):
+    def test_xmlpacket_tag(self, tmp_path: Path) -> None:
         TiffImagePlugin.WRITE_LIBTIFF = True
 
         out = str(tmp_path / "temp.tif")
@@ -341,7 +344,7 @@ class TestFileLibTiff(LibTiffTestCase):
             if 700 in reloaded.tag_v2:
                 assert reloaded.tag_v2[700] == b"xmlpacket tag"
 
-    def test_int_dpi(self, tmp_path):
+    def test_int_dpi(self, tmp_path: Path) -> None:
         # issue #1765
         im = hopper("RGB")
         out = str(tmp_path / "temp.tif")
@@ -351,7 +354,7 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open(out) as reloaded:
             assert reloaded.info["dpi"] == (72.0, 72.0)
 
-    def test_g3_compression(self, tmp_path):
+    def test_g3_compression(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/hopper_g4_500.tif") as i:
             out = str(tmp_path / "temp.tif")
             i.save(out, compression="group3")
@@ -360,7 +363,7 @@ class TestFileLibTiff(LibTiffTestCase):
                 assert reread.info["compression"] == "group3"
                 assert_image_equal(reread, i)
 
-    def test_little_endian(self, tmp_path):
+    def test_little_endian(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/16bit.deflate.tif") as im:
             assert im.getpixel((0, 0)) == 480
             assert im.mode == "I;16"
@@ -379,7 +382,7 @@ class TestFileLibTiff(LibTiffTestCase):
         # UNDONE - libtiff defaults to writing in native endian, so
         # on big endian, we'll get back mode = 'I;16B' here.
 
-    def test_big_endian(self, tmp_path):
+    def test_big_endian(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/16bit.MM.deflate.tif") as im:
             assert im.getpixel((0, 0)) == 480
             assert im.mode == "I;16B"
@@ -396,7 +399,7 @@ class TestFileLibTiff(LibTiffTestCase):
                 assert reread.info["compression"] == im.info["compression"]
                 assert reread.getpixel((0, 0)) == 480
 
-    def test_g4_string_info(self, tmp_path):
+    def test_g4_string_info(self, tmp_path: Path) -> None:
         """Tests String data in info directory"""
         test_file = "Tests/images/hopper_g4_500.tif"
         with Image.open(test_file) as orig:
@@ -409,7 +412,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert "temp.tif" == reread.tag_v2[269]
             assert "temp.tif" == reread.tag[269][0]
 
-    def test_12bit_rawmode(self):
+    def test_12bit_rawmode(self) -> None:
         """Are we generating the same interpretation
         of the image as Imagemagick is?"""
         TiffImagePlugin.READ_LIBTIFF = True
@@ -424,7 +427,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
             assert_image_equal_tofile(im, "Tests/images/12in16bit.tif")
 
-    def test_blur(self, tmp_path):
+    def test_blur(self, tmp_path: Path) -> None:
         # test case from irc, how to do blur on b/w image
         # and save to compressed tif.
         out = str(tmp_path / "temp.tif")
@@ -436,7 +439,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
         assert_image_equal_tofile(im, out)
 
-    def test_compressions(self, tmp_path):
+    def test_compressions(self, tmp_path: Path) -> None:
         # Test various tiff compressions and assert similar image content but reduced
         # file sizes.
         im = hopper("RGB")
@@ -462,7 +465,7 @@ class TestFileLibTiff(LibTiffTestCase):
         assert size_compressed > size_jpeg
         assert size_jpeg > size_jpeg_30
 
-    def test_tiff_jpeg_compression(self, tmp_path):
+    def test_tiff_jpeg_compression(self, tmp_path: Path) -> None:
         im = hopper("RGB")
         out = str(tmp_path / "temp.tif")
         im.save(out, compression="tiff_jpeg")
@@ -470,7 +473,7 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open(out) as reloaded:
             assert reloaded.info["compression"] == "jpeg"
 
-    def test_tiff_deflate_compression(self, tmp_path):
+    def test_tiff_deflate_compression(self, tmp_path: Path) -> None:
         im = hopper("RGB")
         out = str(tmp_path / "temp.tif")
         im.save(out, compression="tiff_deflate")
@@ -478,7 +481,7 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open(out) as reloaded:
             assert reloaded.info["compression"] == "tiff_adobe_deflate"
 
-    def test_quality(self, tmp_path):
+    def test_quality(self, tmp_path: Path) -> None:
         im = hopper("RGB")
         out = str(tmp_path / "temp.tif")
 
@@ -493,7 +496,7 @@ class TestFileLibTiff(LibTiffTestCase):
         im.save(out, compression="jpeg", quality=0)
         im.save(out, compression="jpeg", quality=100)
 
-    def test_cmyk_save(self, tmp_path):
+    def test_cmyk_save(self, tmp_path: Path) -> None:
         im = hopper("CMYK")
         out = str(tmp_path / "temp.tif")
 
@@ -501,7 +504,7 @@ class TestFileLibTiff(LibTiffTestCase):
         assert_image_equal_tofile(im, out)
 
     @pytest.mark.parametrize("im", (hopper("P"), Image.new("P", (1, 1), "#000")))
-    def test_palette_save(self, im, tmp_path):
+    def test_palette_save(self, im: Image.Image, tmp_path: Path) -> None:
         out = str(tmp_path / "temp.tif")
 
         TiffImagePlugin.WRITE_LIBTIFF = True
@@ -513,14 +516,14 @@ class TestFileLibTiff(LibTiffTestCase):
             assert len(reloaded.tag_v2[320]) == 768
 
     @pytest.mark.parametrize("compression", ("tiff_ccitt", "group3", "group4"))
-    def test_bw_compression_w_rgb(self, compression, tmp_path):
+    def test_bw_compression_w_rgb(self, compression: str, tmp_path: Path) -> None:
         im = hopper("RGB")
         out = str(tmp_path / "temp.tif")
 
         with pytest.raises(OSError):
             im.save(out, compression=compression)
 
-    def test_fp_leak(self):
+    def test_fp_leak(self) -> None:
         im = Image.open("Tests/images/hopper_g4_500.tif")
         fn = im.fp.fileno()
 
@@ -534,7 +537,7 @@ class TestFileLibTiff(LibTiffTestCase):
         with pytest.raises(OSError):
             os.close(fn)
 
-    def test_multipage(self):
+    def test_multipage(self) -> None:
         # issue #862
         TiffImagePlugin.READ_LIBTIFF = True
         with Image.open("Tests/images/multipage.tiff") as im:
@@ -557,7 +560,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
         TiffImagePlugin.READ_LIBTIFF = False
 
-    def test_multipage_nframes(self):
+    def test_multipage_nframes(self) -> None:
         # issue #862
         TiffImagePlugin.READ_LIBTIFF = True
         with Image.open("Tests/images/multipage.tiff") as im:
@@ -570,7 +573,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
         TiffImagePlugin.READ_LIBTIFF = False
 
-    def test_multipage_seek_backwards(self):
+    def test_multipage_seek_backwards(self) -> None:
         TiffImagePlugin.READ_LIBTIFF = True
         with Image.open("Tests/images/multipage.tiff") as im:
             im.seek(1)
@@ -581,14 +584,14 @@ class TestFileLibTiff(LibTiffTestCase):
 
         TiffImagePlugin.READ_LIBTIFF = False
 
-    def test__next(self):
+    def test__next(self) -> None:
         TiffImagePlugin.READ_LIBTIFF = True
         with Image.open("Tests/images/hopper.tif") as im:
             assert not im.tag.next
             im.load()
             assert not im.tag.next
 
-    def test_4bit(self):
+    def test_4bit(self) -> None:
         # Arrange
         test_file = "Tests/images/hopper_gray_4bpp.tif"
         original = hopper("L")
@@ -603,7 +606,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert im.mode == "L"
             assert_image_similar(im, original, 7.3)
 
-    def test_gray_semibyte_per_pixel(self):
+    def test_gray_semibyte_per_pixel(self) -> None:
         test_files = (
             (
                 24.8,  # epsilon
@@ -636,7 +639,7 @@ class TestFileLibTiff(LibTiffTestCase):
                     assert im2.mode == "L"
                     assert_image_equal(im, im2)
 
-    def test_save_bytesio(self):
+    def test_save_bytesio(self) -> None:
         # PR 1011
         # Test TIFF saving to io.BytesIO() object.
 
@@ -646,7 +649,7 @@ class TestFileLibTiff(LibTiffTestCase):
         # Generate test image
         pilim = hopper()
 
-        def save_bytesio(compression=None):
+        def save_bytesio(compression: str | None = None) -> None:
             buffer_io = io.BytesIO()
             pilim.save(buffer_io, format="tiff", compression=compression)
             buffer_io.seek(0)
@@ -661,7 +664,7 @@ class TestFileLibTiff(LibTiffTestCase):
         TiffImagePlugin.WRITE_LIBTIFF = False
         TiffImagePlugin.READ_LIBTIFF = False
 
-    def test_save_ycbcr(self, tmp_path):
+    def test_save_ycbcr(self, tmp_path: Path) -> None:
         im = hopper("YCbCr")
         outfile = str(tmp_path / "temp.tif")
         im.save(outfile, compression="jpeg")
@@ -670,7 +673,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert reloaded.tag_v2[530] == (1, 1)
             assert reloaded.tag_v2[532] == (0, 255, 128, 255, 128, 255)
 
-    def test_exif_ifd(self, tmp_path):
+    def test_exif_ifd(self, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.tif")
         with Image.open("Tests/images/tiff_adobe_deflate.tif") as im:
             assert im.tag_v2[34665] == 125456
@@ -680,7 +683,7 @@ class TestFileLibTiff(LibTiffTestCase):
             if Image.core.libtiff_support_custom_tags:
                 assert reloaded.tag_v2[34665] == 125456
 
-    def test_crashing_metadata(self, tmp_path):
+    def test_crashing_metadata(self, tmp_path: Path) -> None:
         # issue 1597
         with Image.open("Tests/images/rdf.tif") as im:
             out = str(tmp_path / "temp.tif")
@@ -690,7 +693,7 @@ class TestFileLibTiff(LibTiffTestCase):
             im.save(out, format="TIFF")
         TiffImagePlugin.WRITE_LIBTIFF = False
 
-    def test_page_number_x_0(self, tmp_path):
+    def test_page_number_x_0(self, tmp_path: Path) -> None:
         # Issue 973
         # Test TIFF with tag 297 (Page Number) having value of 0 0.
         # The first number is the current page number.
@@ -704,7 +707,7 @@ class TestFileLibTiff(LibTiffTestCase):
             # Should not divide by zero
             im.save(outfile)
 
-    def test_fd_duplication(self, tmp_path):
+    def test_fd_duplication(self, tmp_path: Path) -> None:
         # https://github.com/python-pillow/Pillow/issues/1651
 
         tmpfile = str(tmp_path / "temp.tif")
@@ -718,7 +721,7 @@ class TestFileLibTiff(LibTiffTestCase):
         # Should not raise PermissionError.
         os.remove(tmpfile)
 
-    def test_read_icc(self):
+    def test_read_icc(self) -> None:
         with Image.open("Tests/images/hopper.iccprofile.tif") as img:
             icc = img.info.get("icc_profile")
             assert icc is not None
@@ -729,8 +732,8 @@ class TestFileLibTiff(LibTiffTestCase):
         TiffImagePlugin.READ_LIBTIFF = False
         assert icc == icc_libtiff
 
-    def test_write_icc(self, tmp_path):
+    def test_write_icc(self, tmp_path: Path) -> None:
-        def check_write(libtiff):
+        def check_write(libtiff: bool) -> None:
             TiffImagePlugin.WRITE_LIBTIFF = libtiff
 
             with Image.open("Tests/images/hopper.iccprofile.tif") as img:
@@ -749,7 +752,7 @@ class TestFileLibTiff(LibTiffTestCase):
         for libtiff in libtiffs:
             check_write(libtiff)
 
-    def test_multipage_compression(self):
+    def test_multipage_compression(self) -> None:
         with Image.open("Tests/images/compression.tif") as im:
             im.seek(0)
             assert im._compression == "tiff_ccitt"
@@ -765,7 +768,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert im.size == (10, 10)
             im.load()
 
-    def test_save_tiff_with_jpegtables(self, tmp_path):
+    def test_save_tiff_with_jpegtables(self, tmp_path: Path) -> None:
         # Arrange
         outfile = str(tmp_path / "temp.tif")
 
@@ -777,7 +780,7 @@ class TestFileLibTiff(LibTiffTestCase):
             # Should not raise UnicodeDecodeError or anything else
             im.save(outfile)
 
-    def test_16bit_RGB_tiff(self):
+    def test_16bit_RGB_tiff(self) -> None:
         with Image.open("Tests/images/tiff_16bit_RGB.tiff") as im:
             assert im.mode == "RGB"
             assert im.size == (100, 40)
@@ -793,7 +796,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGB_target.png")
 
-    def test_16bit_RGBa_tiff(self):
+    def test_16bit_RGBa_tiff(self) -> None:
         with Image.open("Tests/images/tiff_16bit_RGBa.tiff") as im:
             assert im.mode == "RGBA"
             assert im.size == (100, 40)
@@ -805,7 +808,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGBa_target.png")
 
     @skip_unless_feature("jpg")
-    def test_gimp_tiff(self):
+    def test_gimp_tiff(self) -> None:
         # Read TIFF JPEG images from GIMP [@PIL168]
         filename = "Tests/images/pil168.tif"
         with Image.open(filename) as im:
@@ -818,14 +821,14 @@ class TestFileLibTiff(LibTiffTestCase):
 
             assert_image_equal_tofile(im, "Tests/images/pil168.png")
 
-    def test_sampleformat(self):
+    def test_sampleformat(self) -> None:
         # https://github.com/python-pillow/Pillow/issues/1466
         with Image.open("Tests/images/copyleft.tiff") as im:
             assert im.mode == "RGB"
 
             assert_image_equal_tofile(im, "Tests/images/copyleft.png", mode="RGB")
 
-    def test_sampleformat_write(self, tmp_path):
+    def test_sampleformat_write(self, tmp_path: Path) -> None:
         im = Image.new("F", (1, 1))
         out = str(tmp_path / "temp.tif")
         TiffImagePlugin.WRITE_LIBTIFF = True
@@ -836,7 +839,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert reloaded.mode == "F"
             assert reloaded.getexif()[SAMPLEFORMAT] == 3
 
-    def test_lzma(self, capfd):
+    def test_lzma(self, capfd: pytest.CaptureFixture[str]) -> None:
         try:
             with Image.open("Tests/images/hopper_lzma.tif") as im:
                 assert im.mode == "RGB"
@@ -852,7 +855,7 @@ class TestFileLibTiff(LibTiffTestCase):
             sys.stderr.write(captured.err)
             raise
 
-    def test_webp(self, capfd):
+    def test_webp(self, capfd: pytest.CaptureFixture[str]) -> None:
         try:
             with Image.open("Tests/images/hopper_webp.tif") as im:
                 assert im.mode == "RGB"
@@ -874,7 +877,7 @@ class TestFileLibTiff(LibTiffTestCase):
             sys.stderr.write(captured.err)
             raise
 
-    def test_lzw(self):
+    def test_lzw(self) -> None:
         with Image.open("Tests/images/hopper_lzw.tif") as im:
             assert im.mode == "RGB"
             assert im.size == (128, 128)
@@ -882,12 +885,12 @@ class TestFileLibTiff(LibTiffTestCase):
             im2 = hopper()
             assert_image_similar(im, im2, 5)
 
-    def test_strip_cmyk_jpeg(self):
+    def test_strip_cmyk_jpeg(self) -> None:
         infile = "Tests/images/tiff_strip_cmyk_jpeg.tif"
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/pil_sample_cmyk.jpg", 0.5)
 
-    def test_strip_cmyk_16l_jpeg(self):
+    def test_strip_cmyk_16l_jpeg(self) -> None:
         infile = "Tests/images/tiff_strip_cmyk_16l_jpeg.tif"
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/pil_sample_cmyk.jpg", 0.5)
@@ -895,7 +898,7 @@ class TestFileLibTiff(LibTiffTestCase):
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_strip_ycbcr_jpeg_2x2_sampling(self):
+    def test_strip_ycbcr_jpeg_2x2_sampling(self) -> None:
         infile = "Tests/images/tiff_strip_ycbcr_jpeg_2x2_sampling.tif"
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/flower.jpg", 1.2)
@@ -903,12 +906,12 @@ class TestFileLibTiff(LibTiffTestCase):
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_strip_ycbcr_jpeg_1x1_sampling(self):
+    def test_strip_ycbcr_jpeg_1x1_sampling(self) -> None:
         infile = "Tests/images/tiff_strip_ycbcr_jpeg_1x1_sampling.tif"
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/flower2.jpg", 0.01)
 
-    def test_tiled_cmyk_jpeg(self):
+    def test_tiled_cmyk_jpeg(self) -> None:
         infile = "Tests/images/tiff_tiled_cmyk_jpeg.tif"
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/pil_sample_cmyk.jpg", 0.5)
@@ -916,7 +919,7 @@ class TestFileLibTiff(LibTiffTestCase):
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_tiled_ycbcr_jpeg_1x1_sampling(self):
+    def test_tiled_ycbcr_jpeg_1x1_sampling(self) -> None:
         infile = "Tests/images/tiff_tiled_ycbcr_jpeg_1x1_sampling.tif"
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/flower2.jpg", 0.01)
@@ -924,45 +927,45 @@ class TestFileLibTiff(LibTiffTestCase):
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_tiled_ycbcr_jpeg_2x2_sampling(self):
+    def test_tiled_ycbcr_jpeg_2x2_sampling(self) -> None:
         infile = "Tests/images/tiff_tiled_ycbcr_jpeg_2x2_sampling.tif"
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/flower.jpg", 1.5)
 
-    def test_strip_planar_rgb(self):
+    def test_strip_planar_rgb(self) -> None:
         # gdal_translate -co TILED=no -co INTERLEAVE=BAND -co COMPRESS=LZW \
         # tiff_strip_raw.tif tiff_strip_planar_lzw.tiff
         infile = "Tests/images/tiff_strip_planar_lzw.tiff"
         with Image.open(infile) as im:
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
 
-    def test_tiled_planar_rgb(self):
+    def test_tiled_planar_rgb(self) -> None:
         # gdal_translate -co TILED=yes -co INTERLEAVE=BAND -co COMPRESS=LZW \
         # tiff_tiled_raw.tif tiff_tiled_planar_lzw.tiff
         infile = "Tests/images/tiff_tiled_planar_lzw.tiff"
         with Image.open(infile) as im:
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
 
-    def test_tiled_planar_16bit_RGB(self):
+    def test_tiled_planar_16bit_RGB(self) -> None:
         # gdal_translate -co TILED=yes -co INTERLEAVE=BAND -co COMPRESS=LZW \
         # tiff_16bit_RGB.tiff tiff_tiled_planar_16bit_RGB.tiff
         with Image.open("Tests/images/tiff_tiled_planar_16bit_RGB.tiff") as im:
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGB_target.png")
 
-    def test_strip_planar_16bit_RGB(self):
+    def test_strip_planar_16bit_RGB(self) -> None:
         # gdal_translate -co TILED=no -co INTERLEAVE=BAND -co COMPRESS=LZW \
         # tiff_16bit_RGB.tiff tiff_strip_planar_16bit_RGB.tiff
         with Image.open("Tests/images/tiff_strip_planar_16bit_RGB.tiff") as im:
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGB_target.png")
 
-    def test_tiled_planar_16bit_RGBa(self):
+    def test_tiled_planar_16bit_RGBa(self) -> None:
         # gdal_translate -co TILED=yes \
         # -co INTERLEAVE=BAND -co COMPRESS=LZW -co ALPHA=PREMULTIPLIED \
         # tiff_16bit_RGBa.tiff tiff_tiled_planar_16bit_RGBa.tiff
         with Image.open("Tests/images/tiff_tiled_planar_16bit_RGBa.tiff") as im:
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGBa_target.png")
 
-    def test_strip_planar_16bit_RGBa(self):
+    def test_strip_planar_16bit_RGBa(self) -> None:
         # gdal_translate -co TILED=no \
         # -co INTERLEAVE=BAND -co COMPRESS=LZW -co ALPHA=PREMULTIPLIED \
         # tiff_16bit_RGBa.tiff tiff_strip_planar_16bit_RGBa.tiff
@@ -970,7 +973,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGBa_target.png")
 
     @pytest.mark.parametrize("compression", (None, "jpeg"))
-    def test_block_tile_tags(self, compression, tmp_path):
+    def test_block_tile_tags(self, compression: str | None, tmp_path: Path) -> None:
         im = hopper()
         out = str(tmp_path / "temp.tif")
 
@@ -986,11 +989,11 @@ class TestFileLibTiff(LibTiffTestCase):
             for tag in tags:
                 assert tag not in reloaded.getexif()
 
-    def test_old_style_jpeg(self):
+    def test_old_style_jpeg(self) -> None:
         with Image.open("Tests/images/old-style-jpeg-compression.tif") as im:
             assert_image_equal_tofile(im, "Tests/images/old-style-jpeg-compression.png")
 
-    def test_open_missing_samplesperpixel(self):
+    def test_open_missing_samplesperpixel(self) -> None:
         with Image.open(
             "Tests/images/old-style-jpeg-compression-no-samplesperpixel.tif"
         ) as im:
@@ -1019,21 +1022,23 @@ class TestFileLibTiff(LibTiffTestCase):
             ),
         ],
     )
-    def test_wrong_bits_per_sample(self, file_name, mode, size, tile):
+    def test_wrong_bits_per_sample(
+        self, file_name: str, mode: str, size: tuple[int, int], tile
+    ) -> None:
         with Image.open("Tests/images/" + file_name) as im:
             assert im.mode == mode
             assert im.size == size
             assert im.tile == tile
             im.load()
 
-    def test_no_rows_per_strip(self):
+    def test_no_rows_per_strip(self) -> None:
         # This image does not have a RowsPerStrip TIFF tag
         infile = "Tests/images/no_rows_per_strip.tif"
         with Image.open(infile) as im:
             im.load()
         assert im.size == (950, 975)
 
-    def test_orientation(self):
+    def test_orientation(self) -> None:
         with Image.open("Tests/images/g4_orientation_1.tif") as base_im:
             for i in range(2, 9):
                 with Image.open("Tests/images/g4_orientation_" + str(i) + ".tif") as im:
@@ -1044,7 +1049,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
                     assert_image_similar(base_im, im, 0.7)
 
-    def test_exif_transpose(self):
+    def test_exif_transpose(self) -> None:
         with Image.open("Tests/images/g4_orientation_1.tif") as base_im:
             for i in range(2, 9):
                 with Image.open("Tests/images/g4_orientation_" + str(i) + ".tif") as im:
@@ -1053,7 +1058,7 @@ class TestFileLibTiff(LibTiffTestCase):
                     assert_image_similar(base_im, im, 0.7)
 
     @pytest.mark.valgrind_known_error(reason="Backtrace in Python Core")
-    def test_sampleformat_not_corrupted(self):
+    def test_sampleformat_not_corrupted(self) -> None:
         # Assert that a TIFF image with SampleFormat=UINT tag is not corrupted
         # when saving to a new file.
         # Pillow 6.0 fails with "OSError: cannot identify image file".
@@ -1074,7 +1079,7 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open(out) as im:
             im.load()
 
-    def test_realloc_overflow(self):
+    def test_realloc_overflow(self) -> None:
         TiffImagePlugin.READ_LIBTIFF = True
         with Image.open("Tests/images/tiff_overflow_rows_per_strip.tif") as im:
             with pytest.raises(OSError) as e:
@@ -1085,7 +1090,7 @@ class TestFileLibTiff(LibTiffTestCase):
         TiffImagePlugin.READ_LIBTIFF = False
 
     @pytest.mark.parametrize("compression", ("tiff_adobe_deflate", "jpeg"))
-    def test_save_multistrip(self, compression, tmp_path):
+    def test_save_multistrip(self, compression: str, tmp_path: Path) -> None:
         im = hopper("RGB").resize((256, 256))
         out = str(tmp_path / "temp.tif")
         im.save(out, compression=compression)
@@ -1095,14 +1100,14 @@ class TestFileLibTiff(LibTiffTestCase):
             assert len(im.tag_v2[STRIPOFFSETS]) > 1
 
     @pytest.mark.parametrize("argument", (True, False))
-    def test_save_single_strip(self, argument, tmp_path):
+    def test_save_single_strip(self, argument: bool, tmp_path: Path) -> None:
         im = hopper("RGB").resize((256, 256))
         out = str(tmp_path / "temp.tif")
 
         if not argument:
             TiffImagePlugin.STRIP_SIZE = 2**18
         try:
-            arguments = {"compression": "tiff_adobe_deflate"}
+            arguments: dict[str, str | int] = {"compression": "tiff_adobe_deflate"}
             if argument:
                 arguments["strip_size"] = 2**18
             im.save(out, **arguments)
@@ -1113,13 +1118,13 @@ class TestFileLibTiff(LibTiffTestCase):
             TiffImagePlugin.STRIP_SIZE = 65536
 
     @pytest.mark.parametrize("compression", ("tiff_adobe_deflate", None))
-    def test_save_zero(self, compression, tmp_path):
+    def test_save_zero(self, compression: str | None, tmp_path: Path) -> None:
         im = Image.new("RGB", (0, 0))
         out = str(tmp_path / "temp.tif")
         with pytest.raises(SystemError):
             im.save(out, compression=compression)
 
-    def test_save_many_compressed(self, tmp_path):
+    def test_save_many_compressed(self, tmp_path: Path) -> None:
         im = hopper()
         out = str(tmp_path / "temp.tif")
         for _ in range(10000):
@@ -1133,7 +1138,7 @@ class TestFileLibTiff(LibTiffTestCase):
             ("Tests/images/child_ifd_jpeg.tiff", (20,)),
         ),
     )
-    def test_get_child_images(self, path, sizes):
+    def test_get_child_images(self, path: str, sizes: tuple[int, ...]) -> None:
         with Image.open(path) as im:
             ims = im.get_child_images()
 

Tests/test_file_libtiff_small.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from io import BytesIO
+from pathlib import Path
 
 from PIL import Image
 
@@ -8,7 +9,6 @@ from .test_file_libtiff import LibTiffTestCase
 
 
 class TestFileLibTiffSmall(LibTiffTestCase):
-
     """The small lena image was failing on open in the libtiff
     decoder because the file pointer was set to the wrong place
     by a spurious seek. It wasn't failing with the byteio method.
@@ -17,7 +17,7 @@ class TestFileLibTiffSmall(LibTiffTestCase):
     file just before reading in libtiff. These tests remain
     to ensure that it stays fixed."""
 
-    def test_g4_hopper_file(self, tmp_path):
+    def test_g4_hopper_file(self, tmp_path: Path) -> None:
         """Testing the open file load path"""
 
         test_file = "Tests/images/hopper_g4.tif"
@@ -26,7 +26,7 @@ class TestFileLibTiffSmall(LibTiffTestCase):
                 assert im.size == (128, 128)
                 self._assert_noerr(tmp_path, im)
 
-    def test_g4_hopper_bytesio(self, tmp_path):
+    def test_g4_hopper_bytesio(self, tmp_path: Path) -> None:
         """Testing the bytesio loading code path"""
         test_file = "Tests/images/hopper_g4.tif"
         s = BytesIO()
@@ -37,7 +37,7 @@ class TestFileLibTiffSmall(LibTiffTestCase):
             assert im.size == (128, 128)
             self._assert_noerr(tmp_path, im)
 
-    def test_g4_hopper(self, tmp_path):
+    def test_g4_hopper(self, tmp_path: Path) -> None:
         """The 128x128 lena image failed for some reason."""
 
         test_file = "Tests/images/hopper_g4.tif"

Tests/test_file_mcidas.py

@@ -7,14 +7,14 @@ from PIL import Image, McIdasImagePlugin
 from .helper import assert_image_equal_tofile
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         McIdasImagePlugin.McIdasImageFile(invalid_file)
 
 
-def test_valid_file():
+def test_valid_file() -> None:
     # Arrange
     # https://ghrc.nsstc.nasa.gov/hydro/details/cmx3g8
     # https://ghrc.nsstc.nasa.gov/pub/fieldCampaigns/camex3/cmx3g8/browse/

Tests/test_file_mic.py

@@ -13,7 +13,7 @@ pytestmark = skip_unless_feature("libtiff")
 TEST_FILE = "Tests/images/hopper.mic"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(TEST_FILE) as im:
         im.load()
         assert im.mode == "RGBA"
@@ -28,22 +28,22 @@ def test_sanity():
         assert_image_similar(im, im2, 10)
 
 
-def test_n_frames():
+def test_n_frames() -> None:
     with Image.open(TEST_FILE) as im:
         assert im.n_frames == 1
 
 
-def test_is_animated():
+def test_is_animated() -> None:
     with Image.open(TEST_FILE) as im:
         assert not im.is_animated
 
 
-def test_tell():
+def test_tell() -> None:
     with Image.open(TEST_FILE) as im:
         assert im.tell() == 0
 
 
-def test_seek():
+def test_seek() -> None:
     with Image.open(TEST_FILE) as im:
         im.seek(0)
         assert im.tell() == 0
@@ -53,7 +53,7 @@ def test_seek():
         assert im.tell() == 0
 
 
-def test_close():
+def test_close() -> None:
     with Image.open(TEST_FILE) as im:
         pass
     assert im.ole.fp.closed
@@ -63,7 +63,7 @@ def test_close():
     assert im.ole.fp.closed
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     # Test an invalid OLE file
     invalid_file = "Tests/images/flower.jpg"
     with pytest.raises(SyntaxError):

Tests/test_file_mpo.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import warnings
 from io import BytesIO
+from typing import Any
 
 import pytest
 
@@ -19,7 +20,7 @@ test_files = ["Tests/images/sugarshack.mpo", "Tests/images/frozenpond.mpo"]
 pytestmark = skip_unless_feature("jpg")
 
 
-def roundtrip(im, **options):
+def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
     out = BytesIO()
     im.save(out, "MPO", **options)
     test_bytes = out.tell()
@@ -30,7 +31,7 @@ def roundtrip(im, **options):
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_sanity(test_file):
+def test_sanity(test_file: str) -> None:
     with Image.open(test_file) as im:
         im.load()
         assert im.mode == "RGB"
@@ -39,8 +40,8 @@ def test_sanity(test_file):
 
 
 @pytest.mark.skipif(is_pypy(), reason="Requires CPython")
-def test_unclosed_file():
+def test_unclosed_file() -> None:
-    def open():
+    def open() -> None:
         im = Image.open(test_files[0])
         im.load()
 
@@ -48,14 +49,14 @@ def test_unclosed_file():
         open()
 
 
-def test_closed_file():
+def test_closed_file() -> None:
     with warnings.catch_warnings():
         im = Image.open(test_files[0])
         im.load()
         im.close()
 
 
-def test_seek_after_close():
+def test_seek_after_close() -> None:
     im = Image.open(test_files[0])
     im.close()
 
@@ -63,14 +64,14 @@ def test_seek_after_close():
         im.seek(1)
 
 
-def test_context_manager():
+def test_context_manager() -> None:
     with warnings.catch_warnings():
         with Image.open(test_files[0]) as im:
             im.load()
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_app(test_file):
+def test_app(test_file: str) -> None:
     # Test APP/COM reader (@PIL135)
     with Image.open(test_file) as im:
         assert im.applist[0][0] == "APP1"
@@ -82,7 +83,7 @@ def test_app(test_file):
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_exif(test_file):
+def test_exif(test_file: str) -> None:
     with Image.open(test_file) as im_original:
         im_reloaded = roundtrip(im_original, save_all=True, exif=im_original.getexif())
 
@@ -93,7 +94,7 @@ def test_exif(test_file):
         assert info[34665] == 188
 
 
-def test_frame_size():
+def test_frame_size() -> None:
     # This image has been hexedited to contain a different size
     # in the EXIF data of the second frame
     with Image.open("Tests/images/sugarshack_frame_size.mpo") as im:
@@ -106,7 +107,7 @@ def test_frame_size():
         assert im.size == (640, 480)
 
 
-def test_ignore_frame_size():
+def test_ignore_frame_size() -> None:
     # Ignore the different size of the second frame
     # since this is not a "Large Thumbnail" image
     with Image.open("Tests/images/ignore_frame_size.mpo") as im:
@@ -120,7 +121,7 @@ def test_ignore_frame_size():
         assert im.size == (64, 64)
 
 
-def test_parallax():
+def test_parallax() -> None:
     # Nintendo
     with Image.open("Tests/images/sugarshack.mpo") as im:
         exif = im.getexif()
@@ -133,7 +134,7 @@ def test_parallax():
         assert exif.get_ifd(0x927C)[0xB211] == -3.125
 
 
-def test_reload_exif_after_seek():
+def test_reload_exif_after_seek() -> None:
     with Image.open("Tests/images/sugarshack.mpo") as im:
         exif = im.getexif()
         del exif[296]
@@ -143,14 +144,14 @@ def test_reload_exif_after_seek():
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_mp(test_file):
+def test_mp(test_file: str) -> None:
     with Image.open(test_file) as im:
         mpinfo = im._getmp()
         assert mpinfo[45056] == b"0100"
         assert mpinfo[45057] == 2
 
 
-def test_mp_offset():
+def test_mp_offset() -> None:
     # This image has been manually hexedited to have an IFD offset of 10
     # in APP2 data, in contrast to normal 8
     with Image.open("Tests/images/sugarshack_ifd_offset.mpo") as im:
@@ -159,7 +160,7 @@ def test_mp_offset():
         assert mpinfo[45057] == 2
 
 
-def test_mp_no_data():
+def test_mp_no_data() -> None:
     # This image has been manually hexedited to have the second frame
     # beyond the end of the file
     with Image.open("Tests/images/sugarshack_no_data.mpo") as im:
@@ -168,7 +169,7 @@ def test_mp_no_data():
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_mp_attribute(test_file):
+def test_mp_attribute(test_file: str) -> None:
     with Image.open(test_file) as im:
         mpinfo = im._getmp()
     for frame_number, mpentry in enumerate(mpinfo[0xB002]):
@@ -185,7 +186,7 @@ def test_mp_attribute(test_file):
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_seek(test_file):
+def test_seek(test_file: str) -> None:
     with Image.open(test_file) as im:
         assert im.tell() == 0
         # prior to first image raises an error, both blatant and borderline
@@ -209,13 +210,13 @@ def test_seek(test_file):
         assert im.tell() == 0
 
 
-def test_n_frames():
+def test_n_frames() -> None:
     with Image.open("Tests/images/sugarshack.mpo") as im:
         assert im.n_frames == 2
         assert im.is_animated
 
 
-def test_eoferror():
+def test_eoferror() -> None:
     with Image.open("Tests/images/sugarshack.mpo") as im:
         n_frames = im.n_frames
 
@@ -229,7 +230,7 @@ def test_eoferror():
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_image_grab(test_file):
+def test_image_grab(test_file: str) -> None:
     with Image.open(test_file) as im:
         assert im.tell() == 0
         im0 = im.tobytes()
@@ -244,7 +245,7 @@ def test_image_grab(test_file):
 
 
 @pytest.mark.parametrize("test_file", test_files)
-def test_save(test_file):
+def test_save(test_file: str) -> None:
     with Image.open(test_file) as im:
         assert im.tell() == 0
         jpg0 = roundtrip(im)
@@ -255,7 +256,7 @@ def test_save(test_file):
         assert_image_similar(im, jpg1, 30)
 
 
-def test_save_all():
+def test_save_all() -> None:
     for test_file in test_files:
         with Image.open(test_file) as im:
             im_reloaded = roundtrip(im, save_all=True)

Tests/test_file_msp.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import os
+from pathlib import Path
 
 import pytest
 
@@ -13,7 +14,7 @@ EXTRA_DIR = "Tests/images/picins"
 YA_EXTRA_DIR = "Tests/images/msp"
 
 
-def test_sanity(tmp_path):
+def test_sanity(tmp_path: Path) -> None:
     test_file = str(tmp_path / "temp.msp")
 
     hopper("1").save(test_file)
@@ -25,14 +26,14 @@ def test_sanity(tmp_path):
         assert im.format == "MSP"
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         MspImagePlugin.MspImageFile(invalid_file)
 
 
-def test_bad_checksum():
+def test_bad_checksum() -> None:
     # Arrange
     # This was created by forcing Pillow to save with checksum=0
     bad_checksum = "Tests/images/hopper_bad_checksum.msp"
@@ -42,7 +43,7 @@ def test_bad_checksum():
         MspImagePlugin.MspImageFile(bad_checksum)
 
 
-def test_open_windows_v1():
+def test_open_windows_v1() -> None:
     # Arrange
     # Act
     with Image.open(TEST_FILE) as im:
@@ -51,7 +52,7 @@ def test_open_windows_v1():
         assert isinstance(im, MspImagePlugin.MspImageFile)
 
 
-def _assert_file_image_equal(source_path, target_path):
+def _assert_file_image_equal(source_path: str, target_path: str) -> None:
     with Image.open(source_path) as im:
         assert_image_equal_tofile(im, target_path)
 
@@ -59,7 +60,7 @@ def _assert_file_image_equal(source_path, target_path):
 @pytest.mark.skipif(
     not os.path.exists(EXTRA_DIR), reason="Extra image files not installed"
 )
-def test_open_windows_v2():
+def test_open_windows_v2() -> None:
     files = (
         os.path.join(EXTRA_DIR, f)
         for f in os.listdir(EXTRA_DIR)
@@ -72,7 +73,7 @@ def test_open_windows_v2():
 @pytest.mark.skipif(
     not os.path.exists(YA_EXTRA_DIR), reason="Even More Extra image files not installed"
 )
-def test_msp_v2():
+def test_msp_v2() -> None:
     for f in os.listdir(YA_EXTRA_DIR):
         if ".MSP" not in f:
             continue
@@ -80,7 +81,7 @@ def test_msp_v2():
         _assert_file_image_equal(path, path.replace(".MSP", ".png"))
 
 
-def test_cannot_save_wrong_mode(tmp_path):
+def test_cannot_save_wrong_mode(tmp_path: Path) -> None:
     # Arrange
     im = hopper()
     filename = str(tmp_path / "temp.msp")

Tests/test_file_palm.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import os.path
 import subprocess
+from pathlib import Path
 
 import pytest
 
@@ -10,7 +11,7 @@ from PIL import Image
 from .helper import assert_image_equal, hopper, magick_command
 
 
-def helper_save_as_palm(tmp_path, mode):
+def helper_save_as_palm(tmp_path: Path, mode: str) -> None:
     # Arrange
     im = hopper(mode)
     outfile = str(tmp_path / ("temp_" + mode + ".palm"))
@@ -23,7 +24,7 @@ def helper_save_as_palm(tmp_path, mode):
     assert os.path.getsize(outfile) > 0
 
 
-def open_with_magick(magick, tmp_path, f):
+def open_with_magick(magick: list[str], tmp_path: Path, f: str) -> Image.Image:
     outfile = str(tmp_path / "temp.png")
     rc = subprocess.call(
         magick + [f, outfile], stdout=subprocess.DEVNULL, stderr=subprocess.STDOUT
@@ -32,7 +33,7 @@ def open_with_magick(magick, tmp_path, f):
     return Image.open(outfile)
 
 
-def roundtrip(tmp_path, mode):
+def roundtrip(tmp_path: Path, mode: str) -> None:
     magick = magick_command()
     if not magick:
         return
@@ -45,7 +46,7 @@ def roundtrip(tmp_path, mode):
     assert_image_equal(converted, im)
 
 
-def test_monochrome(tmp_path):
+def test_monochrome(tmp_path: Path) -> None:
     # Arrange
     mode = "1"
 
@@ -55,7 +56,7 @@ def test_monochrome(tmp_path):
 
 
 @pytest.mark.xfail(reason="Palm P image is wrong")
-def test_p_mode(tmp_path):
+def test_p_mode(tmp_path: Path) -> None:
     # Arrange
     mode = "P"
 
@@ -65,6 +66,6 @@ def test_p_mode(tmp_path):
 
 
 @pytest.mark.parametrize("mode", ("L", "RGB"))
-def test_oserror(tmp_path, mode):
+def test_oserror(tmp_path: Path, mode: str) -> None:
     with pytest.raises(OSError):
         helper_save_as_palm(tmp_path, mode)

Tests/test_file_pcd.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 from PIL import Image
 
 
-def test_load_raw():
+def test_load_raw() -> None:
     with Image.open("Tests/images/hopper.pcd") as im:
         im.load()  # should not segfault.
 

Tests/test_file_pcx.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 
 from PIL import Image, ImageFile, PcxImagePlugin
@@ -7,7 +9,7 @@ from PIL import Image, ImageFile, PcxImagePlugin
 from .helper import assert_image_equal, hopper
 
 
-def _roundtrip(tmp_path, im):
+def _roundtrip(tmp_path: Path, im: Image.Image) -> None:
     f = str(tmp_path / "temp.pcx")
     im.save(f)
     with Image.open(f) as im2:
@@ -18,7 +20,7 @@ def _roundtrip(tmp_path, im):
         assert_image_equal(im2, im)
 
 
-def test_sanity(tmp_path):
+def test_sanity(tmp_path: Path) -> None:
     for mode in ("1", "L", "P", "RGB"):
         _roundtrip(tmp_path, hopper(mode))
 
@@ -34,7 +36,7 @@ def test_sanity(tmp_path):
         im.save(f)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
@@ -42,7 +44,7 @@ def test_invalid_file():
 
 
 @pytest.mark.parametrize("mode", ("1", "L", "P", "RGB"))
-def test_odd(tmp_path, mode):
+def test_odd(tmp_path: Path, mode: str) -> None:
     # See issue #523, odd sized images should have a stride that's even.
     # Not that ImageMagick or GIMP write PCX that way.
     # We were not handling properly.
@@ -51,7 +53,7 @@ def test_odd(tmp_path, mode):
     _roundtrip(tmp_path, hopper(mode).resize((511, 511)))
 
 
-def test_odd_read():
+def test_odd_read() -> None:
     # Reading an image with an odd stride, making it malformed
     with Image.open("Tests/images/odd_stride.pcx") as im:
         im.load()
@@ -59,7 +61,7 @@ def test_odd_read():
         assert im.size == (371, 150)
 
 
-def test_pil184():
+def test_pil184() -> None:
     # Check reading of files where xmin/xmax is not zero.
 
     test_file = "Tests/images/pil184.pcx"
@@ -71,7 +73,7 @@ def test_pil184():
         assert im.histogram()[0] + im.histogram()[255] == 447 * 144
 
 
-def test_1px_width(tmp_path):
+def test_1px_width(tmp_path: Path) -> None:
     im = Image.new("L", (1, 256))
     px = im.load()
     for y in range(256):
@@ -79,7 +81,7 @@ def test_1px_width(tmp_path):
     _roundtrip(tmp_path, im)
 
 
-def test_large_count(tmp_path):
+def test_large_count(tmp_path: Path) -> None:
     im = Image.new("L", (256, 1))
     px = im.load()
     for x in range(256):
@@ -87,7 +89,7 @@ def test_large_count(tmp_path):
     _roundtrip(tmp_path, im)
 
 
-def _test_buffer_overflow(tmp_path, im, size=1024):
+def _test_buffer_overflow(tmp_path: Path, im: Image.Image, size: int = 1024) -> None:
     _last = ImageFile.MAXBLOCK
     ImageFile.MAXBLOCK = size
     try:
@@ -96,7 +98,7 @@ def _test_buffer_overflow(tmp_path, im, size=1024):
         ImageFile.MAXBLOCK = _last
 
 
-def test_break_in_count_overflow(tmp_path):
+def test_break_in_count_overflow(tmp_path: Path) -> None:
     im = Image.new("L", (256, 5))
     px = im.load()
     for y in range(4):
@@ -105,7 +107,7 @@ def test_break_in_count_overflow(tmp_path):
     _test_buffer_overflow(tmp_path, im)
 
 
-def test_break_one_in_loop(tmp_path):
+def test_break_one_in_loop(tmp_path: Path) -> None:
     im = Image.new("L", (256, 5))
     px = im.load()
     for y in range(5):
@@ -114,7 +116,7 @@ def test_break_one_in_loop(tmp_path):
     _test_buffer_overflow(tmp_path, im)
 
 
-def test_break_many_in_loop(tmp_path):
+def test_break_many_in_loop(tmp_path: Path) -> None:
     im = Image.new("L", (256, 5))
     px = im.load()
     for y in range(4):
@@ -125,7 +127,7 @@ def test_break_many_in_loop(tmp_path):
     _test_buffer_overflow(tmp_path, im)
 
 
-def test_break_one_at_end(tmp_path):
+def test_break_one_at_end(tmp_path: Path) -> None:
     im = Image.new("L", (256, 5))
     px = im.load()
     for y in range(5):
@@ -135,7 +137,7 @@ def test_break_one_at_end(tmp_path):
     _test_buffer_overflow(tmp_path, im)
 
 
-def test_break_many_at_end(tmp_path):
+def test_break_many_at_end(tmp_path: Path) -> None:
     im = Image.new("L", (256, 5))
     px = im.load()
     for y in range(5):
@@ -147,7 +149,7 @@ def test_break_many_at_end(tmp_path):
     _test_buffer_overflow(tmp_path, im)
 
 
-def test_break_padding(tmp_path):
+def test_break_padding(tmp_path: Path) -> None:
     im = Image.new("L", (257, 5))
     px = im.load()
     for y in range(5):

Tests/test_file_pdf.py

@@ -5,6 +5,8 @@ import os
 import os.path
 import tempfile
 import time
+from pathlib import Path
+from typing import Any, Generator
 
 import pytest
 
@@ -13,7 +15,7 @@ from PIL import Image, PdfParser, features
 from .helper import hopper, mark_if_feature_version, skip_unless_feature
 
 
-def helper_save_as_pdf(tmp_path, mode, **kwargs):
+def helper_save_as_pdf(tmp_path: Path, mode: str, **kwargs: Any) -> str:
     # Arrange
     im = hopper(mode)
     outfile = str(tmp_path / ("temp_" + mode + ".pdf"))
@@ -40,17 +42,17 @@ def helper_save_as_pdf(tmp_path, mode, **kwargs):
 
 
 @pytest.mark.parametrize("mode", ("L", "P", "RGB", "CMYK"))
-def test_save(tmp_path, mode):
+def test_save(tmp_path: Path, mode: str) -> None:
     helper_save_as_pdf(tmp_path, mode)
 
 
 @skip_unless_feature("jpg_2000")
 @pytest.mark.parametrize("mode", ("LA", "RGBA"))
-def test_save_alpha(tmp_path, mode):
+def test_save_alpha(tmp_path: Path, mode: str) -> None:
     helper_save_as_pdf(tmp_path, mode)
 
 
-def test_p_alpha(tmp_path):
+def test_p_alpha(tmp_path: Path) -> None:
     # Arrange
     outfile = str(tmp_path / "temp.pdf")
     with Image.open("Tests/images/pil123p.png") as im:
@@ -66,7 +68,7 @@ def test_p_alpha(tmp_path):
     assert b"\n/SMask " in contents
 
 
-def test_monochrome(tmp_path):
+def test_monochrome(tmp_path: Path) -> None:
     # Arrange
     mode = "1"
 
@@ -75,7 +77,7 @@ def test_monochrome(tmp_path):
     assert os.path.getsize(outfile) < (5000 if features.check("libtiff") else 15000)
 
 
-def test_unsupported_mode(tmp_path):
+def test_unsupported_mode(tmp_path: Path) -> None:
     im = hopper("PA")
     outfile = str(tmp_path / "temp_PA.pdf")
 
@@ -83,7 +85,7 @@ def test_unsupported_mode(tmp_path):
         im.save(outfile)
 
 
-def test_resolution(tmp_path):
+def test_resolution(tmp_path: Path) -> None:
     im = hopper()
 
     outfile = str(tmp_path / "temp.pdf")
@@ -111,7 +113,7 @@ def test_resolution(tmp_path):
         {"dpi": (75, 150), "resolution": 200},
     ),
 )
-def test_dpi(params, tmp_path):
+def test_dpi(params: dict[str, int | tuple[int, int]], tmp_path: Path) -> None:
     im = hopper()
 
     outfile = str(tmp_path / "temp.pdf")
@@ -135,7 +137,7 @@ def test_dpi(params, tmp_path):
 @mark_if_feature_version(
     pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
 )
-def test_save_all(tmp_path):
+def test_save_all(tmp_path: Path) -> None:
     # Single frame image
     helper_save_as_pdf(tmp_path, "RGB", save_all=True)
 
@@ -155,7 +157,7 @@ def test_save_all(tmp_path):
         assert os.path.getsize(outfile) > 0
 
         # Test appending using a generator
-        def im_generator(ims):
+        def im_generator(ims: list[Image.Image]) -> Generator[Image.Image, None, None]:
             yield from ims
 
         im.save(outfile, save_all=True, append_images=im_generator(ims))
@@ -171,7 +173,7 @@ def test_save_all(tmp_path):
     assert os.path.getsize(outfile) > 0
 
 
-def test_multiframe_normal_save(tmp_path):
+def test_multiframe_normal_save(tmp_path: Path) -> None:
     # Test saving a multiframe image without save_all
     with Image.open("Tests/images/dispose_bgnd.gif") as im:
         outfile = str(tmp_path / "temp.pdf")
@@ -181,7 +183,7 @@ def test_multiframe_normal_save(tmp_path):
     assert os.path.getsize(outfile) > 0
 
 
-def test_pdf_open(tmp_path):
+def test_pdf_open(tmp_path: Path) -> None:
     # fail on a buffer full of null bytes
     with pytest.raises(PdfParser.PdfFormatError):
         PdfParser.PdfParser(buf=bytearray(65536))
@@ -218,14 +220,14 @@ def test_pdf_open(tmp_path):
             assert not hopper_pdf.should_close_file
 
 
-def test_pdf_append_fails_on_nonexistent_file():
+def test_pdf_append_fails_on_nonexistent_file() -> None:
     im = hopper("RGB")
     with tempfile.TemporaryDirectory() as temp_dir:
         with pytest.raises(OSError):
             im.save(os.path.join(temp_dir, "nonexistent.pdf"), append=True)
 
 
-def check_pdf_pages_consistency(pdf):
+def check_pdf_pages_consistency(pdf: PdfParser.PdfParser) -> None:
     pages_info = pdf.read_indirect(pdf.pages_ref)
     assert b"Parent" not in pages_info
     assert b"Kids" in pages_info
@@ -243,7 +245,7 @@ def check_pdf_pages_consistency(pdf):
     assert kids_not_used == []
 
 
-def test_pdf_append(tmp_path):
+def test_pdf_append(tmp_path: Path) -> None:
     # make a PDF file
     pdf_filename = helper_save_as_pdf(tmp_path, "RGB", producer="PdfParser")
 
@@ -294,7 +296,7 @@ def test_pdf_append(tmp_path):
         check_pdf_pages_consistency(pdf)
 
 
-def test_pdf_info(tmp_path):
+def test_pdf_info(tmp_path: Path) -> None:
     # make a PDF file
     pdf_filename = helper_save_as_pdf(
         tmp_path,
@@ -323,7 +325,7 @@ def test_pdf_info(tmp_path):
         check_pdf_pages_consistency(pdf)
 
 
-def test_pdf_append_to_bytesio():
+def test_pdf_append_to_bytesio() -> None:
     im = hopper("RGB")
     f = io.BytesIO()
     im.save(f, format="PDF")
@@ -338,7 +340,7 @@ def test_pdf_append_to_bytesio():
 @pytest.mark.timeout(1)
 @pytest.mark.skipif("PILLOW_VALGRIND_TEST" in os.environ, reason="Valgrind is slower")
 @pytest.mark.parametrize("newline", (b"\r", b"\n"))
-def test_redos(newline):
+def test_redos(newline: bytes) -> None:
     malicious = b" trailer<<>>" + newline * 3456
 
     # This particular exception isn't relevant here.

Tests/test_file_pixar.py

@@ -9,7 +9,7 @@ from .helper import assert_image_similar, hopper
 TEST_FILE = "Tests/images/hopper.pxr"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(TEST_FILE) as im:
         im.load()
         assert im.mode == "RGB"
@@ -21,7 +21,7 @@ def test_sanity():
         assert_image_similar(im, im2, 4.8)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):

Tests/test_file_png.py

@@ -5,6 +5,9 @@ import sys
 import warnings
 import zlib
 from io import BytesIO
+from pathlib import Path
+from types import ModuleType
+from typing import Any
 
 import pytest
 
@@ -21,6 +24,7 @@ from .helper import (
     skip_unless_feature,
 )
 
+ElementTree: ModuleType | None
 try:
     from defusedxml import ElementTree
 except ImportError:
@@ -35,7 +39,7 @@ TEST_PNG_FILE = "Tests/images/hopper.png"
 MAGIC = PngImagePlugin._MAGIC
 
 
-def chunk(cid, *data):
+def chunk(cid: bytes, *data: bytes) -> bytes:
     test_file = BytesIO()
     PngImagePlugin.putchunk(*(test_file, cid) + data)
     return test_file.getvalue()
@@ -51,11 +55,11 @@ HEAD = MAGIC + IHDR
 TAIL = IDAT + IEND
 
 
-def load(data):
+def load(data: bytes) -> Image.Image:
     return Image.open(BytesIO(data))
 
 
-def roundtrip(im, **options):
+def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
     out = BytesIO()
     im.save(out, "PNG", **options)
     out.seek(0)
@@ -64,7 +68,7 @@ def roundtrip(im, **options):
 
 @skip_unless_feature("zlib")
 class TestFilePng:
-    def get_chunks(self, filename):
+    def get_chunks(self, filename: str) -> list[bytes]:
         chunks = []
         with open(filename, "rb") as fp:
             fp.read(8)
@@ -79,7 +83,7 @@ class TestFilePng:
                     png.crc(cid, s)
         return chunks
 
-    def test_sanity(self, tmp_path):
+    def test_sanity(self, tmp_path: Path) -> None:
         # internal version number
         assert re.search(r"\d+(\.\d+){1,3}$", features.version_codec("zlib"))
 
@@ -102,13 +106,13 @@ class TestFilePng:
                     reloaded = reloaded.convert(mode)
                 assert_image_equal(reloaded, im)
 
-    def test_invalid_file(self):
+    def test_invalid_file(self) -> None:
         invalid_file = "Tests/images/flower.jpg"
 
         with pytest.raises(SyntaxError):
             PngImagePlugin.PngImageFile(invalid_file)
 
-    def test_broken(self):
+    def test_broken(self) -> None:
         # Check reading of totally broken files.  In this case, the test
         # file was checked into Subversion as a text file.
 
@@ -117,7 +121,7 @@ class TestFilePng:
             with Image.open(test_file):
                 pass
 
-    def test_bad_text(self):
+    def test_bad_text(self) -> None:
         # Make sure PIL can read malformed tEXt chunks (@PIL152)
 
         im = load(HEAD + chunk(b"tEXt") + TAIL)
@@ -135,7 +139,7 @@ class TestFilePng:
         im = load(HEAD + chunk(b"tEXt", b"spam\0egg\0") + TAIL)
         assert im.info == {"spam": "egg\x00"}
 
-    def test_bad_ztxt(self):
+    def test_bad_ztxt(self) -> None:
         # Test reading malformed zTXt chunks (python-pillow/Pillow#318)
 
         im = load(HEAD + chunk(b"zTXt") + TAIL)
@@ -156,7 +160,7 @@ class TestFilePng:
         im = load(HEAD + chunk(b"zTXt", b"spam\0\0" + zlib.compress(b"egg")) + TAIL)
         assert im.info == {"spam": "egg"}
 
-    def test_bad_itxt(self):
+    def test_bad_itxt(self) -> None:
         im = load(HEAD + chunk(b"iTXt") + TAIL)
         assert im.info == {}
 
@@ -200,7 +204,7 @@ class TestFilePng:
         assert im.info["spam"].lang == "en"
         assert im.info["spam"].tkey == "Spam"
 
-    def test_interlace(self):
+    def test_interlace(self) -> None:
         test_file = "Tests/images/pil123p.png"
         with Image.open(test_file) as im:
             assert_image(im, "P", (162, 150))
@@ -215,7 +219,7 @@ class TestFilePng:
 
             im.load()
 
-    def test_load_transparent_p(self):
+    def test_load_transparent_p(self) -> None:
         test_file = "Tests/images/pil123p.png"
         with Image.open(test_file) as im:
             assert_image(im, "P", (162, 150))
@@ -225,7 +229,7 @@ class TestFilePng:
         # image has 124 unique alpha values
         assert len(im.getchannel("A").getcolors()) == 124
 
-    def test_load_transparent_rgb(self):
+    def test_load_transparent_rgb(self) -> None:
         test_file = "Tests/images/rgb_trns.png"
         with Image.open(test_file) as im:
             assert im.info["transparency"] == (0, 255, 52)
@@ -237,7 +241,7 @@ class TestFilePng:
         # image has 876 transparent pixels
         assert im.getchannel("A").getcolors()[0][0] == 876
 
-    def test_save_p_transparent_palette(self, tmp_path):
+    def test_save_p_transparent_palette(self, tmp_path: Path) -> None:
         in_file = "Tests/images/pil123p.png"
         with Image.open(in_file) as im:
             # 'transparency' contains a byte string with the opacity for
@@ -258,7 +262,7 @@ class TestFilePng:
         # image has 124 unique alpha values
         assert len(im.getchannel("A").getcolors()) == 124
 
-    def test_save_p_single_transparency(self, tmp_path):
+    def test_save_p_single_transparency(self, tmp_path: Path) -> None:
         in_file = "Tests/images/p_trns_single.png"
         with Image.open(in_file) as im:
             # pixel value 164 is full transparent
@@ -281,7 +285,7 @@ class TestFilePng:
         # image has 876 transparent pixels
         assert im.getchannel("A").getcolors()[0][0] == 876
 
-    def test_save_p_transparent_black(self, tmp_path):
+    def test_save_p_transparent_black(self, tmp_path: Path) -> None:
         # check if solid black image with full transparency
         # is supported (check for #1838)
         im = Image.new("RGBA", (10, 10), (0, 0, 0, 0))
@@ -299,7 +303,7 @@ class TestFilePng:
         assert_image(im, "RGBA", (10, 10))
         assert im.getcolors() == [(100, (0, 0, 0, 0))]
 
-    def test_save_grayscale_transparency(self, tmp_path):
+    def test_save_grayscale_transparency(self, tmp_path: Path) -> None:
         for mode, num_transparent in {"1": 1994, "L": 559, "I": 559}.items():
             in_file = "Tests/images/" + mode.lower() + "_trns.png"
             with Image.open(in_file) as im:
@@ -320,13 +324,13 @@ class TestFilePng:
             test_im_rgba = test_im.convert("RGBA")
             assert test_im_rgba.getchannel("A").getcolors()[0][0] == num_transparent
 
-    def test_save_rgb_single_transparency(self, tmp_path):
+    def test_save_rgb_single_transparency(self, tmp_path: Path) -> None:
         in_file = "Tests/images/caption_6_33_22.png"
         with Image.open(in_file) as im:
             test_file = str(tmp_path / "temp.png")
             im.save(test_file)
 
-    def test_load_verify(self):
+    def test_load_verify(self) -> None:
         # Check open/load/verify exception (@PIL150)
 
         with Image.open(TEST_PNG_FILE) as im:
@@ -339,7 +343,7 @@ class TestFilePng:
             with pytest.raises(RuntimeError):
                 im.verify()
 
-    def test_verify_struct_error(self):
+    def test_verify_struct_error(self) -> None:
         # Check open/load/verify exception (#1755)
 
         # offsets to test, -10: breaks in i32() in read. (OSError)
@@ -355,7 +359,7 @@ class TestFilePng:
                 with pytest.raises((OSError, SyntaxError)):
                     im.verify()
 
-    def test_verify_ignores_crc_error(self):
+    def test_verify_ignores_crc_error(self) -> None:
         # check ignores crc errors in ancillary chunks
 
         chunk_data = chunk(b"tEXt", b"spam")
@@ -372,7 +376,7 @@ class TestFilePng:
         finally:
             ImageFile.LOAD_TRUNCATED_IMAGES = False
 
-    def test_verify_not_ignores_crc_error_in_required_chunk(self):
+    def test_verify_not_ignores_crc_error_in_required_chunk(self) -> None:
         # check does not ignore crc errors in required chunks
 
         image_data = MAGIC + IHDR[:-1] + b"q" + TAIL
@@ -384,18 +388,18 @@ class TestFilePng:
         finally:
             ImageFile.LOAD_TRUNCATED_IMAGES = False
 
-    def test_roundtrip_dpi(self):
+    def test_roundtrip_dpi(self) -> None:
         # Check dpi roundtripping
 
         with Image.open(TEST_PNG_FILE) as im:
             im = roundtrip(im, dpi=(100.33, 100.33))
         assert im.info["dpi"] == (100.33, 100.33)
 
-    def test_load_float_dpi(self):
+    def test_load_float_dpi(self) -> None:
         with Image.open(TEST_PNG_FILE) as im:
             assert im.info["dpi"] == (95.9866, 95.9866)
 
-    def test_roundtrip_text(self):
+    def test_roundtrip_text(self) -> None:
         # Check text roundtripping
 
         with Image.open(TEST_PNG_FILE) as im:
@@ -407,7 +411,7 @@ class TestFilePng:
         assert im.info == {"TXT": "VALUE", "ZIP": "VALUE"}
         assert im.text == {"TXT": "VALUE", "ZIP": "VALUE"}
 
-    def test_roundtrip_itxt(self):
+    def test_roundtrip_itxt(self) -> None:
         # Check iTXt roundtripping
 
         im = Image.new("RGB", (32, 32))
@@ -423,7 +427,7 @@ class TestFilePng:
         assert im.text["eggs"].lang == "en"
         assert im.text["eggs"].tkey == "Eggs"
 
-    def test_nonunicode_text(self):
+    def test_nonunicode_text(self) -> None:
         # Check so that non-Unicode text is saved as a tEXt rather than iTXt
 
         im = Image.new("RGB", (32, 32))
@@ -432,10 +436,10 @@ class TestFilePng:
         im = roundtrip(im, pnginfo=info)
         assert isinstance(im.info["Text"], str)
 
-    def test_unicode_text(self):
+    def test_unicode_text(self) -> None:
         # Check preservation of non-ASCII characters
 
-        def rt_text(value):
+        def rt_text(value: str) -> None:
             im = Image.new("RGB", (32, 32))
             info = PngImagePlugin.PngInfo()
             info.add_text("Text", value)
@@ -448,7 +452,7 @@ class TestFilePng:
         rt_text(chr(0x4E00) + chr(0x66F0) + chr(0x9FBA) + chr(0x3042) + chr(0xAC00))
         rt_text("A" + chr(0xC4) + chr(0x472) + chr(0x3042))  # Combined
 
-    def test_scary(self):
+    def test_scary(self) -> None:
         # Check reading of evil PNG file.  For information, see:
         # http://scary.beasts.org/security/CESA-2004-001.txt
         # The first byte is removed from pngtest_bad.png
@@ -462,7 +466,7 @@ class TestFilePng:
             with Image.open(pngfile):
                 pass
 
-    def test_trns_rgb(self):
+    def test_trns_rgb(self) -> None:
         # Check writing and reading of tRNS chunks for RGB images.
         # Independent file sample provided by Sebastian Spaeth.
 
@@ -477,7 +481,7 @@ class TestFilePng:
         im = roundtrip(im, transparency=(0, 1, 2))
         assert im.info["transparency"] == (0, 1, 2)
 
-    def test_trns_p(self, tmp_path):
+    def test_trns_p(self, tmp_path: Path) -> None:
         # Check writing a transparency of 0, issue #528
         im = hopper("P")
         im.info["transparency"] = 0
@@ -490,13 +494,13 @@ class TestFilePng:
 
             assert_image_equal(im2.convert("RGBA"), im.convert("RGBA"))
 
-    def test_trns_null(self):
+    def test_trns_null(self) -> None:
         # Check reading images with null tRNS value, issue #1239
         test_file = "Tests/images/tRNS_null_1x1.png"
         with Image.open(test_file) as im:
             assert im.info["transparency"] == 0
 
-    def test_save_icc_profile(self):
+    def test_save_icc_profile(self) -> None:
         with Image.open("Tests/images/icc_profile_none.png") as im:
             assert im.info["icc_profile"] is None
 
@@ -506,40 +510,40 @@ class TestFilePng:
                 im = roundtrip(im, icc_profile=expected_icc)
                 assert im.info["icc_profile"] == expected_icc
 
-    def test_discard_icc_profile(self):
+    def test_discard_icc_profile(self) -> None:
         with Image.open("Tests/images/icc_profile.png") as im:
             assert "icc_profile" in im.info
 
             im = roundtrip(im, icc_profile=None)
         assert "icc_profile" not in im.info
 
-    def test_roundtrip_icc_profile(self):
+    def test_roundtrip_icc_profile(self) -> None:
         with Image.open("Tests/images/icc_profile.png") as im:
             expected_icc = im.info["icc_profile"]
 
             im = roundtrip(im)
         assert im.info["icc_profile"] == expected_icc
 
-    def test_roundtrip_no_icc_profile(self):
+    def test_roundtrip_no_icc_profile(self) -> None:
         with Image.open("Tests/images/icc_profile_none.png") as im:
             assert im.info["icc_profile"] is None
 
             im = roundtrip(im)
         assert "icc_profile" not in im.info
 
-    def test_repr_png(self):
+    def test_repr_png(self) -> None:
         im = hopper()
 
         with Image.open(BytesIO(im._repr_png_())) as repr_png:
             assert repr_png.format == "PNG"
             assert_image_equal(im, repr_png)
 
-    def test_repr_png_error_returns_none(self):
+    def test_repr_png_error_returns_none(self) -> None:
         im = hopper("F")
 
         assert im._repr_png_() is None
 
-    def test_chunk_order(self, tmp_path):
+    def test_chunk_order(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/icc_profile.png") as im:
             test_file = str(tmp_path / "temp.png")
             im.convert("P").save(test_file, dpi=(100, 100))
@@ -560,17 +564,17 @@ class TestFilePng:
         # pHYs - before IDAT
         assert chunks.index(b"pHYs") < chunks.index(b"IDAT")
 
-    def test_getchunks(self):
+    def test_getchunks(self) -> None:
         im = hopper()
 
         chunks = PngImagePlugin.getchunks(im)
         assert len(chunks) == 3
 
-    def test_read_private_chunks(self):
+    def test_read_private_chunks(self) -> None:
         with Image.open("Tests/images/exif.png") as im:
             assert im.private_chunks == [(b"orNT", b"\x01")]
 
-    def test_roundtrip_private_chunk(self):
+    def test_roundtrip_private_chunk(self) -> None:
         # Check private chunk roundtripping
 
         with Image.open(TEST_PNG_FILE) as im:
@@ -588,7 +592,7 @@ class TestFilePng:
             (b"prIV", b"VALUE3", True),
         ]
 
-    def test_textual_chunks_after_idat(self):
+    def test_textual_chunks_after_idat(self) -> None:
         with Image.open("Tests/images/hopper.png") as im:
             assert "comment" in im.text
             for k, v in {
@@ -615,7 +619,7 @@ class TestFilePng:
         with Image.open("Tests/images/hopper_idat_after_image_end.png") as im:
             assert im.text == {"TXT": "VALUE", "ZIP": "VALUE"}
 
-    def test_padded_idat(self):
+    def test_padded_idat(self) -> None:
         # This image has been manually hexedited
         # so that the IDAT chunk has padding at the end
         # Set MAXBLOCK to the length of the actual data
@@ -635,7 +639,7 @@ class TestFilePng:
     @pytest.mark.parametrize(
         "cid", (b"IHDR", b"sRGB", b"pHYs", b"acTL", b"fcTL", b"fdAT")
     )
-    def test_truncated_chunks(self, cid):
+    def test_truncated_chunks(self, cid: bytes) -> None:
         fp = BytesIO()
         with PngImagePlugin.PngStream(fp) as png:
             with pytest.raises(ValueError):
@@ -645,7 +649,7 @@ class TestFilePng:
             png.call(cid, 0, 0)
             ImageFile.LOAD_TRUNCATED_IMAGES = False
 
-    def test_specify_bits(self, tmp_path):
+    def test_specify_bits(self, tmp_path: Path) -> None:
         im = hopper("P")
 
         out = str(tmp_path / "temp.png")
@@ -654,7 +658,7 @@ class TestFilePng:
         with Image.open(out) as reloaded:
             assert len(reloaded.png.im_palette[1]) == 48
 
-    def test_plte_length(self, tmp_path):
+    def test_plte_length(self, tmp_path: Path) -> None:
         im = Image.new("P", (1, 1))
         im.putpalette((1, 1, 1))
 
@@ -664,7 +668,7 @@ class TestFilePng:
         with Image.open(out) as reloaded:
             assert len(reloaded.png.im_palette[1]) == 3
 
-    def test_getxmp(self):
+    def test_getxmp(self) -> None:
         with Image.open("Tests/images/color_snakes.png") as im:
             if ElementTree is None:
                 with pytest.warns(
@@ -679,7 +683,7 @@ class TestFilePng:
                 assert description["PixelXDimension"] == "10"
                 assert description["subject"]["Seq"] is None
 
-    def test_exif(self):
+    def test_exif(self) -> None:
         # With an EXIF chunk
         with Image.open("Tests/images/exif.png") as im:
             exif = im._getexif()
@@ -705,7 +709,7 @@ class TestFilePng:
             exif = im.getexif()
         assert exif[274] == 3
 
-    def test_exif_save(self, tmp_path):
+    def test_exif_save(self, tmp_path: Path) -> None:
         # Test exif is not saved from info
         test_file = str(tmp_path / "temp.png")
         with Image.open("Tests/images/exif.png") as im:
@@ -725,7 +729,7 @@ class TestFilePng:
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_exif_from_jpg(self, tmp_path):
+    def test_exif_from_jpg(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
             test_file = str(tmp_path / "temp.png")
             im.save(test_file, exif=im.getexif())
@@ -734,7 +738,7 @@ class TestFilePng:
             exif = reloaded._getexif()
         assert exif[305] == "Adobe Photoshop CS Macintosh"
 
-    def test_exif_argument(self, tmp_path):
+    def test_exif_argument(self, tmp_path: Path) -> None:
         with Image.open(TEST_PNG_FILE) as im:
             test_file = str(tmp_path / "temp.png")
             im.save(test_file, exif=b"exifstring")
@@ -742,11 +746,11 @@ class TestFilePng:
         with Image.open(test_file) as reloaded:
             assert reloaded.info["exif"] == b"Exif\x00\x00exifstring"
 
-    def test_tell(self):
+    def test_tell(self) -> None:
         with Image.open(TEST_PNG_FILE) as im:
             assert im.tell() == 0
 
-    def test_seek(self):
+    def test_seek(self) -> None:
         with Image.open(TEST_PNG_FILE) as im:
             im.seek(0)
 
@@ -754,7 +758,7 @@ class TestFilePng:
                 im.seek(1)
 
     @pytest.mark.parametrize("buffer", (True, False))
-    def test_save_stdout(self, buffer):
+    def test_save_stdout(self, buffer: bool) -> None:
         old_stdout = sys.stdout
 
         if buffer:
@@ -786,7 +790,7 @@ class TestTruncatedPngPLeaks(PillowLeakTestCase):
     mem_limit = 2 * 1024  # max increase in K
     iterations = 100  # Leak is 56k/iteration, this will leak 5.6megs
 
-    def test_leak_load(self):
+    def test_leak_load(self) -> None:
         with open("Tests/images/hopper.png", "rb") as f:
             DATA = BytesIO(f.read(16 * 1024))
 
@@ -794,7 +798,7 @@ class TestTruncatedPngPLeaks(PillowLeakTestCase):
         with Image.open(DATA) as im:
             im.load()
 
-        def core():
+        def core() -> None:
             with Image.open(DATA) as im:
                 im.load()
 

Tests/test_file_ppm.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import sys
 from io import BytesIO
+from pathlib import Path
 
 import pytest
 
@@ -18,7 +19,7 @@ from .helper import (
 TEST_FILE = "Tests/images/hopper.ppm"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(TEST_FILE) as im:
         assert im.mode == "RGB"
         assert im.size == (128, 128)
@@ -69,7 +70,9 @@ def test_sanity():
         ),
     ),
 )
-def test_arbitrary_maxval(data, mode, pixels):
+def test_arbitrary_maxval(
+    data: bytes, mode: str, pixels: tuple[int | tuple[int, int, int], ...]
+) -> None:
     fp = BytesIO(data)
     with Image.open(fp) as im:
         assert im.size == (3, 1)
@@ -79,7 +82,7 @@ def test_arbitrary_maxval(data, mode, pixels):
         assert tuple(px[x, 0] for x in range(3)) == pixels
 
 
-def test_16bit_pgm():
+def test_16bit_pgm() -> None:
     with Image.open("Tests/images/16_bit_binary.pgm") as im:
         assert im.mode == "I"
         assert im.size == (20, 100)
@@ -88,7 +91,7 @@ def test_16bit_pgm():
         assert_image_equal_tofile(im, "Tests/images/16_bit_binary_pgm.png")
 
 
-def test_16bit_pgm_write(tmp_path):
+def test_16bit_pgm_write(tmp_path: Path) -> None:
     with Image.open("Tests/images/16_bit_binary.pgm") as im:
         filename = str(tmp_path / "temp.pgm")
         im.save(filename, "PPM")
@@ -96,7 +99,7 @@ def test_16bit_pgm_write(tmp_path):
         assert_image_equal_tofile(im, filename)
 
 
-def test_pnm(tmp_path):
+def test_pnm(tmp_path: Path) -> None:
     with Image.open("Tests/images/hopper.pnm") as im:
         assert_image_similar(im, hopper(), 0.0001)
 
@@ -106,7 +109,7 @@ def test_pnm(tmp_path):
         assert_image_equal_tofile(im, filename)
 
 
-def test_pfm(tmp_path):
+def test_pfm(tmp_path: Path) -> None:
     with Image.open("Tests/images/hopper.pfm") as im:
         assert im.info["scale"] == 1.0
         assert_image_equal(im, hopper("F"))
@@ -117,7 +120,7 @@ def test_pfm(tmp_path):
         assert_image_equal_tofile(im, filename)
 
 
-def test_pfm_big_endian(tmp_path):
+def test_pfm_big_endian(tmp_path: Path) -> None:
     with Image.open("Tests/images/hopper_be.pfm") as im:
         assert im.info["scale"] == 2.5
         assert_image_equal(im, hopper("F"))
@@ -138,7 +141,7 @@ def test_pfm_big_endian(tmp_path):
         b"Pf 1 1 -0.0 \0\0\0\0",
     ],
 )
-def test_pfm_invalid(data):
+def test_pfm_invalid(data: bytes) -> None:
     with pytest.raises(ValueError):
         with Image.open(BytesIO(data)):
             pass
@@ -161,12 +164,12 @@ def test_pfm_invalid(data):
         ),
     ),
 )
-def test_plain(plain_path, raw_path):
+def test_plain(plain_path: str, raw_path: str) -> None:
     with Image.open(plain_path) as im:
         assert_image_equal_tofile(im, raw_path)
 
 
-def test_16bit_plain_pgm():
+def test_16bit_plain_pgm() -> None:
     # P2 with maxval 2 ** 16 - 1
     with Image.open("Tests/images/hopper_16bit_plain.pgm") as im:
         assert im.mode == "I"
@@ -185,7 +188,9 @@ def test_16bit_plain_pgm():
         (b"P3\n2 2\n255", b"0 0 0 001 1 1 2 2 2 255 255 255", 10**6),
     ),
 )
-def test_plain_data_with_comment(tmp_path, header, data, comment_count):
+def test_plain_data_with_comment(
+    tmp_path: Path, header: bytes, data: bytes, comment_count: int
+) -> None:
     path1 = str(tmp_path / "temp1.ppm")
     path2 = str(tmp_path / "temp2.ppm")
     comment = b"# comment" * comment_count
@@ -198,7 +203,7 @@ def test_plain_data_with_comment(tmp_path, header, data, comment_count):
 
 
 @pytest.mark.parametrize("data", (b"P1\n128 128\n", b"P3\n128 128\n255\n"))
-def test_plain_truncated_data(tmp_path, data):
+def test_plain_truncated_data(tmp_path: Path, data: bytes) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(data)
@@ -209,7 +214,7 @@ def test_plain_truncated_data(tmp_path, data):
 
 
 @pytest.mark.parametrize("data", (b"P1\n128 128\n1009", b"P3\n128 128\n255\n100A"))
-def test_plain_invalid_data(tmp_path, data):
+def test_plain_invalid_data(tmp_path: Path, data: bytes) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(data)
@@ -226,7 +231,7 @@ def test_plain_invalid_data(tmp_path, data):
         b"P3\n128 128\n255\n012345678910 0",  # token too long
     ),
 )
-def test_plain_ppm_token_too_long(tmp_path, data):
+def test_plain_ppm_token_too_long(tmp_path: Path, data: bytes) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(data)
@@ -236,7 +241,7 @@ def test_plain_ppm_token_too_long(tmp_path, data):
             im.load()
 
 
-def test_plain_ppm_value_too_large(tmp_path):
+def test_plain_ppm_value_too_large(tmp_path: Path) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(b"P3\n128 128\n255\n256")
@@ -246,12 +251,12 @@ def test_plain_ppm_value_too_large(tmp_path):
             im.load()
 
 
-def test_magic():
+def test_magic() -> None:
     with pytest.raises(SyntaxError):
         PpmImagePlugin.PpmImageFile(fp=BytesIO(b"PyInvalid"))
 
 
-def test_header_with_comments(tmp_path):
+def test_header_with_comments(tmp_path: Path) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(b"P6 #comment\n#comment\r12#comment\r8\n128 #comment\n255\n")
@@ -260,7 +265,7 @@ def test_header_with_comments(tmp_path):
         assert im.size == (128, 128)
 
 
-def test_non_integer_token(tmp_path):
+def test_non_integer_token(tmp_path: Path) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(b"P6\nTEST")
@@ -270,7 +275,7 @@ def test_non_integer_token(tmp_path):
             pass
 
 
-def test_header_token_too_long(tmp_path):
+def test_header_token_too_long(tmp_path: Path) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(b"P6\n 01234567890")
@@ -282,7 +287,7 @@ def test_header_token_too_long(tmp_path):
     assert str(e.value) == "Token too long in file header: 01234567890"
 
 
-def test_truncated_file(tmp_path):
+def test_truncated_file(tmp_path: Path) -> None:
     # Test EOF in header
     path = str(tmp_path / "temp.pgm")
     with open(path, "wb") as f:
@@ -301,7 +306,7 @@ def test_truncated_file(tmp_path):
             im.load()
 
 
-def test_not_enough_image_data(tmp_path):
+def test_not_enough_image_data(tmp_path: Path) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(b"P2 1 2 255 255")
@@ -312,7 +317,7 @@ def test_not_enough_image_data(tmp_path):
 
 
 @pytest.mark.parametrize("maxval", (b"0", b"65536"))
-def test_invalid_maxval(maxval, tmp_path):
+def test_invalid_maxval(maxval: bytes, tmp_path: Path) -> None:
     path = str(tmp_path / "temp.ppm")
     with open(path, "wb") as f:
         f.write(b"P6\n3 1 " + maxval)
@@ -324,7 +329,7 @@ def test_invalid_maxval(maxval, tmp_path):
     assert str(e.value) == "maxval must be greater than 0 and less than 65536"
 
 
-def test_neg_ppm():
+def test_neg_ppm() -> None:
     # Storage.c accepted negative values for xsize, ysize.  the
     # internal open_ppm function didn't check for sanity but it
     # has been removed. The default opener doesn't accept negative
@@ -335,7 +340,7 @@ def test_neg_ppm():
             pass
 
 
-def test_mimetypes(tmp_path):
+def test_mimetypes(tmp_path: Path) -> None:
     path = str(tmp_path / "temp.pgm")
 
     with open(path, "wb") as f:
@@ -350,7 +355,7 @@ def test_mimetypes(tmp_path):
 
 
 @pytest.mark.parametrize("buffer", (True, False))
-def test_save_stdout(buffer):
+def test_save_stdout(buffer: bool) -> None:
     old_stdout = sys.stdout
 
     if buffer:

Tests/test_file_psd.py

@@ -11,7 +11,7 @@ from .helper import assert_image_equal_tofile, assert_image_similar, hopper, is_
 test_file = "Tests/images/hopper.psd"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(test_file) as im:
         im.load()
         assert im.mode == "RGB"
@@ -24,8 +24,8 @@ def test_sanity():
 
 
 @pytest.mark.skipif(is_pypy(), reason="Requires CPython")
-def test_unclosed_file():
+def test_unclosed_file() -> None:
-    def open():
+    def open() -> None:
         im = Image.open(test_file)
         im.load()
 
@@ -33,27 +33,27 @@ def test_unclosed_file():
         open()
 
 
-def test_closed_file():
+def test_closed_file() -> None:
     with warnings.catch_warnings():
         im = Image.open(test_file)
         im.load()
         im.close()
 
 
-def test_context_manager():
+def test_context_manager() -> None:
     with warnings.catch_warnings():
         with Image.open(test_file) as im:
             im.load()
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         PsdImagePlugin.PsdImageFile(invalid_file)
 
 
-def test_n_frames():
+def test_n_frames() -> None:
     with Image.open("Tests/images/hopper_merged.psd") as im:
         assert im.n_frames == 1
         assert not im.is_animated
@@ -64,7 +64,7 @@ def test_n_frames():
             assert im.is_animated
 
 
-def test_eoferror():
+def test_eoferror() -> None:
     with Image.open(test_file) as im:
         # PSD seek index starts at 1 rather than 0
         n_frames = im.n_frames + 1
@@ -78,7 +78,7 @@ def test_eoferror():
         im.seek(n_frames - 1)
 
 
-def test_seek_tell():
+def test_seek_tell() -> None:
     with Image.open(test_file) as im:
         layer_number = im.tell()
         assert layer_number == 1
@@ -95,30 +95,30 @@ def test_seek_tell():
         assert layer_number == 2
 
 
-def test_seek_eoferror():
+def test_seek_eoferror() -> None:
     with Image.open(test_file) as im:
         with pytest.raises(EOFError):
             im.seek(-1)
 
 
-def test_open_after_exclusive_load():
+def test_open_after_exclusive_load() -> None:
     with Image.open(test_file) as im:
         im.load()
         im.seek(im.tell() + 1)
         im.load()
 
 
-def test_rgba():
+def test_rgba() -> None:
     with Image.open("Tests/images/rgba.psd") as im:
         assert_image_equal_tofile(im, "Tests/images/imagedraw_square.png")
 
 
-def test_layer_skip():
+def test_layer_skip() -> None:
     with Image.open("Tests/images/five_channels.psd") as im:
         assert im.n_frames == 1
 
 
-def test_icc_profile():
+def test_icc_profile() -> None:
     with Image.open(test_file) as im:
         assert "icc_profile" in im.info
 
@@ -126,12 +126,12 @@ def test_icc_profile():
         assert len(icc_profile) == 3144
 
 
-def test_no_icc_profile():
+def test_no_icc_profile() -> None:
     with Image.open("Tests/images/hopper_merged.psd") as im:
         assert "icc_profile" not in im.info
 
 
-def test_combined_larger_than_size():
+def test_combined_larger_than_size() -> None:
     # The combined size of the individual parts is larger than the
     # declared 'size' of the extra data field, resulting in a backwards seek.
 
@@ -157,7 +157,7 @@ def test_combined_larger_than_size():
         ("Tests/images/timeout-dedc7a4ebd856d79b4359bbcc79e8ef231ce38f6.psd", OSError),
     ],
 )
-def test_crashes(test_file, raises):
+def test_crashes(test_file: str, raises) -> None:
     with open(test_file, "rb") as f:
         with pytest.raises(raises):
             with Image.open(f):

Tests/test_file_qoi.py

@@ -7,7 +7,7 @@ from PIL import Image, QoiImagePlugin
 from .helper import assert_image_equal_tofile
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open("Tests/images/hopper.qoi") as im:
         assert im.mode == "RGB"
         assert im.size == (128, 128)
@@ -23,7 +23,7 @@ def test_sanity():
         assert_image_equal_tofile(im, "Tests/images/pil123rgba.png")
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):

Tests/test_file_sgi.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 
 from PIL import Image, SgiImagePlugin
@@ -12,7 +14,7 @@ from .helper import (
 )
 
 
-def test_rgb():
+def test_rgb() -> None:
     # Created with ImageMagick then renamed:
     # convert hopper.ppm -compress None sgi:hopper.rgb
     test_file = "Tests/images/hopper.rgb"
@@ -22,11 +24,11 @@ def test_rgb():
         assert im.get_format_mimetype() == "image/rgb"
 
 
-def test_rgb16():
+def test_rgb16() -> None:
     assert_image_equal_tofile(hopper(), "Tests/images/hopper16.rgb")
 
 
-def test_l():
+def test_l() -> None:
     # Created with ImageMagick
     # convert hopper.ppm -monochrome -compress None sgi:hopper.bw
     test_file = "Tests/images/hopper.bw"
@@ -36,7 +38,7 @@ def test_l():
         assert im.get_format_mimetype() == "image/sgi"
 
 
-def test_rgba():
+def test_rgba() -> None:
     # Created with ImageMagick:
     # convert transparent.png -compress None transparent.sgi
     test_file = "Tests/images/transparent.sgi"
@@ -46,7 +48,7 @@ def test_rgba():
         assert im.get_format_mimetype() == "image/sgi"
 
 
-def test_rle():
+def test_rle() -> None:
     # Created with ImageMagick:
     # convert hopper.ppm  hopper.sgi
     test_file = "Tests/images/hopper.sgi"
@@ -55,22 +57,22 @@ def test_rle():
         assert_image_equal_tofile(im, "Tests/images/hopper.rgb")
 
 
-def test_rle16():
+def test_rle16() -> None:
     test_file = "Tests/images/tv16.sgi"
 
     with Image.open(test_file) as im:
         assert_image_equal_tofile(im, "Tests/images/tv.rgb")
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(ValueError):
         SgiImagePlugin.SgiImageFile(invalid_file)
 
 
-def test_write(tmp_path):
+def test_write(tmp_path: Path) -> None:
-    def roundtrip(img):
+    def roundtrip(img: Image.Image) -> None:
         out = str(tmp_path / "temp.sgi")
         img.save(out, format="sgi")
         assert_image_equal_tofile(img, out)
@@ -89,7 +91,7 @@ def test_write(tmp_path):
     roundtrip(Image.new("L", (10, 1)))
 
 
-def test_write16(tmp_path):
+def test_write16(tmp_path: Path) -> None:
     test_file = "Tests/images/hopper16.rgb"
 
     with Image.open(test_file) as im:
@@ -99,7 +101,7 @@ def test_write16(tmp_path):
         assert_image_equal_tofile(im, out)
 
 
-def test_unsupported_mode(tmp_path):
+def test_unsupported_mode(tmp_path: Path) -> None:
     im = hopper("LA")
     out = str(tmp_path / "temp.sgi")
 

Tests/test_file_spider.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import tempfile
 import warnings
 from io import BytesIO
+from pathlib import Path
 
 import pytest
 
@@ -13,7 +14,7 @@ from .helper import assert_image_equal_tofile, hopper, is_pypy
 TEST_FILE = "Tests/images/hopper.spider"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(TEST_FILE) as im:
         im.load()
         assert im.mode == "F"
@@ -22,8 +23,8 @@ def test_sanity():
 
 
 @pytest.mark.skipif(is_pypy(), reason="Requires CPython")
-def test_unclosed_file():
+def test_unclosed_file() -> None:
-    def open():
+    def open() -> None:
         im = Image.open(TEST_FILE)
         im.load()
 
@@ -31,20 +32,20 @@ def test_unclosed_file():
         open()
 
 
-def test_closed_file():
+def test_closed_file() -> None:
     with warnings.catch_warnings():
         im = Image.open(TEST_FILE)
         im.load()
         im.close()
 
 
-def test_context_manager():
+def test_context_manager() -> None:
     with warnings.catch_warnings():
         with Image.open(TEST_FILE) as im:
             im.load()
 
 
-def test_save(tmp_path):
+def test_save(tmp_path: Path) -> None:
     # Arrange
     temp = str(tmp_path / "temp.spider")
     im = hopper()
@@ -59,7 +60,7 @@ def test_save(tmp_path):
         assert im2.format == "SPIDER"
 
 
-def test_tempfile():
+def test_tempfile() -> None:
     # Arrange
     im = hopper()
 
@@ -75,11 +76,11 @@ def test_tempfile():
             assert reloaded.format == "SPIDER"
 
 
-def test_is_spider_image():
+def test_is_spider_image() -> None:
     assert SpiderImagePlugin.isSpiderImage(TEST_FILE)
 
 
-def test_tell():
+def test_tell() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         # Act
@@ -89,13 +90,13 @@ def test_tell():
         assert index == 0
 
 
-def test_n_frames():
+def test_n_frames() -> None:
     with Image.open(TEST_FILE) as im:
         assert im.n_frames == 1
         assert not im.is_animated
 
 
-def test_load_image_series():
+def test_load_image_series() -> None:
     # Arrange
     not_spider_file = "Tests/images/hopper.ppm"
     file_list = [TEST_FILE, not_spider_file, "path/not_found.ext"]
@@ -109,7 +110,7 @@ def test_load_image_series():
     assert img_list[0].size == (128, 128)
 
 
-def test_load_image_series_no_input():
+def test_load_image_series_no_input() -> None:
     # Arrange
     file_list = None
 
@@ -120,7 +121,7 @@ def test_load_image_series_no_input():
     assert img_list is None
 
 
-def test_is_int_not_a_number():
+def test_is_int_not_a_number() -> None:
     # Arrange
     not_a_number = "a"
 
@@ -131,7 +132,7 @@ def test_is_int_not_a_number():
     assert ret == 0
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/invalid.spider"
 
     with pytest.raises(OSError):
@@ -139,20 +140,20 @@ def test_invalid_file():
             pass
 
 
-def test_nonstack_file():
+def test_nonstack_file() -> None:
     with Image.open(TEST_FILE) as im:
         with pytest.raises(EOFError):
             im.seek(0)
 
 
-def test_nonstack_dos():
+def test_nonstack_dos() -> None:
     with Image.open(TEST_FILE) as im:
         for i, frame in enumerate(ImageSequence.Iterator(im)):
             assert i <= 1, "Non-stack DOS file test failed"
 
 
 # for issue #4093
-def test_odd_size():
+def test_odd_size() -> None:
     data = BytesIO()
     width = 100
     im = Image.new("F", (width, 64))

Tests/test_file_sun.py

@@ -11,7 +11,7 @@ from .helper import assert_image_equal_tofile, assert_image_similar, hopper
 EXTRA_DIR = "Tests/images/sunraster"
 
 
-def test_sanity():
+def test_sanity() -> None:
     # Arrange
     # Created with ImageMagick: convert hopper.jpg hopper.ras
     test_file = "Tests/images/hopper.ras"
@@ -28,7 +28,7 @@ def test_sanity():
         SunImagePlugin.SunImageFile(invalid_file)
 
 
-def test_im1():
+def test_im1() -> None:
     with Image.open("Tests/images/sunraster.im1") as im:
         assert_image_equal_tofile(im, "Tests/images/sunraster.im1.png")
 
@@ -36,7 +36,7 @@ def test_im1():
 @pytest.mark.skipif(
     not os.path.exists(EXTRA_DIR), reason="Extra image files not installed"
 )
-def test_others():
+def test_others() -> None:
     files = (
         os.path.join(EXTRA_DIR, f)
         for f in os.listdir(EXTRA_DIR)

Tests/test_file_tar.py

@@ -19,7 +19,7 @@ TEST_TAR_FILE = "Tests/images/hopper.tar"
         ("jpg", "hopper.jpg", "JPEG"),
     ),
 )
-def test_sanity(codec, test_path, format):
+def test_sanity(codec: str, test_path: str, format: str) -> None:
     if features.check(codec):
         with TarIO.TarIO(TEST_TAR_FILE, test_path) as tar:
             with Image.open(tar) as im:
@@ -30,18 +30,18 @@ def test_sanity(codec, test_path, format):
 
 
 @pytest.mark.skipif(is_pypy(), reason="Requires CPython")
-def test_unclosed_file():
+def test_unclosed_file() -> None:
     with pytest.warns(ResourceWarning):
         TarIO.TarIO(TEST_TAR_FILE, "hopper.jpg")
 
 
-def test_close():
+def test_close() -> None:
     with warnings.catch_warnings():
         tar = TarIO.TarIO(TEST_TAR_FILE, "hopper.jpg")
         tar.close()
 
 
-def test_contextmanager():
+def test_contextmanager() -> None:
     with warnings.catch_warnings():
         with TarIO.TarIO(TEST_TAR_FILE, "hopper.jpg"):
             pass

Tests/test_file_tga.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import os
 from glob import glob
 from itertools import product
+from pathlib import Path
 
 import pytest
 
@@ -21,8 +22,8 @@ _ORIGIN_TO_ORIENTATION = {"tl": 1, "bl": -1}
 
 
 @pytest.mark.parametrize("mode", _MODES)
-def test_sanity(mode, tmp_path):
+def test_sanity(mode: str, tmp_path: Path) -> None:
-    def roundtrip(original_im):
+    def roundtrip(original_im: Image.Image) -> None:
         out = str(tmp_path / "temp.tga")
 
         original_im.save(out, rle=rle)
@@ -64,7 +65,7 @@ def test_sanity(mode, tmp_path):
                     roundtrip(original_im)
 
 
-def test_palette_depth_16(tmp_path):
+def test_palette_depth_16(tmp_path: Path) -> None:
     with Image.open("Tests/images/p_16.tga") as im:
         assert_image_equal_tofile(im.convert("RGB"), "Tests/images/p_16.png")
 
@@ -74,7 +75,7 @@ def test_palette_depth_16(tmp_path):
             assert_image_equal_tofile(reloaded.convert("RGB"), "Tests/images/p_16.png")
 
 
-def test_id_field():
+def test_id_field() -> None:
     # tga file with id field
     test_file = "Tests/images/tga_id_field.tga"
 
@@ -84,7 +85,7 @@ def test_id_field():
         assert im.size == (100, 100)
 
 
-def test_id_field_rle():
+def test_id_field_rle() -> None:
     # tga file with id field
     test_file = "Tests/images/rgb32rle.tga"
 
@@ -94,7 +95,7 @@ def test_id_field_rle():
         assert im.size == (199, 199)
 
 
-def test_cross_scan_line():
+def test_cross_scan_line() -> None:
     with Image.open("Tests/images/cross_scan_line.tga") as im:
         assert_image_equal_tofile(im, "Tests/images/cross_scan_line.png")
 
@@ -103,7 +104,7 @@ def test_cross_scan_line():
             im.load()
 
 
-def test_save(tmp_path):
+def test_save(tmp_path: Path) -> None:
     test_file = "Tests/images/tga_id_field.tga"
     with Image.open(test_file) as im:
         out = str(tmp_path / "temp.tga")
@@ -120,7 +121,7 @@ def test_save(tmp_path):
         assert test_im.size == (100, 100)
 
 
-def test_small_palette(tmp_path):
+def test_small_palette(tmp_path: Path) -> None:
     im = Image.new("P", (1, 1))
     colors = [0, 0, 0]
     im.putpalette(colors)
@@ -132,7 +133,7 @@ def test_small_palette(tmp_path):
         assert reloaded.getpalette() == colors
 
 
-def test_save_wrong_mode(tmp_path):
+def test_save_wrong_mode(tmp_path: Path) -> None:
     im = hopper("PA")
     out = str(tmp_path / "temp.tga")
 
@@ -140,7 +141,7 @@ def test_save_wrong_mode(tmp_path):
         im.save(out)
 
 
-def test_save_mapdepth():
+def test_save_mapdepth() -> None:
     # This image has been manually hexedited from 200x32_p_bl_raw.tga
     # to include an origin
     test_file = "Tests/images/200x32_p_bl_raw_origin.tga"
@@ -148,7 +149,7 @@ def test_save_mapdepth():
         assert_image_equal_tofile(im, "Tests/images/tga/common/200x32_p.png")
 
 
-def test_save_id_section(tmp_path):
+def test_save_id_section(tmp_path: Path) -> None:
     test_file = "Tests/images/rgb32rle.tga"
     with Image.open(test_file) as im:
         out = str(tmp_path / "temp.tga")
@@ -179,7 +180,7 @@ def test_save_id_section(tmp_path):
         assert "id_section" not in test_im.info
 
 
-def test_save_orientation(tmp_path):
+def test_save_orientation(tmp_path: Path) -> None:
     test_file = "Tests/images/rgb32rle.tga"
     out = str(tmp_path / "temp.tga")
     with Image.open(test_file) as im:
@@ -190,7 +191,7 @@ def test_save_orientation(tmp_path):
         assert test_im.info["orientation"] == 1
 
 
-def test_horizontal_orientations():
+def test_horizontal_orientations() -> None:
     # These images have been manually hexedited to have the relevant orientations
     with Image.open("Tests/images/rgb32rle_top_right.tga") as im:
         assert im.load()[90, 90][:3] == (0, 0, 0)
@@ -199,7 +200,7 @@ def test_horizontal_orientations():
         assert im.load()[90, 90][:3] == (0, 255, 0)
 
 
-def test_save_rle(tmp_path):
+def test_save_rle(tmp_path: Path) -> None:
     test_file = "Tests/images/rgb32rle.tga"
     with Image.open(test_file) as im:
         assert im.info["compression"] == "tga_rle"
@@ -232,7 +233,7 @@ def test_save_rle(tmp_path):
         assert test_im.info["compression"] == "tga_rle"
 
 
-def test_save_l_transparency(tmp_path):
+def test_save_l_transparency(tmp_path: Path) -> None:
     # There are 559 transparent pixels in la.tga.
     num_transparent = 559
 

Tests/test_file_tiff.py

@@ -3,6 +3,9 @@ from __future__ import annotations
 import os
 import warnings
 from io import BytesIO
+from pathlib import Path
+from types import ModuleType
+from typing import Generator
 
 import pytest
 
@@ -19,6 +22,7 @@ from .helper import (
     is_win32,
 )
 
+ElementTree: ModuleType | None
 try:
     from defusedxml import ElementTree
 except ImportError:
@@ -26,7 +30,7 @@ except ImportError:
 
 
 class TestFileTiff:
-    def test_sanity(self, tmp_path):
+    def test_sanity(self, tmp_path: Path) -> None:
         filename = str(tmp_path / "temp.tif")
 
         hopper("RGB").save(filename)
@@ -58,21 +62,21 @@ class TestFileTiff:
             pass
 
     @pytest.mark.skipif(is_pypy(), reason="Requires CPython")
-    def test_unclosed_file(self):
+    def test_unclosed_file(self) -> None:
-        def open():
+        def open() -> None:
             im = Image.open("Tests/images/multipage.tiff")
             im.load()
 
         with pytest.warns(ResourceWarning):
             open()
 
-    def test_closed_file(self):
+    def test_closed_file(self) -> None:
         with warnings.catch_warnings():
             im = Image.open("Tests/images/multipage.tiff")
             im.load()
             im.close()
 
-    def test_seek_after_close(self):
+    def test_seek_after_close(self) -> None:
         im = Image.open("Tests/images/multipage.tiff")
         im.close()
 
@@ -81,12 +85,12 @@ class TestFileTiff:
         with pytest.raises(ValueError):
             im.seek(1)
 
-    def test_context_manager(self):
+    def test_context_manager(self) -> None:
         with warnings.catch_warnings():
             with Image.open("Tests/images/multipage.tiff") as im:
                 im.load()
 
-    def test_mac_tiff(self):
+    def test_mac_tiff(self) -> None:
         # Read RGBa images from macOS [@PIL136]
 
         filename = "Tests/images/pil136.tiff"
@@ -98,7 +102,7 @@ class TestFileTiff:
 
             assert_image_similar_tofile(im, "Tests/images/pil136.png", 1)
 
-    def test_bigtiff(self, tmp_path):
+    def test_bigtiff(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/hopper_bigtiff.tif") as im:
             assert_image_equal_tofile(im, "Tests/images/hopper.tif")
 
@@ -109,13 +113,13 @@ class TestFileTiff:
             outfile = str(tmp_path / "temp.tif")
             im.save(outfile, save_all=True, append_images=[im], tiffinfo=im.tag_v2)
 
-    def test_set_legacy_api(self):
+    def test_set_legacy_api(self) -> None:
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         with pytest.raises(Exception) as e:
             ifd.legacy_api = None
         assert str(e.value) == "Not allowing setting of legacy api"
 
-    def test_xyres_tiff(self):
+    def test_xyres_tiff(self) -> None:
         filename = "Tests/images/pil168.tif"
         with Image.open(filename) as im:
             # legacy api
@@ -128,7 +132,7 @@ class TestFileTiff:
 
             assert im.info["dpi"] == (72.0, 72.0)
 
-    def test_xyres_fallback_tiff(self):
+    def test_xyres_fallback_tiff(self) -> None:
         filename = "Tests/images/compression.tif"
         with Image.open(filename) as im:
             # v2 api
@@ -142,7 +146,7 @@ class TestFileTiff:
             # Fallback "inch".
             assert im.info["dpi"] == (100.0, 100.0)
 
-    def test_int_resolution(self):
+    def test_int_resolution(self) -> None:
         filename = "Tests/images/pil168.tif"
         with Image.open(filename) as im:
             # Try to read a file where X,Y_RESOLUTION are ints
@@ -155,14 +159,14 @@ class TestFileTiff:
         "resolution_unit, dpi",
         [(None, 72.8), (2, 72.8), (3, 184.912)],
     )
-    def test_load_float_dpi(self, resolution_unit, dpi):
+    def test_load_float_dpi(self, resolution_unit: int | None, dpi: float) -> None:
         with Image.open(
             "Tests/images/hopper_float_dpi_" + str(resolution_unit) + ".tif"
         ) as im:
             assert im.tag_v2.get(RESOLUTION_UNIT) == resolution_unit
             assert im.info["dpi"] == (dpi, dpi)
 
-    def test_save_float_dpi(self, tmp_path):
+    def test_save_float_dpi(self, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.tif")
         with Image.open("Tests/images/hopper.tif") as im:
             dpi = (72.2, 72.2)
@@ -171,7 +175,7 @@ class TestFileTiff:
             with Image.open(outfile) as reloaded:
                 assert reloaded.info["dpi"] == dpi
 
-    def test_save_setting_missing_resolution(self):
+    def test_save_setting_missing_resolution(self) -> None:
         b = BytesIO()
         with Image.open("Tests/images/10ct_32bit_128.tiff") as im:
             im.save(b, format="tiff", resolution=123.45)
@@ -179,7 +183,7 @@ class TestFileTiff:
             assert im.tag_v2[X_RESOLUTION] == 123.45
             assert im.tag_v2[Y_RESOLUTION] == 123.45
 
-    def test_invalid_file(self):
+    def test_invalid_file(self) -> None:
         invalid_file = "Tests/images/flower.jpg"
 
         with pytest.raises(SyntaxError):
@@ -190,30 +194,30 @@ class TestFileTiff:
             TiffImagePlugin.TiffImageFile(invalid_file)
         TiffImagePlugin.PREFIXES.pop()
 
-    def test_bad_exif(self):
+    def test_bad_exif(self) -> None:
         with Image.open("Tests/images/hopper_bad_exif.jpg") as i:
             # Should not raise struct.error.
             with pytest.warns(UserWarning):
                 i._getexif()
 
-    def test_save_rgba(self, tmp_path):
+    def test_save_rgba(self, tmp_path: Path) -> None:
         im = hopper("RGBA")
         outfile = str(tmp_path / "temp.tif")
         im.save(outfile)
 
-    def test_save_unsupported_mode(self, tmp_path):
+    def test_save_unsupported_mode(self, tmp_path: Path) -> None:
         im = hopper("HSV")
         outfile = str(tmp_path / "temp.tif")
         with pytest.raises(OSError):
             im.save(outfile)
 
-    def test_8bit_s(self):
+    def test_8bit_s(self) -> None:
         with Image.open("Tests/images/8bit.s.tif") as im:
             im.load()
             assert im.mode == "L"
             assert im.getpixel((50, 50)) == 184
 
-    def test_little_endian(self):
+    def test_little_endian(self) -> None:
         with Image.open("Tests/images/16bit.cropped.tif") as im:
             assert im.getpixel((0, 0)) == 480
             assert im.mode == "I;16"
@@ -223,7 +227,7 @@ class TestFileTiff:
         assert b[0] == ord(b"\xe0")
         assert b[1] == ord(b"\x01")
 
-    def test_big_endian(self):
+    def test_big_endian(self) -> None:
         with Image.open("Tests/images/16bit.MM.cropped.tif") as im:
             assert im.getpixel((0, 0)) == 480
             assert im.mode == "I;16B"
@@ -233,7 +237,7 @@ class TestFileTiff:
         assert b[0] == ord(b"\x01")
         assert b[1] == ord(b"\xe0")
 
-    def test_16bit_r(self):
+    def test_16bit_r(self) -> None:
         with Image.open("Tests/images/16bit.r.tif") as im:
             assert im.getpixel((0, 0)) == 480
             assert im.mode == "I;16"
@@ -242,14 +246,14 @@ class TestFileTiff:
         assert b[0] == ord(b"\xe0")
         assert b[1] == ord(b"\x01")
 
-    def test_16bit_s(self):
+    def test_16bit_s(self) -> None:
         with Image.open("Tests/images/16bit.s.tif") as im:
             im.load()
             assert im.mode == "I"
             assert im.getpixel((0, 0)) == 32767
             assert im.getpixel((0, 1)) == 0
 
-    def test_12bit_rawmode(self):
+    def test_12bit_rawmode(self) -> None:
         """Are we generating the same interpretation
         of the image as Imagemagick is?"""
 
@@ -262,7 +266,7 @@ class TestFileTiff:
 
             assert_image_equal_tofile(im, "Tests/images/12in16bit.tif")
 
-    def test_32bit_float(self):
+    def test_32bit_float(self) -> None:
         # Issue 614, specific 32-bit float format
         path = "Tests/images/10ct_32bit_128.tiff"
         with Image.open(path) as im:
@@ -271,7 +275,7 @@ class TestFileTiff:
             assert im.getpixel((0, 0)) == -0.4526388943195343
             assert im.getextrema() == (-3.140936851501465, 3.140684127807617)
 
-    def test_unknown_pixel_mode(self):
+    def test_unknown_pixel_mode(self) -> None:
         with pytest.raises(OSError):
             with Image.open("Tests/images/hopper_unknown_pixel_mode.tif"):
                 pass
@@ -283,12 +287,12 @@ class TestFileTiff:
             ("Tests/images/multipage.tiff", 3),
         ),
     )
-    def test_n_frames(self, path, n_frames):
+    def test_n_frames(self, path: str, n_frames: int) -> None:
         with Image.open(path) as im:
             assert im.n_frames == n_frames
             assert im.is_animated == (n_frames != 1)
 
-    def test_eoferror(self):
+    def test_eoferror(self) -> None:
         with Image.open("Tests/images/multipage-lastframe.tif") as im:
             n_frames = im.n_frames
 
@@ -300,7 +304,7 @@ class TestFileTiff:
             # Test that seeking to the last frame does not raise an error
             im.seek(n_frames - 1)
 
-    def test_multipage(self):
+    def test_multipage(self) -> None:
         # issue #862
         with Image.open("Tests/images/multipage.tiff") as im:
             # file is a multipage tiff: 10x10 green, 10x10 red, 20x20 blue
@@ -324,13 +328,13 @@ class TestFileTiff:
             assert im.size == (20, 20)
             assert im.convert("RGB").getpixel((0, 0)) == (0, 0, 255)
 
-    def test_multipage_last_frame(self):
+    def test_multipage_last_frame(self) -> None:
         with Image.open("Tests/images/multipage-lastframe.tif") as im:
             im.load()
             assert im.size == (20, 20)
             assert im.convert("RGB").getpixel((0, 0)) == (0, 0, 255)
 
-    def test_frame_order(self):
+    def test_frame_order(self) -> None:
         # A frame can't progress to itself after reading
         with Image.open("Tests/images/multipage_single_frame_loop.tiff") as im:
             assert im.n_frames == 1
@@ -343,7 +347,7 @@ class TestFileTiff:
         with Image.open("Tests/images/multipage_out_of_order.tiff") as im:
             assert im.n_frames == 3
 
-    def test___str__(self):
+    def test___str__(self) -> None:
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
             # Act
@@ -352,7 +356,7 @@ class TestFileTiff:
             # Assert
             assert isinstance(ret, str)
 
-    def test_dict(self):
+    def test_dict(self) -> None:
         # Arrange
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
@@ -392,7 +396,7 @@ class TestFileTiff:
             }
             assert dict(im.tag) == legacy_tags
 
-    def test__delitem__(self):
+    def test__delitem__(self) -> None:
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
             len_before = len(dict(im.ifd))
@@ -401,36 +405,36 @@ class TestFileTiff:
             assert len_before == len_after + 1
 
     @pytest.mark.parametrize("legacy_api", (False, True))
-    def test_load_byte(self, legacy_api):
+    def test_load_byte(self, legacy_api: bool) -> None:
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         data = b"abc"
         ret = ifd.load_byte(data, legacy_api)
         assert ret == b"abc"
 
-    def test_load_string(self):
+    def test_load_string(self) -> None:
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         data = b"abc\0"
         ret = ifd.load_string(data, False)
         assert ret == "abc"
 
-    def test_load_float(self):
+    def test_load_float(self) -> None:
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         data = b"abcdabcd"
         ret = ifd.load_float(data, False)
         assert ret == (1.6777999408082104e22, 1.6777999408082104e22)
 
-    def test_load_double(self):
+    def test_load_double(self) -> None:
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         data = b"abcdefghabcdefgh"
         ret = ifd.load_double(data, False)
         assert ret == (8.540883223036124e194, 8.540883223036124e194)
 
-    def test_ifd_tag_type(self):
+    def test_ifd_tag_type(self) -> None:
         with Image.open("Tests/images/ifd_tag_type.tiff") as im:
             assert 0x8825 in im.tag_v2
 
-    def test_exif(self, tmp_path):
+    def test_exif(self, tmp_path: Path) -> None:
-        def check_exif(exif):
+        def check_exif(exif: Image.Exif) -> None:
             assert sorted(exif.keys()) == [
                 256,
                 257,
@@ -481,7 +485,7 @@ class TestFileTiff:
             exif = im.getexif()
             check_exif(exif)
 
-    def test_modify_exif(self, tmp_path):
+    def test_modify_exif(self, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.tif")
         with Image.open("Tests/images/ifd_tag_type.tiff") as im:
             exif = im.getexif()
@@ -493,7 +497,7 @@ class TestFileTiff:
             exif = im.getexif()
             assert exif[264] == 100
 
-    def test_reload_exif_after_seek(self):
+    def test_reload_exif_after_seek(self) -> None:
         with Image.open("Tests/images/multipage.tiff") as im:
             exif = im.getexif()
             del exif[256]
@@ -501,7 +505,7 @@ class TestFileTiff:
 
             assert 256 in exif
 
-    def test_exif_frames(self):
+    def test_exif_frames(self) -> None:
         # Test that EXIF data can change across frames
         with Image.open("Tests/images/g4-multi.tiff") as im:
             assert im.getexif()[273] == (328, 815)
@@ -510,7 +514,7 @@ class TestFileTiff:
             assert im.getexif()[273] == (1408, 1907)
 
     @pytest.mark.parametrize("mode", ("1", "L"))
-    def test_photometric(self, mode, tmp_path):
+    def test_photometric(self, mode: str, tmp_path: Path) -> None:
         filename = str(tmp_path / "temp.tif")
         im = hopper(mode)
         im.save(filename, tiffinfo={262: 0})
@@ -518,13 +522,13 @@ class TestFileTiff:
             assert reloaded.tag_v2[262] == 0
             assert_image_equal(im, reloaded)
 
-    def test_seek(self):
+    def test_seek(self) -> None:
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
             im.seek(0)
             assert im.tell() == 0
 
-    def test_seek_eof(self):
+    def test_seek_eof(self) -> None:
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
             assert im.tell() == 0
@@ -533,21 +537,21 @@ class TestFileTiff:
             with pytest.raises(EOFError):
                 im.seek(1)
 
-    def test__limit_rational_int(self):
+    def test__limit_rational_int(self) -> None:
         from PIL.TiffImagePlugin import _limit_rational
 
         value = 34
         ret = _limit_rational(value, 65536)
         assert ret == (34, 1)
 
-    def test__limit_rational_float(self):
+    def test__limit_rational_float(self) -> None:
         from PIL.TiffImagePlugin import _limit_rational
 
         value = 22.3
         ret = _limit_rational(value, 65536)
         assert ret == (223, 10)
 
-    def test_4bit(self):
+    def test_4bit(self) -> None:
         test_file = "Tests/images/hopper_gray_4bpp.tif"
         original = hopper("L")
         with Image.open(test_file) as im:
@@ -555,7 +559,7 @@ class TestFileTiff:
             assert im.mode == "L"
             assert_image_similar(im, original, 7.3)
 
-    def test_gray_semibyte_per_pixel(self):
+    def test_gray_semibyte_per_pixel(self) -> None:
         test_files = (
             (
                 24.8,  # epsilon
@@ -588,7 +592,7 @@ class TestFileTiff:
                         assert im2.mode == "L"
                         assert_image_equal(im, im2)
 
-    def test_with_underscores(self, tmp_path):
+    def test_with_underscores(self, tmp_path: Path) -> None:
         kwargs = {"resolution_unit": "inch", "x_resolution": 72, "y_resolution": 36}
         filename = str(tmp_path / "temp.tif")
         hopper("RGB").save(filename, **kwargs)
@@ -601,7 +605,7 @@ class TestFileTiff:
             assert im.tag_v2[X_RESOLUTION] == 72
             assert im.tag_v2[Y_RESOLUTION] == 36
 
-    def test_roundtrip_tiff_uint16(self, tmp_path):
+    def test_roundtrip_tiff_uint16(self, tmp_path: Path) -> None:
         # Test an image of all '0' values
         pixel_value = 0x1234
         infile = "Tests/images/uint16_1_4660.tif"
@@ -613,7 +617,7 @@ class TestFileTiff:
 
             assert_image_equal_tofile(im, tmpfile)
 
-    def test_rowsperstrip(self, tmp_path):
+    def test_rowsperstrip(self, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.tif")
         im = hopper()
         im.save(outfile, tiffinfo={278: 256})
@@ -621,25 +625,25 @@ class TestFileTiff:
         with Image.open(outfile) as im:
             assert im.tag_v2[278] == 256
 
-    def test_strip_raw(self):
+    def test_strip_raw(self) -> None:
         infile = "Tests/images/tiff_strip_raw.tif"
         with Image.open(infile) as im:
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
 
-    def test_strip_planar_raw(self):
+    def test_strip_planar_raw(self) -> None:
         # gdal_translate -of GTiff -co INTERLEAVE=BAND \
         # tiff_strip_raw.tif tiff_strip_planar_raw.tiff
         infile = "Tests/images/tiff_strip_planar_raw.tif"
         with Image.open(infile) as im:
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
 
-    def test_strip_planar_raw_with_overviews(self):
+    def test_strip_planar_raw_with_overviews(self) -> None:
         # gdaladdo tiff_strip_planar_raw2.tif 2 4 8 16
         infile = "Tests/images/tiff_strip_planar_raw_with_overviews.tif"
         with Image.open(infile) as im:
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
 
-    def test_tiled_planar_raw(self):
+    def test_tiled_planar_raw(self) -> None:
         # gdal_translate -of GTiff -co TILED=YES -co BLOCKXSIZE=32 \
         # -co BLOCKYSIZE=32 -co INTERLEAVE=BAND \
         # tiff_tiled_raw.tif tiff_tiled_planar_raw.tiff
@@ -647,7 +651,7 @@ class TestFileTiff:
         with Image.open(infile) as im:
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
 
-    def test_planar_configuration_save(self, tmp_path):
+    def test_planar_configuration_save(self, tmp_path: Path) -> None:
         infile = "Tests/images/tiff_tiled_planar_raw.tif"
         with Image.open(infile) as im:
             assert im._planar_configuration == 2
@@ -659,7 +663,7 @@ class TestFileTiff:
                 assert_image_equal_tofile(reloaded, infile)
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
-    def test_palette(self, mode, tmp_path):
+    def test_palette(self, mode: str, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.tif")
 
         im = hopper(mode)
@@ -668,7 +672,7 @@ class TestFileTiff:
         with Image.open(outfile) as reloaded:
             assert_image_equal(im.convert("RGB"), reloaded.convert("RGB"))
 
-    def test_tiff_save_all(self):
+    def test_tiff_save_all(self) -> None:
         mp = BytesIO()
         with Image.open("Tests/images/multipage.tiff") as im:
             im.save(mp, format="tiff", save_all=True)
@@ -688,7 +692,7 @@ class TestFileTiff:
             assert reread.n_frames == 3
 
         # Test appending using a generator
-        def im_generator(ims):
+        def im_generator(ims: list[Image.Image]) -> Generator[Image.Image, None, None]:
             yield from ims
 
         mp = BytesIO()
@@ -698,7 +702,7 @@ class TestFileTiff:
         with Image.open(mp) as reread:
             assert reread.n_frames == 3
 
-    def test_saving_icc_profile(self, tmp_path):
+    def test_saving_icc_profile(self, tmp_path: Path) -> None:
         # Tests saving TIFF with icc_profile set.
         # At the time of writing this will only work for non-compressed tiffs
         # as libtiff does not support embedded ICC profiles,
@@ -712,7 +716,7 @@ class TestFileTiff:
         with Image.open(tmpfile) as reloaded:
             assert b"Dummy value" == reloaded.info["icc_profile"]
 
-    def test_save_icc_profile(self, tmp_path):
+    def test_save_icc_profile(self, tmp_path: Path) -> None:
         im = hopper()
         assert "icc_profile" not in im.info
 
@@ -723,14 +727,14 @@ class TestFileTiff:
         with Image.open(outfile) as reloaded:
             assert reloaded.info["icc_profile"] == icc_profile
 
-    def test_save_bmp_compression(self, tmp_path):
+    def test_save_bmp_compression(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/hopper.bmp") as im:
             assert im.info["compression"] == 0
 
             outfile = str(tmp_path / "temp.tif")
             im.save(outfile)
 
-    def test_discard_icc_profile(self, tmp_path):
+    def test_discard_icc_profile(self, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.tif")
 
         with Image.open("Tests/images/icc_profile.png") as im:
@@ -741,7 +745,7 @@ class TestFileTiff:
         with Image.open(outfile) as reloaded:
             assert "icc_profile" not in reloaded.info
 
-    def test_getxmp(self):
+    def test_getxmp(self) -> None:
         with Image.open("Tests/images/lab.tif") as im:
             if ElementTree is None:
                 with pytest.warns(
@@ -756,7 +760,7 @@ class TestFileTiff:
                 assert description[0]["format"] == "image/tiff"
                 assert description[3]["BitsPerSample"]["Seq"]["li"] == ["8", "8", "8"]
 
-    def test_get_photoshop_blocks(self):
+    def test_get_photoshop_blocks(self) -> None:
         with Image.open("Tests/images/lab.tif") as im:
             assert list(im.get_photoshop_blocks().keys()) == [
                 1061,
@@ -782,7 +786,7 @@ class TestFileTiff:
                 4001,
             ]
 
-    def test_tiff_chunks(self, tmp_path):
+    def test_tiff_chunks(self, tmp_path: Path) -> None:
         tmpfile = str(tmp_path / "temp.tif")
 
         im = hopper()
@@ -803,7 +807,7 @@ class TestFileTiff:
 
         assert_image_equal_tofile(im, tmpfile)
 
-    def test_close_on_load_exclusive(self, tmp_path):
+    def test_close_on_load_exclusive(self, tmp_path: Path) -> None:
         # similar to test_fd_leak, but runs on unixlike os
         tmpfile = str(tmp_path / "temp.tif")
 
@@ -816,7 +820,7 @@ class TestFileTiff:
         im.load()
         assert fp.closed
 
-    def test_close_on_load_nonexclusive(self, tmp_path):
+    def test_close_on_load_nonexclusive(self, tmp_path: Path) -> None:
         tmpfile = str(tmp_path / "temp.tif")
 
         with Image.open("Tests/images/uint16_1_4660.tif") as im:
@@ -838,7 +842,7 @@ class TestFileTiff:
         not os.path.exists("Tests/images/string_dimension.tiff"),
         reason="Extra image files not installed",
     )
-    def test_string_dimension(self):
+    def test_string_dimension(self) -> None:
         # Assert that an error is raised if one of the dimensions is a string
         with Image.open("Tests/images/string_dimension.tiff") as im:
             with pytest.raises(OSError):
@@ -846,7 +850,7 @@ class TestFileTiff:
 
     @pytest.mark.timeout(6)
     @pytest.mark.filterwarnings("ignore:Truncated File Read")
-    def test_timeout(self):
+    def test_timeout(self) -> None:
         with Image.open("Tests/images/timeout-6646305047838720") as im:
             ImageFile.LOAD_TRUNCATED_IMAGES = True
             im.load()
@@ -859,7 +863,7 @@ class TestFileTiff:
         ],
     )
     @pytest.mark.timeout(2)
-    def test_oom(self, test_file):
+    def test_oom(self, test_file: str) -> None:
         with pytest.raises(UnidentifiedImageError):
             with pytest.warns(UserWarning):
                 with Image.open(test_file):
@@ -868,7 +872,7 @@ class TestFileTiff:
 
 @pytest.mark.skipif(not is_win32(), reason="Windows only")
 class TestFileTiffW32:
-    def test_fd_leak(self, tmp_path):
+    def test_fd_leak(self, tmp_path: Path) -> None:
         tmpfile = str(tmp_path / "temp.tif")
 
         # this is an mmaped file.

Tests/test_file_tiff_metadata.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import io
 import struct
+from pathlib import Path
 
 import pytest
 
@@ -13,7 +14,7 @@ from .helper import assert_deep_equal, hopper
 TAG_IDS = {info.name: info.value for info in TiffTags.TAGS_V2.values()}
 
 
-def test_rt_metadata(tmp_path):
+def test_rt_metadata(tmp_path: Path) -> None:
     """Test writing arbitrary metadata into the tiff image directory
     Use case is ImageJ private tags, one numeric, one arbitrary
     data.  https://github.com/python-pillow/Pillow/issues/291
@@ -79,7 +80,7 @@ def test_rt_metadata(tmp_path):
         assert loaded.tag_v2[ImageJMetaDataByteCounts] == (8, len(bin_data) - 8)
 
 
-def test_read_metadata():
+def test_read_metadata() -> None:
     with Image.open("Tests/images/hopper_g4.tif") as img:
         assert {
             "YResolution": IFDRational(4294967295, 113653537),
@@ -120,7 +121,7 @@ def test_read_metadata():
         } == img.tag.named()
 
 
-def test_write_metadata(tmp_path):
+def test_write_metadata(tmp_path: Path) -> None:
     """Test metadata writing through the python code"""
     with Image.open("Tests/images/hopper.tif") as img:
         f = str(tmp_path / "temp.tiff")
@@ -157,7 +158,7 @@ def test_write_metadata(tmp_path):
             assert value == reloaded[tag], f"{tag} didn't roundtrip"
 
 
-def test_change_stripbytecounts_tag_type(tmp_path):
+def test_change_stripbytecounts_tag_type(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.tiff")
     with Image.open("Tests/images/hopper.tif") as im:
         info = im.tag_v2
@@ -176,19 +177,21 @@ def test_change_stripbytecounts_tag_type(tmp_path):
         assert reloaded.tag_v2.tagtype[TiffImagePlugin.STRIPBYTECOUNTS] == TiffTags.LONG
 
 
-def test_no_duplicate_50741_tag():
+def test_no_duplicate_50741_tag() -> None:
     assert TAG_IDS["MakerNoteSafety"] == 50741
     assert TAG_IDS["BestQualityScale"] == 50780
 
 
-def test_iptc(tmp_path):
+def test_iptc(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.tiff")
     with Image.open("Tests/images/hopper.Lab.tif") as im:
         im.save(out)
 
 
 @pytest.mark.parametrize("value, expected", ((b"test", "test"), (1, "1")))
-def test_writing_other_types_to_ascii(value, expected, tmp_path):
+def test_writing_other_types_to_ascii(
+    value: bytes | int, expected: str, tmp_path: Path
+) -> None:
     info = TiffImagePlugin.ImageFileDirectory_v2()
 
     tag = TiffTags.TAGS_V2[271]
@@ -205,7 +208,7 @@ def test_writing_other_types_to_ascii(value, expected, tmp_path):
 
 
 @pytest.mark.parametrize("value", (1, IFDRational(1)))
-def test_writing_other_types_to_bytes(value, tmp_path):
+def test_writing_other_types_to_bytes(value: int | IFDRational, tmp_path: Path) -> None:
     im = hopper()
     info = TiffImagePlugin.ImageFileDirectory_v2()
 
@@ -221,7 +224,7 @@ def test_writing_other_types_to_bytes(value, tmp_path):
         assert reloaded.tag_v2[700] == b"\x01"
 
 
-def test_writing_other_types_to_undefined(tmp_path):
+def test_writing_other_types_to_undefined(tmp_path: Path) -> None:
     im = hopper()
     info = TiffImagePlugin.ImageFileDirectory_v2()
 
@@ -237,7 +240,7 @@ def test_writing_other_types_to_undefined(tmp_path):
         assert reloaded.tag_v2[33723] == b"1"
 
 
-def test_undefined_zero(tmp_path):
+def test_undefined_zero(tmp_path: Path) -> None:
     # Check that the tag has not been changed since this test was created
     tag = TiffTags.TAGS_V2[45059]
     assert tag.type == TiffTags.UNDEFINED
@@ -252,7 +255,7 @@ def test_undefined_zero(tmp_path):
     assert info[45059] == original
 
 
-def test_empty_metadata():
+def test_empty_metadata() -> None:
     f = io.BytesIO(b"II*\x00\x08\x00\x00\x00")
     head = f.read(8)
     info = TiffImagePlugin.ImageFileDirectory(head)
@@ -261,7 +264,7 @@ def test_empty_metadata():
         info.load(f)
 
 
-def test_iccprofile(tmp_path):
+def test_iccprofile(tmp_path: Path) -> None:
     # https://github.com/python-pillow/Pillow/issues/1462
     out = str(tmp_path / "temp.tiff")
     with Image.open("Tests/images/hopper.iccprofile.tif") as im:
@@ -272,7 +275,7 @@ def test_iccprofile(tmp_path):
         assert im.info["icc_profile"] == reloaded.info["icc_profile"]
 
 
-def test_iccprofile_binary():
+def test_iccprofile_binary() -> None:
     # https://github.com/python-pillow/Pillow/issues/1526
     # We should be able to load this,
     # but probably won't be able to save it.
@@ -282,19 +285,19 @@ def test_iccprofile_binary():
         assert im.info["icc_profile"]
 
 
-def test_iccprofile_save_png(tmp_path):
+def test_iccprofile_save_png(tmp_path: Path) -> None:
     with Image.open("Tests/images/hopper.iccprofile.tif") as im:
         outfile = str(tmp_path / "temp.png")
         im.save(outfile)
 
 
-def test_iccprofile_binary_save_png(tmp_path):
+def test_iccprofile_binary_save_png(tmp_path: Path) -> None:
     with Image.open("Tests/images/hopper.iccprofile_binary.tif") as im:
         outfile = str(tmp_path / "temp.png")
         im.save(outfile)
 
 
-def test_exif_div_zero(tmp_path):
+def test_exif_div_zero(tmp_path: Path) -> None:
     im = hopper()
     info = TiffImagePlugin.ImageFileDirectory_v2()
     info[41988] = TiffImagePlugin.IFDRational(0, 0)
@@ -307,7 +310,7 @@ def test_exif_div_zero(tmp_path):
         assert 0 == reloaded.tag_v2[41988].denominator
 
 
-def test_ifd_unsigned_rational(tmp_path):
+def test_ifd_unsigned_rational(tmp_path: Path) -> None:
     im = hopper()
     info = TiffImagePlugin.ImageFileDirectory_v2()
 
@@ -338,7 +341,7 @@ def test_ifd_unsigned_rational(tmp_path):
         assert 1 == reloaded.tag_v2[41493].denominator
 
 
-def test_ifd_signed_rational(tmp_path):
+def test_ifd_signed_rational(tmp_path: Path) -> None:
     im = hopper()
     info = TiffImagePlugin.ImageFileDirectory_v2()
 
@@ -381,7 +384,7 @@ def test_ifd_signed_rational(tmp_path):
         assert -1 == reloaded.tag_v2[37380].denominator
 
 
-def test_ifd_signed_long(tmp_path):
+def test_ifd_signed_long(tmp_path: Path) -> None:
     im = hopper()
     info = TiffImagePlugin.ImageFileDirectory_v2()
 
@@ -394,7 +397,7 @@ def test_ifd_signed_long(tmp_path):
         assert reloaded.tag_v2[37000] == -60000
 
 
-def test_empty_values():
+def test_empty_values() -> None:
     data = io.BytesIO(
         b"II*\x00\x08\x00\x00\x00\x03\x00\x1a\x01\x05\x00\x00\x00\x00\x00"
         b"\x00\x00\x00\x00\x1b\x01\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00"
@@ -409,7 +412,7 @@ def test_empty_values():
     assert 33432 in info
 
 
-def test_photoshop_info(tmp_path):
+def test_photoshop_info(tmp_path: Path) -> None:
     with Image.open("Tests/images/issue_2278.tif") as im:
         assert len(im.tag_v2[34377]) == 70
         assert isinstance(im.tag_v2[34377], bytes)
@@ -420,7 +423,7 @@ def test_photoshop_info(tmp_path):
         assert isinstance(reloaded.tag_v2[34377], bytes)
 
 
-def test_too_many_entries():
+def test_too_many_entries() -> None:
     ifd = TiffImagePlugin.ImageFileDirectory_v2()
 
     #    277: ("SamplesPerPixel", SHORT, 1),
@@ -432,7 +435,7 @@ def test_too_many_entries():
         assert ifd[277] == 4
 
 
-def test_tag_group_data():
+def test_tag_group_data() -> None:
     base_ifd = TiffImagePlugin.ImageFileDirectory_v2()
     interop_ifd = TiffImagePlugin.ImageFileDirectory_v2(group=40965)
     for ifd in (base_ifd, interop_ifd):
@@ -446,7 +449,7 @@ def test_tag_group_data():
     assert base_ifd.tagtype[2] != interop_ifd.tagtype[256]
 
 
-def test_empty_subifd(tmp_path):
+def test_empty_subifd(tmp_path: Path) -> None:
     out = str(tmp_path / "temp.jpg")
 
     im = hopper()

Tests/test_file_wal.py

@@ -7,7 +7,7 @@ from .helper import assert_image_equal_tofile
 TEST_FILE = "Tests/images/hopper.wal"
 
 
-def test_open():
+def test_open() -> None:
     with WalImageFile.open(TEST_FILE) as im:
         assert im.format == "WAL"
         assert im.format_description == "Quake2 Texture"
@@ -19,7 +19,7 @@ def test_open():
         assert_image_equal_tofile(im, "Tests/images/hopper_wal.png")
 
 
-def test_load():
+def test_load() -> None:
     with WalImageFile.open(TEST_FILE) as im:
         assert im.load()[0, 0] == 122
 

Tests/test_file_webp.py

@@ -4,6 +4,7 @@ import io
 import re
 import sys
 import warnings
+from pathlib import Path
 
 import pytest
 
@@ -26,7 +27,7 @@ except ImportError:
 
 
 class TestUnsupportedWebp:
-    def test_unsupported(self):
+    def test_unsupported(self) -> None:
         if HAVE_WEBP:
             WebPImagePlugin.SUPPORTED = False
 
@@ -42,15 +43,15 @@ class TestUnsupportedWebp:
 
 @skip_unless_feature("webp")
 class TestFileWebp:
-    def setup_method(self):
+    def setup_method(self) -> None:
         self.rgb_mode = "RGB"
 
-    def test_version(self):
+    def test_version(self) -> None:
         _webp.WebPDecoderVersion()
         _webp.WebPDecoderBuggyAlpha()
         assert re.search(r"\d+\.\d+\.\d+$", features.version_module("webp"))
 
-    def test_read_rgb(self):
+    def test_read_rgb(self) -> None:
         """
         Can we read a RGB mode WebP file without error?
         Does it have the bits we expect?
@@ -67,7 +68,7 @@ class TestFileWebp:
             # dwebp -ppm ../../Tests/images/hopper.webp -o hopper_webp_bits.ppm
             assert_image_similar_tofile(image, "Tests/images/hopper_webp_bits.ppm", 1.0)
 
-    def _roundtrip(self, tmp_path, mode, epsilon, args={}):
+    def _roundtrip(self, tmp_path: Path, mode, epsilon, args={}) -> None:
         temp_file = str(tmp_path / "temp.webp")
 
         hopper(mode).save(temp_file, **args)
@@ -93,7 +94,7 @@ class TestFileWebp:
                 target = target.convert(self.rgb_mode)
             assert_image_similar(image, target, epsilon)
 
-    def test_write_rgb(self, tmp_path):
+    def test_write_rgb(self, tmp_path: Path) -> None:
         """
         Can we write a RGB mode file to webp without error?
         Does it have the bits we expect?
@@ -101,7 +102,7 @@ class TestFileWebp:
 
         self._roundtrip(tmp_path, self.rgb_mode, 12.5)
 
-    def test_write_method(self, tmp_path):
+    def test_write_method(self, tmp_path: Path) -> None:
         self._roundtrip(tmp_path, self.rgb_mode, 12.0, {"method": 6})
 
         buffer_no_args = io.BytesIO()
@@ -112,7 +113,7 @@ class TestFileWebp:
         assert buffer_no_args.getbuffer() != buffer_method.getbuffer()
 
     @skip_unless_feature("webp_anim")
-    def test_save_all(self, tmp_path):
+    def test_save_all(self, tmp_path: Path) -> None:
         temp_file = str(tmp_path / "temp.webp")
         im = Image.new("RGB", (1, 1))
         im2 = Image.new("RGB", (1, 1), "#f00")
@@ -124,14 +125,14 @@ class TestFileWebp:
             reloaded.seek(1)
             assert_image_similar(im2, reloaded, 1)
 
-    def test_icc_profile(self, tmp_path):
+    def test_icc_profile(self, tmp_path: Path) -> None:
         self._roundtrip(tmp_path, self.rgb_mode, 12.5, {"icc_profile": None})
         if _webp.HAVE_WEBPANIM:
             self._roundtrip(
                 tmp_path, self.rgb_mode, 12.5, {"icc_profile": None, "save_all": True}
             )
 
-    def test_write_unsupported_mode_L(self, tmp_path):
+    def test_write_unsupported_mode_L(self, tmp_path: Path) -> None:
         """
         Saving a black-and-white file to WebP format should work, and be
         similar to the original file.
@@ -139,7 +140,7 @@ class TestFileWebp:
 
         self._roundtrip(tmp_path, "L", 10.0)
 
-    def test_write_unsupported_mode_P(self, tmp_path):
+    def test_write_unsupported_mode_P(self, tmp_path: Path) -> None:
         """
         Saving a palette-based file to WebP format should work, and be
         similar to the original file.
@@ -148,14 +149,14 @@ class TestFileWebp:
         self._roundtrip(tmp_path, "P", 50.0)
 
     @pytest.mark.skipif(sys.maxsize <= 2**32, reason="Requires 64-bit system")
-    def test_write_encoding_error_message(self, tmp_path):
+    def test_write_encoding_error_message(self, tmp_path: Path) -> None:
         temp_file = str(tmp_path / "temp.webp")
         im = Image.new("RGB", (15000, 15000))
         with pytest.raises(ValueError) as e:
             im.save(temp_file, method=0)
         assert str(e.value) == "encoding error 6"
 
-    def test_WebPEncode_with_invalid_args(self):
+    def test_WebPEncode_with_invalid_args(self) -> None:
         """
         Calling encoder functions with no arguments should result in an error.
         """
@@ -166,7 +167,7 @@ class TestFileWebp:
         with pytest.raises(TypeError):
             _webp.WebPEncode()
 
-    def test_WebPDecode_with_invalid_args(self):
+    def test_WebPDecode_with_invalid_args(self) -> None:
         """
         Calling decoder functions with no arguments should result in an error.
         """
@@ -177,14 +178,14 @@ class TestFileWebp:
         with pytest.raises(TypeError):
             _webp.WebPDecode()
 
-    def test_no_resource_warning(self, tmp_path):
+    def test_no_resource_warning(self, tmp_path: Path) -> None:
         file_path = "Tests/images/hopper.webp"
         with Image.open(file_path) as image:
             temp_file = str(tmp_path / "temp.webp")
             with warnings.catch_warnings():
                 image.save(temp_file)
 
-    def test_file_pointer_could_be_reused(self):
+    def test_file_pointer_could_be_reused(self) -> None:
         file_path = "Tests/images/hopper.webp"
         with open(file_path, "rb") as blob:
             Image.open(blob).load()
@@ -195,14 +196,14 @@ class TestFileWebp:
         (0, (0,), (-1, 0, 1, 2), (253, 254, 255, 256)),
     )
     @skip_unless_feature("webp_anim")
-    def test_invalid_background(self, background, tmp_path):
+    def test_invalid_background(self, background, tmp_path: Path) -> None:
         temp_file = str(tmp_path / "temp.webp")
         im = hopper()
         with pytest.raises(OSError):
             im.save(temp_file, save_all=True, append_images=[im], background=background)
 
     @skip_unless_feature("webp_anim")
-    def test_background_from_gif(self, tmp_path):
+    def test_background_from_gif(self, tmp_path: Path) -> None:
         # Save L mode GIF with background
         with Image.open("Tests/images/no_palette_with_background.gif") as im:
             out_webp = str(tmp_path / "temp.webp")
@@ -227,7 +228,7 @@ class TestFileWebp:
         assert difference < 5
 
     @skip_unless_feature("webp_anim")
-    def test_duration(self, tmp_path):
+    def test_duration(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/dispose_bgnd.gif") as im:
             assert im.info["duration"] == 1000
 
@@ -238,7 +239,7 @@ class TestFileWebp:
             reloaded.load()
             assert reloaded.info["duration"] == 1000
 
-    def test_roundtrip_rgba_palette(self, tmp_path):
+    def test_roundtrip_rgba_palette(self, tmp_path: Path) -> None:
         temp_file = str(tmp_path / "temp.webp")
         im = Image.new("RGBA", (1, 1)).convert("P")
         assert im.mode == "P"

Tests/test_file_webp_alpha.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 
 from PIL import Image
@@ -14,12 +16,12 @@ from .helper import (
 _webp = pytest.importorskip("PIL._webp", reason="WebP support not installed")
 
 
-def setup_module():
+def setup_module() -> None:
     if _webp.WebPDecoderBuggyAlpha():
         pytest.skip("Buggy early version of WebP installed, not testing transparency")
 
 
-def test_read_rgba():
+def test_read_rgba() -> None:
     """
     Can we read an RGBA mode file without error?
     Does it have the bits we expect?
@@ -39,7 +41,7 @@ def test_read_rgba():
         assert_image_similar_tofile(image, "Tests/images/transparent.png", 20.0)
 
 
-def test_write_lossless_rgb(tmp_path):
+def test_write_lossless_rgb(tmp_path: Path) -> None:
     """
     Can we write an RGBA mode file with lossless compression without error?
     Does it have the bits we expect?
@@ -68,7 +70,7 @@ def test_write_lossless_rgb(tmp_path):
         assert_image_equal(image, pil_image)
 
 
-def test_write_rgba(tmp_path):
+def test_write_rgba(tmp_path: Path) -> None:
     """
     Can we write a RGBA mode file to WebP without error.
     Does it have the bits we expect?
@@ -99,7 +101,7 @@ def test_write_rgba(tmp_path):
             assert_image_similar(image, pil_image, 1.0)
 
 
-def test_keep_rgb_values_when_transparent(tmp_path):
+def test_keep_rgb_values_when_transparent(tmp_path: Path) -> None:
     """
     Saving transparent pixels should retain their original RGB values
     when using the "exact" parameter.
@@ -128,7 +130,7 @@ def test_keep_rgb_values_when_transparent(tmp_path):
         assert_image_equal(reloaded.convert("RGB"), image)
 
 
-def test_write_unsupported_mode_PA(tmp_path):
+def test_write_unsupported_mode_PA(tmp_path: Path) -> None:
     """
     Saving a palette-based file with transparency to WebP format
     should work, and be similar to the original file.

Tests/test_file_webp_animated.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 from packaging.version import parse as parse_version
 
@@ -18,7 +20,7 @@ pytestmark = [
 ]
 
 
-def test_n_frames():
+def test_n_frames() -> None:
     """Ensure that WebP format sets n_frames and is_animated attributes correctly."""
 
     with Image.open("Tests/images/hopper.webp") as im:
@@ -30,7 +32,7 @@ def test_n_frames():
         assert im.is_animated
 
 
-def test_write_animation_L(tmp_path):
+def test_write_animation_L(tmp_path: Path) -> None:
     """
     Convert an animated GIF to animated WebP, then compare the frame count, and first
     and last frames to ensure they're visually similar.
@@ -60,13 +62,13 @@ def test_write_animation_L(tmp_path):
             assert_image_similar(im, orig.convert("RGBA"), 32.9)
 
 
-def test_write_animation_RGB(tmp_path):
+def test_write_animation_RGB(tmp_path: Path) -> None:
     """
     Write an animated WebP from RGB frames, and ensure the frames
     are visually similar to the originals.
     """
 
-    def check(temp_file):
+    def check(temp_file) -> None:
         with Image.open(temp_file) as im:
             assert im.n_frames == 2
 
@@ -105,7 +107,7 @@ def test_write_animation_RGB(tmp_path):
             check(temp_file2)
 
 
-def test_timestamp_and_duration(tmp_path):
+def test_timestamp_and_duration(tmp_path: Path) -> None:
     """
     Try passing a list of durations, and make sure the encoded
     timestamps and durations are correct.
@@ -136,7 +138,7 @@ def test_timestamp_and_duration(tmp_path):
             ts += durations[frame]
 
 
-def test_float_duration(tmp_path):
+def test_float_duration(tmp_path: Path) -> None:
     temp_file = str(tmp_path / "temp.webp")
     with Image.open("Tests/images/iss634.apng") as im:
         assert im.info["duration"] == 70.0
@@ -148,7 +150,7 @@ def test_float_duration(tmp_path):
         assert reloaded.info["duration"] == 70
 
 
-def test_seeking(tmp_path):
+def test_seeking(tmp_path: Path) -> None:
     """
     Create an animated WebP file, and then try seeking through frames in reverse-order,
     verifying the timestamps and durations are correct.
@@ -179,7 +181,7 @@ def test_seeking(tmp_path):
             ts -= dur
 
 
-def test_seek_errors():
+def test_seek_errors() -> None:
     with Image.open("Tests/images/iss634.webp") as im:
         with pytest.raises(EOFError):
             im.seek(-1)

Tests/test_file_webp_lossless.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 
 from PIL import Image
@@ -10,7 +12,7 @@ _webp = pytest.importorskip("PIL._webp", reason="WebP support not installed")
 RGB_MODE = "RGB"
 
 
-def test_write_lossless_rgb(tmp_path):
+def test_write_lossless_rgb(tmp_path: Path) -> None:
     if _webp.WebPDecoderVersion() < 0x0200:
         pytest.skip("lossless not included")
 

Tests/test_file_webp_metadata.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
 from io import BytesIO
+from pathlib import Path
+from types import ModuleType
 
 import pytest
 
@@ -13,13 +15,14 @@ pytestmark = [
     skip_unless_feature("webp_mux"),
 ]
 
+ElementTree: ModuleType | None
 try:
     from defusedxml import ElementTree
 except ImportError:
     ElementTree = None
 
 
-def test_read_exif_metadata():
+def test_read_exif_metadata() -> None:
     file_path = "Tests/images/flower.webp"
     with Image.open(file_path) as image:
         assert image.format == "WEBP"
@@ -37,7 +40,7 @@ def test_read_exif_metadata():
             assert exif_data == expected_exif
 
 
-def test_read_exif_metadata_without_prefix():
+def test_read_exif_metadata_without_prefix() -> None:
     with Image.open("Tests/images/flower2.webp") as im:
         # Assert prefix is not present
         assert im.info["exif"][:6] != b"Exif\x00\x00"
@@ -49,7 +52,7 @@ def test_read_exif_metadata_without_prefix():
 @mark_if_feature_version(
     pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
 )
-def test_write_exif_metadata():
+def test_write_exif_metadata() -> None:
     file_path = "Tests/images/flower.jpg"
     test_buffer = BytesIO()
     with Image.open(file_path) as image:
@@ -63,7 +66,7 @@ def test_write_exif_metadata():
     assert webp_exif == expected_exif[6:], "WebP EXIF didn't match"
 
 
-def test_read_icc_profile():
+def test_read_icc_profile() -> None:
     file_path = "Tests/images/flower2.webp"
     with Image.open(file_path) as image:
         assert image.format == "WEBP"
@@ -80,7 +83,7 @@ def test_read_icc_profile():
 @mark_if_feature_version(
     pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
 )
-def test_write_icc_metadata():
+def test_write_icc_metadata() -> None:
     file_path = "Tests/images/flower2.jpg"
     test_buffer = BytesIO()
     with Image.open(file_path) as image:
@@ -100,7 +103,7 @@ def test_write_icc_metadata():
 @mark_if_feature_version(
     pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
 )
-def test_read_no_exif():
+def test_read_no_exif() -> None:
     file_path = "Tests/images/flower.jpg"
     test_buffer = BytesIO()
     with Image.open(file_path) as image:
@@ -113,7 +116,7 @@ def test_read_no_exif():
         assert not webp_image._getexif()
 
 
-def test_getxmp():
+def test_getxmp() -> None:
     with Image.open("Tests/images/flower.webp") as im:
         assert "xmp" not in im.info
         assert im.getxmp() == {}
@@ -133,7 +136,7 @@ def test_getxmp():
 
 
 @skip_unless_feature("webp_anim")
-def test_write_animated_metadata(tmp_path):
+def test_write_animated_metadata(tmp_path: Path) -> None:
     iccp_data = b"<iccp_data>"
     exif_data = b"<exif_data>"
     xmp_data = b"<xmp_data>"

Tests/test_file_wmf.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 
 from PIL import Image, WmfImagePlugin
@@ -7,7 +9,7 @@ from PIL import Image, WmfImagePlugin
 from .helper import assert_image_similar_tofile, hopper
 
 
-def test_load_raw():
+def test_load_raw() -> None:
     # Test basic EMF open and rendering
     with Image.open("Tests/images/drawing.emf") as im:
         if hasattr(Image.core, "drawwmf"):
@@ -25,17 +27,17 @@ def test_load_raw():
             assert_image_similar_tofile(im, "Tests/images/drawing_wmf_ref.png", 2.0)
 
 
-def test_load():
+def test_load() -> None:
     with Image.open("Tests/images/drawing.emf") as im:
         if hasattr(Image.core, "drawwmf"):
             assert im.load()[0, 0] == (255, 255, 255)
 
 
-def test_register_handler(tmp_path):
+def test_register_handler(tmp_path: Path) -> None:
     class TestHandler:
         methodCalled = False
 
-        def save(self, im, fp, filename):
+        def save(self, im, fp, filename) -> None:
             self.methodCalled = True
 
     handler = TestHandler()
@@ -51,12 +53,12 @@ def test_register_handler(tmp_path):
     WmfImagePlugin.register_handler(original_handler)
 
 
-def test_load_float_dpi():
+def test_load_float_dpi() -> None:
     with Image.open("Tests/images/drawing.emf") as im:
         assert im.info["dpi"] == 1423.7668161434979
 
 
-def test_load_set_dpi():
+def test_load_set_dpi() -> None:
     with Image.open("Tests/images/drawing.wmf") as im:
         assert im.size == (82, 82)
 
@@ -68,7 +70,7 @@ def test_load_set_dpi():
 
 
 @pytest.mark.parametrize("ext", (".wmf", ".emf"))
-def test_save(ext, tmp_path):
+def test_save(ext, tmp_path: Path) -> None:
     im = hopper()
 
     tmpfile = str(tmp_path / ("temp" + ext))

Tests/test_file_xbm.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from io import BytesIO
+from pathlib import Path
 
 import pytest
 
@@ -32,14 +33,14 @@ static char basic_bits[] = {
 """
 
 
-def test_pil151():
+def test_pil151() -> None:
     with Image.open(BytesIO(PIL151)) as im:
         im.load()
         assert im.mode == "1"
         assert im.size == (32, 32)
 
 
-def test_open():
+def test_open() -> None:
     # Arrange
     # Created with `convert hopper.png hopper.xbm`
     filename = "Tests/images/hopper.xbm"
@@ -51,7 +52,7 @@ def test_open():
         assert im.size == (128, 128)
 
 
-def test_open_filename_with_underscore():
+def test_open_filename_with_underscore() -> None:
     # Arrange
     # Created with `convert hopper.png hopper_underscore.xbm`
     filename = "Tests/images/hopper_underscore.xbm"
@@ -63,14 +64,14 @@ def test_open_filename_with_underscore():
         assert im.size == (128, 128)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         XbmImagePlugin.XbmImageFile(invalid_file)
 
 
-def test_save_wrong_mode(tmp_path):
+def test_save_wrong_mode(tmp_path: Path) -> None:
     im = hopper()
     out = str(tmp_path / "temp.xbm")
 
@@ -78,7 +79,7 @@ def test_save_wrong_mode(tmp_path):
         im.save(out)
 
 
-def test_hotspot(tmp_path):
+def test_hotspot(tmp_path: Path) -> None:
     im = hopper("1")
     out = str(tmp_path / "temp.xbm")
 

Tests/test_file_xpm.py

@@ -9,7 +9,7 @@ from .helper import assert_image_similar, hopper
 TEST_FILE = "Tests/images/hopper.xpm"
 
 
-def test_sanity():
+def test_sanity() -> None:
     with Image.open(TEST_FILE) as im:
         im.load()
         assert im.mode == "P"
@@ -20,14 +20,14 @@ def test_sanity():
         assert_image_similar(im.convert("RGB"), hopper("RGB"), 60)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     invalid_file = "Tests/images/flower.jpg"
 
     with pytest.raises(SyntaxError):
         XpmImagePlugin.XpmImageFile(invalid_file)
 
 
-def test_load_read():
+def test_load_read() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         dummy_bytes = 1

Tests/test_file_xvthumb.py

@@ -9,7 +9,7 @@ from .helper import assert_image_similar, hopper
 TEST_FILE = "Tests/images/hopper.p7"
 
 
-def test_open():
+def test_open() -> None:
     # Act
     with Image.open(TEST_FILE) as im:
         # Assert
@@ -20,7 +20,7 @@ def test_open():
         assert_image_similar(im, im_hopper, 9)
 
 
-def test_unexpected_eof():
+def test_unexpected_eof() -> None:
     # Test unexpected EOF reading XV thumbnail file
     # Arrange
     bad_file = "Tests/images/hopper_bad.p7"
@@ -30,7 +30,7 @@ def test_unexpected_eof():
         XVThumbImagePlugin.XVThumbImageFile(bad_file)
 
 
-def test_invalid_file():
+def test_invalid_file() -> None:
     # Arrange
     invalid_file = "Tests/images/flower.jpg"
 

Tests/test_fontfile.py

@@ -1,11 +1,13 @@
 from __future__ import annotations
 
+from pathlib import Path
+
 import pytest
 
 from PIL import FontFile
 
 
-def test_save(tmp_path):
+def test_save(tmp_path: Path) -> None:
     tempname = str(tmp_path / "temp.pil")
 
     font = FontFile.FontFile()

Tests/test_format_hsv.py

@@ -2,30 +2,27 @@ from __future__ import annotations
 
 import colorsys
 import itertools
+from typing import Callable
 
 from PIL import Image
 
 from .helper import assert_image_similar, hopper
 
 
-def int_to_float(i):
+def int_to_float(i: int) -> float:
     return i / 255
 
 
-def str_to_float(i):
+def tuple_to_ints(tp: tuple[float, float, float]) -> tuple[int, int, int]:
-    return ord(i) / 255
-
-
-def tuple_to_ints(tp):
     x, y, z = tp
     return int(x * 255.0), int(y * 255.0), int(z * 255.0)
 
 
-def test_sanity():
+def test_sanity() -> None:
     Image.new("HSV", (100, 100))
 
 
-def wedge():
+def wedge() -> Image.Image:
     w = Image._wedge()
     w90 = w.rotate(90)
 
@@ -49,7 +46,11 @@ def wedge():
     return img
 
 
-def to_xxx_colorsys(im, func, mode):
+def to_xxx_colorsys(
+    im: Image.Image,
+    func: Callable[[float, float, float], tuple[float, float, float]],
+    mode: str,
+) -> Image.Image:
     # convert the hard way using the library colorsys routines.
 
     (r, g, b) = im.split()
@@ -70,15 +71,15 @@ def to_xxx_colorsys(im, func, mode):
     return hsv
 
 
-def to_hsv_colorsys(im):
+def to_hsv_colorsys(im: Image.Image) -> Image.Image:
     return to_xxx_colorsys(im, colorsys.rgb_to_hsv, "HSV")
 
 
-def to_rgb_colorsys(im):
+def to_rgb_colorsys(im: Image.Image) -> Image.Image:
     return to_xxx_colorsys(im, colorsys.hsv_to_rgb, "RGB")
 
 
-def test_wedge():
+def test_wedge() -> None:
     src = wedge().resize((3 * 32, 32), Image.Resampling.BILINEAR)
     im = src.convert("HSV")
     comparable = to_hsv_colorsys(src)
@@ -110,7 +111,7 @@ def test_wedge():
     )
 
 
-def test_convert():
+def test_convert() -> None:
     im = hopper("RGB").convert("HSV")
     comparable = to_hsv_colorsys(hopper("RGB"))
 
@@ -128,7 +129,7 @@ def test_convert():
     )
 
 
-def test_hsv_to_rgb():
+def test_hsv_to_rgb() -> None:
     comparable = to_hsv_colorsys(hopper("RGB"))
     converted = comparable.convert("RGB")
     comparable = to_rgb_colorsys(comparable)

Tests/test_format_lab.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 from PIL import Image
 
 
-def test_white():
+def test_white() -> None:
     with Image.open("Tests/images/lab.tif") as i:
         i.load()
 
@@ -24,7 +24,7 @@ def test_white():
     assert list(b) == [128] * 100
 
 
-def test_green():
+def test_green() -> None:
     # l= 50 (/100), a = -100 (-128 .. 128) b=0 in PS
     # == RGB: 0, 152, 117
     with Image.open("Tests/images/lab-green.tif") as i:
@@ -32,7 +32,7 @@ def test_green():
     assert k == (128, 28, 128)
 
 
-def test_red():
+def test_red() -> None:
     # l= 50 (/100), a = 100 (-128 .. 128) b=0 in PS
     # == RGB: 255, 0, 124
     with Image.open("Tests/images/lab-red.tif") as i:

Tests/test_image.py

@@ -7,6 +7,8 @@ import shutil
 import sys
 import tempfile
 import warnings
+from pathlib import Path
+from typing import IO
 
 import pytest
 
@@ -60,19 +62,19 @@ class TestImage:
             "HSV",
         ),
     )
-    def test_image_modes_success(self, mode):
+    def test_image_modes_success(self, mode: str) -> None:
         Image.new(mode, (1, 1))
 
     @pytest.mark.parametrize("mode", ("", "bad", "very very long"))
-    def test_image_modes_fail(self, mode):
+    def test_image_modes_fail(self, mode: str) -> None:
         with pytest.raises(ValueError) as e:
             Image.new(mode, (1, 1))
         assert str(e.value) == "unrecognized image mode"
 
-    def test_exception_inheritance(self):
+    def test_exception_inheritance(self) -> None:
         assert issubclass(UnidentifiedImageError, OSError)
 
-    def test_sanity(self):
+    def test_sanity(self) -> None:
         im = Image.new("L", (100, 100))
         assert repr(im)[:45] == "<PIL.Image.Image image mode=L size=100x100 at"
         assert im.mode == "L"
@@ -97,9 +99,9 @@ class TestImage:
         # with pytest.raises(MemoryError):
         #   Image.new("L", (1000000, 1000000))
 
-    def test_repr_pretty(self):
+    def test_repr_pretty(self) -> None:
         class Pretty:
-            def text(self, text):
+            def text(self, text: str) -> None:
                 self.pretty_output = text
 
         im = Image.new("L", (100, 100))
@@ -108,7 +110,7 @@ class TestImage:
         im._repr_pretty_(p, None)
         assert p.pretty_output == "<PIL.Image.Image image mode=L size=100x100>"
 
-    def test_open_formats(self):
+    def test_open_formats(self) -> None:
         PNGFILE = "Tests/images/hopper.png"
         JPGFILE = "Tests/images/hopper.jpg"
 
@@ -130,7 +132,7 @@ class TestImage:
                 assert im.mode == "RGB"
                 assert im.size == (128, 128)
 
-    def test_width_height(self):
+    def test_width_height(self) -> None:
         im = Image.new("RGB", (1, 2))
         assert im.width == 1
         assert im.height == 2
@@ -138,31 +140,29 @@ class TestImage:
         with pytest.raises(AttributeError):
             im.size = (3, 4)
 
-    def test_set_mode(self):
+    def test_set_mode(self) -> None:
         im = Image.new("RGB", (1, 1))
 
         with pytest.raises(AttributeError):
             im.mode = "P"
 
-    def test_invalid_image(self):
+    def test_invalid_image(self) -> None:
         im = io.BytesIO(b"")
         with pytest.raises(UnidentifiedImageError):
             with Image.open(im):
                 pass
 
-    def test_bad_mode(self):
+    def test_bad_mode(self) -> None:
         with pytest.raises(ValueError):
             with Image.open("filename", "bad mode"):
                 pass
 
-    def test_stringio(self):
+    def test_stringio(self) -> None:
         with pytest.raises(ValueError):
             with Image.open(io.StringIO()):
                 pass
 
-    def test_pathlib(self, tmp_path):
+    def test_pathlib(self, tmp_path: Path) -> None:
-        from PIL.Image import Path
-
         with Image.open(Path("Tests/images/multipage-mmap.tiff")) as im:
             assert im.mode == "P"
             assert im.size == (10, 10)
@@ -179,11 +179,13 @@ class TestImage:
                     os.remove(temp_file)
                 im.save(Path(temp_file))
 
-    def test_fp_name(self, tmp_path):
+    def test_fp_name(self, tmp_path: Path) -> None:
         temp_file = str(tmp_path / "temp.jpg")
 
         class FP:
-            def write(self, b):
+            name: str
+
+            def write(self, b: bytes) -> None:
                 pass
 
         fp = FP()
@@ -192,7 +194,7 @@ class TestImage:
         im = hopper()
         im.save(fp)
 
-    def test_tempfile(self):
+    def test_tempfile(self) -> None:
         # see #1460, pathlib support breaks tempfile.TemporaryFile on py27
         # Will error out on save on 3.0.0
         im = hopper()
@@ -201,13 +203,13 @@ class TestImage:
             fp.seek(0)
             assert_image_similar_tofile(im, fp, 20)
 
-    def test_unknown_extension(self, tmp_path):
+    def test_unknown_extension(self, tmp_path: Path) -> None:
         im = hopper()
         temp_file = str(tmp_path / "temp.unknown")
         with pytest.raises(ValueError):
             im.save(temp_file)
 
-    def test_internals(self):
+    def test_internals(self) -> None:
         im = Image.new("L", (100, 100))
         im.readonly = 1
         im._copy()
@@ -222,7 +224,7 @@ class TestImage:
         sys.platform == "cygwin",
         reason="Test requires opening an mmaped file for writing",
     )
-    def test_readonly_save(self, tmp_path):
+    def test_readonly_save(self, tmp_path: Path) -> None:
         temp_file = str(tmp_path / "temp.bmp")
         shutil.copy("Tests/images/rgb32bf-rgba.bmp", temp_file)
 
@@ -230,7 +232,7 @@ class TestImage:
             assert im.readonly
             im.save(temp_file)
 
-    def test_dump(self, tmp_path):
+    def test_dump(self, tmp_path: Path) -> None:
         im = Image.new("L", (10, 10))
         im._dump(str(tmp_path / "temp_L.ppm"))
 
@@ -241,7 +243,7 @@ class TestImage:
         with pytest.raises(ValueError):
             im._dump(str(tmp_path / "temp_HSV.ppm"))
 
-    def test_comparison_with_other_type(self):
+    def test_comparison_with_other_type(self) -> None:
         # Arrange
         item = Image.new("RGB", (25, 25), "#000")
         num = 12
@@ -251,7 +253,7 @@ class TestImage:
         assert item is not None
         assert item != num
 
-    def test_expand_x(self):
+    def test_expand_x(self) -> None:
         # Arrange
         im = hopper()
         orig_size = im.size
@@ -264,7 +266,7 @@ class TestImage:
         assert im.size[0] == orig_size[0] + 2 * xmargin
         assert im.size[1] == orig_size[1] + 2 * xmargin
 
-    def test_expand_xy(self):
+    def test_expand_xy(self) -> None:
         # Arrange
         im = hopper()
         orig_size = im.size
@@ -278,12 +280,12 @@ class TestImage:
         assert im.size[0] == orig_size[0] + 2 * xmargin
         assert im.size[1] == orig_size[1] + 2 * ymargin
 
-    def test_getbands(self):
+    def test_getbands(self) -> None:
         # Assert
         assert hopper("RGB").getbands() == ("R", "G", "B")
         assert hopper("YCbCr").getbands() == ("Y", "Cb", "Cr")
 
-    def test_getchannel_wrong_params(self):
+    def test_getchannel_wrong_params(self) -> None:
         im = hopper()
 
         with pytest.raises(ValueError):
@@ -295,7 +297,7 @@ class TestImage:
         with pytest.raises(ValueError):
             im.getchannel("1")
 
-    def test_getchannel(self):
+    def test_getchannel(self) -> None:
         im = hopper("YCbCr")
         Y, Cb, Cr = im.split()
 
@@ -306,7 +308,7 @@ class TestImage:
         assert_image_equal(Cr, im.getchannel(2))
         assert_image_equal(Cr, im.getchannel("Cr"))
 
-    def test_getbbox(self):
+    def test_getbbox(self) -> None:
         # Arrange
         im = hopper()
 
@@ -316,7 +318,7 @@ class TestImage:
         # Assert
         assert bbox == (0, 0, 128, 128)
 
-    def test_ne(self):
+    def test_ne(self) -> None:
         # Arrange
         im1 = Image.new("RGB", (25, 25), "black")
         im2 = Image.new("RGB", (25, 25), "white")
@@ -324,7 +326,7 @@ class TestImage:
         # Act / Assert
         assert im1 != im2
 
-    def test_alpha_composite(self):
+    def test_alpha_composite(self) -> None:
         # https://stackoverflow.com/questions/3374878
         # Arrange
         expected_colors = sorted(
@@ -355,7 +357,7 @@ class TestImage:
         img_colors = sorted(img.getcolors())
         assert img_colors == expected_colors
 
-    def test_alpha_inplace(self):
+    def test_alpha_inplace(self) -> None:
         src = Image.new("RGBA", (128, 128), "blue")
 
         over = Image.new("RGBA", (128, 128), "red")
@@ -407,7 +409,7 @@ class TestImage:
         with pytest.raises(ValueError):
             source.alpha_composite(over, (0, 0), (0, -1))
 
-    def test_register_open_duplicates(self):
+    def test_register_open_duplicates(self) -> None:
         # Arrange
         factory, accept = Image.OPEN["JPEG"]
         id_length = len(Image.ID)
@@ -418,7 +420,7 @@ class TestImage:
         # Assert
         assert len(Image.ID) == id_length
 
-    def test_registered_extensions_uninitialized(self):
+    def test_registered_extensions_uninitialized(self) -> None:
         # Arrange
         Image._initialized = 0
 
@@ -428,7 +430,7 @@ class TestImage:
         # Assert
         assert Image._initialized == 2
 
-    def test_registered_extensions(self):
+    def test_registered_extensions(self) -> None:
         # Arrange
         # Open an image to trigger plugin registration
         with Image.open("Tests/images/rgb.jpg"):
@@ -442,7 +444,7 @@ class TestImage:
         for ext in [".cur", ".icns", ".tif", ".tiff"]:
             assert ext in extensions
 
-    def test_effect_mandelbrot(self):
+    def test_effect_mandelbrot(self) -> None:
         # Arrange
         size = (512, 512)
         extent = (-3, -2.5, 2, 2.5)
@@ -455,7 +457,7 @@ class TestImage:
         assert im.size == (512, 512)
         assert_image_equal_tofile(im, "Tests/images/effect_mandelbrot.png")
 
-    def test_effect_mandelbrot_bad_arguments(self):
+    def test_effect_mandelbrot_bad_arguments(self) -> None:
         # Arrange
         size = (512, 512)
         # Get coordinates the wrong way round:
@@ -467,7 +469,7 @@ class TestImage:
         with pytest.raises(ValueError):
             Image.effect_mandelbrot(size, extent, quality)
 
-    def test_effect_noise(self):
+    def test_effect_noise(self) -> None:
         # Arrange
         size = (100, 100)
         sigma = 128
@@ -485,7 +487,7 @@ class TestImage:
         p4 = im.getpixel((0, 4))
         assert_not_all_same([p0, p1, p2, p3, p4])
 
-    def test_effect_spread(self):
+    def test_effect_spread(self) -> None:
         # Arrange
         im = hopper()
         distance = 10
@@ -497,7 +499,7 @@ class TestImage:
         assert im.size == (128, 128)
         assert_image_similar_tofile(im2, "Tests/images/effect_spread.png", 110)
 
-    def test_effect_spread_zero(self):
+    def test_effect_spread_zero(self) -> None:
         # Arrange
         im = hopper()
         distance = 0
@@ -508,7 +510,7 @@ class TestImage:
         # Assert
         assert_image_equal(im, im2)
 
-    def test_check_size(self):
+    def test_check_size(self) -> None:
         # Checking that the _check_size function throws value errors when we want it to
         with pytest.raises(ValueError):
             Image.new("RGB", 0)  # not a tuple
@@ -537,10 +539,10 @@ class TestImage:
         "PILLOW_VALGRIND_TEST" in os.environ, reason="Valgrind is slower"
     )
     @pytest.mark.parametrize("size", ((0, 100000000), (100000000, 0)))
-    def test_empty_image(self, size):
+    def test_empty_image(self, size: tuple[int, int]) -> None:
         Image.new("RGB", size)
 
-    def test_storage_neg(self):
+    def test_storage_neg(self) -> None:
         # Storage.c accepted negative values for xsize, ysize.  Was
         # test_neg_ppm, but the core function for that has been
         # removed Calling directly into core to test the error in
@@ -549,13 +551,13 @@ class TestImage:
         with pytest.raises(ValueError):
             Image.core.fill("RGB", (2, -2), (0, 0, 0))
 
-    def test_one_item_tuple(self):
+    def test_one_item_tuple(self) -> None:
         for mode in ("I", "F", "L"):
             im = Image.new(mode, (100, 100), (5,))
             px = im.load()
             assert px[0, 0] == 5
 
-    def test_linear_gradient_wrong_mode(self):
+    def test_linear_gradient_wrong_mode(self) -> None:
         # Arrange
         wrong_mode = "RGB"
 
@@ -564,7 +566,7 @@ class TestImage:
             Image.linear_gradient(wrong_mode)
 
     @pytest.mark.parametrize("mode", ("L", "P", "I", "F"))
-    def test_linear_gradient(self, mode):
+    def test_linear_gradient(self, mode: str) -> None:
         # Arrange
         target_file = "Tests/images/linear_gradient.png"
 
@@ -580,7 +582,7 @@ class TestImage:
             target = target.convert(mode)
         assert_image_equal(im, target)
 
-    def test_radial_gradient_wrong_mode(self):
+    def test_radial_gradient_wrong_mode(self) -> None:
         # Arrange
         wrong_mode = "RGB"
 
@@ -589,7 +591,7 @@ class TestImage:
             Image.radial_gradient(wrong_mode)
 
     @pytest.mark.parametrize("mode", ("L", "P", "I", "F"))
-    def test_radial_gradient(self, mode):
+    def test_radial_gradient(self, mode: str) -> None:
         # Arrange
         target_file = "Tests/images/radial_gradient.png"
 
@@ -605,7 +607,7 @@ class TestImage:
             target = target.convert(mode)
         assert_image_equal(im, target)
 
-    def test_register_extensions(self):
+    def test_register_extensions(self) -> None:
         test_format = "a"
         exts = ["b", "c"]
         for ext in exts:
@@ -621,7 +623,7 @@ class TestImage:
 
         assert ext_individual == ext_multiple
 
-    def test_remap_palette(self):
+    def test_remap_palette(self) -> None:
         # Test identity transform
         with Image.open("Tests/images/hopper.gif") as im:
             assert_image_equal(im, im.remap_palette(list(range(256))))
@@ -640,7 +642,7 @@ class TestImage:
             with pytest.raises(ValueError):
                 im.remap_palette(None)
 
-    def test_remap_palette_transparency(self):
+    def test_remap_palette_transparency(self) -> None:
         im = Image.new("P", (1, 2), (0, 0, 0))
         im.putpixel((0, 1), (255, 0, 0))
         im.info["transparency"] = 0
@@ -655,7 +657,7 @@ class TestImage:
         im_remapped = im.remap_palette([1, 0])
         assert "transparency" not in im_remapped.info
 
-    def test__new(self):
+    def test__new(self) -> None:
         im = hopper("RGB")
         im_p = hopper("P")
 
@@ -664,7 +666,11 @@ class TestImage:
         blank_p.palette = None
         blank_pa.palette = None
 
-        def _make_new(base_image, image, palette_result=None):
+        def _make_new(
+            base_image: Image.Image,
+            image: Image.Image,
+            palette_result: ImagePalette.ImagePalette | None = None,
+        ) -> None:
             new_image = base_image._new(image.im)
             assert new_image.mode == image.mode
             assert new_image.size == image.size
@@ -679,17 +685,20 @@ class TestImage:
         _make_new(im, blank_p, ImagePalette.ImagePalette())
         _make_new(im, blank_pa, ImagePalette.ImagePalette())
 
-    def test_p_from_rgb_rgba(self):
+    @pytest.mark.parametrize(
-        for mode, color in [
+        "mode, color",
+        (
             ("RGB", "#DDEEFF"),
             ("RGB", (221, 238, 255)),
             ("RGBA", (221, 238, 255, 255)),
-        ]:
+        ),
+    )
+    def test_p_from_rgb_rgba(self, mode: str, color: str | tuple[int, ...]) -> None:
         im = Image.new("P", (100, 100), color)
         expected = Image.new(mode, (100, 100), color)
         assert_image_equal(im.convert(mode), expected)
 
-    def test_no_resource_warning_on_save(self, tmp_path):
+    def test_no_resource_warning_on_save(self, tmp_path: Path) -> None:
         # https://github.com/python-pillow/Pillow/issues/835
         # Arrange
         test_file = "Tests/images/hopper.png"
@@ -700,7 +709,7 @@ class TestImage:
             with warnings.catch_warnings():
                 im.save(temp_file)
 
-    def test_no_new_file_on_error(self, tmp_path):
+    def test_no_new_file_on_error(self, tmp_path: Path) -> None:
         temp_file = str(tmp_path / "temp.jpg")
 
         im = Image.new("RGB", (0, 0))
@@ -709,10 +718,10 @@ class TestImage:
 
         assert not os.path.exists(temp_file)
 
-    def test_load_on_nonexclusive_multiframe(self):
+    def test_load_on_nonexclusive_multiframe(self) -> None:
         with open("Tests/images/frozenpond.mpo", "rb") as fp:
 
-            def act(fp):
+            def act(fp: IO[bytes]) -> None:
                 im = Image.open(fp)
                 im.load()
 
@@ -723,7 +732,7 @@ class TestImage:
 
             assert not fp.closed
 
-    def test_empty_exif(self):
+    def test_empty_exif(self) -> None:
         with Image.open("Tests/images/exif.png") as im:
             exif = im.getexif()
         assert dict(exif)
@@ -739,7 +748,7 @@ class TestImage:
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
-    def test_exif_jpeg(self, tmp_path):
+    def test_exif_jpeg(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/exif-72dpi-int.jpg") as im:  # Little endian
             exif = im.getexif()
             assert 258 not in exif
@@ -785,7 +794,7 @@ class TestImage:
 
     @skip_unless_feature("webp")
     @skip_unless_feature("webp_anim")
-    def test_exif_webp(self, tmp_path):
+    def test_exif_webp(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/hopper.webp") as im:
             exif = im.getexif()
             assert exif == {}
@@ -795,7 +804,7 @@ class TestImage:
             exif[40963] = 455
             exif[305] = "Pillow test"
 
-            def check_exif():
+            def check_exif() -> None:
                 with Image.open(out) as reloaded:
                     reloaded_exif = reloaded.getexif()
                     assert reloaded_exif[258] == 8
@@ -807,7 +816,7 @@ class TestImage:
             im.save(out, exif=exif, save_all=True)
             check_exif()
 
-    def test_exif_png(self, tmp_path):
+    def test_exif_png(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/exif.png") as im:
             exif = im.getexif()
             assert exif == {274: 1}
@@ -823,7 +832,7 @@ class TestImage:
             reloaded_exif = reloaded.getexif()
             assert reloaded_exif == {258: 8, 40963: 455, 305: "Pillow test"}
 
-    def test_exif_interop(self):
+    def test_exif_interop(self) -> None:
         with Image.open("Tests/images/flower.jpg") as im:
             exif = im.getexif()
             assert exif.get_ifd(0xA005) == {
@@ -837,7 +846,7 @@ class TestImage:
             reloaded_exif.load(exif.tobytes())
             assert reloaded_exif.get_ifd(0xA005) == exif.get_ifd(0xA005)
 
-    def test_exif_ifd1(self):
+    def test_exif_ifd1(self) -> None:
         with Image.open("Tests/images/flower.jpg") as im:
             exif = im.getexif()
             assert exif.get_ifd(ExifTags.IFD.IFD1) == {
@@ -849,7 +858,7 @@ class TestImage:
                 283: 180.0,
             }
 
-    def test_exif_ifd(self):
+    def test_exif_ifd(self) -> None:
         with Image.open("Tests/images/flower.jpg") as im:
             exif = im.getexif()
         del exif.get_ifd(0x8769)[0xA005]
@@ -858,7 +867,7 @@ class TestImage:
         reloaded_exif.load(exif.tobytes())
         assert reloaded_exif.get_ifd(0x8769) == exif.get_ifd(0x8769)
 
-    def test_exif_load_from_fp(self):
+    def test_exif_load_from_fp(self) -> None:
         with Image.open("Tests/images/flower.jpg") as im:
             data = im.info["exif"]
             if data.startswith(b"Exif\x00\x00"):
@@ -879,7 +888,7 @@ class TestImage:
                 34665: 196,
             }
 
-    def test_exif_hide_offsets(self):
+    def test_exif_hide_offsets(self) -> None:
         with Image.open("Tests/images/flower.jpg") as im:
             exif = im.getexif()
 
@@ -905,18 +914,18 @@ class TestImage:
                 assert exif.get_ifd(0xA005)
 
     @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
-    def test_zero_tobytes(self, size):
+    def test_zero_tobytes(self, size: tuple[int, int]) -> None:
         im = Image.new("RGB", size)
         assert im.tobytes() == b""
 
     @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
-    def test_zero_frombytes(self, size):
+    def test_zero_frombytes(self, size: tuple[int, int]) -> None:
         Image.frombytes("RGB", size, b"")
 
         im = Image.new("RGB", size)
         im.frombytes(b"")
 
-    def test_has_transparency_data(self):
+    def test_has_transparency_data(self) -> None:
         for mode in ("1", "L", "P", "RGB"):
             im = Image.new(mode, (1, 1))
             assert not im.has_transparency_data
@@ -941,7 +950,7 @@ class TestImage:
         assert im.palette.mode == "RGBA"
         assert im.has_transparency_data
 
-    def test_apply_transparency(self):
+    def test_apply_transparency(self) -> None:
         im = Image.new("P", (1, 1))
         im.putpalette((0, 0, 0, 1, 1, 1))
         assert im.palette.colors == {(0, 0, 0): 0, (1, 1, 1): 1}
@@ -970,7 +979,7 @@ class TestImage:
             im.apply_transparency()
             assert im.palette.colors[(27, 35, 6, 214)] == 24
 
-    def test_constants(self):
+    def test_constants(self) -> None:
         for enum in (
             Image.Transpose,
             Image.Transform,
@@ -995,7 +1004,7 @@ class TestImage:
             "01r_00.pcx",
         ],
     )
-    def test_overrun(self, path):
+    def test_overrun(self, path: str) -> None:
         """For overrun completeness, test as:
         valgrind pytest -qq Tests/test_image.py::TestImage::test_overrun | grep decode.c
         """
@@ -1009,7 +1018,7 @@ class TestImage:
 
                 assert buffer_overrun or truncated
 
-    def test_fli_overrun2(self):
+    def test_fli_overrun2(self) -> None:
         with Image.open("Tests/images/fli_overrun2.bin") as im:
             try:
                 im.seek(1)
@@ -1017,12 +1026,12 @@ class TestImage:
             except OSError as e:
                 assert str(e) == "buffer overrun when reading image file"
 
-    def test_exit_fp(self):
+    def test_exit_fp(self) -> None:
         with Image.new("L", (1, 1)) as im:
             pass
         assert not hasattr(im, "fp")
 
-    def test_close_graceful(self, caplog):
+    def test_close_graceful(self, caplog: pytest.LogCaptureFixture) -> None:
         with Image.open("Tests/images/hopper.jpg") as im:
             copy = im.copy()
             with caplog.at_level(logging.DEBUG):
@@ -1033,17 +1042,17 @@ class TestImage:
 
 
 class MockEncoder:
-    pass
+    args: tuple[str, ...]
 
 
-def mock_encode(*args):
+def mock_encode(*args: str) -> MockEncoder:
     encoder = MockEncoder()
     encoder.args = args
     return encoder
 
 
 class TestRegistry:
-    def test_encode_registry(self):
+    def test_encode_registry(self) -> None:
         Image.register_encoder("MOCK", mock_encode)
         assert "MOCK" in Image.ENCODERS
 
@@ -1052,6 +1061,6 @@ class TestRegistry:
         assert isinstance(enc, MockEncoder)
         assert enc.args == ("RGB", "args", "extra")
 
-    def test_encode_registry_fail(self):
+    def test_encode_registry_fail(self) -> None:
         with pytest.raises(OSError):
             Image._getencoder("RGB", "DoesNotExist", ("args",), extra=("extra",))

Tests/test_image_access.py

@@ -4,6 +4,7 @@ import os
 import subprocess
 import sys
 import sysconfig
+from types import ModuleType
 
 import pytest
 
@@ -23,6 +24,7 @@ else:
     except ImportError:
         cffi = None
 
+numpy: ModuleType | None
 try:
     import numpy
 except ImportError:
@@ -35,16 +37,16 @@ class AccessTest:
     _need_cffi_access = False
 
     @classmethod
-    def setup_class(cls):
+    def setup_class(cls) -> None:
         Image.USE_CFFI_ACCESS = cls._need_cffi_access
 
     @classmethod
-    def teardown_class(cls):
+    def teardown_class(cls) -> None:
         Image.USE_CFFI_ACCESS = cls._init_cffi_access
 
 
 class TestImagePutPixel(AccessTest):
-    def test_sanity(self):
+    def test_sanity(self) -> None:
         im1 = hopper()
         im2 = Image.new(im1.mode, im1.size, 0)
 
@@ -71,9 +73,10 @@ class TestImagePutPixel(AccessTest):
         pix1 = im1.load()
         pix2 = im2.load()
 
-        for x, y in ((0, "0"), ("0", 0)):
         with pytest.raises(TypeError):
-                pix1[x, y]
+            pix1[0, "0"]
+        with pytest.raises(TypeError):
+            pix1["0", 0]
 
         for y in range(im1.size[1]):
             for x in range(im1.size[0]):
@@ -81,7 +84,7 @@ class TestImagePutPixel(AccessTest):
 
         assert_image_equal(im1, im2)
 
-    def test_sanity_negative_index(self):
+    def test_sanity_negative_index(self) -> None:
         im1 = hopper()
         im2 = Image.new(im1.mode, im1.size, 0)
 
@@ -119,16 +122,17 @@ class TestImagePutPixel(AccessTest):
         assert_image_equal(im1, im2)
 
     @pytest.mark.skipif(numpy is None, reason="NumPy not installed")
-    def test_numpy(self):
+    def test_numpy(self) -> None:
         im = hopper()
         pix = im.load()
 
+        assert numpy is not None
         assert pix[numpy.int32(1), numpy.int32(2)] == (18, 20, 59)
 
 
 class TestImageGetPixel(AccessTest):
     @staticmethod
-    def color(mode):
+    def color(mode: str) -> int | tuple[int, ...]:
         bands = Image.getmodebands(mode)
         if bands == 1:
             return 1
@@ -138,12 +142,13 @@ class TestImageGetPixel(AccessTest):
             return (16, 32, 49)
         return tuple(range(1, bands + 1))
 
-    def check(self, mode, expected_color=None):
+    def check(self, mode: str, expected_color_int: int | None = None) -> None:
         if self._need_cffi_access and mode.startswith("BGR;"):
             pytest.skip("Support not added to deprecated module for BGR;* modes")
 
-        if not expected_color:
+        expected_color = (
-            expected_color = self.color(mode)
+            self.color(mode) if expected_color_int is None else expected_color_int
+        )
 
         # check putpixel
         im = Image.new(mode, (1, 1), None)
@@ -222,25 +227,23 @@ class TestImageGetPixel(AccessTest):
             "YCbCr",
         ),
     )
-    def test_basic(self, mode):
+    def test_basic(self, mode: str) -> None:
         self.check(mode)
 
-    def test_list(self):
+    def test_list(self) -> None:
         im = hopper()
         assert im.getpixel([0, 0]) == (20, 20, 70)
 
     @pytest.mark.parametrize("mode", ("I;16", "I;16B"))
-    @pytest.mark.parametrize(
+    @pytest.mark.parametrize("expected_color", (2**15 - 1, 2**15, 2**15 + 1, 2**16 - 1))
-        "expected_color", (2**15 - 1, 2**15, 2**15 + 1, 2**16 - 1)
+    def test_signedness(self, mode: str, expected_color: int) -> None:
-    )
-    def test_signedness(self, mode, expected_color):
         # see https://github.com/python-pillow/Pillow/issues/452
         # pixelaccess is using signed int* instead of uint*
         self.check(mode, expected_color)
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
     @pytest.mark.parametrize("color", ((255, 0, 0), (255, 0, 0, 255)))
-    def test_p_putpixel_rgb_rgba(self, mode, color):
+    def test_p_putpixel_rgb_rgba(self, mode: str, color: tuple[int, ...]) -> None:
         im = Image.new(mode, (1, 1))
         im.putpixel((0, 0), color)
 
@@ -264,7 +267,7 @@ class TestCffiGetPixel(TestImageGetPixel):
 class TestCffi(AccessTest):
     _need_cffi_access = True
 
-    def _test_get_access(self, im):
+    def _test_get_access(self, im: Image.Image) -> None:
         """Do we get the same thing as the old pixel access
 
         Using private interfaces, forcing a capi access and
@@ -282,7 +285,7 @@ class TestCffi(AccessTest):
         with pytest.raises(ValueError):
             access[(access.xsize + 1, access.ysize + 1)]
 
-    def test_get_vs_c(self):
+    def test_get_vs_c(self) -> None:
         with pytest.warns(DeprecationWarning):
             rgb = hopper("RGB")
             rgb.load()
@@ -301,7 +304,7 @@ class TestCffi(AccessTest):
         # im = Image.new('I;32B', (10, 10), 2**10)
         # self._test_get_access(im)
 
-    def _test_set_access(self, im, color):
+    def _test_set_access(self, im: Image.Image, color: tuple[int, ...] | float) -> None:
         """Are we writing the correct bits into the image?
 
         Using private interfaces, forcing a capi access and
@@ -322,7 +325,7 @@ class TestCffi(AccessTest):
         with pytest.raises(ValueError):
             access[(0, 0)] = color
 
-    def test_set_vs_c(self):
+    def test_set_vs_c(self) -> None:
         rgb = hopper("RGB")
         with pytest.warns(DeprecationWarning):
             rgb.load()
@@ -345,11 +348,11 @@ class TestCffi(AccessTest):
         # self._test_set_access(im, 2**13-1)
 
     @pytest.mark.filterwarnings("ignore::DeprecationWarning")
-    def test_not_implemented(self):
+    def test_not_implemented(self) -> None:
         assert PyAccess.new(hopper("BGR;15")) is None
 
     # ref https://github.com/python-pillow/Pillow/pull/2009
-    def test_reference_counting(self):
+    def test_reference_counting(self) -> None:
         size = 10
 
         for _ in range(10):
@@ -361,7 +364,7 @@ class TestCffi(AccessTest):
                 assert px[i, 0] == 0
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
-    def test_p_putpixel_rgb_rgba(self, mode):
+    def test_p_putpixel_rgb_rgba(self, mode: str) -> None:
         for color in ((255, 0, 0), (255, 0, 0, 127 if mode == "PA" else 255)):
             im = Image.new(mode, (1, 1))
             with pytest.warns(DeprecationWarning):
@@ -379,7 +382,7 @@ class TestImagePutPixelError(AccessTest):
     INVALID_TYPES = ["foo", 1.0, None]
 
     @pytest.mark.parametrize("mode", IMAGE_MODES1)
-    def test_putpixel_type_error1(self, mode):
+    def test_putpixel_type_error1(self, mode: str) -> None:
         im = hopper(mode)
         for v in self.INVALID_TYPES:
             with pytest.raises(TypeError, match="color must be int or tuple"):
@@ -402,14 +405,16 @@ class TestImagePutPixelError(AccessTest):
             ),
         ),
     )
-    def test_putpixel_invalid_number_of_bands(self, mode, band_numbers, match):
+    def test_putpixel_invalid_number_of_bands(
+        self, mode: str, band_numbers: tuple[int, ...], match: str
+    ) -> None:
         im = hopper(mode)
         for band_number in band_numbers:
             with pytest.raises(TypeError, match=match):
                 im.putpixel((0, 0), (0,) * band_number)
 
     @pytest.mark.parametrize("mode", IMAGE_MODES2)
-    def test_putpixel_type_error2(self, mode):
+    def test_putpixel_type_error2(self, mode: str) -> None:
         im = hopper(mode)
         for v in self.INVALID_TYPES:
             with pytest.raises(
@@ -418,7 +423,7 @@ class TestImagePutPixelError(AccessTest):
                 im.putpixel((0, 0), v)
 
     @pytest.mark.parametrize("mode", IMAGE_MODES1 + IMAGE_MODES2)
-    def test_putpixel_overflow_error(self, mode):
+    def test_putpixel_overflow_error(self, mode: str) -> None:
         im = hopper(mode)
         with pytest.raises(OverflowError):
             im.putpixel((0, 0), 2**80)
@@ -427,10 +432,10 @@ class TestImagePutPixelError(AccessTest):
 class TestEmbeddable:
     @pytest.mark.xfail(reason="failing test")
     @pytest.mark.skipif(not is_win32(), reason="requires Windows")
-    def test_embeddable(self):
+    def test_embeddable(self) -> None:
         import ctypes
 
-        from setuptools.command.build_ext import new_compiler
+        from setuptools.command import build_ext
 
         with open("embed_pil.c", "w", encoding="utf-8") as fh:
             fh.write(
@@ -459,7 +464,7 @@ int main(int argc, char* argv[])
                 % sys.prefix.replace("\\", "\\\\")
             )
 
-        compiler = new_compiler()
+        compiler = getattr(build_ext, "new_compiler")()
         compiler.add_include_dir(sysconfig.get_config_var("INCLUDEPY"))
 
         libdir = sysconfig.get_config_var("LIBDIR") or sysconfig.get_config_var(
@@ -473,7 +478,7 @@ int main(int argc, char* argv[])
         env["PATH"] = sys.prefix + ";" + env["PATH"]
 
         # do not display the Windows Error Reporting dialog
-        ctypes.windll.kernel32.SetErrorMode(0x0002)
+        getattr(ctypes, "windll").kernel32.SetErrorMode(0x0002)
 
         process = subprocess.Popen(["embed_pil.exe"], env=env)
         process.communicate()

Tests/test_image_array.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from typing import Any
+
 import pytest
 from packaging.version import parse as parse_version
 
@@ -12,12 +14,12 @@ numpy = pytest.importorskip("numpy", reason="NumPy not installed")
 im = hopper().resize((128, 100))
 
 
-def test_toarray():
+def test_toarray() -> None:
-    def test(mode):
+    def test(mode: str) -> tuple[tuple[int, ...], str, int]:
         ai = numpy.array(im.convert(mode))
         return ai.shape, ai.dtype.str, ai.nbytes
 
-    def test_with_dtype(dtype):
+    def test_with_dtype(dtype) -> None:
         ai = numpy.array(im, dtype=dtype)
         assert ai.dtype == dtype
 
@@ -46,18 +48,18 @@ def test_toarray():
                 numpy.array(im_truncated)
 
 
-def test_fromarray():
+def test_fromarray() -> None:
     class Wrapper:
         """Class with API matching Image.fromarray"""
 
-        def __init__(self, img, arr_params):
+        def __init__(self, img: Image.Image, arr_params: dict[str, Any]) -> None:
             self.img = img
             self.__array_interface__ = arr_params
 
-        def tobytes(self):
+        def tobytes(self) -> bytes:
             return self.img.tobytes()
 
-    def test(mode):
+    def test(mode: str) -> tuple[str, tuple[int, int], bool]:
         i = im.convert(mode)
         a = numpy.array(i)
         # Make wrapper instance for image, new array interface
@@ -89,7 +91,7 @@ def test_fromarray():
         Image.fromarray(wrapped)
 
 
-def test_fromarray_palette():
+def test_fromarray_palette() -> None:
     # Arrange
     i = im.convert("L")
     a = numpy.array(i)