Merge branch 'main' into msys

.ci/install.sh

@@ -23,7 +23,7 @@ if [[ $(uname) != CYGWIN* ]]; then
     sudo apt-get -qq install libfreetype6-dev liblcms2-dev libtiff-dev python3-tk\
                              ghostscript libjpeg-turbo8-dev libopenjp2-7-dev\
                              cmake meson imagemagick libharfbuzz-dev libfribidi-dev\
-                             sway wl-clipboard libopenblas-dev
+                             sway wl-clipboard libopenblas-dev nasm
 fi
 
 python3 -m pip install --upgrade pip
@@ -36,6 +36,9 @@ python3 -m pip install -U pytest
 python3 -m pip install -U pytest-cov
 python3 -m pip install -U pytest-timeout
 python3 -m pip install pyroma
+# optional test dependency, only install if there's a binary package.
+# fails on beta 3.14 and PyPy
+python3 -m pip install --only-binary=:all: pyarrow || true
 
 if [[ $(uname) != CYGWIN* ]]; then
     python3 -m pip install numpy
@@ -50,7 +53,7 @@ if [[ $(uname) != CYGWIN* ]]; then
     # Pyroma uses non-isolated build and fails with old setuptools
     if [[ $GHA_PYTHON_VERSION == 3.9 ]]; then
         # To match pyproject.toml
-        python3 -m pip install "setuptools>=67.8"
+        python3 -m pip install "setuptools>=77"
     fi
 
     # webp
@@ -62,6 +65,9 @@ if [[ $(uname) != CYGWIN* ]]; then
     # raqm
     pushd depends && ./install_raqm.sh && popd
 
+    # libavif
+    pushd depends && ./install_libavif.sh && popd
+
     # extra test images
     pushd depends && ./install_extra_test_images.sh && popd
 else

.ci/requirements-cibw.txt

@@ -1 +1 @@
-cibuildwheel==2.23.1
+cibuildwheel==2.23.3

.ci/requirements-mypy.txt

@@ -1,9 +1,10 @@
-mypy==1.15.0
+mypy==1.16.0
 IceSpringPySideStubs-PyQt6
 IceSpringPySideStubs-PySide6
 ipython
 numpy
 packaging
+pyarrow-stubs
 pytest
 sphinx
 types-atheris

.clang-format

@@ -1,5 +1,26 @@
 # A clang-format style that approximates Python's PEP 7
 # Useful for IDE integration
+Language: C
+BasedOnStyle: Google
+AlwaysBreakAfterReturnType: All
+AllowShortIfStatementsOnASingleLine: false
+AlignAfterOpenBracket: BlockIndent
+BinPackArguments: false
+BinPackParameters: false
+BreakBeforeBraces: Attach
+ColumnLimit: 88
+DerivePointerAlignment: false
+IndentGotoLabels: false
+IndentWidth: 4
+PointerAlignment: Right
+ReflowComments: true
+SortIncludes: false
+SpaceBeforeParens: ControlStatements
+SpacesInParentheses: false
+TabWidth: 4
+UseTab: Never
+---
+Language: Cpp
 BasedOnStyle: Google
 AlwaysBreakAfterReturnType: All
 AllowShortIfStatementsOnASingleLine: false
@@ -11,7 +32,6 @@ ColumnLimit: 88
 DerivePointerAlignment: false
 IndentGotoLabels: false
 IndentWidth: 4
-Language: Cpp
 PointerAlignment: Right
 ReflowComments: true
 SortIncludes: false

.github/ISSUE_TEMPLATE/RELEASE.md

@@ -0,0 +1,46 @@
+---
+name: "Maintainers only: Release"
+about: For maintainers to schedule a quarterly release
+labels: Release
+---
+
+## Main release
+
+Released quarterly on January 2nd, April 1st, July 1st and October 15th.
+
+* [ ] Open a release ticket e.g. https://github.com/python-pillow/Pillow/issues/3154
+* [ ] Develop and prepare release in `main` branch.
+  * [ ] Add release notes e.g. https://github.com/python-pillow/Pillow/pull/8885
+* [ ] Check [GitHub Actions](https://github.com/python-pillow/Pillow/actions) to confirm passing tests in `main` branch.
+* [ ] Check that all the wheel builds pass the tests in the [GitHub Actions "Wheels" workflow](https://github.com/python-pillow/Pillow/actions/workflows/wheels.yml) jobs by manually triggering them.
+* [ ] In compliance with [PEP 440](https://peps.python.org/pep-0440/), update version identifier in `src/PIL/_version.py`
+* [ ] Run pre-release check via `make release-test` in a freshly cloned repo.
+* [ ] Create branch and tag for release e.g.:
+  ```bash
+  git branch [[MAJOR.MINOR]].x
+  git tag [[MAJOR.MINOR]].0
+  git push --tags
+  ```
+* [ ] Check the [GitHub Actions "Wheels" workflow](https://github.com/python-pillow/Pillow/actions/workflows/wheels.yml) has passed, including the "Upload release to PyPI" job. This will have been triggered by the new tag.
+* [ ] Publish the [release on GitHub](https://github.com/python-pillow/Pillow/releases).
+* [ ] In compliance with [PEP 440](https://peps.python.org/pep-0440/), increment and append `.dev0` to version identifier in `src/PIL/_version.py` and then:
+  ```bash
+  git push --all
+   ```
+
+## Publicize release
+
+* [ ] Announce release availability via [Mastodon](https://fosstodon.org/@pillow) e.g. https://fosstodon.org/@pillow/110639450470725321
+
+## Documentation
+
+* [ ] Make sure the [default version for Read the Docs](https://pillow.readthedocs.io/en/stable/) is up-to-date with the release changes
+
+## Docker images
+
+* [ ] Update Pillow in the Docker Images repository
+  ```bash
+  git clone https://github.com/python-pillow/docker-images
+  cd docker-images
+  ./update-pillow-tag.sh [[release tag]]
+  ```

.github/workflows/macos-install.sh

@@ -6,6 +6,8 @@ if [[ "$ImageOS" == "macos13" ]]; then
     brew uninstall gradle maven
 fi
 brew install \
+    aom \
+    dav1d \
     freetype \
     ghostscript \
     jpeg-turbo \
@@ -14,6 +16,8 @@ brew install \
     libtiff \
     little-cms2 \
     openjpeg \
+    rav1e \
+    svt-av1 \
     webp
 export PKG_CONFIG_PATH="/usr/local/opt/openblas/lib/pkgconfig"
 
@@ -26,6 +30,12 @@ python3 -m pip install -U pytest-cov
 python3 -m pip install -U pytest-timeout
 python3 -m pip install pyroma
 python3 -m pip install numpy
+# optional test dependency, only install if there's a binary package.
+# fails on beta 3.14 and PyPy
+python3 -m pip install --only-binary=:all: pyarrow || true
+
+# libavif
+pushd depends && ./install_libavif.sh && popd
 
 # extra test images
 pushd depends && ./install_extra_test_images.sh && popd

.github/workflows/test-docker.yml

@@ -47,8 +47,8 @@ jobs:
           centos-stream-10-amd64,
           debian-12-bookworm-x86,
           debian-12-bookworm-amd64,
-          fedora-40-amd64,
           fedora-41-amd64,
+          fedora-42-amd64,
           gentoo,
           ubuntu-22.04-jammy-amd64,
           ubuntu-24.04-noble-amd64,

.github/workflows/test-valgrind-memory.yml

@@ -0,0 +1,60 @@
+name: Test Valgrind Memory Leaks
+
+# like the Docker tests, but running valgrind only on *.c/*.h changes.
+
+# this is very expensive. Only run on the pull request.
+on:
+  # push:
+  #   branches:
+  #     - "**"
+  #   paths:
+  #     - ".github/workflows/test-valgrind.yml"
+  #     - "**.c"
+  #     - "**.h"
+  pull_request:
+    paths:
+      - ".github/workflows/test-valgrind.yml"
+      - "**.c"
+      - "**.h"
+      - "depends/docker-test-valgrind-memory.sh"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        docker: [
+          ubuntu-22.04-jammy-amd64-valgrind,
+        ]
+        dockerTag: [main]
+
+    name: ${{ matrix.docker }}
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        persist-credentials: false
+
+    - name: Build system information
+      run: python3 .github/workflows/system-info.py
+
+    - name: Docker pull
+      run: |
+        docker pull pythonpillow/${{ matrix.docker }}:${{ matrix.dockerTag }}
+
+    - name: Build and Run Valgrind
+      run: |
+        # The Pillow user in the docker container is UID 1001
+        sudo chown -R 1001 $GITHUB_WORKSPACE
+        docker run --name pillow_container -e "PILLOW_VALGRIND_TEST=true" -v $GITHUB_WORKSPACE:/Pillow pythonpillow/${{ matrix.docker }}:${{ matrix.dockerTag }} /Pillow/depends/docker-test-valgrind-memory.sh
+        sudo chown -R runner $GITHUB_WORKSPACE

.github/workflows/test-windows.yml

@@ -31,18 +31,17 @@ env:
 
 jobs:
   build:
-    runs-on: ${{ matrix.os }}
+    runs-on: windows-latest
     strategy:
       fail-fast: false
       matrix:
         python-version: ["pypy3.11", "pypy3.10", "3.10", "3.11", "3.12", "3.13", "3.14"]
         architecture: ["x64"]
-        os: ["windows-latest"]
         include:
             # Test the oldest Python on 32-bit
-            - { python-version: "3.9", architecture: "x86", os: "windows-2019" }
+            - { python-version: "3.9", architecture: "x86" }
 
-    timeout-minutes: 30
+    timeout-minutes: 45
 
     name: Python ${{ matrix.python-version }} (${{ matrix.architecture }})
 
@@ -84,18 +83,22 @@ jobs:
         python3 -m pip install --upgrade pip
 
     - name: Install CPython dependencies
-      if: "!contains(matrix.python-version, 'pypy') && matrix.architecture != 'x86'"
+      if: "!contains(matrix.python-version, 'pypy') && !contains(matrix.python-version, '3.14') && matrix.architecture != 'x86'"
       run: |
         python3 -m pip install PyQt6
 
+    - name: Install PyArrow dependency
+      run: |
+        python3 -m pip install --only-binary=:all: pyarrow || true
+
     - name: Install dependencies
       id: install
       run: |
         choco install nasm --no-progress
         echo "C:\Program Files\NASM" >> $env:GITHUB_PATH
 
-        choco install ghostscript --version=10.5.0 --no-progress
+        choco install ghostscript --version=10.5.1 --no-progress
-        echo "C:\Program Files\gs\gs10.05.0\bin" >> $env:GITHUB_PATH
+        echo "C:\Program Files\gs\gs10.05.1\bin" >> $env:GITHUB_PATH
 
         # Install extra test images
         xcopy /S /Y Tests\test-images\* Tests\images
@@ -145,6 +148,10 @@ jobs:
       if: steps.build-cache.outputs.cache-hit != 'true'
       run: "& winbuild\\build\\build_dep_libpng.cmd"
 
+    - name: Build dependencies / libavif
+      if: steps.build-cache.outputs.cache-hit != 'true' && matrix.architecture == 'x64'
+      run: "& winbuild\\build\\build_dep_libavif.cmd"
+
     # for FreeType WOFF2 font support
     - name: Build dependencies / brotli
       if: steps.build-cache.outputs.cache-hit != 'true'

.github/workflows/test.yml

@@ -70,7 +70,7 @@ jobs:
         persist-credentials: false
 
     - name: Set up Python ${{ matrix.python-version }}
-      uses: Quansight-Labs/setup-python@v5
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
         allow-prereleases: true

.github/workflows/wheels-dependencies.sh

@@ -25,7 +25,7 @@ else
     MB_ML_LIBC=${AUDITWHEEL_POLICY::9}
     MB_ML_VER=${AUDITWHEEL_POLICY:9}
 fi
-PLAT=$CIBW_ARCHS
+PLAT="${CIBW_ARCHS:-$AUDITWHEEL_ARCH}"
 
 # Define custom utilities
 source wheels/multibuild/common_utils.sh
@@ -38,13 +38,14 @@ ARCHIVE_SDIR=pillow-depends-main
 
 # Package versions for fresh source builds
 FREETYPE_VERSION=2.13.3
-HARFBUZZ_VERSION=10.4.0
+HARFBUZZ_VERSION=11.2.1
-LIBPNG_VERSION=1.6.47
+LIBPNG_VERSION=1.6.48
 JPEGTURBO_VERSION=3.1.0
 OPENJPEG_VERSION=2.5.3
-XZ_VERSION=5.6.4
+XZ_VERSION=5.8.1
 TIFF_VERSION=4.7.0
 LCMS2_VERSION=2.17
+ZLIB_VERSION=1.3.1
 ZLIB_NG_VERSION=2.2.4
 LIBWEBP_VERSION=1.5.0
 BZIP2_VERSION=1.0.8
@@ -64,11 +65,7 @@ function build_pkg_config {
 
 function build_zlib_ng {
     if [ -e zlib-stamp ]; then return; fi
-    fetch_unpack https://github.com/zlib-ng/zlib-ng/archive/$ZLIB_NG_VERSION.tar.gz zlib-ng-$ZLIB_NG_VERSION.tar.gz
+    build_github zlib-ng/zlib-ng $ZLIB_NG_VERSION --zlib-compat
-    (cd zlib-ng-$ZLIB_NG_VERSION \
-        && ./configure --prefix=$BUILD_PREFIX --zlib-compat \
-        && make -j4 \
-        && make install)
 
     if [ -n "$IS_MACOS" ]; then
         # Ensure that on macOS, the library name is an absolute path, not an
@@ -95,7 +92,7 @@ function build_harfbuzz {
 
     local out_dir=$(fetch_unpack https://github.com/harfbuzz/harfbuzz/releases/download/$HARFBUZZ_VERSION/harfbuzz-$HARFBUZZ_VERSION.tar.xz harfbuzz-$HARFBUZZ_VERSION.tar.xz)
     (cd $out_dir \
-        && meson setup build --prefix=$BUILD_PREFIX --libdir=$BUILD_PREFIX/lib --buildtype=release -Dfreetype=enabled -Dglib=disabled)
+        && meson setup build --prefix=$BUILD_PREFIX --libdir=$BUILD_PREFIX/lib --buildtype=minsize -Dfreetype=enabled -Dglib=disabled -Dtests=disabled)
     (cd $out_dir/build \
         && meson install)
     touch harfbuzz-stamp
@@ -106,7 +103,11 @@ function build {
     if [ -z "$IS_ALPINE" ] && [ -z "$SANITIZER" ] && [ -z "$IS_MACOS" ]; then
         yum remove -y zlib-devel
     fi
-    build_zlib_ng
+    if [[ -n "$IS_MACOS" ]] && [[ "$MACOSX_DEPLOYMENT_TARGET" == "10.10" || "$MACOSX_DEPLOYMENT_TARGET" == "10.13" ]]; then
+        build_new_zlib
+    else
+        build_zlib_ng
+    fi
 
     build_simple xcb-proto 1.17.0 https://xorg.freedesktop.org/archive/individual/proto
     if [ -n "$IS_MACOS" ]; then

.github/workflows/wheels.yml

@@ -121,14 +121,17 @@ jobs:
   windows:
     if: github.event_name != 'schedule' || github.repository_owner == 'python-pillow'
     name: Windows ${{ matrix.cibw_arch }}
-    runs-on: windows-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         include:
           - cibw_arch: x86
+            os: windows-latest
           - cibw_arch: AMD64
+            os: windows-latest
           - cibw_arch: ARM64
+            os: windows-11-arm
     steps:
       - uses: actions/checkout@v4
         with:
@@ -157,7 +160,7 @@ jobs:
           # Install extra test images
           xcopy /S /Y Tests\test-images\* Tests\images
 
-          & python.exe winbuild\build_prepare.py -v --no-imagequant --architecture=${{ matrix.cibw_arch }}
+          & python.exe winbuild\build_prepare.py -v --no-imagequant --no-avif --architecture=${{ matrix.cibw_arch }}
         shell: pwsh
 
       - name: Build wheels
@@ -240,7 +243,7 @@ jobs:
           path: dist
           merge-multiple: true
       - name: Upload wheels to scientific-python-nightly-wheels
-        uses: scientific-python/upload-nightly-action@82396a2ed4269ba06c6b2988bb4fd568ef3c3d6b # 0.6.1
+        uses: scientific-python/upload-nightly-action@b36e8c0c10dbcfd2e05bf95f17ef8c14fd708dbf # 0.6.2
         with:
           artifacts_path: dist
           anaconda_nightly_upload_token: ${{ secrets.ANACONDA_ORG_UPLOAD_TOKEN }}

.github/zizmor.yml

@@ -0,0 +1,7 @@
+# Configuration for the zizmor static analysis tool, run via pre-commit in CI
+# https://woodruffw.github.io/zizmor/configuration/
+rules:
+  unpinned-uses:
+    config:
+      policies:
+        "*": ref-pin

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.9.9
+    rev: v0.11.12
     hooks:
       - id: ruff
         args: [--exit-non-zero-on-fix]
@@ -24,7 +24,7 @@ repos:
         exclude: (Makefile$|\.bat$|\.cmake$|\.eps$|\.fits$|\.gd$|\.opt$)
 
   - repo: https://github.com/pre-commit/mirrors-clang-format
-    rev: v19.1.7
+    rev: v20.1.5
     hooks:
       - id: clang-format
         types: [c]
@@ -44,20 +44,21 @@ repos:
       - id: check-json
       - id: check-toml
       - id: check-yaml
+        args: [--allow-multiple-documents]
       - id: end-of-file-fixer
         exclude: ^Tests/images/
       - id: trailing-whitespace
         exclude: ^.github/.*TEMPLATE|^Tests/(fonts|images)/
 
   - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.31.2
+    rev: 0.33.0
     hooks:
       - id: check-github-workflows
       - id: check-readthedocs
       - id: check-renovate
 
   - repo: https://github.com/woodruffw/zizmor-pre-commit
-    rev: v1.4.1
+    rev: v1.9.0
     hooks:
       - id: zizmor
 
@@ -67,12 +68,12 @@ repos:
       - id: sphinx-lint
 
   - repo: https://github.com/tox-dev/pyproject-fmt
-    rev: v2.5.1
+    rev: v2.6.0
     hooks:
       - id: pyproject-fmt
 
   - repo: https://github.com/abravalheri/validate-pyproject
-    rev: v0.23
+    rev: v0.24.1
     hooks:
       - id: validate-pyproject
         additional_dependencies: [trove-classifiers>=2024.10.12]

Makefile

@@ -23,6 +23,10 @@ doc html:
 htmlview:
 	$(MAKE) -C docs htmlview
 
+.PHONY: htmllive
+htmllive:
+	$(MAKE) -C docs htmllive
+
 .PHONY: doccheck
 doccheck:
 	$(MAKE) doc
@@ -43,6 +47,7 @@ help:
 	@echo "  docserve           run an HTTP server on the docs directory"
 	@echo "  html               make HTML docs"
 	@echo "  htmlview           open the index page built by the html target in your browser"
+	@echo "  htmllive           rebuild and reload HTML files in your browser"
 	@echo "  install            make and install"
 	@echo "  install-coverage   make and install with C coverage"
 	@echo "  lint               run the lint checks"
@@ -92,13 +97,27 @@ test:
 	python3 -c "import pytest" > /dev/null 2>&1 || python3 -m pip install pytest
 	python3 -m pytest -qq
 
+.PHONY: test-p
+test-p:
+	python3 -c "import xdist" > /dev/null 2>&1 || python3 -m pip install pytest-xdist
+	python3 -m pytest -qq -n auto
+
+
 .PHONY: valgrind
 valgrind:
 	python3 -c "import pytest_valgrind" > /dev/null 2>&1 || python3 -m pip install pytest-valgrind
-	PYTHONMALLOC=malloc valgrind --suppressions=Tests/oss-fuzz/python.supp --leak-check=no \
+	PILLOW_VALGRIND_TEST=true PYTHONMALLOC=malloc valgrind --suppressions=Tests/oss-fuzz/python.supp --leak-check=no \
             --log-file=/tmp/valgrind-output \
             python3 -m pytest --no-memcheck -vv --valgrind --valgrind-log=/tmp/valgrind-output
 
+.PHONY: valgrind-leak
+valgrind-leak:
+	python3 -c "import pytest_valgrind" > /dev/null 2>&1 || python3 -m pip install pytest-valgrind
+	PILLOW_VALGRIND_TEST=true PYTHONMALLOC=malloc valgrind --suppressions=Tests/oss-fuzz/python.supp \
+	    --leak-check=full --show-leak-kinds=definite --errors-for-leak-kinds=definite \
+            --log-file=/tmp/valgrind-output \
+            python3 -m pytest -vv --valgrind --valgrind-log=/tmp/valgrind-output
+
 .PHONY: readme
 readme:
 	python3 -c "import markdown2" > /dev/null 2>&1 || python3 -m pip install markdown2

README.md

@@ -95,7 +95,7 @@ This library provides extensive file format support, an efficient internal repre
 
 The core image library is designed for fast access to data stored in a few basic pixel formats. It should provide a solid foundation for a general image processing tool.
 
-## More Information
+## More information
 
 - [Documentation](https://pillow.readthedocs.io/)
   - [Installation](https://pillow.readthedocs.io/en/latest/installation/basic-installation.html)
@@ -107,6 +107,6 @@ The core image library is designed for fast access to data stored in a few basic
 - [Changelog](https://github.com/python-pillow/Pillow/releases)
   - [Pre-fork](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst#pre-fork)
 
-## Report a Vulnerability
+## Report a vulnerability
 
 To report a security vulnerability, please follow the procedure described in the [Tidelift security policy](https://tidelift.com/docs/security).

RELEASING.md

@@ -1,34 +1,15 @@
-# Release Checklist
+# Release checklist
 
 See https://pillow.readthedocs.io/en/stable/releasenotes/versioning.html for
 information about how the version numbers line up with releases.
 
-## Main Release
+## Main release
 
 Released quarterly on January 2nd, April 1st, July 1st and October 15th.
 
-* [ ] Open a release ticket e.g. https://github.com/python-pillow/Pillow/issues/3154
+* [ ] Create a new issue and select the "Maintainers only: Release" template.
-* [ ] Develop and prepare release in `main` branch.
+
-* [ ] Check [GitHub Actions](https://github.com/python-pillow/Pillow/actions) to confirm passing tests in `main` branch.
+## Point release
-* [ ] Check that all the wheel builds pass the tests in the [GitHub Actions "Wheels" workflow](https://github.com/python-pillow/Pillow/actions/workflows/wheels.yml) jobs by manually triggering them.
-* [ ] In compliance with [PEP 440](https://peps.python.org/pep-0440/), update version identifier in `src/PIL/_version.py`
-* [ ] Run pre-release check via `make release-test` in a freshly cloned repo.
-* [ ] Create branch and tag for release e.g.:
-  ```bash
-  git branch 5.2.x
-  git tag 5.2.0
-  git push --tags
-  ```
-* [ ] Check the [GitHub Actions "Wheels" workflow](https://github.com/python-pillow/Pillow/actions/workflows/wheels.yml)
-  has passed, including the "Upload release to PyPI" job. This will have been triggered
-  by the new tag.
-* [ ] Publish the [release on GitHub](https://github.com/python-pillow/Pillow/releases).
-* [ ] In compliance with [PEP 440](https://peps.python.org/pep-0440/),
-      increment and append `.dev0` to version identifier in `src/PIL/_version.py` and then:
-  ```bash
-  git push --all
-   ```
-## Point Release
 
 Released as needed for security, installation or critical bug fixes.
 
@@ -58,7 +39,7 @@ Released as needed for security, installation or critical bug fixes.
   git push
   ```
 
-## Embargoed Release
+## Embargoed release
 
 Released as needed privately to individual vendors for critical security-related bug fixes.
 
@@ -82,7 +63,7 @@ Released as needed privately to individual vendors for critical security-related
   git push origin 2.5.x
   ```
 
-## Publicize Release
+## Publicize release
 
 * [ ] Announce release availability via [Mastodon](https://fosstodon.org/@pillow) e.g. https://fosstodon.org/@pillow/110639450470725321
 
@@ -90,7 +71,7 @@ Released as needed privately to individual vendors for critical security-related
 
 * [ ] Make sure the [default version for Read the Docs](https://pillow.readthedocs.io/en/stable/) is up-to-date with the release changes
 
-## Docker Images
+## Docker images
 
 * [ ] Update Pillow in the Docker Images repository
   ```bash

Tests/README.rst

@@ -1,4 +1,4 @@
-Pillow Tests
+Pillow tests
 ============
 
 Test scripts are named ``test_xxx.py``. Helper classes and functions can be found in ``helper.py``.

Tests/check_j2k_overflow.py

@@ -9,6 +9,6 @@ from PIL import Image
 
 def test_j2k_overflow(tmp_path: Path) -> None:
     im = Image.new("RGBA", (1024, 131584))
-    target = str(tmp_path / "temp.jpc")
+    target = tmp_path / "temp.jpc"
     with pytest.raises(OSError):
         im.save(target)

Tests/check_large_memory.py

@@ -32,7 +32,7 @@ pytestmark = pytest.mark.skipif(sys.maxsize <= 2**32, reason="requires 64-bit sy
 
 
 def _write_png(tmp_path: Path, xdim: int, ydim: int) -> None:
-    f = str(tmp_path / "temp.png")
+    f = tmp_path / "temp.png"
     im = Image.new("L", (xdim, ydim), 0)
     im.save(f)
 

Tests/check_large_memory_numpy.py

@@ -28,7 +28,7 @@ pytestmark = pytest.mark.skipif(sys.maxsize <= 2**32, reason="requires 64-bit sy
 def _write_png(tmp_path: Path, xdim: int, ydim: int) -> None:
     dtype = np.uint8
     a = np.zeros((xdim, ydim), dtype=dtype)
-    f = str(tmp_path / "temp.png")
+    f = tmp_path / "temp.png"
     im = Image.fromarray(a, "L")
     im.save(f)
 

Tests/check_wheel.py

@@ -1,20 +1,24 @@
 from __future__ import annotations
 
+import platform
 import sys
 
 from PIL import features
 
+from .helper import is_pypy
+
 
 def test_wheel_modules() -> None:
     expected_modules = {"pil", "tkinter", "freetype2", "littlecms2", "webp"}
 
-    # tkinter is not available in cibuildwheel installed CPython on Windows
+    if sys.platform == "win32":
-    try:
+        # tkinter is not available in cibuildwheel installed CPython on Windows
-        import tkinter
+        try:
+            import tkinter
 
-        assert tkinter
+            assert tkinter
-    except ImportError:
+        except ImportError:
-        expected_modules.remove("tkinter")
+            expected_modules.remove("tkinter")
 
     assert set(features.get_supported_modules()) == expected_modules
 
@@ -40,5 +44,7 @@ def test_wheel_features() -> None:
 
     if sys.platform == "win32":
         expected_features.remove("xcb")
+    elif sys.platform == "darwin" and not is_pypy() and platform.processor() != "arm":
+        expected_features.remove("zlib_ng")
 
     assert set(features.get_supported_features()) == expected_features

Tests/helper.py

@@ -13,6 +13,7 @@ import tempfile
 from collections.abc import Sequence
 from functools import lru_cache
 from io import BytesIO
+from pathlib import Path
 from typing import Any, Callable
 
 import pytest
@@ -95,7 +96,10 @@ def assert_image_equal(a: Image.Image, b: Image.Image, msg: str | None = None) -
 
 
 def assert_image_equal_tofile(
-    a: Image.Image, filename: str, msg: str | None = None, mode: str | None = None
+    a: Image.Image,
+    filename: str | Path,
+    msg: str | None = None,
+    mode: str | None = None,
 ) -> None:
     with Image.open(filename) as img:
         if mode:
@@ -136,7 +140,7 @@ def assert_image_similar(
 
 def assert_image_similar_tofile(
     a: Image.Image,
-    filename: str,
+    filename: str | Path,
     epsilon: float,
     msg: str | None = None,
 ) -> None:
@@ -157,6 +161,12 @@ def assert_tuple_approx_equal(
             pytest.fail(msg + ": " + repr(actuals) + " != " + repr(targets))
 
 
+def timeout_unless_slower_valgrind(timeout: float) -> pytest.MarkDecorator:
+    if "PILLOW_VALGRIND_TEST" in os.environ:
+        return pytest.mark.pil_noop_mark()
+    return pytest.mark.timeout(timeout)
+
+
 def skip_unless_feature(feature: str) -> pytest.MarkDecorator:
     reason = f"{feature} not available"
     return pytest.mark.skipif(not features.check(feature), reason=reason)

Tests/images/full_gimp_palette.gpl

@@ -0,0 +1,260 @@
+GIMP Palette
+Name: fullpalette
+Columns: 4
+#
+  0   0   0     Index 0
+  1   1   1     Index 1
+  2   2   2     Index 2
+  3   3   3     Index 3
+  4   4   4     Index 4
+  5   5   5     Index 5
+  6   6   6     Index 6
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Tests/oss-fuzz/python.supp

@@ -14,3 +14,23 @@
    fun:_TIFFReadEncodedTileAndAllocBuffer
    ...
 }
+
+{
+   <python_alloc_possible_leak>
+   Memcheck:Leak
+   match-leak-kinds: all
+   fun:malloc
+   fun:_PyMem_RawMalloc
+   fun:PyObject_Malloc
+   ...
+}
+
+{
+   <python_realloc_possible_leak>
+   Memcheck:Leak
+   match-leak-kinds: all
+   fun:malloc
+   fun:_PyMem_RawRealloc
+   fun:PyMem_Realloc
+   ...
+}

Tests/test_arrow.py

@@ -0,0 +1,164 @@
+from __future__ import annotations
+
+import pytest
+
+from PIL import Image
+
+from .helper import hopper
+
+
+@pytest.mark.parametrize(
+    "mode, dest_modes",
+    (
+        ("L", ["I", "F", "LA", "RGB", "RGBA", "RGBX", "CMYK", "YCbCr", "HSV"]),
+        ("I", ["L", "F"]),  # Technically I;32 can work for any 4x8bit storage.
+        ("F", ["I", "L", "LA", "RGB", "RGBA", "RGBX", "CMYK", "YCbCr", "HSV"]),
+        ("LA", ["L", "F"]),
+        ("RGB", ["L", "F"]),
+        ("RGBA", ["L", "F"]),
+        ("RGBX", ["L", "F"]),
+        ("CMYK", ["L", "F"]),
+        ("YCbCr", ["L", "F"]),
+        ("HSV", ["L", "F"]),
+    ),
+)
+def test_invalid_array_type(mode: str, dest_modes: list[str]) -> None:
+    img = hopper(mode)
+    for dest_mode in dest_modes:
+        with pytest.raises(ValueError):
+            Image.fromarrow(img, dest_mode, img.size)
+
+
+def test_invalid_array_size() -> None:
+    img = hopper("RGB")
+
+    assert img.size != (10, 10)
+    with pytest.raises(ValueError):
+        Image.fromarrow(img, "RGB", (10, 10))
+
+
+def test_release_schema() -> None:
+    # these should not error out, valgrind should be clean
+    img = hopper("L")
+    schema = img.__arrow_c_schema__()
+    del schema
+
+
+def test_release_array() -> None:
+    # these should not error out, valgrind should be clean
+    img = hopper("L")
+    array, schema = img.__arrow_c_array__()
+    del array
+    del schema
+
+
+def test_readonly() -> None:
+    img = hopper("L")
+    reloaded = Image.fromarrow(img, img.mode, img.size)
+    assert reloaded.readonly == 1
+    reloaded._readonly = 0
+    assert reloaded.readonly == 1
+
+
+def test_multiblock_l_image() -> None:
+    block_size = Image.core.get_block_size()
+
+    # check a 2 block image in single channel mode
+    size = (4096, 2 * block_size // 4096)
+    img = Image.new("L", size, 128)
+
+    with pytest.raises(ValueError):
+        (schema, arr) = img.__arrow_c_array__()
+
+
+def test_multiblock_rgba_image() -> None:
+    block_size = Image.core.get_block_size()
+
+    # check a 2 block image in 4 channel mode
+    size = (4096, (block_size // 4096) // 2)
+    img = Image.new("RGBA", size, (128, 127, 126, 125))
+
+    with pytest.raises(ValueError):
+        (schema, arr) = img.__arrow_c_array__()
+
+
+def test_multiblock_l_schema() -> None:
+    block_size = Image.core.get_block_size()
+
+    # check a 2 block image in single channel mode
+    size = (4096, 2 * block_size // 4096)
+    img = Image.new("L", size, 128)
+
+    with pytest.raises(ValueError):
+        img.__arrow_c_schema__()
+
+
+def test_multiblock_rgba_schema() -> None:
+    block_size = Image.core.get_block_size()
+
+    # check a 2 block image in 4 channel mode
+    size = (4096, (block_size // 4096) // 2)
+    img = Image.new("RGBA", size, (128, 127, 126, 125))
+
+    with pytest.raises(ValueError):
+        img.__arrow_c_schema__()
+
+
+def test_singleblock_l_image() -> None:
+    Image.core.set_use_block_allocator(1)
+
+    block_size = Image.core.get_block_size()
+
+    # check a 2 block image in 4 channel mode
+    size = (4096, 2 * (block_size // 4096))
+    img = Image.new("L", size, 128)
+    assert img.im.isblock()
+
+    (schema, arr) = img.__arrow_c_array__()
+    assert schema
+    assert arr
+
+    Image.core.set_use_block_allocator(0)
+
+
+def test_singleblock_rgba_image() -> None:
+    Image.core.set_use_block_allocator(1)
+    block_size = Image.core.get_block_size()
+
+    # check a 2 block image in 4 channel mode
+    size = (4096, (block_size // 4096) // 2)
+    img = Image.new("RGBA", size, (128, 127, 126, 125))
+    assert img.im.isblock()
+
+    (schema, arr) = img.__arrow_c_array__()
+    assert schema
+    assert arr
+    Image.core.set_use_block_allocator(0)
+
+
+def test_singleblock_l_schema() -> None:
+    Image.core.set_use_block_allocator(1)
+    block_size = Image.core.get_block_size()
+
+    # check a 2 block image in single channel mode
+    size = (4096, 2 * block_size // 4096)
+    img = Image.new("L", size, 128)
+    assert img.im.isblock()
+
+    schema = img.__arrow_c_schema__()
+    assert schema
+    Image.core.set_use_block_allocator(0)
+
+
+def test_singleblock_rgba_schema() -> None:
+    Image.core.set_use_block_allocator(1)
+    block_size = Image.core.get_block_size()
+
+    # check a 2 block image in 4 channel mode
+    size = (4096, (block_size // 4096) // 2)
+    img = Image.new("RGBA", size, (128, 127, 126, 125))
+    assert img.im.isblock()
+
+    schema = img.__arrow_c_schema__()
+    assert schema
+    Image.core.set_use_block_allocator(0)

Tests/test_deprecate.py

@@ -47,7 +47,6 @@ def test_unknown_version() -> None:
     ],
 )
 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)
 

Tests/test_file_apng.py

@@ -12,6 +12,7 @@ from PIL import Image, ImageSequence, PngImagePlugin
 # (referenced from https://wiki.mozilla.org/APNG_Specification)
 def test_apng_basic() -> None:
     with Image.open("Tests/images/apng/single_frame.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert not im.is_animated
         assert im.n_frames == 1
         assert im.get_format_mimetype() == "image/apng"
@@ -20,6 +21,7 @@ def test_apng_basic() -> None:
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
     with Image.open("Tests/images/apng/single_frame_default.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.is_animated
         assert im.n_frames == 2
         assert im.get_format_mimetype() == "image/apng"
@@ -52,6 +54,7 @@ def test_apng_basic() -> None:
 )
 def test_apng_fdat(filename: str) -> None:
     with Image.open(filename) as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
@@ -59,31 +62,37 @@ def test_apng_fdat(filename: str) -> None:
 
 def test_apng_dispose() -> None:
     with Image.open("Tests/images/apng/dispose_op_none.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
     with Image.open("Tests/images/apng/dispose_op_background.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 0, 0, 0)
         assert im.getpixel((64, 32)) == (0, 0, 0, 0)
 
     with Image.open("Tests/images/apng/dispose_op_background_final.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
     with Image.open("Tests/images/apng/dispose_op_previous.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
     with Image.open("Tests/images/apng/dispose_op_previous_final.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
     with Image.open("Tests/images/apng/dispose_op_previous_first.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 0, 0, 0)
         assert im.getpixel((64, 32)) == (0, 0, 0, 0)
@@ -91,21 +100,25 @@ def test_apng_dispose() -> None:
 
 def test_apng_dispose_region() -> None:
     with Image.open("Tests/images/apng/dispose_op_none_region.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
     with Image.open("Tests/images/apng/dispose_op_background_before_region.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 0, 0, 0)
         assert im.getpixel((64, 32)) == (0, 0, 0, 0)
 
     with Image.open("Tests/images/apng/dispose_op_background_region.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 0, 255, 255)
         assert im.getpixel((64, 32)) == (0, 0, 0, 0)
 
     with Image.open("Tests/images/apng/dispose_op_previous_region.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
@@ -132,6 +145,7 @@ def test_apng_dispose_op_previous_frame() -> None:
     #     ],
     # )
     with Image.open("Tests/images/apng/dispose_op_previous_frame.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (255, 0, 0, 255)
 
@@ -145,26 +159,31 @@ def test_apng_dispose_op_background_p_mode() -> None:
 
 def test_apng_blend() -> None:
     with Image.open("Tests/images/apng/blend_op_source_solid.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
     with Image.open("Tests/images/apng/blend_op_source_transparent.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 0, 0, 0)
         assert im.getpixel((64, 32)) == (0, 0, 0, 0)
 
     with Image.open("Tests/images/apng/blend_op_source_near_transparent.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 2)
         assert im.getpixel((64, 32)) == (0, 255, 0, 2)
 
     with Image.open("Tests/images/apng/blend_op_over.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
     with Image.open("Tests/images/apng/blend_op_over_near_transparent.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 97)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
@@ -178,6 +197,7 @@ def test_apng_blend_transparency() -> None:
 
 def test_apng_chunk_order() -> None:
     with Image.open("Tests/images/apng/fctl_actl.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
@@ -233,24 +253,28 @@ def test_apng_num_plays() -> None:
 
 def test_apng_mode() -> None:
     with Image.open("Tests/images/apng/mode_16bit.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.mode == "RGBA"
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 0, 128, 191)
         assert im.getpixel((64, 32)) == (0, 0, 128, 191)
 
     with Image.open("Tests/images/apng/mode_grayscale.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.mode == "L"
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == 128
         assert im.getpixel((64, 32)) == 255
 
     with Image.open("Tests/images/apng/mode_grayscale_alpha.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.mode == "LA"
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (128, 191)
         assert im.getpixel((64, 32)) == (128, 191)
 
     with Image.open("Tests/images/apng/mode_palette.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.mode == "P"
         im.seek(im.n_frames - 1)
         im = im.convert("RGB")
@@ -258,6 +282,7 @@ def test_apng_mode() -> None:
         assert im.getpixel((64, 32)) == (0, 255, 0)
 
     with Image.open("Tests/images/apng/mode_palette_alpha.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.mode == "P"
         im.seek(im.n_frames - 1)
         im = im.convert("RGBA")
@@ -265,6 +290,7 @@ def test_apng_mode() -> None:
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
     with Image.open("Tests/images/apng/mode_palette_1bit_alpha.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.mode == "P"
         im.seek(im.n_frames - 1)
         im = im.convert("RGBA")
@@ -274,25 +300,31 @@ def test_apng_mode() -> None:
 
 def test_apng_chunk_errors() -> None:
     with Image.open("Tests/images/apng/chunk_no_actl.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert not im.is_animated
 
     with pytest.warns(UserWarning):
         with Image.open("Tests/images/apng/chunk_multi_actl.png") as im:
             im.load()
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert not im.is_animated
 
     with Image.open("Tests/images/apng/chunk_actl_after_idat.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert not im.is_animated
 
     with Image.open("Tests/images/apng/chunk_no_fctl.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         with pytest.raises(SyntaxError):
             im.seek(im.n_frames - 1)
 
     with Image.open("Tests/images/apng/chunk_repeat_fctl.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         with pytest.raises(SyntaxError):
             im.seek(im.n_frames - 1)
 
     with Image.open("Tests/images/apng/chunk_no_fdat.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         with pytest.raises(SyntaxError):
             im.seek(im.n_frames - 1)
 
@@ -300,26 +332,31 @@ def test_apng_chunk_errors() -> None:
 def test_apng_syntax_errors() -> None:
     with pytest.warns(UserWarning):
         with Image.open("Tests/images/apng/syntax_num_frames_zero.png") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
             assert not im.is_animated
             with pytest.raises(OSError):
                 im.load()
 
     with pytest.warns(UserWarning):
         with Image.open("Tests/images/apng/syntax_num_frames_zero_default.png") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
             assert not im.is_animated
             im.load()
 
     # we can handle this case gracefully
     with Image.open("Tests/images/apng/syntax_num_frames_low.png") as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
 
     with pytest.raises(OSError):
         with Image.open("Tests/images/apng/syntax_num_frames_high.png") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
             im.seek(im.n_frames - 1)
             im.load()
 
     with pytest.warns(UserWarning):
         with Image.open("Tests/images/apng/syntax_num_frames_invalid.png") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
             assert not im.is_animated
             im.load()
 
@@ -339,16 +376,18 @@ def test_apng_syntax_errors() -> None:
 def test_apng_sequence_errors(test_file: str) -> None:
     with pytest.raises(SyntaxError):
         with Image.open(f"Tests/images/apng/{test_file}") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
             im.seek(im.n_frames - 1)
             im.load()
 
 
 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")
+        test_file = tmp_path / "temp.png"
         im.save(test_file, save_all=True)
 
     with Image.open(test_file) as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.load()
         assert not im.is_animated
         assert im.n_frames == 1
@@ -364,6 +403,7 @@ def test_apng_save(tmp_path: Path) -> None:
         )
 
     with Image.open(test_file) as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.load()
         assert im.is_animated
         assert im.n_frames == 2
@@ -375,7 +415,7 @@ def test_apng_save(tmp_path: Path) -> None:
 
 
 def test_apng_save_alpha(tmp_path: Path) -> None:
-    test_file = str(tmp_path / "temp.png")
+    test_file = tmp_path / "temp.png"
 
     im = Image.new("RGBA", (1, 1), (255, 0, 0, 255))
     im2 = Image.new("RGBA", (1, 1), (255, 0, 0, 127))
@@ -393,7 +433,7 @@ def test_apng_save_split_fdat(tmp_path: Path) -> None:
     # frames with image data spanning multiple fdAT chunks (in this case
     # both the default image and first animation frame will span multiple
     # data chunks)
-    test_file = str(tmp_path / "temp.png")
+    test_file = tmp_path / "temp.png"
     with Image.open("Tests/images/old-style-jpeg-compression.png") as im:
         frames = [im.copy(), Image.new("RGBA", im.size, (255, 0, 0, 255))]
         im.save(
@@ -403,12 +443,13 @@ def test_apng_save_split_fdat(tmp_path: Path) -> None:
             append_images=frames,
         )
     with Image.open(test_file) as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         im.seek(im.n_frames - 1)
         im.load()
 
 
 def test_apng_save_duration_loop(tmp_path: Path) -> None:
-    test_file = str(tmp_path / "temp.png")
+    test_file = tmp_path / "temp.png"
     with Image.open("Tests/images/apng/delay.png") as im:
         frames = []
         durations = []
@@ -445,6 +486,7 @@ def test_apng_save_duration_loop(tmp_path: Path) -> None:
         test_file, save_all=True, append_images=[frame, frame], duration=[500, 100, 150]
     )
     with Image.open(test_file) as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.n_frames == 1
         assert "duration" not in im.info
 
@@ -456,6 +498,7 @@ def test_apng_save_duration_loop(tmp_path: Path) -> None:
         duration=[500, 100, 150],
     )
     with Image.open(test_file) as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.n_frames == 2
         assert im.info["duration"] == 600
 
@@ -466,12 +509,13 @@ def test_apng_save_duration_loop(tmp_path: Path) -> None:
     frame.info["duration"] = 300
     frame.save(test_file, save_all=True, append_images=[frame, different_frame])
     with Image.open(test_file) as im:
+        assert isinstance(im, PngImagePlugin.PngImageFile)
         assert im.n_frames == 2
         assert im.info["duration"] == 600
 
 
 def test_apng_save_disposal(tmp_path: Path) -> None:
-    test_file = str(tmp_path / "temp.png")
+    test_file = tmp_path / "temp.png"
     size = (128, 64)
     red = Image.new("RGBA", size, (255, 0, 0, 255))
     green = Image.new("RGBA", size, (0, 255, 0, 255))
@@ -572,7 +616,7 @@ def test_apng_save_disposal(tmp_path: Path) -> None:
 
 
 def test_apng_save_disposal_previous(tmp_path: Path) -> None:
-    test_file = str(tmp_path / "temp.png")
+    test_file = tmp_path / "temp.png"
     size = (128, 64)
     blue = Image.new("RGBA", size, (0, 0, 255, 255))
     red = Image.new("RGBA", size, (255, 0, 0, 255))
@@ -594,7 +638,7 @@ def test_apng_save_disposal_previous(tmp_path: Path) -> None:
 
 
 def test_apng_save_blend(tmp_path: Path) -> None:
-    test_file = str(tmp_path / "temp.png")
+    test_file = tmp_path / "temp.png"
     size = (128, 64)
     red = Image.new("RGBA", size, (255, 0, 0, 255))
     green = Image.new("RGBA", size, (0, 255, 0, 255))
@@ -662,7 +706,7 @@ def test_apng_save_blend(tmp_path: Path) -> None:
 
 
 def test_apng_save_size(tmp_path: Path) -> None:
-    test_file = str(tmp_path / "temp.png")
+    test_file = tmp_path / "temp.png"
 
     im = Image.new("L", (100, 100))
     im.save(test_file, save_all=True, append_images=[Image.new("L", (200, 200))])
@@ -686,7 +730,7 @@ def test_seek_after_close() -> None:
 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")
+    test_file = tmp_path / "temp.png"
 
     im = Image.new("L", (1, 1))
     im.save(
@@ -700,7 +744,7 @@ def test_different_modes_in_later_frames(
 
 
 def test_different_durations(tmp_path: Path) -> None:
-    test_file = str(tmp_path / "temp.png")
+    test_file = tmp_path / "temp.png"
 
     with Image.open("Tests/images/apng/different_durations.png") as im:
         for _ in range(3):

Tests/test_file_avif.py

@@ -0,0 +1,779 @@
+from __future__ import annotations
+
+import gc
+import os
+import re
+import warnings
+from collections.abc import Generator, Sequence
+from contextlib import contextmanager
+from io import BytesIO
+from pathlib import Path
+from typing import Any
+
+import pytest
+
+from PIL import (
+    AvifImagePlugin,
+    Image,
+    ImageDraw,
+    ImageFile,
+    UnidentifiedImageError,
+    features,
+)
+
+from .helper import (
+    PillowLeakTestCase,
+    assert_image,
+    assert_image_similar,
+    assert_image_similar_tofile,
+    hopper,
+    skip_unless_feature,
+)
+
+try:
+    from PIL import _avif
+
+    HAVE_AVIF = True
+except ImportError:
+    HAVE_AVIF = False
+
+
+TEST_AVIF_FILE = "Tests/images/avif/hopper.avif"
+
+
+def assert_xmp_orientation(xmp: bytes, expected: int) -> None:
+    assert int(xmp.split(b'tiff:Orientation="')[1].split(b'"')[0]) == expected
+
+
+def roundtrip(im: ImageFile.ImageFile, **options: Any) -> ImageFile.ImageFile:
+    out = BytesIO()
+    im.save(out, "AVIF", **options)
+    return Image.open(out)
+
+
+def skip_unless_avif_decoder(codec_name: str) -> pytest.MarkDecorator:
+    reason = f"{codec_name} decode not available"
+    return pytest.mark.skipif(
+        not HAVE_AVIF or not _avif.decoder_codec_available(codec_name), reason=reason
+    )
+
+
+def skip_unless_avif_encoder(codec_name: str) -> pytest.MarkDecorator:
+    reason = f"{codec_name} encode not available"
+    return pytest.mark.skipif(
+        not HAVE_AVIF or not _avif.encoder_codec_available(codec_name), reason=reason
+    )
+
+
+def is_docker_qemu() -> bool:
+    try:
+        init_proc_exe = os.readlink("/proc/1/exe")
+    except (FileNotFoundError, PermissionError):
+        return False
+    return "qemu" in init_proc_exe
+
+
+class TestUnsupportedAvif:
+    def test_unsupported(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setattr(AvifImagePlugin, "SUPPORTED", False)
+
+        with pytest.warns(UserWarning):
+            with pytest.raises(UnidentifiedImageError):
+                with Image.open(TEST_AVIF_FILE):
+                    pass
+
+    def test_unsupported_open(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setattr(AvifImagePlugin, "SUPPORTED", False)
+
+        with pytest.raises(SyntaxError):
+            AvifImagePlugin.AvifImageFile(TEST_AVIF_FILE)
+
+
+@skip_unless_feature("avif")
+class TestFileAvif:
+    def test_version(self) -> None:
+        version = features.version_module("avif")
+        assert version is not None
+        assert re.search(r"^\d+\.\d+\.\d+$", version)
+
+    def test_codec_version(self) -> None:
+        assert AvifImagePlugin.get_codec_version("unknown") is None
+
+        for codec_name in ("aom", "dav1d", "rav1e", "svt"):
+            codec_version = AvifImagePlugin.get_codec_version(codec_name)
+            if _avif.decoder_codec_available(
+                codec_name
+            ) or _avif.encoder_codec_available(codec_name):
+                assert codec_version is not None
+                assert re.search(r"^v?\d+\.\d+\.\d+(-([a-z\d])+)*$", codec_version)
+            else:
+                assert codec_version is None
+
+    def test_read(self) -> None:
+        """
+        Can we read an AVIF file without error?
+        Does it have the bits we expect?
+        """
+
+        with Image.open(TEST_AVIF_FILE) as image:
+            assert image.mode == "RGB"
+            assert image.size == (128, 128)
+            assert image.format == "AVIF"
+            assert image.get_format_mimetype() == "image/avif"
+            image.getdata()
+
+            # generated with:
+            # avifdec hopper.avif hopper_avif_write.png
+            assert_image_similar_tofile(
+                image, "Tests/images/avif/hopper_avif_write.png", 11.5
+            )
+
+    def test_write_rgb(self, tmp_path: Path) -> None:
+        """
+        Can we write a RGB mode file to avif without error?
+        Does it have the bits we expect?
+        """
+
+        temp_file = tmp_path / "temp.avif"
+
+        im = hopper()
+        im.save(temp_file)
+        with Image.open(temp_file) as reloaded:
+            assert reloaded.mode == "RGB"
+            assert reloaded.size == (128, 128)
+            assert reloaded.format == "AVIF"
+            reloaded.getdata()
+
+            # avifdec hopper.avif avif/hopper_avif_write.png
+            assert_image_similar_tofile(
+                reloaded, "Tests/images/avif/hopper_avif_write.png", 6.02
+            )
+
+            # This test asserts that the images are similar. If the average pixel
+            # difference between the two images is less than the epsilon value,
+            # then we're going to accept that it's a reasonable lossy version of
+            # the image.
+            assert_image_similar(reloaded, im, 8.62)
+
+    def test_AvifEncoder_with_invalid_args(self) -> None:
+        """
+        Calling encoder functions with no arguments should result in an error.
+        """
+        with pytest.raises(TypeError):
+            _avif.AvifEncoder()
+
+    def test_AvifDecoder_with_invalid_args(self) -> None:
+        """
+        Calling decoder functions with no arguments should result in an error.
+        """
+        with pytest.raises(TypeError):
+            _avif.AvifDecoder()
+
+    def test_invalid_dimensions(self, tmp_path: Path) -> None:
+        test_file = tmp_path / "temp.avif"
+        im = Image.new("RGB", (0, 0))
+        with pytest.raises(ValueError):
+            im.save(test_file)
+
+    def test_encoder_finish_none_error(
+        self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+    ) -> None:
+        """Save should raise an OSError if AvifEncoder.finish returns None"""
+
+        class _mock_avif:
+            class AvifEncoder:
+                def __init__(self, *args: Any) -> None:
+                    pass
+
+                def add(self, *args: Any) -> None:
+                    pass
+
+                def finish(self) -> None:
+                    return None
+
+        monkeypatch.setattr(AvifImagePlugin, "_avif", _mock_avif)
+
+        im = Image.new("RGB", (150, 150))
+        test_file = tmp_path / "temp.avif"
+        with pytest.raises(OSError):
+            im.save(test_file)
+
+    def test_no_resource_warning(self, tmp_path: Path) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            with warnings.catch_warnings():
+                warnings.simplefilter("error")
+
+                im.save(tmp_path / "temp.avif")
+
+    @pytest.mark.parametrize("major_brand", [b"avif", b"avis", b"mif1", b"msf1"])
+    def test_accept_ftyp_brands(self, major_brand: bytes) -> None:
+        data = b"\x00\x00\x00\x1cftyp%s\x00\x00\x00\x00" % major_brand
+        assert AvifImagePlugin._accept(data) is True
+
+    def test_file_pointer_could_be_reused(self) -> None:
+        with open(TEST_AVIF_FILE, "rb") as blob:
+            with Image.open(blob) as im:
+                im.load()
+            with Image.open(blob) as im:
+                im.load()
+
+    def test_background_from_gif(self, tmp_path: Path) -> None:
+        with Image.open("Tests/images/chi.gif") as im:
+            original_value = im.convert("RGB").getpixel((1, 1))
+
+            # Save as AVIF
+            out_avif = tmp_path / "temp.avif"
+            im.save(out_avif, save_all=True)
+
+        # Save as GIF
+        out_gif = tmp_path / "temp.gif"
+        with Image.open(out_avif) as im:
+            im.save(out_gif)
+
+        with Image.open(out_gif) as reread:
+            reread_value = reread.convert("RGB").getpixel((1, 1))
+        difference = sum([abs(original_value[i] - reread_value[i]) for i in range(3)])
+        assert difference <= 6
+
+    def test_save_single_frame(self, tmp_path: Path) -> None:
+        temp_file = tmp_path / "temp.avif"
+        with Image.open("Tests/images/chi.gif") as im:
+            im.save(temp_file)
+        with Image.open(temp_file) as im:
+            assert im.n_frames == 1
+
+    def test_invalid_file(self) -> None:
+        invalid_file = "Tests/images/flower.jpg"
+
+        with pytest.raises(SyntaxError):
+            AvifImagePlugin.AvifImageFile(invalid_file)
+
+    def test_load_transparent_rgb(self) -> None:
+        test_file = "Tests/images/avif/transparency.avif"
+        with Image.open(test_file) as im:
+            assert_image(im, "RGBA", (64, 64))
+
+            # image has 876 transparent pixels
+            assert im.getchannel("A").getcolors()[0] == (876, 0)
+
+    def test_save_transparent(self, tmp_path: Path) -> None:
+        im = Image.new("RGBA", (10, 10), (0, 0, 0, 0))
+        assert im.getcolors() == [(100, (0, 0, 0, 0))]
+
+        test_file = tmp_path / "temp.avif"
+        im.save(test_file)
+
+        # check if saved image contains the same transparency
+        with Image.open(test_file) as im:
+            assert_image(im, "RGBA", (10, 10))
+            assert im.getcolors() == [(100, (0, 0, 0, 0))]
+
+    def test_save_icc_profile(self) -> None:
+        with Image.open("Tests/images/avif/icc_profile_none.avif") as im:
+            assert "icc_profile" not in im.info
+
+            with Image.open("Tests/images/avif/icc_profile.avif") as with_icc:
+                expected_icc = with_icc.info["icc_profile"]
+                assert expected_icc is not None
+
+                im = roundtrip(im, icc_profile=expected_icc)
+                assert im.info["icc_profile"] == expected_icc
+
+    def test_discard_icc_profile(self) -> None:
+        with Image.open("Tests/images/avif/icc_profile.avif") as im:
+            im = roundtrip(im, icc_profile=None)
+        assert "icc_profile" not in im.info
+
+    def test_roundtrip_icc_profile(self) -> None:
+        with Image.open("Tests/images/avif/icc_profile.avif") 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) -> None:
+        with Image.open("Tests/images/avif/icc_profile_none.avif") as im:
+            assert "icc_profile" not in im.info
+
+            im = roundtrip(im)
+        assert "icc_profile" not in im.info
+
+    def test_exif(self) -> None:
+        # With an EXIF chunk
+        with Image.open("Tests/images/avif/exif.avif") as im:
+            exif = im.getexif()
+        assert exif[274] == 1
+
+        with Image.open("Tests/images/avif/xmp_tags_orientation.avif") as im:
+            exif = im.getexif()
+        assert exif[274] == 3
+
+    @pytest.mark.parametrize("use_bytes", [True, False])
+    @pytest.mark.parametrize("orientation", [1, 2, 3, 4, 5, 6, 7, 8])
+    def test_exif_save(
+        self,
+        tmp_path: Path,
+        use_bytes: bool,
+        orientation: int,
+    ) -> None:
+        exif = Image.Exif()
+        exif[274] = orientation
+        exif_data = exif.tobytes()
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            im.save(test_file, exif=exif_data if use_bytes else exif)
+
+        with Image.open(test_file) as reloaded:
+            if orientation == 1:
+                assert "exif" not in reloaded.info
+            else:
+                assert reloaded.getexif()[274] == orientation
+                assert reloaded.info["exif"] == exif_data
+
+    def test_exif_without_orientation(self, tmp_path: Path) -> None:
+        exif = Image.Exif()
+        exif[272] = b"test"
+        exif_data = exif.tobytes()
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            im.save(test_file, exif=exif)
+
+        with Image.open(test_file) as reloaded:
+            assert reloaded.info["exif"] == exif_data
+
+    def test_exif_invalid(self, tmp_path: Path) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            with pytest.raises(SyntaxError):
+                im.save(test_file, exif=b"invalid")
+
+    @pytest.mark.parametrize(
+        "rot, mir, exif_orientation",
+        [
+            (0, 0, 4),
+            (0, 1, 2),
+            (1, 0, 5),
+            (1, 1, 7),
+            (2, 0, 2),
+            (2, 1, 4),
+            (3, 0, 7),
+            (3, 1, 5),
+        ],
+    )
+    def test_rot_mir_exif(
+        self, rot: int, mir: int, exif_orientation: int, tmp_path: Path
+    ) -> None:
+        with Image.open(f"Tests/images/avif/rot{rot}mir{mir}.avif") as im:
+            exif = im.getexif()
+            assert exif[274] == exif_orientation
+
+            test_file = tmp_path / "temp.avif"
+            im.save(test_file, exif=exif)
+        with Image.open(test_file) as reloaded:
+            assert reloaded.getexif()[274] == exif_orientation
+
+    def test_xmp(self) -> None:
+        with Image.open("Tests/images/avif/xmp_tags_orientation.avif") as im:
+            xmp = im.info["xmp"]
+        assert_xmp_orientation(xmp, 3)
+
+    def test_xmp_save(self, tmp_path: Path) -> None:
+        xmp_arg = "\n".join(
+            [
+                '<?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>',
+                '<x:xmpmeta xmlns:x="adobe:ns:meta/">',
+                ' <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">',
+                '  <rdf:Description rdf:about=""',
+                '    xmlns:tiff="http://ns.adobe.com/tiff/1.0/"',
+                '   tiff:Orientation="1"/>',
+                " </rdf:RDF>",
+                "</x:xmpmeta>",
+                '<?xpacket end="r"?>',
+            ]
+        )
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            im.save(test_file, xmp=xmp_arg)
+
+        with Image.open(test_file) as reloaded:
+            xmp = reloaded.info["xmp"]
+        assert_xmp_orientation(xmp, 1)
+
+    def test_tell(self) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            assert im.tell() == 0
+
+    def test_seek(self) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            im.seek(0)
+
+            with pytest.raises(EOFError):
+                im.seek(1)
+
+    @pytest.mark.parametrize("subsampling", ["4:4:4", "4:2:2", "4:2:0", "4:0:0"])
+    def test_encoder_subsampling(self, tmp_path: Path, subsampling: str) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            im.save(test_file, subsampling=subsampling)
+
+    def test_encoder_subsampling_invalid(self, tmp_path: Path) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            with pytest.raises(ValueError):
+                im.save(test_file, subsampling="foo")
+
+    @pytest.mark.parametrize("value", ["full", "limited"])
+    def test_encoder_range(self, tmp_path: Path, value: str) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            im.save(test_file, range=value)
+
+    def test_encoder_range_invalid(self, tmp_path: Path) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            with pytest.raises(ValueError):
+                im.save(test_file, range="foo")
+
+    @skip_unless_avif_encoder("aom")
+    def test_encoder_codec_param(self, tmp_path: Path) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            im.save(test_file, codec="aom")
+
+    def test_encoder_codec_invalid(self, tmp_path: Path) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            with pytest.raises(ValueError):
+                im.save(test_file, codec="foo")
+
+    @skip_unless_avif_decoder("dav1d")
+    def test_decoder_codec_cannot_encode(self, tmp_path: Path) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            with pytest.raises(ValueError):
+                im.save(test_file, codec="dav1d")
+
+    @skip_unless_avif_encoder("aom")
+    @pytest.mark.parametrize(
+        "advanced",
+        [
+            {
+                "aq-mode": "1",
+                "enable-chroma-deltaq": "1",
+            },
+            (("aq-mode", "1"), ("enable-chroma-deltaq", "1")),
+            [("aq-mode", "1"), ("enable-chroma-deltaq", "1")],
+        ],
+    )
+    def test_encoder_advanced_codec_options(
+        self, advanced: dict[str, str] | Sequence[tuple[str, str]]
+    ) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            ctrl_buf = BytesIO()
+            im.save(ctrl_buf, "AVIF", codec="aom")
+            test_buf = BytesIO()
+            im.save(
+                test_buf,
+                "AVIF",
+                codec="aom",
+                advanced=advanced,
+            )
+            assert ctrl_buf.getvalue() != test_buf.getvalue()
+
+    @skip_unless_avif_encoder("aom")
+    @pytest.mark.parametrize("advanced", [{"foo": "bar"}, {"foo": 1234}, 1234])
+    def test_encoder_advanced_codec_options_invalid(
+        self, tmp_path: Path, advanced: dict[str, str] | int
+    ) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            with pytest.raises(ValueError):
+                im.save(test_file, codec="aom", advanced=advanced)
+
+    @skip_unless_avif_decoder("aom")
+    def test_decoder_codec_param(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setattr(AvifImagePlugin, "DECODE_CODEC_CHOICE", "aom")
+
+        with Image.open(TEST_AVIF_FILE) as im:
+            assert im.size == (128, 128)
+
+    @skip_unless_avif_encoder("rav1e")
+    def test_encoder_codec_cannot_decode(
+        self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+    ) -> None:
+        monkeypatch.setattr(AvifImagePlugin, "DECODE_CODEC_CHOICE", "rav1e")
+
+        with pytest.raises(ValueError):
+            with Image.open(TEST_AVIF_FILE):
+                pass
+
+    def test_decoder_codec_invalid(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setattr(AvifImagePlugin, "DECODE_CODEC_CHOICE", "foo")
+
+        with pytest.raises(ValueError):
+            with Image.open(TEST_AVIF_FILE):
+                pass
+
+    @skip_unless_avif_encoder("aom")
+    def test_encoder_codec_available(self) -> None:
+        assert _avif.encoder_codec_available("aom") is True
+
+    def test_encoder_codec_available_bad_params(self) -> None:
+        with pytest.raises(TypeError):
+            _avif.encoder_codec_available()
+
+    @skip_unless_avif_decoder("dav1d")
+    def test_encoder_codec_available_cannot_decode(self) -> None:
+        assert _avif.encoder_codec_available("dav1d") is False
+
+    def test_encoder_codec_available_invalid(self) -> None:
+        assert _avif.encoder_codec_available("foo") is False
+
+    def test_encoder_quality_valueerror(self, tmp_path: Path) -> None:
+        with Image.open(TEST_AVIF_FILE) as im:
+            test_file = tmp_path / "temp.avif"
+            with pytest.raises(ValueError):
+                im.save(test_file, quality="invalid")
+
+    @skip_unless_avif_decoder("aom")
+    def test_decoder_codec_available(self) -> None:
+        assert _avif.decoder_codec_available("aom") is True
+
+    def test_decoder_codec_available_bad_params(self) -> None:
+        with pytest.raises(TypeError):
+            _avif.decoder_codec_available()
+
+    @skip_unless_avif_encoder("rav1e")
+    def test_decoder_codec_available_cannot_decode(self) -> None:
+        assert _avif.decoder_codec_available("rav1e") is False
+
+    def test_decoder_codec_available_invalid(self) -> None:
+        assert _avif.decoder_codec_available("foo") is False
+
+    def test_p_mode_transparency(self, tmp_path: Path) -> None:
+        im = Image.new("P", size=(64, 64))
+        draw = ImageDraw.Draw(im)
+        draw.rectangle(xy=[(0, 0), (32, 32)], fill=255)
+        draw.rectangle(xy=[(32, 32), (64, 64)], fill=255)
+
+        out_png = tmp_path / "temp.png"
+        im.save(out_png, transparency=0)
+        with Image.open(out_png) as im_png:
+            out_avif = tmp_path / "temp.avif"
+            im_png.save(out_avif, quality=100)
+
+            with Image.open(out_avif) as expected:
+                assert_image_similar(im_png.convert("RGBA"), expected, 0.17)
+
+    def test_decoder_strict_flags(self) -> None:
+        # This would fail if full avif strictFlags were enabled
+        with Image.open("Tests/images/avif/hopper-missing-pixi.avif") as im:
+            assert im.size == (128, 128)
+
+    @skip_unless_avif_encoder("aom")
+    @pytest.mark.parametrize("speed", [-1, 1, 11])
+    def test_aom_optimizations(self, tmp_path: Path, speed: int) -> None:
+        test_file = tmp_path / "temp.avif"
+        hopper().save(test_file, codec="aom", speed=speed)
+
+    @skip_unless_avif_encoder("svt")
+    def test_svt_optimizations(self, tmp_path: Path) -> None:
+        test_file = tmp_path / "temp.avif"
+        hopper().save(test_file, codec="svt", speed=1)
+
+
+@skip_unless_feature("avif")
+class TestAvifAnimation:
+    @contextmanager
+    def star_frames(self) -> Generator[list[Image.Image], None, None]:
+        with Image.open("Tests/images/avif/star.png") as f:
+            yield [f, f.rotate(90), f.rotate(180), f.rotate(270)]
+
+    def test_n_frames(self) -> None:
+        """
+        Ensure that AVIF format sets n_frames and is_animated attributes
+        correctly.
+        """
+
+        with Image.open(TEST_AVIF_FILE) as im:
+            assert im.n_frames == 1
+            assert not im.is_animated
+
+        with Image.open("Tests/images/avif/star.avifs") as im:
+            assert im.n_frames == 5
+            assert im.is_animated
+
+    def test_write_animation_P(self, tmp_path: Path) -> None:
+        """
+        Convert an animated GIF to animated AVIF, then compare the frame
+        count, and ensure the frames are visually similar to the originals.
+        """
+
+        with Image.open("Tests/images/avif/star.gif") as original:
+            assert original.n_frames > 1
+
+            temp_file = tmp_path / "temp.avif"
+            original.save(temp_file, save_all=True)
+            with Image.open(temp_file) as im:
+                assert im.n_frames == original.n_frames
+
+                # Compare first frame in P mode to frame from original GIF
+                assert_image_similar(im, original.convert("RGBA"), 2)
+
+                # Compare later frames in RGBA mode to frames from original GIF
+                for frame in range(1, original.n_frames):
+                    original.seek(frame)
+                    im.seek(frame)
+                    assert_image_similar(im, original, 2.54)
+
+    def test_write_animation_RGBA(self, tmp_path: Path) -> None:
+        """
+        Write an animated AVIF from RGBA frames, and ensure the frames
+        are visually similar to the originals.
+        """
+
+        def check(temp_file: Path) -> None:
+            with Image.open(temp_file) as im:
+                assert im.n_frames == 4
+
+                # Compare first frame to original
+                assert_image_similar(im, frame1, 2.7)
+
+                # Compare second frame to original
+                im.seek(1)
+                assert_image_similar(im, frame2, 4.1)
+
+        with self.star_frames() as frames:
+            frame1 = frames[0]
+            frame2 = frames[1]
+            temp_file1 = tmp_path / "temp.avif"
+            frames[0].copy().save(temp_file1, save_all=True, append_images=frames[1:])
+            check(temp_file1)
+
+            # Test appending using a generator
+            def imGenerator(
+                ims: list[Image.Image],
+            ) -> Generator[Image.Image, None, None]:
+                yield from ims
+
+            temp_file2 = tmp_path / "temp_generator.avif"
+            frames[0].copy().save(
+                temp_file2,
+                save_all=True,
+                append_images=imGenerator(frames[1:]),
+            )
+            check(temp_file2)
+
+    def test_sequence_dimension_mismatch_check(self, tmp_path: Path) -> None:
+        temp_file = tmp_path / "temp.avif"
+        frame1 = Image.new("RGB", (100, 100))
+        frame2 = Image.new("RGB", (150, 150))
+        with pytest.raises(ValueError):
+            frame1.save(temp_file, save_all=True, append_images=[frame2])
+
+    def test_heif_raises_unidentified_image_error(self) -> None:
+        with pytest.raises(UnidentifiedImageError):
+            with Image.open("Tests/images/avif/hopper.heif"):
+                pass
+
+    @pytest.mark.parametrize("alpha_premultiplied", [False, True])
+    def test_alpha_premultiplied(
+        self, tmp_path: Path, alpha_premultiplied: bool
+    ) -> None:
+        temp_file = tmp_path / "temp.avif"
+        color = (200, 200, 200, 1)
+        im = Image.new("RGBA", (1, 1), color)
+        im.save(temp_file, alpha_premultiplied=alpha_premultiplied)
+
+        expected = (255, 255, 255, 1) if alpha_premultiplied else color
+        with Image.open(temp_file) as reloaded:
+            assert reloaded.getpixel((0, 0)) == expected
+
+    def test_timestamp_and_duration(self, tmp_path: Path) -> None:
+        """
+        Try passing a list of durations, and make sure the encoded
+        timestamps and durations are correct.
+        """
+
+        durations = [1, 10, 20, 30, 40]
+        temp_file = tmp_path / "temp.avif"
+        with self.star_frames() as frames:
+            frames[0].save(
+                temp_file,
+                save_all=True,
+                append_images=(frames[1:] + [frames[0]]),
+                duration=durations,
+            )
+
+        with Image.open(temp_file) as im:
+            assert im.n_frames == 5
+            assert im.is_animated
+
+            # Check that timestamps and durations match original values specified
+            timestamp = 0
+            for frame in range(im.n_frames):
+                im.seek(frame)
+                im.load()
+                assert im.info["duration"] == durations[frame]
+                assert im.info["timestamp"] == timestamp
+                timestamp += durations[frame]
+
+    def test_seeking(self, tmp_path: Path) -> None:
+        """
+        Create an animated AVIF file, and then try seeking through frames in
+        reverse-order, verifying the timestamps and durations are correct.
+        """
+
+        duration = 33
+        temp_file = tmp_path / "temp.avif"
+        with self.star_frames() as frames:
+            frames[0].save(
+                temp_file,
+                save_all=True,
+                append_images=(frames[1:] + [frames[0]]),
+                duration=duration,
+            )
+
+        with Image.open(temp_file) as im:
+            assert im.n_frames == 5
+            assert im.is_animated
+
+            # Traverse frames in reverse, checking timestamps and durations
+            timestamp = duration * (im.n_frames - 1)
+            for frame in reversed(range(im.n_frames)):
+                im.seek(frame)
+                im.load()
+                assert im.info["duration"] == duration
+                assert im.info["timestamp"] == timestamp
+                timestamp -= duration
+
+    def test_seek_errors(self) -> None:
+        with Image.open("Tests/images/avif/star.avifs") as im:
+            with pytest.raises(EOFError):
+                im.seek(-1)
+
+            with pytest.raises(EOFError):
+                im.seek(42)
+
+
+MAX_THREADS = os.cpu_count() or 1
+
+
+@skip_unless_feature("avif")
+class TestAvifLeaks(PillowLeakTestCase):
+    mem_limit = MAX_THREADS * 3 * 1024
+    iterations = 100
+
+    @pytest.mark.skipif(
+        is_docker_qemu(), reason="Skipping on cross-architecture containers"
+    )
+    def test_leak_load(self) -> None:
+        with open(TEST_AVIF_FILE, "rb") as f:
+            im_data = f.read()
+
+        def core() -> None:
+            with Image.open(BytesIO(im_data)) as im:
+                im.load()
+            gc.collect()
+
+        self._test_leak(core)

Tests/test_file_blp.py

@@ -46,7 +46,7 @@ def test_invalid_file() -> None:
 
 
 def test_save(tmp_path: Path) -> None:
-    f = str(tmp_path / "temp.blp")
+    f = tmp_path / "temp.blp"
 
     for version in ("BLP1", "BLP2"):
         im = hopper("P")
@@ -56,7 +56,7 @@ def test_save(tmp_path: Path) -> None:
             assert_image_equal(im.convert("RGB"), reloaded)
 
         with Image.open("Tests/images/transparent.png") as im:
-            f = str(tmp_path / "temp.blp")
+            f = tmp_path / "temp.blp"
             im.convert("P").save(f, blp_version=version)
 
             with Image.open(f) as reloaded:

Tests/test_file_bmp.py

@@ -15,25 +15,19 @@ from .helper import (
 )
 
 
-def test_sanity(tmp_path: Path) -> None:
+@pytest.mark.parametrize("mode", ("1", "L", "P", "RGB"))
-    def roundtrip(im: Image.Image) -> None:
+def test_sanity(mode: str, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.bmp")
+    outfile = tmp_path / "temp.bmp"
 
-        im.save(outfile, "BMP")
+    im = hopper(mode)
+    im.save(outfile, "BMP")
 
-        with Image.open(outfile) as reloaded:
+    with Image.open(outfile) as reloaded:
-            reloaded.load()
+        reloaded.load()
-            assert im.mode == reloaded.mode
+        assert im.mode == reloaded.mode
-            assert im.size == reloaded.size
+        assert im.size == reloaded.size
-            assert reloaded.format == "BMP"
+        assert reloaded.format == "BMP"
-            assert reloaded.get_format_mimetype() == "image/bmp"
+        assert reloaded.get_format_mimetype() == "image/bmp"
-
-    roundtrip(hopper())
-
-    roundtrip(hopper("1"))
-    roundtrip(hopper("L"))
-    roundtrip(hopper("P"))
-    roundtrip(hopper("RGB"))
 
 
 def test_invalid_file() -> None:
@@ -66,7 +60,7 @@ def test_small_palette(tmp_path: Path) -> None:
     colors = [0, 0, 0, 125, 125, 125, 255, 255, 255]
     im.putpalette(colors)
 
-    out = str(tmp_path / "temp.bmp")
+    out = tmp_path / "temp.bmp"
     im.save(out)
 
     with Image.open(out) as reloaded:
@@ -74,7 +68,7 @@ def test_small_palette(tmp_path: Path) -> None:
 
 
 def test_save_too_large(tmp_path: Path) -> None:
-    outfile = str(tmp_path / "temp.bmp")
+    outfile = tmp_path / "temp.bmp"
     with Image.new("RGB", (1, 1)) as im:
         im._size = (37838, 37838)
         with pytest.raises(ValueError):
@@ -96,7 +90,7 @@ def test_dpi() -> None:
 def test_save_bmp_with_dpi(tmp_path: Path) -> None:
     # Test for #1301
     # Arrange
-    outfile = str(tmp_path / "temp.jpg")
+    outfile = tmp_path / "temp.jpg"
     with Image.open("Tests/images/hopper.bmp") as im:
         assert im.info["dpi"] == (95.98654816726399, 95.98654816726399)
 
@@ -112,7 +106,7 @@ def test_save_bmp_with_dpi(tmp_path: Path) -> None:
 
 
 def test_save_float_dpi(tmp_path: Path) -> None:
-    outfile = str(tmp_path / "temp.bmp")
+    outfile = tmp_path / "temp.bmp"
     with Image.open("Tests/images/hopper.bmp") as im:
         im.save(outfile, dpi=(72.21216100543306, 72.21216100543306))
         with Image.open(outfile) as reloaded:
@@ -152,7 +146,7 @@ def test_dib_header_size(header_size: int, path: str) -> None:
 
 
 def test_save_dib(tmp_path: Path) -> None:
-    outfile = str(tmp_path / "temp.dib")
+    outfile = tmp_path / "temp.dib"
 
     with Image.open("Tests/images/clipboard.dib") as im:
         im.save(outfile)
@@ -196,9 +190,9 @@ def test_rle8() -> None:
     # Signal end of bitmap before the image is finished
     with open("Tests/images/bmp/g/pal8rle.bmp", "rb") as fp:
         data = fp.read(1063) + b"\x01"
-        with Image.open(io.BytesIO(data)) as im:
+    with Image.open(io.BytesIO(data)) as im:
-            with pytest.raises(ValueError):
+        with pytest.raises(ValueError):
-                im.load()
+            im.load()
 
 
 def test_rle4() -> None:
@@ -220,9 +214,9 @@ def test_rle4() -> None:
 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:
+    with Image.open(io.BytesIO(data)) as im:
-            with pytest.raises(ValueError):
+        with pytest.raises(ValueError):
-                im.load()
+            im.load()
 
 
 def test_offset() -> None:
@@ -230,3 +224,13 @@ def test_offset() -> None:
     # to exclude the palette size from the pixel data offset
     with Image.open("Tests/images/pal8_offset.bmp") as im:
         assert_image_equal_tofile(im, "Tests/images/bmp/g/pal8.bmp")
+
+
+def test_use_raw_alpha(monkeypatch: pytest.MonkeyPatch) -> None:
+    with Image.open("Tests/images/bmp/g/rgb32.bmp") as im:
+        assert im.info["compression"] == BmpImagePlugin.BmpImageFile.COMPRESSIONS["RAW"]
+        assert im.mode == "RGB"
+
+    monkeypatch.setattr(BmpImagePlugin, "USE_RAW_ALPHA", True)
+    with Image.open("Tests/images/bmp/g/rgb32.bmp") as im:
+        assert im.mode == "RGBA"

Tests/test_file_bufrstub.py

@@ -43,7 +43,7 @@ def test_load() -> None:
 def test_save(tmp_path: Path) -> None:
     # Arrange
     im = hopper()
-    tmpfile = str(tmp_path / "temp.bufr")
+    tmpfile = tmp_path / "temp.bufr"
 
     # Act / Assert: stub cannot save without an implemented handler
     with pytest.raises(OSError):
@@ -79,7 +79,7 @@ def test_handler(tmp_path: Path) -> None:
         im.load()
         assert handler.is_loaded()
 
-        temp_file = str(tmp_path / "temp.bufr")
+        temp_file = tmp_path / "temp.bufr"
         im.save(temp_file)
         assert handler.saved
 

Tests/test_file_dcx.py

@@ -69,12 +69,14 @@ def test_tell() -> None:
 
 def test_n_frames() -> None:
     with Image.open(TEST_FILE) as im:
+        assert isinstance(im, DcxImagePlugin.DcxImageFile)
         assert im.n_frames == 1
         assert not im.is_animated
 
 
 def test_eoferror() -> None:
     with Image.open(TEST_FILE) as im:
+        assert isinstance(im, DcxImagePlugin.DcxImageFile)
         n_frames = im.n_frames
 
         # Test seeking past the last frame

Tests/test_file_dds.py

@@ -9,7 +9,13 @@ import pytest
 
 from PIL import DdsImagePlugin, Image
 
-from .helper import assert_image_equal, assert_image_equal_tofile, hopper
+from .helper import (
+    assert_image_equal,
+    assert_image_equal_tofile,
+    assert_image_similar,
+    assert_image_similar_tofile,
+    hopper,
+)
 
 TEST_FILE_DXT1 = "Tests/images/dxt1-rgb-4bbp-noalpha_MipMaps-1.dds"
 TEST_FILE_DXT3 = "Tests/images/dxt3-argb-8bbp-explicitalpha_MipMaps-1.dds"
@@ -109,6 +115,32 @@ def test_sanity_ati1_bc4u(image_path: str) -> None:
         assert_image_equal_tofile(im, TEST_FILE_ATI1.replace(".dds", ".png"))
 
 
+def test_dx10_bc2(tmp_path: Path) -> None:
+    out = tmp_path / "temp.dds"
+    with Image.open(TEST_FILE_DXT3) as im:
+        im.save(out, pixel_format="BC2")
+
+    with Image.open(out) as reloaded:
+        assert reloaded.format == "DDS"
+        assert reloaded.mode == "RGBA"
+        assert reloaded.size == (256, 256)
+
+        assert_image_similar(im, reloaded, 3.81)
+
+
+def test_dx10_bc3(tmp_path: Path) -> None:
+    out = tmp_path / "temp.dds"
+    with Image.open(TEST_FILE_DXT5) as im:
+        im.save(out, pixel_format="BC3")
+
+    with Image.open(out) as reloaded:
+        assert reloaded.format == "DDS"
+        assert reloaded.mode == "RGBA"
+        assert reloaded.size == (256, 256)
+
+        assert_image_similar(im, reloaded, 3.69)
+
+
 @pytest.mark.parametrize(
     "image_path",
     (
@@ -368,9 +400,9 @@ def test_not_implemented(test_file: str) -> None:
 
 
 def test_save_unsupported_mode(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.dds")
+    out = tmp_path / "temp.dds"
     im = hopper("HSV")
-    with pytest.raises(OSError):
+    with pytest.raises(OSError, match="cannot write mode HSV as DDS"):
         im.save(out)
 
 
@@ -384,10 +416,98 @@ def test_save_unsupported_mode(tmp_path: Path) -> None:
     ],
 )
 def test_save(mode: str, test_file: str, tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.dds")
+    out = tmp_path / "temp.dds"
     with Image.open(test_file) as im:
         assert im.mode == mode
         im.save(out)
 
-        with Image.open(out) as reloaded:
+        assert_image_equal_tofile(im, out)
-            assert_image_equal(im, reloaded)
+
+
+def test_save_unsupported_pixel_format(tmp_path: Path) -> None:
+    out = tmp_path / "temp.dds"
+    im = hopper()
+    with pytest.raises(OSError, match="cannot write pixel format UNKNOWN"):
+        im.save(out, pixel_format="UNKNOWN")
+
+
+def test_save_dxt1(tmp_path: Path) -> None:
+    # RGB
+    out = tmp_path / "temp.dds"
+    with Image.open(TEST_FILE_DXT1) as im:
+        im.convert("RGB").save(out, pixel_format="DXT1")
+    assert_image_similar_tofile(im, out, 1.84)
+
+    # RGBA
+    im_alpha = im.copy()
+    im_alpha.putpixel((0, 0), (0, 0, 0, 0))
+    im_alpha.save(out, pixel_format="DXT1")
+    with Image.open(out) as reloaded:
+        assert reloaded.getpixel((0, 0)) == (0, 0, 0, 0)
+
+    # L
+    im_l = im.convert("L")
+    im_l.save(out, pixel_format="DXT1")
+    assert_image_similar_tofile(im_l.convert("RGBA"), out, 6.07)
+
+    # LA
+    im_alpha.convert("LA").save(out, pixel_format="DXT1")
+    with Image.open(out) as reloaded:
+        assert reloaded.getpixel((0, 0)) == (0, 0, 0, 0)
+
+
+def test_save_dxt3(tmp_path: Path) -> None:
+    # RGB
+    out = tmp_path / "temp.dds"
+    with Image.open(TEST_FILE_DXT3) as im:
+        im_rgb = im.convert("RGB")
+    im_rgb.save(out, pixel_format="DXT3")
+    assert_image_similar_tofile(im_rgb.convert("RGBA"), out, 1.26)
+
+    # RGBA
+    im.save(out, pixel_format="DXT3")
+    assert_image_similar_tofile(im, out, 3.81)
+
+    # L
+    im_l = im.convert("L")
+    im_l.save(out, pixel_format="DXT3")
+    assert_image_similar_tofile(im_l.convert("RGBA"), out, 5.89)
+
+    # LA
+    im_la = im.convert("LA")
+    im_la.save(out, pixel_format="DXT3")
+    assert_image_similar_tofile(im_la.convert("RGBA"), out, 8.44)
+
+
+def test_save_dxt5(tmp_path: Path) -> None:
+    # RGB
+    out = tmp_path / "temp.dds"
+    with Image.open(TEST_FILE_DXT1) as im:
+        im.convert("RGB").save(out, pixel_format="DXT5")
+    assert_image_similar_tofile(im, out, 1.84)
+
+    # RGBA
+    with Image.open(TEST_FILE_DXT5) as im_rgba:
+        im_rgba.save(out, pixel_format="DXT5")
+    assert_image_similar_tofile(im_rgba, out, 3.69)
+
+    # L
+    im_l = im.convert("L")
+    im_l.save(out, pixel_format="DXT5")
+    assert_image_similar_tofile(im_l.convert("RGBA"), out, 6.07)
+
+    # LA
+    im_la = im_rgba.convert("LA")
+    im_la.save(out, pixel_format="DXT5")
+    assert_image_similar_tofile(im_la.convert("RGBA"), out, 8.32)
+
+
+def test_save_dx10_bc5(tmp_path: Path) -> None:
+    out = tmp_path / "temp.dds"
+    with Image.open(TEST_FILE_DX10_BC5_TYPELESS) as im:
+        im.save(out, pixel_format="BC5")
+    assert_image_similar_tofile(im, out, 9.56)
+
+    im = hopper("L")
+    with pytest.raises(OSError, match="only RGB mode can be written as BC5"):
+        im.save(out, pixel_format="BC5")

Tests/test_file_eps.py

@@ -15,6 +15,7 @@ from .helper import (
     is_win32,
     mark_if_feature_version,
     skip_unless_feature,
+    timeout_unless_slower_valgrind,
 )
 
 HAS_GHOSTSCRIPT = EpsImagePlugin.has_ghostscript()
@@ -86,6 +87,8 @@ simple_eps_file_with_long_binary_data = (
 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:
+        assert isinstance(image, EpsImagePlugin.EpsImageFile)
+
         image.load(scale=scale)
         assert image.mode == "RGB"
         assert image.size == expected_size
@@ -227,6 +230,8 @@ def test_showpage() -> None:
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 def test_transparency() -> None:
     with Image.open("Tests/images/eps/reqd_showpage.eps") as plot_image:
+        assert isinstance(plot_image, EpsImagePlugin.EpsImageFile)
+
         plot_image.load(transparency=True)
         assert plot_image.mode == "RGBA"
 
@@ -239,7 +244,7 @@ def test_transparency() -> None:
 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:
+        with open(tmp_path / "temp.eps", "wb") as fh:
             image1.save(fh, "EPS")
 
 
@@ -274,7 +279,7 @@ def test_1(filename: str) -> None:
 
 def test_image_mode_not_supported(tmp_path: Path) -> None:
     im = hopper("RGBA")
-    tmpfile = str(tmp_path / "temp.eps")
+    tmpfile = tmp_path / "temp.eps"
     with pytest.raises(ValueError):
         im.save(tmpfile)
 
@@ -308,6 +313,7 @@ def test_render_scale2() -> None:
 
     # Zero bounding box
     with Image.open(FILE1) as image1_scale2:
+        assert isinstance(image1_scale2, EpsImagePlugin.EpsImageFile)
         image1_scale2.load(scale=2)
         with Image.open(FILE1_COMPARE_SCALE2) as image1_scale2_compare:
             image1_scale2_compare = image1_scale2_compare.convert("RGB")
@@ -316,6 +322,7 @@ def test_render_scale2() -> None:
 
     # Non-zero bounding box
     with Image.open(FILE2) as image2_scale2:
+        assert isinstance(image2_scale2, EpsImagePlugin.EpsImageFile)
         image2_scale2.load(scale=2)
         with Image.open(FILE2_COMPARE_SCALE2) as image2_scale2_compare:
             image2_scale2_compare = image2_scale2_compare.convert("RGB")
@@ -392,7 +399,7 @@ def test_emptyline() -> None:
     assert image.format == "EPS"
 
 
-@pytest.mark.timeout(timeout=5)
+@timeout_unless_slower_valgrind(5)
 @pytest.mark.parametrize(
     "test_file",
     ["Tests/images/eps/timeout-d675703545fee17acab56e5fec644c19979175de.eps"],

Tests/test_file_fli.py

@@ -7,7 +7,12 @@ import pytest
 
 from PIL import FliImagePlugin, Image, ImageFile
 
-from .helper import assert_image_equal, assert_image_equal_tofile, is_pypy
+from .helper import (
+    assert_image_equal,
+    assert_image_equal_tofile,
+    is_pypy,
+    timeout_unless_slower_valgrind,
+)
 
 # created as an export of a palette image from Gimp2.6
 # save as...-> hopper.fli, default options.
@@ -22,6 +27,8 @@ animated_test_file_with_prefix_chunk = "Tests/images/2422.flc"
 
 def test_sanity() -> None:
     with Image.open(static_test_file) as im:
+        assert isinstance(im, FliImagePlugin.FliImageFile)
+
         im.load()
         assert im.mode == "P"
         assert im.size == (128, 128)
@@ -29,6 +36,8 @@ def test_sanity() -> None:
         assert not im.is_animated
 
     with Image.open(animated_test_file) as im:
+        assert isinstance(im, FliImagePlugin.FliImageFile)
+
         assert im.mode == "P"
         assert im.size == (320, 200)
         assert im.format == "FLI"
@@ -112,16 +121,19 @@ def test_palette_chunk_second() -> None:
 
 def test_n_frames() -> None:
     with Image.open(static_test_file) as im:
+        assert isinstance(im, FliImagePlugin.FliImageFile)
         assert im.n_frames == 1
         assert not im.is_animated
 
     with Image.open(animated_test_file) as im:
+        assert isinstance(im, FliImagePlugin.FliImageFile)
         assert im.n_frames == 384
         assert im.is_animated
 
 
 def test_eoferror() -> None:
     with Image.open(animated_test_file) as im:
+        assert isinstance(im, FliImagePlugin.FliImageFile)
         n_frames = im.n_frames
 
         # Test seeking past the last frame
@@ -166,6 +178,7 @@ def test_seek_tell() -> None:
 
 def test_seek() -> None:
     with Image.open(animated_test_file) as im:
+        assert isinstance(im, FliImagePlugin.FliImageFile)
         im.seek(50)
 
         assert_image_equal_tofile(im, "Tests/images/a_fli.png")
@@ -181,7 +194,7 @@ def test_seek() -> None:
         "Tests/images/timeout-bff0a9dc7243a8e6ede2408d2ffa6a9964698b87.fli",
     ],
 )
-@pytest.mark.timeout(timeout=3)
+@timeout_unless_slower_valgrind(3)
 def test_timeouts(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:

Tests/test_file_fpx.py

@@ -22,10 +22,11 @@ def test_sanity() -> None:
 
 def test_close() -> None:
     with Image.open("Tests/images/input_bw_one_band.fpx") as im:
-        pass
+        assert isinstance(im, FpxImagePlugin.FpxImageFile)
     assert im.ole.fp.closed
 
     im = Image.open("Tests/images/input_bw_one_band.fpx")
+    assert isinstance(im, FpxImagePlugin.FpxImageFile)
     im.close()
     assert im.ole.fp.closed
 

Tests/test_file_gif.py

@@ -228,7 +228,7 @@ def test_optimize_if_palette_can_be_reduced_by_half() -> None:
 
 
 def test_full_palette_second_frame(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = Image.new("P", (1, 256))
 
     full_palette_im = Image.new("P", (1, 256))
@@ -249,7 +249,7 @@ def test_full_palette_second_frame(tmp_path: Path) -> None:
 
 
 def test_roundtrip(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = hopper()
     im.save(out)
     with Image.open(out) as reread:
@@ -258,7 +258,7 @@ def test_roundtrip(tmp_path: Path) -> None:
 
 def test_roundtrip2(tmp_path: Path) -> None:
     # see https://github.com/python-pillow/Pillow/issues/403
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     with Image.open(TEST_GIF) as im:
         im2 = im.copy()
         im2.save(out)
@@ -268,7 +268,7 @@ def test_roundtrip2(tmp_path: Path) -> None:
 
 def test_roundtrip_save_all(tmp_path: Path) -> None:
     # Single frame image
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = hopper()
     im.save(out, save_all=True)
     with Image.open(out) as reread:
@@ -276,7 +276,7 @@ def test_roundtrip_save_all(tmp_path: Path) -> None:
 
     # Multiframe image
     with Image.open("Tests/images/dispose_bgnd.gif") as im:
-        out = str(tmp_path / "temp.gif")
+        out = tmp_path / "temp.gif"
         im.save(out, save_all=True)
 
     with Image.open(out) as reread:
@@ -284,7 +284,7 @@ def test_roundtrip_save_all(tmp_path: Path) -> None:
 
 
 def test_roundtrip_save_all_1(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = Image.new("1", (1, 1))
     im2 = Image.new("1", (1, 1), 1)
     im.save(out, save_all=True, append_images=[im2])
@@ -329,7 +329,7 @@ def test_headers_saving_for_animated_gifs(tmp_path: Path) -> None:
     with Image.open("Tests/images/dispose_bgnd.gif") as im:
         info = im.info.copy()
 
-        out = str(tmp_path / "temp.gif")
+        out = tmp_path / "temp.gif"
         im.save(out, save_all=True)
     with Image.open(out) as reread:
         for header in important_headers:
@@ -345,7 +345,7 @@ def test_palette_handling(tmp_path: Path) -> None:
         im = im.resize((100, 100), Image.Resampling.LANCZOS)
         im2 = im.convert("P", palette=Image.Palette.ADAPTIVE, colors=256)
 
-        f = str(tmp_path / "temp.gif")
+        f = tmp_path / "temp.gif"
         im2.save(f, optimize=True)
 
     with Image.open(f) as reloaded:
@@ -356,7 +356,7 @@ def test_palette_434(tmp_path: Path) -> None:
     # see https://github.com/python-pillow/Pillow/issues/434
 
     def roundtrip(im: Image.Image, **kwargs: bool) -> Image.Image:
-        out = str(tmp_path / "temp.gif")
+        out = tmp_path / "temp.gif"
         im.copy().save(out, "GIF", **kwargs)
         reloaded = Image.open(out)
 
@@ -402,6 +402,7 @@ def test_save_netpbm_l_mode(tmp_path: Path) -> None:
 
 def test_seek() -> None:
     with Image.open("Tests/images/dispose_none.gif") as img:
+        assert isinstance(img, GifImagePlugin.GifImageFile)
         frame_count = 0
         try:
             while True:
@@ -446,10 +447,12 @@ def test_seek_rewind() -> None:
 def test_n_frames(path: str, n_frames: int) -> None:
     # Test is_animated before n_frames
     with Image.open(path) as im:
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         assert im.is_animated == (n_frames != 1)
 
     # Test is_animated after n_frames
     with Image.open(path) as im:
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         assert im.n_frames == n_frames
         assert im.is_animated == (n_frames != 1)
 
@@ -459,6 +462,7 @@ def test_no_change() -> None:
     with Image.open("Tests/images/dispose_bgnd.gif") as im:
         im.seek(1)
         expected = im.copy()
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         assert im.n_frames == 5
         assert_image_equal(im, expected)
 
@@ -466,17 +470,20 @@ def test_no_change() -> None:
     with Image.open("Tests/images/dispose_bgnd.gif") as im:
         im.seek(3)
         expected = im.copy()
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         assert im.is_animated
         assert_image_equal(im, expected)
 
     with Image.open("Tests/images/comment_after_only_frame.gif") as im:
         expected = Image.new("P", (1, 1))
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         assert not im.is_animated
         assert_image_equal(im, expected)
 
 
 def test_eoferror() -> None:
     with Image.open(TEST_GIF) as im:
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         n_frames = im.n_frames
 
         # Test seeking past the last frame
@@ -495,6 +502,7 @@ def test_first_frame_transparency() -> None:
 
 def test_dispose_none() -> None:
     with Image.open("Tests/images/dispose_none.gif") as img:
+        assert isinstance(img, GifImagePlugin.GifImageFile)
         try:
             while True:
                 img.seek(img.tell() + 1)
@@ -518,6 +526,7 @@ def test_dispose_none_load_end() -> None:
 
 def test_dispose_background() -> None:
     with Image.open("Tests/images/dispose_bgnd.gif") as img:
+        assert isinstance(img, GifImagePlugin.GifImageFile)
         try:
             while True:
                 img.seek(img.tell() + 1)
@@ -571,6 +580,7 @@ def test_transparent_dispose(
 
 def test_dispose_previous() -> None:
     with Image.open("Tests/images/dispose_prev.gif") as img:
+        assert isinstance(img, GifImagePlugin.GifImageFile)
         try:
             while True:
                 img.seek(img.tell() + 1)
@@ -599,7 +609,7 @@ def test_previous_frame_loaded() -> None:
 
 
 def test_save_dispose(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im_list = [
         Image.new("L", (100, 100), "#000"),
         Image.new("L", (100, 100), "#111"),
@@ -608,6 +618,7 @@ def test_save_dispose(tmp_path: Path) -> None:
     for method in range(4):
         im_list[0].save(out, save_all=True, append_images=im_list[1:], disposal=method)
         with Image.open(out) as img:
+            assert isinstance(img, GifImagePlugin.GifImageFile)
             for _ in range(2):
                 img.seek(img.tell() + 1)
                 assert img.disposal_method == method
@@ -621,13 +632,14 @@ def test_save_dispose(tmp_path: Path) -> None:
     )
 
     with Image.open(out) as img:
+        assert isinstance(img, GifImagePlugin.GifImageFile)
         for i in range(2):
             img.seek(img.tell() + 1)
             assert img.disposal_method == i + 1
 
 
 def test_dispose2_palette(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     # Four colors: white, gray, black, red
     circles = [(255, 255, 255), (153, 153, 153), (0, 0, 0), (255, 0, 0)]
@@ -661,7 +673,7 @@ def test_dispose2_palette(tmp_path: Path) -> None:
 
 
 def test_dispose2_diff(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     # 4 frames: red/blue, red/red, blue/blue, red/blue
     circles = [
@@ -703,7 +715,7 @@ def test_dispose2_diff(tmp_path: Path) -> None:
 
 
 def test_dispose2_background(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im_list = []
 
@@ -729,7 +741,7 @@ def test_dispose2_background(tmp_path: Path) -> None:
 
 
 def test_dispose2_background_frame(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im_list = [Image.new("RGBA", (1, 20))]
 
@@ -743,11 +755,12 @@ def test_dispose2_background_frame(tmp_path: Path) -> None:
     im_list[0].save(out, save_all=True, append_images=im_list[1:], disposal=2)
 
     with Image.open(out) as im:
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         assert im.n_frames == 3
 
 
 def test_dispose2_previous_frame(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im = Image.new("P", (100, 100))
     im.info["transparency"] = 0
@@ -766,7 +779,7 @@ def test_dispose2_previous_frame(tmp_path: Path) -> None:
 
 
 def test_dispose2_without_transparency(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im = Image.new("P", (100, 100))
 
@@ -781,7 +794,7 @@ def test_dispose2_without_transparency(tmp_path: Path) -> None:
 
 
 def test_transparency_in_second_frame(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     with Image.open("Tests/images/different_transparency.gif") as im:
         assert im.info["transparency"] == 0
 
@@ -811,7 +824,7 @@ def test_no_transparency_in_second_frame() -> None:
 
 
 def test_remapped_transparency(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im = Image.new("P", (1, 2))
     im2 = im.copy()
@@ -829,7 +842,7 @@ def test_remapped_transparency(tmp_path: Path) -> None:
 def test_duration(tmp_path: Path) -> None:
     duration = 1000
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = Image.new("L", (100, 100), "#000")
 
     # Check that the argument has priority over the info settings
@@ -843,7 +856,7 @@ def test_duration(tmp_path: Path) -> None:
 def test_multiple_duration(tmp_path: Path) -> None:
     duration_list = [1000, 2000, 3000]
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im_list = [
         Image.new("L", (100, 100), "#000"),
         Image.new("L", (100, 100), "#111"),
@@ -878,7 +891,7 @@ def test_multiple_duration(tmp_path: Path) -> None:
 def test_roundtrip_info_duration(tmp_path: Path) -> None:
     duration_list = [100, 500, 500]
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     with Image.open("Tests/images/transparent_dispose.gif") as im:
         assert [
             frame.info["duration"] for frame in ImageSequence.Iterator(im)
@@ -893,7 +906,7 @@ def test_roundtrip_info_duration(tmp_path: Path) -> None:
 
 
 def test_roundtrip_info_duration_combined(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     with Image.open("Tests/images/duplicate_frame.gif") as im:
         assert [frame.info["duration"] for frame in ImageSequence.Iterator(im)] == [
             1000,
@@ -911,7 +924,7 @@ def test_roundtrip_info_duration_combined(tmp_path: Path) -> None:
 def test_identical_frames(tmp_path: Path) -> None:
     duration_list = [1000, 1500, 2000, 4000]
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im_list = [
         Image.new("L", (100, 100), "#000"),
         Image.new("L", (100, 100), "#000"),
@@ -924,6 +937,8 @@ def test_identical_frames(tmp_path: Path) -> None:
         out, save_all=True, append_images=im_list[1:], duration=duration_list
     )
     with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
+
         # Assert that the first three frames were combined
         assert reread.n_frames == 2
 
@@ -944,7 +959,7 @@ def test_identical_frames(tmp_path: Path) -> None:
 def test_identical_frames_to_single_frame(
     duration: int | list[int], tmp_path: Path
 ) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im_list = [
         Image.new("L", (100, 100), "#000"),
         Image.new("L", (100, 100), "#000"),
@@ -953,6 +968,8 @@ def test_identical_frames_to_single_frame(
 
     im_list[0].save(out, save_all=True, append_images=im_list[1:], duration=duration)
     with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
+
         # Assert that all frames were combined
         assert reread.n_frames == 1
 
@@ -961,7 +978,7 @@ def test_identical_frames_to_single_frame(
 
 
 def test_loop_none(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = Image.new("L", (100, 100), "#000")
     im.save(out, loop=None)
     with Image.open(out) as reread:
@@ -971,7 +988,7 @@ def test_loop_none(tmp_path: Path) -> None:
 def test_number_of_loops(tmp_path: Path) -> None:
     number_of_loops = 2
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = Image.new("L", (100, 100), "#000")
     im.save(out, loop=number_of_loops)
     with Image.open(out) as reread:
@@ -987,7 +1004,7 @@ def test_number_of_loops(tmp_path: Path) -> None:
 
 
 def test_background(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = Image.new("L", (100, 100), "#000")
     im.info["background"] = 1
     im.save(out)
@@ -996,7 +1013,7 @@ def test_background(tmp_path: Path) -> None:
 
 
 def test_webp_background(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     # Test opaque WebP background
     if features.check("webp"):
@@ -1014,7 +1031,7 @@ 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"
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = Image.new("L", (100, 100), "#000")
     im.info["comment"] = b"Test comment text"
     im.save(out)
@@ -1031,7 +1048,7 @@ def test_comment(tmp_path: Path) -> None:
 
 
 def test_comment_over_255(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = Image.new("L", (100, 100), "#000")
     comment = b"Test comment text"
     while len(comment) < 256:
@@ -1057,7 +1074,7 @@ def test_read_multiple_comment_blocks() -> None:
 
 
 def test_empty_string_comment(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     with Image.open("Tests/images/chi.gif") as im:
         assert "comment" in im.info
 
@@ -1091,7 +1108,7 @@ def test_retain_comment_in_subsequent_frames(tmp_path: Path) -> None:
         assert "comment" not in im.info
 
     # Test that a saved image keeps the comment
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     with Image.open("Tests/images/dispose_prev.gif") as im:
         im.save(out, save_all=True, comment="Test")
 
@@ -1101,7 +1118,7 @@ def test_retain_comment_in_subsequent_frames(tmp_path: Path) -> None:
 
 
 def test_version(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     def assert_version_after_save(im: Image.Image, version: bytes) -> None:
         im.save(out)
@@ -1131,7 +1148,7 @@ def test_version(tmp_path: Path) -> None:
 
 
 def test_append_images(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     # Test appending single frame images
     im = Image.new("RGB", (100, 100), "#f00")
@@ -1139,6 +1156,14 @@ def test_append_images(tmp_path: Path) -> None:
     im.copy().save(out, save_all=True, append_images=ims)
 
     with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
+        assert reread.n_frames == 3
+
+    # Test append_images without save_all
+    im.copy().save(out, append_images=ims)
+
+    with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
         assert reread.n_frames == 3
 
     # Tests appending using a generator
@@ -1148,6 +1173,7 @@ def test_append_images(tmp_path: Path) -> None:
     im.save(out, save_all=True, append_images=im_generator(ims))
 
     with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
         assert reread.n_frames == 3
 
     # Tests appending single and multiple frame images
@@ -1156,11 +1182,12 @@ def test_append_images(tmp_path: Path) -> None:
             im.save(out, save_all=True, append_images=[im2])
 
     with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
         assert reread.n_frames == 10
 
 
 def test_append_different_size_image(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im = Image.new("RGB", (100, 100))
     bigger_im = Image.new("RGB", (200, 200), "#f00")
@@ -1187,7 +1214,7 @@ def test_transparent_optimize(tmp_path: Path) -> None:
     im.frombytes(data)
     im.putpalette(palette)
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im.save(out, transparency=im.getpixel((252, 0)))
 
     with Image.open(out) as reloaded:
@@ -1195,7 +1222,7 @@ def test_transparent_optimize(tmp_path: Path) -> None:
 
 
 def test_removed_transparency(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im = Image.new("RGB", (256, 1))
 
     for x in range(256):
@@ -1210,7 +1237,7 @@ def test_removed_transparency(tmp_path: Path) -> None:
 
 
 def test_rgb_transparency(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     # Single frame
     im = Image.new("RGB", (1, 1))
@@ -1232,7 +1259,7 @@ def test_rgb_transparency(tmp_path: Path) -> None:
 
 
 def test_rgba_transparency(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im = hopper("P")
     im.save(out, save_all=True, append_images=[Image.new("RGBA", im.size)])
@@ -1242,25 +1269,26 @@ def test_rgba_transparency(tmp_path: Path) -> None:
         assert_image_equal(hopper("P").convert("RGB"), reloaded)
 
 
-def test_background_outside_palettte(tmp_path: Path) -> None:
+def test_background_outside_palettte() -> 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: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im = Image.new("RGB", (100, 100), "#fff")
     ims = [Image.new("RGB", (100, 100), "#000")]
     im.save(out, save_all=True, append_images=ims)
 
     with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
         assert reread.n_frames == 2
 
 
 def test_bbox_alpha(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im = Image.new("RGBA", (1, 2), (255, 0, 0, 255))
     im.putpixel((0, 1), (255, 0, 0, 0))
@@ -1268,6 +1296,7 @@ def test_bbox_alpha(tmp_path: Path) -> None:
     im.save(out, save_all=True, append_images=[im2])
 
     with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
         assert reread.n_frames == 2
 
 
@@ -1279,7 +1308,7 @@ def test_palette_save_L(tmp_path: Path) -> None:
     palette = im.getpalette()
     assert palette is not None
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im_l.save(out, palette=bytes(palette))
 
     with Image.open(out) as reloaded:
@@ -1290,7 +1319,7 @@ def test_palette_save_P(tmp_path: Path) -> None:
     im = Image.new("P", (1, 2))
     im.putpixel((0, 1), 1)
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im.save(out, palette=bytes((1, 2, 3, 4, 5, 6)))
 
     with Image.open(out) as reloaded:
@@ -1306,7 +1335,7 @@ def test_palette_save_duplicate_entries(tmp_path: Path) -> None:
 
     im.putpalette((0, 0, 0, 0, 0, 0))
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im.save(out, palette=[0, 0, 0, 0, 0, 0, 1, 1, 1])
 
     with Image.open(out) as reloaded:
@@ -1321,7 +1350,7 @@ def test_palette_save_all_P(tmp_path: Path) -> None:
         frame.putpalette(color)
         frames.append(frame)
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     frames[0].save(
         out, save_all=True, palette=[255, 0, 0, 0, 255, 0], append_images=frames[1:]
     )
@@ -1344,7 +1373,7 @@ def test_palette_save_ImagePalette(tmp_path: Path) -> None:
     im = hopper("P")
     palette = ImagePalette.ImagePalette("RGB", list(range(256))[::-1] * 3)
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im.save(out, palette=palette)
 
     with Image.open(out) as reloaded:
@@ -1357,7 +1386,7 @@ def test_save_I(tmp_path: Path) -> None:
 
     im = hopper("I")
 
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     im.save(out)
 
     with Image.open(out) as reloaded:
@@ -1419,6 +1448,7 @@ def test_extents(
 ) -> None:
     monkeypatch.setattr(GifImagePlugin, "LOADING_STRATEGY", loading_strategy)
     with Image.open("Tests/images/" + test_file) as im:
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         assert im.size == (100, 100)
 
         # Check that n_frames does not change the size
@@ -1441,7 +1471,7 @@ def test_missing_background() -> None:
 
 
 def test_saving_rgba(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
     with Image.open("Tests/images/transparent.png") as im:
         im.save(out)
 
@@ -1452,7 +1482,7 @@ def test_saving_rgba(tmp_path: Path) -> None:
 
 @pytest.mark.parametrize("params", ({}, {"disposal": 2, "optimize": False}))
 def test_p_rgba(tmp_path: Path, params: dict[str, Any]) -> None:
-    out = str(tmp_path / "temp.gif")
+    out = tmp_path / "temp.gif"
 
     im1 = Image.new("P", (100, 100))
     d = ImageDraw.Draw(im1)
@@ -1466,4 +1496,5 @@ def test_p_rgba(tmp_path: Path, params: dict[str, Any]) -> None:
     im1.save(out, save_all=True, append_images=[im2], **params)
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, GifImagePlugin.GifImageFile)
         assert reloaded.n_frames == 2

Tests/test_file_gimppalette.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from io import BytesIO
+
 import pytest
 
 from PIL.GimpPaletteFile import GimpPaletteFile
@@ -14,17 +16,20 @@ def test_sanity() -> None:
             GimpPaletteFile(fp)
 
     with open("Tests/images/bad_palette_file.gpl", "rb") as fp:
-        with pytest.raises(SyntaxError):
+        with pytest.raises(SyntaxError, match="bad palette file"):
             GimpPaletteFile(fp)
 
     with open("Tests/images/bad_palette_entry.gpl", "rb") as fp:
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match="bad palette entry"):
             GimpPaletteFile(fp)
 
 
-def test_get_palette() -> None:
+@pytest.mark.parametrize(
+    "filename, size", (("custom_gimp_palette.gpl", 8), ("full_gimp_palette.gpl", 256))
+)
+def test_get_palette(filename: str, size: int) -> None:
     # Arrange
-    with open("Tests/images/custom_gimp_palette.gpl", "rb") as fp:
+    with open("Tests/images/" + filename, "rb") as fp:
         palette_file = GimpPaletteFile(fp)
 
     # Act
@@ -32,3 +37,36 @@ def test_get_palette() -> None:
 
     # Assert
     assert mode == "RGB"
+    assert len(palette) / 3 == size
+
+
+def test_frombytes() -> None:
+    # Test that __init__ stops reading after 260 lines
+    with open("Tests/images/custom_gimp_palette.gpl", "rb") as fp:
+        custom_data = fp.read()
+    custom_data += b"#\n" * 300 + b"  0   0   0     Index 12"
+    b = BytesIO(custom_data)
+    palette = GimpPaletteFile(b)
+    assert len(palette.palette) / 3 == 8
+
+    # Test that __init__ only reads 256 entries
+    with open("Tests/images/full_gimp_palette.gpl", "rb") as fp:
+        full_data = fp.read()
+    data = full_data.replace(b"#\n", b"") + b"  0   0   0     Index 256"
+    b = BytesIO(data)
+    palette = GimpPaletteFile(b)
+    assert len(palette.palette) / 3 == 256
+
+    # Test that frombytes() can read beyond that
+    palette = GimpPaletteFile.frombytes(data)
+    assert len(palette.palette) / 3 == 257
+
+    # Test that __init__ raises an error if a comment is too long
+    data = full_data[:-1] + b"a" * 100
+    b = BytesIO(data)
+    with pytest.raises(SyntaxError, match="bad palette file"):
+        palette = GimpPaletteFile(b)
+
+    # Test that frombytes() can read the data regardless
+    palette = GimpPaletteFile.frombytes(data)
+    assert len(palette.palette) / 3 == 256

Tests/test_file_gribstub.py

@@ -43,7 +43,7 @@ def test_load() -> None:
 def test_save(tmp_path: Path) -> None:
     # Arrange
     im = hopper()
-    tmpfile = str(tmp_path / "temp.grib")
+    tmpfile = tmp_path / "temp.grib"
 
     # Act / Assert: stub cannot save without an implemented handler
     with pytest.raises(OSError):
@@ -79,7 +79,7 @@ def test_handler(tmp_path: Path) -> None:
         im.load()
         assert handler.is_loaded()
 
-        temp_file = str(tmp_path / "temp.grib")
+        temp_file = tmp_path / "temp.grib"
         im.save(temp_file)
         assert handler.saved
 

Tests/test_file_hdf5stub.py

@@ -43,7 +43,7 @@ def test_save() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
         dummy_fp = BytesIO()
-        dummy_filename = "dummy.filename"
+        dummy_filename = "dummy.h5"
 
         # Act / Assert: stub cannot save without an implemented handler
         with pytest.raises(OSError):
@@ -81,7 +81,7 @@ def test_handler(tmp_path: Path) -> None:
         im.load()
         assert handler.is_loaded()
 
-        temp_file = str(tmp_path / "temp.h5")
+        temp_file = tmp_path / "temp.h5"
         im.save(temp_file)
         assert handler.saved
 

Tests/test_file_icns.py

@@ -43,7 +43,7 @@ def test_load() -> None:
 
 
 def test_save(tmp_path: Path) -> None:
-    temp_file = str(tmp_path / "temp.icns")
+    temp_file = tmp_path / "temp.icns"
 
     with Image.open(TEST_FILE) as im:
         im.save(temp_file)
@@ -60,7 +60,7 @@ def test_save(tmp_path: Path) -> None:
 
 
 def test_save_append_images(tmp_path: Path) -> None:
-    temp_file = str(tmp_path / "temp.icns")
+    temp_file = tmp_path / "temp.icns"
     provided_im = Image.new("RGBA", (32, 32), (255, 0, 0, 128))
 
     with Image.open(TEST_FILE) as im:
@@ -69,6 +69,7 @@ def test_save_append_images(tmp_path: Path) -> None:
         assert_image_similar_tofile(im, temp_file, 1)
 
         with Image.open(temp_file) as reread:
+            assert isinstance(reread, IcnsImagePlugin.IcnsImageFile)
             reread.size = (16, 16)
             reread.load(2)
             assert_image_equal(reread, provided_im)
@@ -90,6 +91,7 @@ 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:
+        assert isinstance(im, IcnsImagePlugin.IcnsImageFile)
         for w, h, r in im.info["sizes"]:
             wr = w * r
             hr = h * r
@@ -118,6 +120,7 @@ def test_older_icon() -> None:
             wr = w * r
             hr = h * r
             with Image.open("Tests/images/pillow2.icns") as im2:
+                assert isinstance(im2, IcnsImagePlugin.IcnsImageFile)
                 im2.size = (w, h)
                 im2.load(r)
                 assert im2.mode == "RGBA"
@@ -135,6 +138,7 @@ def test_jp2_icon() -> None:
             wr = w * r
             hr = h * r
             with Image.open("Tests/images/pillow3.icns") as im2:
+                assert isinstance(im2, IcnsImagePlugin.IcnsImageFile)
                 im2.size = (w, h)
                 im2.load(r)
                 assert im2.mode == "RGBA"

Tests/test_file_ico.py

@@ -41,7 +41,7 @@ def test_black_and_white() -> None:
 
 
 def test_palette(tmp_path: Path) -> None:
-    temp_file = str(tmp_path / "temp.ico")
+    temp_file = tmp_path / "temp.ico"
 
     im = Image.new("P", (16, 16))
     im.save(temp_file)
@@ -77,6 +77,7 @@ def test_save_to_bytes() -> None:
     # The other one
     output.seek(0)
     with Image.open(output) as reloaded:
+        assert isinstance(reloaded, IcoImagePlugin.IcoImageFile)
         reloaded.size = (32, 32)
 
         assert im.mode == reloaded.mode
@@ -88,12 +89,13 @@ def test_save_to_bytes() -> None:
 
 
 def test_getpixel(tmp_path: Path) -> None:
-    temp_file = str(tmp_path / "temp.ico")
+    temp_file = tmp_path / "temp.ico"
 
     im = hopper()
     im.save(temp_file, "ico", sizes=[(32, 32), (64, 64)])
 
     with Image.open(temp_file) as reloaded:
+        assert isinstance(reloaded, IcoImagePlugin.IcoImageFile)
         reloaded.load()
         reloaded.size = (32, 32)
 
@@ -101,8 +103,8 @@ def test_getpixel(tmp_path: Path) -> None:
 
 
 def test_no_duplicates(tmp_path: Path) -> None:
-    temp_file = str(tmp_path / "temp.ico")
+    temp_file = tmp_path / "temp.ico"
-    temp_file2 = str(tmp_path / "temp2.ico")
+    temp_file2 = tmp_path / "temp2.ico"
 
     im = hopper()
     sizes = [(32, 32), (64, 64)]
@@ -115,8 +117,8 @@ def test_no_duplicates(tmp_path: Path) -> None:
 
 
 def test_different_bit_depths(tmp_path: Path) -> None:
-    temp_file = str(tmp_path / "temp.ico")
+    temp_file = tmp_path / "temp.ico"
-    temp_file2 = str(tmp_path / "temp2.ico")
+    temp_file2 = tmp_path / "temp2.ico"
 
     im = hopper()
     im.save(temp_file, "ico", bitmap_format="bmp", sizes=[(128, 128)])
@@ -132,8 +134,8 @@ def test_different_bit_depths(tmp_path: Path) -> None:
     assert os.path.getsize(temp_file) != os.path.getsize(temp_file2)
 
     # Test that only matching sizes of different bit depths are saved
-    temp_file3 = str(tmp_path / "temp3.ico")
+    temp_file3 = tmp_path / "temp3.ico"
-    temp_file4 = str(tmp_path / "temp4.ico")
+    temp_file4 = tmp_path / "temp4.ico"
 
     im.save(temp_file3, "ico", bitmap_format="bmp", sizes=[(128, 128)])
     im.save(
@@ -167,6 +169,7 @@ def test_save_to_bytes_bmp(mode: str) -> None:
     # The other one
     output.seek(0)
     with Image.open(output) as reloaded:
+        assert isinstance(reloaded, IcoImagePlugin.IcoImageFile)
         reloaded.size = (32, 32)
 
         assert "RGBA" == reloaded.mode
@@ -178,6 +181,7 @@ def test_save_to_bytes_bmp(mode: str) -> None:
 
 def test_incorrect_size() -> None:
     with Image.open(TEST_ICO_FILE) as im:
+        assert isinstance(im, IcoImagePlugin.IcoImageFile)
         with pytest.raises(ValueError):
             im.size = (1, 1)
 
@@ -186,7 +190,7 @@ 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:
-        outfile = str(tmp_path / "temp_saved_hopper_256x256.ico")
+        outfile = tmp_path / "temp_saved_hopper_256x256.ico"
 
         # Act
         im.save(outfile)
@@ -202,7 +206,7 @@ def test_only_save_relevant_sizes(tmp_path: Path) -> None:
     """
     # Arrange
     with Image.open("Tests/images/python.ico") as im:  # 16x16, 32x32, 48x48
-        outfile = str(tmp_path / "temp_saved_python.ico")
+        outfile = tmp_path / "temp_saved_python.ico"
         # Act
         im.save(outfile)
 
@@ -215,10 +219,11 @@ 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))
-    outfile = str(tmp_path / "temp_saved_multi_icon.ico")
+    outfile = tmp_path / "temp_saved_multi_icon.ico"
     im.save(outfile, sizes=[(32, 32), (128, 128)], append_images=[provided_im])
 
     with Image.open(outfile) as reread:
+        assert isinstance(reread, IcoImagePlugin.IcoImageFile)
         assert_image_equal(reread, hopper("RGBA"))
 
         reread.size = (32, 32)
@@ -235,7 +240,7 @@ def test_unexpected_size() -> None:
 
 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")
+        outfile = tmp_path / "temp_saved_hopper_draw.ico"
 
         draw = ImageDraw.Draw(im)
         draw.line((0, 0) + im.size, "#f00")

Tests/test_file_im.py

@@ -23,7 +23,7 @@ def test_sanity() -> None:
 
 
 def test_name_limit(tmp_path: Path) -> None:
-    out = str(tmp_path / ("name_limit_test" * 7 + ".im"))
+    out = tmp_path / ("name_limit_test" * 7 + ".im")
     with Image.open(TEST_IM) as im:
         im.save(out)
     assert filecmp.cmp(out, "Tests/images/hopper_long_name.im")
@@ -68,12 +68,14 @@ def test_tell() -> None:
 
 def test_n_frames() -> None:
     with Image.open(TEST_IM) as im:
+        assert isinstance(im, ImImagePlugin.ImImageFile)
         assert im.n_frames == 1
         assert not im.is_animated
 
 
 def test_eoferror() -> None:
     with Image.open(TEST_IM) as im:
+        assert isinstance(im, ImImagePlugin.ImImageFile)
         n_frames = im.n_frames
 
         # Test seeking past the last frame
@@ -87,7 +89,7 @@ def test_eoferror() -> None:
 
 @pytest.mark.parametrize("mode", ("RGB", "P", "PA"))
 def test_roundtrip(mode: str, tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.im")
+    out = tmp_path / "temp.im"
     im = hopper(mode)
     im.save(out)
     assert_image_equal_tofile(im, out)
@@ -98,7 +100,7 @@ def test_small_palette(tmp_path: Path) -> None:
     colors = [0, 1, 2]
     im.putpalette(colors)
 
-    out = str(tmp_path / "temp.im")
+    out = tmp_path / "temp.im"
     im.save(out)
 
     with Image.open(out) as reloaded:
@@ -106,7 +108,7 @@ def test_small_palette(tmp_path: Path) -> None:
 
 
 def test_save_unsupported_mode(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.im")
+    out = tmp_path / "temp.im"
     im = hopper("HSV")
     with pytest.raises(ValueError):
         im.save(out)

Tests/test_file_jpeg.py

@@ -32,6 +32,7 @@ from .helper import (
     is_win32,
     mark_if_feature_version,
     skip_unless_feature,
+    timeout_unless_slower_valgrind,
 )
 
 ElementTree: ModuleType | None
@@ -83,7 +84,7 @@ class TestFileJpeg:
 
     @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
     def test_zero(self, size: tuple[int, int], tmp_path: Path) -> None:
-        f = str(tmp_path / "temp.jpg")
+        f = tmp_path / "temp.jpg"
         im = Image.new("RGB", size)
         with pytest.raises(ValueError):
             im.save(f)
@@ -91,6 +92,7 @@ class TestFileJpeg:
     def test_app(self) -> None:
         # Test APP/COM reader (@PIL135)
         with Image.open(TEST_FILE) as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             assert im.applist[0] == ("APP0", b"JFIF\x00\x01\x01\x01\x00`\x00`\x00\x00")
             assert im.applist[1] == (
                 "COM",
@@ -143,14 +145,16 @@ class TestFileJpeg:
             assert k > 0.9
             # roundtrip, and check again
             im = self.roundtrip(im)
-            c, m, y, k = (x / 255.0 for x in im.getpixel((0, 0)))
+            cmyk = im.getpixel((0, 0))
+            assert isinstance(cmyk, tuple)
+            c, m, y, k = (x / 255.0 for x in cmyk)
             assert c == 0.0
             assert m > 0.8
             assert y > 0.8
             assert k == 0.0
-            c, m, y, k = (
+            cmyk = im.getpixel((im.size[0] - 1, im.size[1] - 1))
-                x / 255.0 for x in im.getpixel((im.size[0] - 1, im.size[1] - 1))
+            assert isinstance(cmyk, tuple)
-            )
+            k = cmyk[3] / 255.0
             assert k > 0.9
 
     def test_rgb(self) -> None:
@@ -194,7 +198,7 @@ class TestFileJpeg:
             icc_profile = im1.info["icc_profile"]
             assert len(icc_profile) == 3144
             # Roundtrip via physical file.
-            f = str(tmp_path / "temp.jpg")
+            f = tmp_path / "temp.jpg"
             im1.save(f, icc_profile=icc_profile)
         with Image.open(f) as im2:
             assert im2.info.get("icc_profile") == icc_profile
@@ -238,7 +242,7 @@ class TestFileJpeg:
         # Sometimes the meta data on the icc_profile block is bigger than
         # Image.MAXBLOCK or the image size.
         with Image.open("Tests/images/icc_profile_big.jpg") as im:
-            f = str(tmp_path / "temp.jpg")
+            f = tmp_path / "temp.jpg"
             icc_profile = im.info["icc_profile"]
             # Should not raise OSError for image with icc larger than image size.
             im.save(
@@ -250,11 +254,11 @@ class TestFileJpeg:
             )
 
         with Image.open("Tests/images/flower2.jpg") as im:
-            f = str(tmp_path / "temp2.jpg")
+            f = tmp_path / "temp2.jpg"
             im.save(f, progressive=True, quality=94, icc_profile=b" " * 53955)
 
         with Image.open("Tests/images/flower2.jpg") as im:
-            f = str(tmp_path / "temp3.jpg")
+            f = tmp_path / "temp3.jpg"
             im.save(f, progressive=True, quality=94, exif=b" " * 43668)
 
     def test_optimize(self) -> None:
@@ -268,7 +272,7 @@ class TestFileJpeg:
 
     def test_optimize_large_buffer(self, tmp_path: Path) -> None:
         # https://github.com/python-pillow/Pillow/issues/148
-        f = str(tmp_path / "temp.jpg")
+        f = tmp_path / "temp.jpg"
         # this requires ~ 1.5x Image.MAXBLOCK
         im = Image.new("RGB", (4096, 4096), 0xFF3333)
         im.save(f, format="JPEG", optimize=True)
@@ -288,13 +292,13 @@ class TestFileJpeg:
         assert im1_bytes >= im3_bytes
 
     def test_progressive_large_buffer(self, tmp_path: Path) -> None:
-        f = str(tmp_path / "temp.jpg")
+        f = 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: Path) -> None:
-        f = str(tmp_path / "temp.jpg")
+        f = 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)
@@ -307,7 +311,7 @@ class TestFileJpeg:
 
     def test_large_exif(self, tmp_path: Path) -> None:
         # https://github.com/python-pillow/Pillow/issues/148
-        f = str(tmp_path / "temp.jpg")
+        f = tmp_path / "temp.jpg"
         im = hopper()
         im.save(f, "JPEG", quality=90, exif=b"1" * 65533)
 
@@ -316,6 +320,8 @@ class TestFileJpeg:
 
     def test_exif_typeerror(self) -> None:
         with Image.open("Tests/images/exif_typeerror.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
+
             # Should not raise a TypeError
             im._getexif()
 
@@ -335,7 +341,7 @@ class TestFileJpeg:
             assert exif[gps_index] == expected_exif_gps
 
         # Writing
-        f = str(tmp_path / "temp.jpg")
+        f = tmp_path / "temp.jpg"
         exif = Image.Exif()
         exif[gps_index] = expected_exif_gps
         hopper().save(f, exif=exif)
@@ -500,20 +506,21 @@ class TestFileJpeg:
 
     def test_mp(self) -> None:
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             assert im._getmp() is None
 
     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")
+            f = tmp_path / "temp.jpg"
             im.save(f, quality="keep")
         # Grayscale
         with Image.open("Tests/images/hopper_gray.jpg") as im:
-            f = str(tmp_path / "temp.jpg")
+            f = tmp_path / "temp.jpg"
             im.save(f, quality="keep")
         # CMYK
         with Image.open("Tests/images/pil_sample_cmyk.jpg") as im:
-            f = str(tmp_path / "temp.jpg")
+            f = tmp_path / "temp.jpg"
             im.save(f, quality="keep")
 
     def test_junk_jpeg_header(self) -> None:
@@ -558,12 +565,14 @@ class TestFileJpeg:
             with Image.open(test_file) as im:
                 im.save(b, "JPEG", qtables=[[n] * 64] * n)
             with Image.open(b) as im:
+                assert isinstance(im, JpegImagePlugin.JpegImageFile)
                 assert len(im.quantization) == n
                 reloaded = self.roundtrip(im, qtables="keep")
                 assert im.quantization == reloaded.quantization
                 assert max(reloaded.quantization[0]) <= 255
 
         with Image.open("Tests/images/hopper.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             qtables = im.quantization
             reloaded = self.roundtrip(im, qtables=qtables, subsampling=0)
             assert im.quantization == reloaded.quantization
@@ -663,6 +672,7 @@ class TestFileJpeg:
 
     def test_load_16bit_qtables(self) -> None:
         with Image.open("Tests/images/hopper_16bit_qtables.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             assert len(im.quantization) == 2
             assert len(im.quantization[0]) == 64
             assert max(im.quantization[0]) > 255
@@ -705,6 +715,7 @@ class TestFileJpeg:
     @pytest.mark.skipif(not djpeg_available(), reason="djpeg not available")
     def test_load_djpeg(self) -> None:
         with Image.open(TEST_FILE) as img:
+            assert isinstance(img, JpegImagePlugin.JpegImageFile)
             img.load_djpeg()
             assert_image_similar_tofile(img, TEST_FILE, 5)
 
@@ -726,7 +737,7 @@ class TestFileJpeg:
 
     def test_MAXBLOCK_scaling(self, tmp_path: Path) -> None:
         im = self.gen_random_image((512, 512))
-        f = str(tmp_path / "temp.jpeg")
+        f = tmp_path / "temp.jpeg"
         im.save(f, quality=100, optimize=True)
 
         with Image.open(f) as reloaded:
@@ -762,7 +773,7 @@ class TestFileJpeg:
 
     def test_save_tiff_with_dpi(self, tmp_path: Path) -> None:
         # Arrange
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         with Image.open("Tests/images/hopper.tif") as im:
             # Act
             im.save(outfile, "JPEG", dpi=im.info["dpi"])
@@ -773,7 +784,7 @@ class TestFileJpeg:
                 assert im.info["dpi"] == reloaded.info["dpi"]
 
     def test_save_dpi_rounding(self, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.jpg")
+        outfile = tmp_path / "temp.jpg"
         with Image.open("Tests/images/hopper.jpg") as im:
             im.save(outfile, dpi=(72.2, 72.2))
 
@@ -859,7 +870,7 @@ class TestFileJpeg:
             exif = im.getexif()
             assert exif[282] == 180
 
-            out = str(tmp_path / "out.jpg")
+            out = tmp_path / "out.jpg"
             with warnings.catch_warnings():
                 warnings.simplefilter("error")
 
@@ -909,6 +920,7 @@ class TestFileJpeg:
 
     def test_photoshop_malformed_and_multiple(self) -> None:
         with Image.open("Tests/images/app13-multiple.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             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"]
@@ -1005,7 +1017,7 @@ class TestFileJpeg:
                 assert im.getxmp() == {"xmpmeta": None}
 
     def test_save_xmp(self, tmp_path: Path) -> None:
-        f = str(tmp_path / "temp.jpg")
+        f = tmp_path / "temp.jpg"
         im = hopper()
         im.save(f, xmp=b"XMP test")
         with Image.open(f) as reloaded:
@@ -1024,7 +1036,7 @@ class TestFileJpeg:
         with pytest.raises(ValueError):
             im.save(f, xmp=b"1" * 65505)
 
-    @pytest.mark.timeout(timeout=1)
+    @timeout_unless_slower_valgrind(1)
     def test_eof(self, monkeypatch: pytest.MonkeyPatch) -> None:
         # Even though this decoder never says that it is finished
         # the image should still end when there is no new data
@@ -1084,6 +1096,7 @@ class TestFileJpeg:
 
     def test_deprecation(self) -> None:
         with Image.open(TEST_FILE) as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             with pytest.warns(DeprecationWarning):
                 assert im.huffman_ac == {}
             with pytest.warns(DeprecationWarning):
@@ -1094,7 +1107,7 @@ class TestFileJpeg:
 @skip_unless_feature("jpg")
 class TestFileCloseW32:
     def test_fd_leak(self, tmp_path: Path) -> None:
-        tmpfile = str(tmp_path / "temp.jpg")
+        tmpfile = tmp_path / "temp.jpg"
 
         with Image.open("Tests/images/hopper.jpg") as im:
             im.save(tmpfile)

Tests/test_file_jpeg2k.py

@@ -99,7 +99,7 @@ def test_bytesio(card: ImageFile.ImageFile) -> None:
 def test_lossless(card: ImageFile.ImageFile, 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")
+        outfile = tmp_path / "temp_test-card.png"
         im.save(outfile)
     assert_image_similar(im, card, 1.0e-3)
 
@@ -213,7 +213,7 @@ def test_header_errors() -> None:
 
 
 def test_layers_type(card: ImageFile.ImageFile, tmp_path: Path) -> None:
-    outfile = str(tmp_path / "temp_layers.jp2")
+    outfile = tmp_path / "temp_layers.jp2"
     for quality_layers in [[100, 50, 10], (100, 50, 10), None]:
         card.save(outfile, quality_layers=quality_layers)
 
@@ -228,12 +228,14 @@ def test_layers(card: ImageFile.ImageFile) -> None:
     out.seek(0)
 
     with Image.open(out) as im:
+        assert isinstance(im, Jpeg2KImagePlugin.Jpeg2KImageFile)
         im.layers = 1
         im.load()
         assert_image_similar(im, card, 13)
 
     out.seek(0)
     with Image.open(out) as im:
+        assert isinstance(im, Jpeg2KImagePlugin.Jpeg2KImageFile)
         im.layers = 3
         im.load()
         assert_image_similar(im, card, 0.4)
@@ -289,7 +291,7 @@ def test_mct(card: ImageFile.ImageFile) -> None:
 
 
 def test_sgnd(tmp_path: Path) -> None:
-    outfile = str(tmp_path / "temp.jp2")
+    outfile = tmp_path / "temp.jp2"
 
     im = Image.new("L", (1, 1))
     im.save(outfile)
@@ -455,8 +457,8 @@ def test_comment() -> None:
     # Test an image that is truncated partway through a codestream
     with open("Tests/images/comment.jp2", "rb") as fp:
         b = BytesIO(fp.read(130))
-        with Image.open(b) as im:
+    with Image.open(b) as im:
-            pass
+        pass
 
 
 def test_save_comment(card: ImageFile.ImageFile) -> None:

Tests/test_file_libtiff.py

@@ -36,10 +36,11 @@ class LibTiffTestCase:
         im.load()
         im.getdata()
 
+        assert isinstance(im, TiffImagePlugin.TiffImageFile)
         assert im._compression == "group4"
 
         # can we write it back out, in a different form.
-        out = str(tmp_path / "temp.png")
+        out = tmp_path / "temp.png"
         im.save(out)
 
         out_bytes = io.BytesIO()
@@ -80,7 +81,7 @@ class TestFileLibTiff(LibTiffTestCase):
         s = io.BytesIO()
         with open(test_file, "rb") as f:
             s.write(f.read())
-            s.seek(0)
+        s.seek(0)
         with Image.open(s) as im:
             assert im.size == (500, 500)
             self._assert_noerr(tmp_path, im)
@@ -123,7 +124,7 @@ class TestFileLibTiff(LibTiffTestCase):
         """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:
-            out = str(tmp_path / "temp.tif")
+            out = tmp_path / "temp.tif"
             rot = orig.transpose(Image.Transpose.ROTATE_90)
             assert rot.size == (500, 500)
             rot.save(out)
@@ -151,8 +152,9 @@ class TestFileLibTiff(LibTiffTestCase):
     @pytest.mark.parametrize("legacy_api", (False, True))
     def test_write_metadata(self, legacy_api: bool, tmp_path: Path) -> None:
         """Test metadata writing through libtiff"""
-        f = str(tmp_path / "temp.tiff")
+        f = tmp_path / "temp.tiff"
         with Image.open("Tests/images/hopper_g4.tif") as img:
+            assert isinstance(img, TiffImagePlugin.TiffImageFile)
             img.save(f, tiffinfo=img.tag)
 
             if legacy_api:
@@ -170,6 +172,7 @@ class TestFileLibTiff(LibTiffTestCase):
         ]
 
         with Image.open(f) as loaded:
+            assert isinstance(loaded, TiffImagePlugin.TiffImageFile)
             if legacy_api:
                 reloaded = loaded.tag.named()
             else:
@@ -212,6 +215,7 @@ class TestFileLibTiff(LibTiffTestCase):
         # Exclude ones that have special meaning
         # that we're already testing them
         with Image.open("Tests/images/hopper_g4.tif") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             for tag in im.tag_v2:
                 try:
                     del core_items[tag]
@@ -247,7 +251,7 @@ class TestFileLibTiff(LibTiffTestCase):
             # Extra samples really doesn't make sense in this application.
             del new_ifd[338]
 
-            out = str(tmp_path / "temp.tif")
+            out = tmp_path / "temp.tif"
             monkeypatch.setattr(TiffImagePlugin, "WRITE_LIBTIFF", True)
 
             im.save(out, tiffinfo=new_ifd)
@@ -313,10 +317,11 @@ class TestFileLibTiff(LibTiffTestCase):
         ) -> None:
             im = hopper()
 
-            out = str(tmp_path / "temp.tif")
+            out = tmp_path / "temp.tif"
             im.save(out, tiffinfo=tiffinfo)
 
             with Image.open(out) as reloaded:
+                assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
                 for tag, value in tiffinfo.items():
                     reloaded_value = reloaded.tag_v2[tag]
                     if (
@@ -347,14 +352,16 @@ class TestFileLibTiff(LibTiffTestCase):
         )
 
     def test_osubfiletype(self, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         with Image.open("Tests/images/g4_orientation_6.tif") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             im.tag_v2[OSUBFILETYPE] = 1
             im.save(outfile)
 
     def test_subifd(self, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         with Image.open("Tests/images/g4_orientation_6.tif") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             im.tag_v2[SUBIFD] = 10000
 
             # Should not segfault
@@ -365,17 +372,18 @@ class TestFileLibTiff(LibTiffTestCase):
     ) -> None:
         monkeypatch.setattr(TiffImagePlugin, "WRITE_LIBTIFF", True)
 
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
         hopper().save(out, tiffinfo={700: b"xmlpacket tag"})
 
         with Image.open(out) as reloaded:
+            assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
             if 700 in reloaded.tag_v2:
                 assert reloaded.tag_v2[700] == b"xmlpacket tag"
 
     def test_int_dpi(self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
         # issue #1765
         im = hopper("RGB")
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
         monkeypatch.setattr(TiffImagePlugin, "WRITE_LIBTIFF", True)
         im.save(out, dpi=(72, 72))
         with Image.open(out) as reloaded:
@@ -383,7 +391,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
     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")
+            out = tmp_path / "temp.tif"
             i.save(out, compression="group3")
 
             with Image.open(out) as reread:
@@ -400,7 +408,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert b[0] == ord(b"\xe0")
             assert b[1] == ord(b"\x01")
 
-            out = str(tmp_path / "temp.tif")
+            out = tmp_path / "temp.tif"
             # out = "temp.le.tif"
             im.save(out)
         with Image.open(out) as reread:
@@ -420,7 +428,7 @@ class TestFileLibTiff(LibTiffTestCase):
             assert b[0] == ord(b"\x01")
             assert b[1] == ord(b"\xe0")
 
-            out = str(tmp_path / "temp.tif")
+            out = tmp_path / "temp.tif"
             im.save(out)
             with Image.open(out) as reread:
                 assert reread.info["compression"] == im.info["compression"]
@@ -430,12 +438,15 @@ class TestFileLibTiff(LibTiffTestCase):
         """Tests String data in info directory"""
         test_file = "Tests/images/hopper_g4_500.tif"
         with Image.open(test_file) as orig:
-            out = str(tmp_path / "temp.tif")
+            assert isinstance(orig, TiffImagePlugin.TiffImageFile)
+
+            out = tmp_path / "temp.tif"
 
             orig.tag[269] = "temp.tif"
             orig.save(out)
 
         with Image.open(out) as reread:
+            assert isinstance(reread, TiffImagePlugin.TiffImageFile)
             assert "temp.tif" == reread.tag_v2[269]
             assert "temp.tif" == reread.tag[269][0]
 
@@ -457,7 +468,7 @@ class TestFileLibTiff(LibTiffTestCase):
     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")
+        out = tmp_path / "temp.tif"
         with Image.open("Tests/images/pport_g4.tif") as im:
             im = im.convert("L")
 
@@ -470,7 +481,7 @@ class TestFileLibTiff(LibTiffTestCase):
         # Test various tiff compressions and assert similar image content but reduced
         # file sizes.
         im = hopper("RGB")
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
         im.save(out)
         size_raw = os.path.getsize(out)
 
@@ -494,7 +505,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
     def test_tiff_jpeg_compression(self, tmp_path: Path) -> None:
         im = hopper("RGB")
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
         im.save(out, compression="tiff_jpeg")
 
         with Image.open(out) as reloaded:
@@ -502,7 +513,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
     def test_tiff_deflate_compression(self, tmp_path: Path) -> None:
         im = hopper("RGB")
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
         im.save(out, compression="tiff_deflate")
 
         with Image.open(out) as reloaded:
@@ -510,7 +521,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
     def test_quality(self, tmp_path: Path) -> None:
         im = hopper("RGB")
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
 
         with pytest.raises(ValueError):
             im.save(out, compression="tiff_lzw", quality=50)
@@ -525,7 +536,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
     def test_cmyk_save(self, tmp_path: Path) -> None:
         im = hopper("CMYK")
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
 
         im.save(out, compression="tiff_adobe_deflate")
         assert_image_equal_tofile(im, out)
@@ -534,19 +545,20 @@ class TestFileLibTiff(LibTiffTestCase):
     def test_palette_save(
         self, im: Image.Image, monkeypatch: pytest.MonkeyPatch, tmp_path: Path
     ) -> None:
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
 
         monkeypatch.setattr(TiffImagePlugin, "WRITE_LIBTIFF", True)
         im.save(out)
 
         with Image.open(out) as reloaded:
             # colormap/palette tag
+            assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
             assert len(reloaded.tag_v2[320]) == 768
 
     @pytest.mark.parametrize("compression", ("tiff_ccitt", "group3", "group4"))
     def test_bw_compression_w_rgb(self, compression: str, tmp_path: Path) -> None:
         im = hopper("RGB")
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
 
         with pytest.raises(OSError):
             im.save(out, compression=compression)
@@ -572,6 +584,7 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open("Tests/images/multipage.tiff") as im:
             # file is a multipage tiff,  10x10 green, 10x10 red, 20x20 blue
 
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             im.seek(0)
             assert im.size == (10, 10)
             assert im.convert("RGB").getpixel((0, 0)) == (0, 128, 0)
@@ -591,6 +604,7 @@ class TestFileLibTiff(LibTiffTestCase):
         # issue #862
         monkeypatch.setattr(TiffImagePlugin, "READ_LIBTIFF", True)
         with Image.open("Tests/images/multipage.tiff") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             frames = im.n_frames
             assert frames == 3
             for _ in range(frames):
@@ -610,6 +624,7 @@ class TestFileLibTiff(LibTiffTestCase):
     def test__next(self, monkeypatch: pytest.MonkeyPatch) -> None:
         monkeypatch.setattr(TiffImagePlugin, "READ_LIBTIFF", True)
         with Image.open("Tests/images/hopper.tif") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert not im.tag.next
             im.load()
             assert not im.tag.next
@@ -686,25 +701,29 @@ class TestFileLibTiff(LibTiffTestCase):
 
     def test_save_ycbcr(self, tmp_path: Path) -> None:
         im = hopper("YCbCr")
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         im.save(outfile, compression="jpeg")
 
         with Image.open(outfile) as reloaded:
+            assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
             assert reloaded.tag_v2[530] == (1, 1)
             assert reloaded.tag_v2[532] == (0, 255, 128, 255, 128, 255)
 
     def test_exif_ifd(self) -> None:
         out = io.BytesIO()
         with Image.open("Tests/images/tiff_adobe_deflate.tif") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im.tag_v2[34665] == 125456
             im.save(out, "TIFF")
 
             with Image.open(out) as reloaded:
+                assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
                 assert 34665 not in reloaded.tag_v2
 
             im.save(out, "TIFF", tiffinfo={34665: 125456})
 
         with Image.open(out) as reloaded:
+            assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
             if Image.core.libtiff_support_custom_tags:
                 assert reloaded.tag_v2[34665] == 125456
 
@@ -713,7 +732,7 @@ class TestFileLibTiff(LibTiffTestCase):
     ) -> None:
         # issue 1597
         with Image.open("Tests/images/rdf.tif") as im:
-            out = str(tmp_path / "temp.tif")
+            out = tmp_path / "temp.tif"
 
             monkeypatch.setattr(TiffImagePlugin, "WRITE_LIBTIFF", True)
             # this shouldn't crash
@@ -724,7 +743,7 @@ class TestFileLibTiff(LibTiffTestCase):
         # Test TIFF with tag 297 (Page Number) having value of 0 0.
         # The first number is the current page number.
         # The second is the total number of pages, zero means not available.
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         # Created by printing a page in Chrome to PDF, then:
         # /usr/bin/gs -q -sDEVICE=tiffg3 -sOutputFile=total-pages-zero.tif
         # -dNOPAUSE /tmp/test.pdf -c quit
@@ -736,7 +755,7 @@ class TestFileLibTiff(LibTiffTestCase):
     def test_fd_duplication(self, tmp_path: Path) -> None:
         # https://github.com/python-pillow/Pillow/issues/1651
 
-        tmpfile = str(tmp_path / "temp.tif")
+        tmpfile = tmp_path / "temp.tif"
         with open(tmpfile, "wb") as f:
             with open("Tests/images/g4-multi.tiff", "rb") as src:
                 f.write(src.read())
@@ -779,13 +798,14 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open("Tests/images/hopper.iccprofile.tif") as img:
             icc_profile = img.info["icc_profile"]
 
-            out = str(tmp_path / "temp.tif")
+            out = tmp_path / "temp.tif"
             img.save(out, icc_profile=icc_profile)
         with Image.open(out) as reloaded:
             assert icc_profile == reloaded.info["icc_profile"]
 
     def test_multipage_compression(self) -> None:
         with Image.open("Tests/images/compression.tif") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             im.seek(0)
             assert im._compression == "tiff_ccitt"
             assert im.size == (10, 10)
@@ -802,7 +822,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
     def test_save_tiff_with_jpegtables(self, tmp_path: Path) -> None:
         # Arrange
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
 
         # Created with ImageMagick: convert hopper.jpg hopper_jpg.tif
         # Contains JPEGTables (347) tag
@@ -864,7 +884,7 @@ class TestFileLibTiff(LibTiffTestCase):
         self, monkeypatch: pytest.MonkeyPatch, tmp_path: Path
     ) -> None:
         im = Image.new("F", (1, 1))
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
         monkeypatch.setattr(TiffImagePlugin, "WRITE_LIBTIFF", True)
         im.save(out)
 
@@ -1008,7 +1028,7 @@ class TestFileLibTiff(LibTiffTestCase):
     @pytest.mark.parametrize("compression", (None, "jpeg"))
     def test_block_tile_tags(self, compression: str | None, tmp_path: Path) -> None:
         im = hopper()
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
 
         tags = {
             TiffImagePlugin.TILEWIDTH: 256,
@@ -1026,6 +1046,17 @@ class TestFileLibTiff(LibTiffTestCase):
         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_old_style_jpeg_orientation(self) -> None:
+        with open("Tests/images/old-style-jpeg-compression.tif", "rb") as fp:
+            data = fp.read()
+
+        # Set EXIF Orientation to 2
+        data = data[:102] + b"\x02" + data[103:]
+
+        with Image.open(io.BytesIO(data)) as im:
+            im = im.transpose(Image.Transpose.FLIP_LEFT_RIGHT)
+        assert_image_equal_tofile(im, "Tests/images/old-style-jpeg-compression.png")
+
     def test_open_missing_samplesperpixel(self) -> None:
         with Image.open(
             "Tests/images/old-style-jpeg-compression-no-samplesperpixel.tif"
@@ -1079,6 +1110,7 @@ class TestFileLibTiff(LibTiffTestCase):
         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:
+                    assert isinstance(im, TiffImagePlugin.TiffImageFile)
                     assert 274 in im.tag_v2
 
                     im.load()
@@ -1147,7 +1179,7 @@ class TestFileLibTiff(LibTiffTestCase):
     @pytest.mark.parametrize("compression", ("tiff_adobe_deflate", "jpeg"))
     def test_save_multistrip(self, compression: str, tmp_path: Path) -> None:
         im = hopper("RGB").resize((256, 256))
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
         im.save(out, compression=compression)
 
         with Image.open(out) as im:
@@ -1160,7 +1192,7 @@ class TestFileLibTiff(LibTiffTestCase):
         self, argument: bool, tmp_path: Path, monkeypatch: pytest.MonkeyPatch
     ) -> None:
         im = hopper("RGB").resize((256, 256))
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
 
         if not argument:
             monkeypatch.setattr(TiffImagePlugin, "STRIP_SIZE", 2**18)
@@ -1176,13 +1208,13 @@ class TestFileLibTiff(LibTiffTestCase):
     @pytest.mark.parametrize("compression", ("tiff_adobe_deflate", None))
     def test_save_zero(self, compression: str | None, tmp_path: Path) -> None:
         im = Image.new("RGB", (0, 0))
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
         with pytest.raises(SystemError):
             im.save(out, compression=compression)
 
     def test_save_many_compressed(self, tmp_path: Path) -> None:
         im = hopper()
-        out = str(tmp_path / "temp.tif")
+        out = tmp_path / "temp.tif"
         for _ in range(10000):
             im.save(out, compression="jpeg")
 

Tests/test_file_libtiff_small.py

@@ -32,7 +32,7 @@ class TestFileLibTiffSmall(LibTiffTestCase):
         s = BytesIO()
         with open(test_file, "rb") as f:
             s.write(f.read())
-            s.seek(0)
+        s.seek(0)
         with Image.open(s) as im:
             assert im.size == (128, 128)
             self._assert_noerr(tmp_path, im)

Tests/test_file_mic.py

@@ -30,11 +30,13 @@ def test_sanity() -> None:
 
 def test_n_frames() -> None:
     with Image.open(TEST_FILE) as im:
+        assert isinstance(im, MicImagePlugin.MicImageFile)
         assert im.n_frames == 1
 
 
 def test_is_animated() -> None:
     with Image.open(TEST_FILE) as im:
+        assert isinstance(im, MicImagePlugin.MicImageFile)
         assert not im.is_animated
 
 
@@ -55,10 +57,11 @@ def test_seek() -> None:
 
 def test_close() -> None:
     with Image.open(TEST_FILE) as im:
-        pass
+        assert isinstance(im, MicImagePlugin.MicImageFile)
     assert im.ole.fp.closed
 
     im = Image.open(TEST_FILE)
+    assert isinstance(im, MicImagePlugin.MicImageFile)
     im.close()
     assert im.ole.fp.closed
 

Tests/test_file_mpo.py

@@ -6,7 +6,7 @@ from typing import Any
 
 import pytest
 
-from PIL import Image, ImageFile, MpoImagePlugin
+from PIL import Image, ImageFile, JpegImagePlugin, MpoImagePlugin
 
 from .helper import (
     assert_image_equal,
@@ -80,6 +80,7 @@ def test_context_manager() -> None:
 def test_app(test_file: str) -> None:
     # Test APP/COM reader (@PIL135)
     with Image.open(test_file) as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         assert im.applist[0][0] == "APP1"
         assert im.applist[1][0] == "APP2"
         assert im.applist[1][1].startswith(
@@ -220,12 +221,14 @@ def test_seek(test_file: str) -> None:
 
 def test_n_frames() -> None:
     with Image.open("Tests/images/sugarshack.mpo") as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         assert im.n_frames == 2
         assert im.is_animated
 
 
 def test_eoferror() -> None:
     with Image.open("Tests/images/sugarshack.mpo") as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         n_frames = im.n_frames
 
         # Test seeking past the last frame
@@ -239,6 +242,8 @@ def test_eoferror() -> None:
 
 def test_adopt_jpeg() -> None:
     with Image.open("Tests/images/hopper.jpg") as im:
+        assert isinstance(im, JpegImagePlugin.JpegImageFile)
+
         with pytest.raises(ValueError):
             MpoImagePlugin.MpoImageFile.adopt(im)
 

Tests/test_file_msp.py

@@ -15,7 +15,7 @@ YA_EXTRA_DIR = "Tests/images/msp"
 
 
 def test_sanity(tmp_path: Path) -> None:
-    test_file = str(tmp_path / "temp.msp")
+    test_file = tmp_path / "temp.msp"
 
     hopper("1").save(test_file)
 
@@ -84,7 +84,7 @@ def test_msp_v2() -> None:
 def test_cannot_save_wrong_mode(tmp_path: Path) -> None:
     # Arrange
     im = hopper()
-    filename = str(tmp_path / "temp.msp")
+    filename = tmp_path / "temp.msp"
 
     # Act/Assert
     with pytest.raises(OSError):

Tests/test_file_palm.py

@@ -14,7 +14,7 @@ from .helper import assert_image_equal, hopper, magick_command
 def helper_save_as_palm(tmp_path: Path, mode: str) -> None:
     # Arrange
     im = hopper(mode)
-    outfile = str(tmp_path / ("temp_" + mode + ".palm"))
+    outfile = tmp_path / ("temp_" + mode + ".palm")
 
     # Act
     im.save(outfile)
@@ -25,7 +25,7 @@ def helper_save_as_palm(tmp_path: Path, mode: str) -> None:
 
 
 def open_with_magick(magick: list[str], tmp_path: Path, f: str) -> Image.Image:
-    outfile = str(tmp_path / "temp.png")
+    outfile = tmp_path / "temp.png"
     rc = subprocess.call(
         magick + [f, outfile], stdout=subprocess.DEVNULL, stderr=subprocess.STDOUT
     )
@@ -43,6 +43,11 @@ def roundtrip(tmp_path: Path, mode: str) -> None:
 
     im.save(outfile)
     converted = open_with_magick(magick, tmp_path, outfile)
+    if mode == "P":
+        assert converted.mode == "P"
+
+        im = im.convert("RGB")
+        converted = converted.convert("RGB")
     assert_image_equal(converted, im)
 
 
@@ -55,7 +60,6 @@ def test_monochrome(tmp_path: Path) -> None:
     roundtrip(tmp_path, mode)
 
 
-@pytest.mark.xfail(reason="Palm P image is wrong")
 def test_p_mode(tmp_path: Path) -> None:
     # Arrange
     mode = "P"

Tests/test_file_pcx.py

@@ -11,7 +11,7 @@ from .helper import assert_image_equal, hopper
 
 
 def _roundtrip(tmp_path: Path, im: Image.Image) -> None:
-    f = str(tmp_path / "temp.pcx")
+    f = tmp_path / "temp.pcx"
     im.save(f)
     with Image.open(f) as im2:
         assert im2.mode == im.mode
@@ -31,7 +31,7 @@ def test_sanity(tmp_path: Path) -> None:
     _roundtrip(tmp_path, im)
 
     # Test an unsupported mode
-    f = str(tmp_path / "temp.pcx")
+    f = tmp_path / "temp.pcx"
     im = hopper("RGBA")
     with pytest.raises(ValueError):
         im.save(f)

Tests/test_file_pdf.py

@@ -13,7 +13,12 @@ import pytest
 
 from PIL import Image, PdfParser, features
 
-from .helper import hopper, mark_if_feature_version, skip_unless_feature
+from .helper import (
+    hopper,
+    mark_if_feature_version,
+    skip_unless_feature,
+    timeout_unless_slower_valgrind,
+)
 
 
 def helper_save_as_pdf(tmp_path: Path, mode: str, **kwargs: Any) -> str:
@@ -55,7 +60,7 @@ def test_save_alpha(tmp_path: Path, mode: str) -> None:
 
 def test_p_alpha(tmp_path: Path) -> None:
     # Arrange
-    outfile = str(tmp_path / "temp.pdf")
+    outfile = tmp_path / "temp.pdf"
     with Image.open("Tests/images/pil123p.png") as im:
         assert im.mode == "P"
         assert isinstance(im.info["transparency"], bytes)
@@ -80,7 +85,7 @@ def test_monochrome(tmp_path: Path) -> None:
 
 def test_unsupported_mode(tmp_path: Path) -> None:
     im = hopper("PA")
-    outfile = str(tmp_path / "temp_PA.pdf")
+    outfile = tmp_path / "temp_PA.pdf"
 
     with pytest.raises(ValueError):
         im.save(outfile)
@@ -89,7 +94,7 @@ def test_unsupported_mode(tmp_path: Path) -> None:
 def test_resolution(tmp_path: Path) -> None:
     im = hopper()
 
-    outfile = str(tmp_path / "temp.pdf")
+    outfile = tmp_path / "temp.pdf"
     im.save(outfile, resolution=150)
 
     with open(outfile, "rb") as fp:
@@ -117,7 +122,7 @@ def test_resolution(tmp_path: Path) -> None:
 def test_dpi(params: dict[str, int | tuple[int, int]], tmp_path: Path) -> None:
     im = hopper()
 
-    outfile = str(tmp_path / "temp.pdf")
+    outfile = tmp_path / "temp.pdf"
     im.save(outfile, "PDF", **params)
 
     with open(outfile, "rb") as fp:
@@ -144,7 +149,7 @@ def test_save_all(tmp_path: Path) -> None:
 
     # Multiframe image
     with Image.open("Tests/images/dispose_bgnd.gif") as im:
-        outfile = str(tmp_path / "temp.pdf")
+        outfile = tmp_path / "temp.pdf"
         im.save(outfile, save_all=True)
 
         assert os.path.isfile(outfile)
@@ -177,7 +182,7 @@ def test_save_all(tmp_path: Path) -> None:
 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")
+        outfile = tmp_path / "temp.pdf"
         im.save(outfile)
 
     assert os.path.isfile(outfile)
@@ -339,8 +344,7 @@ def test_pdf_append_to_bytesio() -> None:
     assert len(f.getvalue()) > initial_size
 
 
-@pytest.mark.timeout(1)
+@timeout_unless_slower_valgrind(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: bytes) -> None:
     malicious = b" trailer<<>>" + newline * 3456

Tests/test_file_png.py

@@ -68,7 +68,7 @@ def roundtrip(im: Image.Image, **options: Any) -> PngImagePlugin.PngImageFile:
 
 @skip_unless_feature("zlib")
 class TestFilePng:
-    def get_chunks(self, filename: str) -> list[bytes]:
+    def get_chunks(self, filename: Path) -> list[bytes]:
         chunks = []
         with open(filename, "rb") as fp:
             fp.read(8)
@@ -89,7 +89,7 @@ class TestFilePng:
         assert version is not None
         assert re.search(r"\d+(\.\d+){1,3}(\.zlib\-ng)?$", version)
 
-        test_file = str(tmp_path / "temp.png")
+        test_file = tmp_path / "temp.png"
 
         hopper("RGB").save(test_file)
 
@@ -250,7 +250,7 @@ class TestFilePng:
             # each palette entry
             assert len(im.info["transparency"]) == 256
 
-            test_file = str(tmp_path / "temp.png")
+            test_file = tmp_path / "temp.png"
             im.save(test_file)
 
         # check if saved image contains same transparency
@@ -271,7 +271,7 @@ class TestFilePng:
             assert im.info["transparency"] == 164
             assert im.getpixel((31, 31)) == 164
 
-            test_file = str(tmp_path / "temp.png")
+            test_file = tmp_path / "temp.png"
             im.save(test_file)
 
         # check if saved image contains same transparency
@@ -294,7 +294,7 @@ class TestFilePng:
         assert im.getcolors() == [(100, (0, 0, 0, 0))]
 
         im = im.convert("P")
-        test_file = str(tmp_path / "temp.png")
+        test_file = tmp_path / "temp.png"
         im.save(test_file)
 
         # check if saved image contains same transparency
@@ -315,7 +315,7 @@ class TestFilePng:
                 im_rgba = im.convert("RGBA")
             assert im_rgba.getchannel("A").getcolors()[0][0] == num_transparent
 
-            test_file = str(tmp_path / "temp.png")
+            test_file = tmp_path / "temp.png"
             im.save(test_file)
 
             with Image.open(test_file) as test_im:
@@ -329,7 +329,7 @@ class TestFilePng:
     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")
+            test_file = tmp_path / "temp.png"
             im.save(test_file)
 
     def test_load_verify(self) -> None:
@@ -488,7 +488,7 @@ class TestFilePng:
         im = hopper("P")
         im.info["transparency"] = 0
 
-        f = str(tmp_path / "temp.png")
+        f = tmp_path / "temp.png"
         im.save(f)
 
         with Image.open(f) as im2:
@@ -549,7 +549,7 @@ class TestFilePng:
 
     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")
+            test_file = tmp_path / "temp.png"
             im.convert("P").save(test_file, dpi=(100, 100))
 
         chunks = self.get_chunks(test_file)
@@ -576,6 +576,7 @@ class TestFilePng:
 
     def test_read_private_chunks(self) -> None:
         with Image.open("Tests/images/exif.png") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
             assert im.private_chunks == [(b"orNT", b"\x01")]
 
     def test_roundtrip_private_chunk(self) -> None:
@@ -598,6 +599,7 @@ class TestFilePng:
 
     def test_textual_chunks_after_idat(self, monkeypatch: pytest.MonkeyPatch) -> None:
         with Image.open("Tests/images/hopper.png") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
             assert "comment" in im.text
             for k, v in {
                 "date:create": "2014-09-04T09:37:08+03:00",
@@ -607,15 +609,19 @@ class TestFilePng:
 
         # Raises a SyntaxError in load_end
         with Image.open("Tests/images/broken_data_stream.png") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
             with pytest.raises(OSError):
                 assert isinstance(im.text, dict)
 
         # Raises an EOFError in load_end
         with Image.open("Tests/images/hopper_idat_after_image_end.png") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
             assert im.text == {"TXT": "VALUE", "ZIP": "VALUE"}
 
         # Raises a UnicodeDecodeError in load_end
         with Image.open("Tests/images/truncated_image.png") as im:
+            assert isinstance(im, PngImagePlugin.PngImageFile)
+
             # The file is truncated
             with pytest.raises(OSError):
                 im.text
@@ -661,7 +667,7 @@ class TestFilePng:
     def test_specify_bits(self, save_all: bool, tmp_path: Path) -> None:
         im = hopper("P")
 
-        out = str(tmp_path / "temp.png")
+        out = tmp_path / "temp.png"
         im.save(out, bits=4, save_all=save_all)
 
         with Image.open(out) as reloaded:
@@ -671,8 +677,8 @@ class TestFilePng:
         im = Image.new("P", (1, 1))
         im.putpalette((1, 1, 1))
 
-        out = str(tmp_path / "temp.png")
+        out = tmp_path / "temp.png"
-        im.save(str(tmp_path / "temp.png"))
+        im.save(out)
 
         with Image.open(out) as reloaded:
             assert len(reloaded.png.im_palette[1]) == 3
@@ -721,11 +727,12 @@ class TestFilePng:
 
     def test_exif_save(self, tmp_path: Path) -> None:
         # Test exif is not saved from info
-        test_file = str(tmp_path / "temp.png")
+        test_file = tmp_path / "temp.png"
         with Image.open("Tests/images/exif.png") as im:
             im.save(test_file)
 
         with Image.open(test_file) as reloaded:
+            assert isinstance(reloaded, PngImagePlugin.PngImageFile)
             assert reloaded._getexif() is None
 
         # Test passing in exif
@@ -741,7 +748,7 @@ class TestFilePng:
     )
     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")
+            test_file = tmp_path / "temp.png"
             im.save(test_file, exif=im.getexif())
 
         with Image.open(test_file) as reloaded:
@@ -750,7 +757,7 @@ class TestFilePng:
 
     def test_exif_argument(self, tmp_path: Path) -> None:
         with Image.open(TEST_PNG_FILE) as im:
-            test_file = str(tmp_path / "temp.png")
+            test_file = tmp_path / "temp.png"
             im.save(test_file, exif=b"exifstring")
 
         with Image.open(test_file) as reloaded:

Tests/test_file_ppm.py

@@ -94,7 +94,7 @@ def test_16bit_pgm() -> None:
 
 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")
+        filename = tmp_path / "temp.pgm"
         im.save(filename, "PPM")
         assert_image_equal_tofile(im, filename)
 
@@ -106,7 +106,7 @@ def test_pnm(tmp_path: Path) -> None:
     with Image.open("Tests/images/hopper.pnm") as im:
         assert_image_similar(im, hopper(), 0.0001)
 
-        filename = str(tmp_path / "temp.pnm")
+        filename = tmp_path / "temp.pnm"
         im.save(filename)
 
         assert_image_equal_tofile(im, filename)
@@ -117,7 +117,7 @@ def test_pfm(tmp_path: Path) -> None:
         assert im.info["scale"] == 1.0
         assert_image_equal(im, hopper("F"))
 
-        filename = str(tmp_path / "tmp.pfm")
+        filename = tmp_path / "tmp.pfm"
         im.save(filename)
 
         assert_image_equal_tofile(im, filename)
@@ -128,7 +128,7 @@ def test_pfm_big_endian(tmp_path: Path) -> None:
         assert im.info["scale"] == 2.5
         assert_image_equal(im, hopper("F"))
 
-        filename = str(tmp_path / "tmp.pfm")
+        filename = tmp_path / "tmp.pfm"
         im.save(filename)
 
         assert_image_equal_tofile(im, filename)
@@ -194,8 +194,8 @@ def test_16bit_plain_pgm() -> None:
 def test_plain_data_with_comment(
     tmp_path: Path, header: bytes, data: bytes, comment_count: int
 ) -> None:
-    path1 = str(tmp_path / "temp1.ppm")
+    path1 = tmp_path / "temp1.ppm"
-    path2 = str(tmp_path / "temp2.ppm")
+    path2 = tmp_path / "temp2.ppm"
     comment = b"# comment" * comment_count
     with open(path1, "wb") as f1, open(path2, "wb") as f2:
         f1.write(header + b"\n\n" + data)
@@ -207,7 +207,7 @@ def test_plain_data_with_comment(
 
 @pytest.mark.parametrize("data", (b"P1\n128 128\n", b"P3\n128 128\n255\n"))
 def test_plain_truncated_data(tmp_path: Path, data: bytes) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(data)
 
@@ -218,7 +218,7 @@ def test_plain_truncated_data(tmp_path: Path, data: bytes) -> None:
 
 @pytest.mark.parametrize("data", (b"P1\n128 128\n1009", b"P3\n128 128\n255\n100A"))
 def test_plain_invalid_data(tmp_path: Path, data: bytes) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(data)
 
@@ -235,7 +235,7 @@ def test_plain_invalid_data(tmp_path: Path, data: bytes) -> None:
     ),
 )
 def test_plain_ppm_token_too_long(tmp_path: Path, data: bytes) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(data)
 
@@ -245,7 +245,7 @@ def test_plain_ppm_token_too_long(tmp_path: Path, data: bytes) -> None:
 
 
 def test_plain_ppm_value_negative(tmp_path: Path) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(b"P3\n128 128\n255\n-1")
 
@@ -255,7 +255,7 @@ def test_plain_ppm_value_negative(tmp_path: Path) -> None:
 
 
 def test_plain_ppm_value_too_large(tmp_path: Path) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(b"P3\n128 128\n255\n256")
 
@@ -270,7 +270,7 @@ def test_magic() -> None:
 
 
 def test_header_with_comments(tmp_path: Path) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(b"P6 #comment\n#comment\r12#comment\r8\n128 #comment\n255\n")
 
@@ -279,7 +279,7 @@ def test_header_with_comments(tmp_path: Path) -> None:
 
 
 def test_non_integer_token(tmp_path: Path) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(b"P6\nTEST")
 
@@ -289,7 +289,7 @@ def test_non_integer_token(tmp_path: Path) -> None:
 
 
 def test_header_token_too_long(tmp_path: Path) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(b"P6\n 01234567890")
 
@@ -300,7 +300,7 @@ def test_header_token_too_long(tmp_path: Path) -> None:
 
 def test_truncated_file(tmp_path: Path) -> None:
     # Test EOF in header
-    path = str(tmp_path / "temp.pgm")
+    path = tmp_path / "temp.pgm"
     with open(path, "wb") as f:
         f.write(b"P6")
 
@@ -316,7 +316,7 @@ def test_truncated_file(tmp_path: Path) -> None:
 
 
 def test_not_enough_image_data(tmp_path: Path) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(b"P2 1 2 255 255")
 
@@ -327,7 +327,7 @@ def test_not_enough_image_data(tmp_path: Path) -> None:
 
 @pytest.mark.parametrize("maxval", (b"0", b"65536"))
 def test_invalid_maxval(maxval: bytes, tmp_path: Path) -> None:
-    path = str(tmp_path / "temp.ppm")
+    path = tmp_path / "temp.ppm"
     with open(path, "wb") as f:
         f.write(b"P6\n3 1 " + maxval)
 
@@ -350,7 +350,7 @@ def test_neg_ppm() -> None:
 
 
 def test_mimetypes(tmp_path: Path) -> None:
-    path = str(tmp_path / "temp.pgm")
+    path = tmp_path / "temp.pgm"
 
     with open(path, "wb") as f:
         f.write(b"P4\n128 128\n255")

Tests/test_file_psd.py

@@ -59,17 +59,21 @@ def test_invalid_file() -> None:
 
 def test_n_frames() -> None:
     with Image.open("Tests/images/hopper_merged.psd") as im:
+        assert isinstance(im, PsdImagePlugin.PsdImageFile)
         assert im.n_frames == 1
         assert not im.is_animated
 
     for path in [test_file, "Tests/images/negative_layer_count.psd"]:
         with Image.open(path) as im:
+            assert isinstance(im, PsdImagePlugin.PsdImageFile)
             assert im.n_frames == 2
             assert im.is_animated
 
 
 def test_eoferror() -> None:
     with Image.open(test_file) as im:
+        assert isinstance(im, PsdImagePlugin.PsdImageFile)
+
         # PSD seek index starts at 1 rather than 0
         n_frames = im.n_frames + 1
 
@@ -119,11 +123,13 @@ def test_rgba() -> None:
 
 def test_negative_top_left_layer() -> None:
     with Image.open("Tests/images/negative_top_left_layer.psd") as im:
+        assert isinstance(im, PsdImagePlugin.PsdImageFile)
         assert im.layers[0][2] == (-50, -50, 50, 50)
 
 
 def test_layer_skip() -> None:
     with Image.open("Tests/images/five_channels.psd") as im:
+        assert isinstance(im, PsdImagePlugin.PsdImageFile)
         assert im.n_frames == 1
 
 
@@ -175,5 +181,6 @@ def test_crashes(test_file: str, raises: type[Exception]) -> None:
 def test_layer_crashes(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
+            assert isinstance(im, PsdImagePlugin.PsdImageFile)
             with pytest.raises(SyntaxError):
                 im.layers

Tests/test_file_sgi.py

@@ -71,31 +71,33 @@ def test_invalid_file() -> None:
         SgiImagePlugin.SgiImageFile(invalid_file)
 
 
-def test_write(tmp_path: Path) -> None:
+def roundtrip(img: Image.Image, tmp_path: Path) -> None:
-    def roundtrip(img: Image.Image) -> None:
+    out = tmp_path / "temp.sgi"
-        out = str(tmp_path / "temp.sgi")
+    img.save(out, format="sgi")
-        img.save(out, format="sgi")
+    assert_image_equal_tofile(img, out)
+
+    out = tmp_path / "fp.sgi"
+    with open(out, "wb") as fp:
+        img.save(fp)
         assert_image_equal_tofile(img, out)
 
-        out = str(tmp_path / "fp.sgi")
+        assert not fp.closed
-        with open(out, "wb") as fp:
-            img.save(fp)
-            assert_image_equal_tofile(img, out)
 
-            assert not fp.closed
 
-    for mode in ("L", "RGB", "RGBA"):
+@pytest.mark.parametrize("mode", ("L", "RGB", "RGBA"))
-        roundtrip(hopper(mode))
+def test_write(mode: str, tmp_path: Path) -> None:
+    roundtrip(hopper(mode), tmp_path)
 
-    # Test 1 dimension for an L mode image
+
-    roundtrip(Image.new("L", (10, 1)))
+def test_write_L_mode_1_dimension(tmp_path: Path) -> None:
+    roundtrip(Image.new("L", (10, 1)), tmp_path)
 
 
 def test_write16(tmp_path: Path) -> None:
     test_file = "Tests/images/hopper16.rgb"
 
     with Image.open(test_file) as im:
-        out = str(tmp_path / "temp.sgi")
+        out = tmp_path / "temp.sgi"
         im.save(out, format="sgi", bpc=2)
 
         assert_image_equal_tofile(im, out)
@@ -103,7 +105,7 @@ def test_write16(tmp_path: Path) -> None:
 
 def test_unsupported_mode(tmp_path: Path) -> None:
     im = hopper("LA")
-    out = str(tmp_path / "temp.sgi")
+    out = tmp_path / "temp.sgi"
 
     with pytest.raises(ValueError):
         im.save(out, format="sgi")

Tests/test_file_spider.py

@@ -51,7 +51,7 @@ def test_context_manager() -> None:
 
 def test_save(tmp_path: Path) -> None:
     # Arrange
-    temp = str(tmp_path / "temp.spider")
+    temp = tmp_path / "temp.spider"
     im = hopper()
 
     # Act
@@ -96,6 +96,7 @@ def test_tell() -> None:
 
 def test_n_frames() -> None:
     with Image.open(TEST_FILE) as im:
+        assert isinstance(im, SpiderImagePlugin.SpiderImageFile)
         assert im.n_frames == 1
         assert not im.is_animated
 

Tests/test_file_tga.py

@@ -1,8 +1,6 @@
 from __future__ import annotations
 
 import os
-from glob import glob
-from itertools import product
 from pathlib import Path
 
 import pytest
@@ -15,16 +13,29 @@ _TGA_DIR = os.path.join("Tests", "images", "tga")
 _TGA_DIR_COMMON = os.path.join(_TGA_DIR, "common")
 
 
-_MODES = ("L", "LA", "P", "RGB", "RGBA")
 _ORIGINS = ("tl", "bl")
 
 _ORIGIN_TO_ORIENTATION = {"tl": 1, "bl": -1}
 
 
-@pytest.mark.parametrize("mode", _MODES)
+@pytest.mark.parametrize(
-def test_sanity(mode: str, tmp_path: Path) -> None:
+    "size_mode",
+    (
+        ("1x1", "L"),
+        ("200x32", "L"),
+        ("200x32", "LA"),
+        ("200x32", "P"),
+        ("200x32", "RGB"),
+        ("200x32", "RGBA"),
+    ),
+)
+@pytest.mark.parametrize("origin", _ORIGINS)
+@pytest.mark.parametrize("rle", (True, False))
+def test_sanity(
+    size_mode: tuple[str, str], origin: str, rle: str, tmp_path: Path
+) -> None:
     def roundtrip(original_im: Image.Image) -> None:
-        out = str(tmp_path / "temp.tga")
+        out = tmp_path / "temp.tga"
 
         original_im.save(out, rle=rle)
         with Image.open(out) as saved_im:
@@ -36,36 +47,29 @@ def test_sanity(mode: str, tmp_path: Path) -> None:
 
             assert_image_equal(saved_im, original_im)
 
-    png_paths = glob(os.path.join(_TGA_DIR_COMMON, f"*x*_{mode.lower()}.png"))
+    size, mode = size_mode
+    png_path = os.path.join(_TGA_DIR_COMMON, size + "_" + mode.lower() + ".png")
+    with Image.open(png_path) as reference_im:
+        assert reference_im.mode == mode
 
-    for png_path in png_paths:
+        path_no_ext = os.path.splitext(png_path)[0]
-        with Image.open(png_path) as reference_im:
+        tga_path = "{}_{}_{}.tga".format(path_no_ext, origin, "rle" if rle else "raw")
-            assert reference_im.mode == mode
 
-            path_no_ext = os.path.splitext(png_path)[0]
+        with Image.open(tga_path) as original_im:
-            for origin, rle in product(_ORIGINS, (True, False)):
+            assert original_im.format == "TGA"
-                tga_path = "{}_{}_{}.tga".format(
+            assert original_im.get_format_mimetype() == "image/x-tga"
-                    path_no_ext, origin, "rle" if rle else "raw"
+            if rle:
-                )
+                assert original_im.info["compression"] == "tga_rle"
+            assert original_im.info["orientation"] == _ORIGIN_TO_ORIENTATION[origin]
+            if mode == "P":
+                assert original_im.getpalette() == reference_im.getpalette()
 
-                with Image.open(tga_path) as original_im:
+            assert_image_equal(original_im, reference_im)
-                    assert original_im.format == "TGA"
-                    assert original_im.get_format_mimetype() == "image/x-tga"
-                    if rle:
-                        assert original_im.info["compression"] == "tga_rle"
-                    assert (
-                        original_im.info["orientation"]
-                        == _ORIGIN_TO_ORIENTATION[origin]
-                    )
-                    if mode == "P":
-                        assert original_im.getpalette() == reference_im.getpalette()
 
-                    assert_image_equal(original_im, reference_im)
+            roundtrip(original_im)
-
-                    roundtrip(original_im)
 
 
-def test_palette_depth_8(tmp_path: Path) -> None:
+def test_palette_depth_8() -> None:
     with pytest.raises(UnidentifiedImageError):
         Image.open("Tests/images/p_8.tga")
 
@@ -76,7 +80,7 @@ def test_palette_depth_16(tmp_path: Path) -> None:
         assert im.palette.mode == "RGBA"
         assert_image_equal_tofile(im.convert("RGBA"), "Tests/images/p_16.png")
 
-        out = str(tmp_path / "temp.png")
+        out = tmp_path / "temp.png"
         im.save(out)
         with Image.open(out) as reloaded:
             assert_image_equal_tofile(reloaded.convert("RGBA"), "Tests/images/p_16.png")
@@ -122,7 +126,7 @@ def test_cross_scan_line() -> None:
 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")
+        out = tmp_path / "temp.tga"
 
         # Save
         im.save(out)
@@ -141,7 +145,7 @@ def test_small_palette(tmp_path: Path) -> None:
     colors = [0, 0, 0]
     im.putpalette(colors)
 
-    out = str(tmp_path / "temp.tga")
+    out = tmp_path / "temp.tga"
     im.save(out)
 
     with Image.open(out) as reloaded:
@@ -155,7 +159,7 @@ def test_missing_palette() -> None:
 
 def test_save_wrong_mode(tmp_path: Path) -> None:
     im = hopper("PA")
-    out = str(tmp_path / "temp.tga")
+    out = tmp_path / "temp.tga"
 
     with pytest.raises(OSError):
         im.save(out)
@@ -172,7 +176,7 @@ def test_save_mapdepth() -> None:
 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")
+        out = tmp_path / "temp.tga"
 
         # Check there is no id section
         im.save(out)
@@ -202,7 +206,7 @@ def test_save_id_section(tmp_path: Path) -> None:
 
 def test_save_orientation(tmp_path: Path) -> None:
     test_file = "Tests/images/rgb32rle.tga"
-    out = str(tmp_path / "temp.tga")
+    out = tmp_path / "temp.tga"
     with Image.open(test_file) as im:
         assert im.info["orientation"] == -1
 
@@ -229,7 +233,7 @@ def test_save_rle(tmp_path: Path) -> None:
     with Image.open(test_file) as im:
         assert im.info["compression"] == "tga_rle"
 
-        out = str(tmp_path / "temp.tga")
+        out = tmp_path / "temp.tga"
 
         # Save
         im.save(out)
@@ -266,7 +270,7 @@ def test_save_l_transparency(tmp_path: Path) -> None:
         assert im.mode == "LA"
         assert im.getchannel("A").getcolors()[0][0] == num_transparent
 
-        out = str(tmp_path / "temp.tga")
+        out = tmp_path / "temp.tga"
         im.save(out)
 
     with Image.open(out) as test_im:

Tests/test_file_tiff.py

@@ -9,7 +9,13 @@ from types import ModuleType
 
 import pytest
 
-from PIL import Image, ImageFile, TiffImagePlugin, UnidentifiedImageError
+from PIL import (
+    Image,
+    ImageFile,
+    JpegImagePlugin,
+    TiffImagePlugin,
+    UnidentifiedImageError,
+)
 from PIL.TiffImagePlugin import RESOLUTION_UNIT, X_RESOLUTION, Y_RESOLUTION
 
 from .helper import (
@@ -20,6 +26,7 @@ from .helper import (
     hopper,
     is_pypy,
     is_win32,
+    timeout_unless_slower_valgrind,
 )
 
 ElementTree: ModuleType | None
@@ -31,7 +38,7 @@ except ImportError:
 
 class TestFileTiff:
     def test_sanity(self, tmp_path: Path) -> None:
-        filename = str(tmp_path / "temp.tif")
+        filename = tmp_path / "temp.tif"
 
         hopper("RGB").save(filename)
 
@@ -112,20 +119,23 @@ class TestFileTiff:
             assert_image_equal_tofile(im, "Tests/images/hopper.tif")
 
         with Image.open("Tests/images/hopper_bigtiff.tif") as im:
-            outfile = str(tmp_path / "temp.tif")
+            outfile = tmp_path / "temp.tif"
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             im.save(outfile, save_all=True, append_images=[im], tiffinfo=im.tag_v2)
 
     def test_bigtiff_save(self, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         im = hopper()
         im.save(outfile, big_tiff=True)
 
         with Image.open(outfile) as reloaded:
+            assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
             assert reloaded.tag_v2._bigtiff is True
 
         im.save(outfile, save_all=True, append_images=[im], big_tiff=True)
 
         with Image.open(outfile) as reloaded:
+            assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
             assert reloaded.tag_v2._bigtiff is True
 
     def test_seek_too_large(self) -> None:
@@ -140,6 +150,8 @@ class TestFileTiff:
     def test_xyres_tiff(self) -> None:
         filename = "Tests/images/pil168.tif"
         with Image.open(filename) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
+
             # legacy api
             assert isinstance(im.tag[X_RESOLUTION][0], tuple)
             assert isinstance(im.tag[Y_RESOLUTION][0], tuple)
@@ -153,6 +165,8 @@ class TestFileTiff:
     def test_xyres_fallback_tiff(self) -> None:
         filename = "Tests/images/compression.tif"
         with Image.open(filename) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
+
             # v2 api
             assert isinstance(im.tag_v2[X_RESOLUTION], TiffImagePlugin.IFDRational)
             assert isinstance(im.tag_v2[Y_RESOLUTION], TiffImagePlugin.IFDRational)
@@ -167,6 +181,8 @@ class TestFileTiff:
     def test_int_resolution(self) -> None:
         filename = "Tests/images/pil168.tif"
         with Image.open(filename) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
+
             # Try to read a file where X,Y_RESOLUTION are ints
             im.tag_v2[X_RESOLUTION] = 71
             im.tag_v2[Y_RESOLUTION] = 71
@@ -181,11 +197,12 @@ class TestFileTiff:
         with Image.open(
             "Tests/images/hopper_float_dpi_" + str(resolution_unit) + ".tif"
         ) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im.tag_v2.get(RESOLUTION_UNIT) == resolution_unit
             assert im.info["dpi"] == (dpi, dpi)
 
     def test_save_float_dpi(self, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         with Image.open("Tests/images/hopper.tif") as im:
             dpi = (72.2, 72.2)
             im.save(outfile, dpi=dpi)
@@ -198,6 +215,7 @@ class TestFileTiff:
         with Image.open("Tests/images/10ct_32bit_128.tiff") as im:
             im.save(b, format="tiff", resolution=123.45)
         with Image.open(b) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im.tag_v2[X_RESOLUTION] == 123.45
             assert im.tag_v2[Y_RESOLUTION] == 123.45
 
@@ -213,19 +231,21 @@ class TestFileTiff:
         TiffImagePlugin.PREFIXES.pop()
 
     def test_bad_exif(self) -> None:
-        with Image.open("Tests/images/hopper_bad_exif.jpg") as i:
+        with Image.open("Tests/images/hopper_bad_exif.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
+
             # Should not raise struct.error.
             with pytest.warns(UserWarning):
-                i._getexif()
+                im._getexif()
 
     def test_save_rgba(self, tmp_path: Path) -> None:
         im = hopper("RGBA")
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         im.save(outfile)
 
     def test_save_unsupported_mode(self, tmp_path: Path) -> None:
         im = hopper("HSV")
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         with pytest.raises(OSError):
             im.save(outfile)
 
@@ -307,11 +327,13 @@ class TestFileTiff:
     )
     def test_n_frames(self, path: str, n_frames: int) -> None:
         with Image.open(path) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im.n_frames == n_frames
             assert im.is_animated == (n_frames != 1)
 
     def test_eoferror(self) -> None:
         with Image.open("Tests/images/multipage-lastframe.tif") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             n_frames = im.n_frames
 
             # Test seeking past the last frame
@@ -355,19 +377,24 @@ class TestFileTiff:
     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 isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im.n_frames == 1
 
         # A frame can't progress to a frame that has already been read
         with Image.open("Tests/images/multipage_multiple_frame_loop.tiff") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im.n_frames == 2
 
         # Frames don't have to be in sequence
         with Image.open("Tests/images/multipage_out_of_order.tiff") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im.n_frames == 3
 
     def test___str__(self) -> None:
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
+
             # Act
             ret = str(im.ifd)
 
@@ -378,6 +405,8 @@ class TestFileTiff:
         # Arrange
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
+
             # v2 interface
             v2_tags = {
                 256: 55,
@@ -417,6 +446,7 @@ class TestFileTiff:
     def test__delitem__(self) -> None:
         filename = "Tests/images/pil136.tiff"
         with Image.open(filename) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             len_before = len(dict(im.ifd))
             del im.ifd[256]
             len_after = len(dict(im.ifd))
@@ -449,6 +479,7 @@ class TestFileTiff:
 
     def test_ifd_tag_type(self) -> None:
         with Image.open("Tests/images/ifd_tag_type.tiff") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert 0x8825 in im.tag_v2
 
     def test_exif(self, tmp_path: Path) -> None:
@@ -485,14 +516,14 @@ class TestFileTiff:
             assert gps[0] == b"\x03\x02\x00\x00"
             assert gps[18] == "WGS-84"
 
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         with Image.open("Tests/images/ifd_tag_type.tiff") as im:
             exif = im.getexif()
             check_exif(exif)
 
             im.save(outfile, exif=exif)
 
-        outfile2 = str(tmp_path / "temp2.tif")
+        outfile2 = tmp_path / "temp2.tif"
         with Image.open(outfile) as im:
             exif = im.getexif()
             check_exif(exif)
@@ -504,7 +535,7 @@ class TestFileTiff:
             check_exif(exif)
 
     def test_modify_exif(self, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         with Image.open("Tests/images/ifd_tag_type.tiff") as im:
             exif = im.getexif()
             exif[264] = 100
@@ -533,10 +564,11 @@ class TestFileTiff:
 
     @pytest.mark.parametrize("mode", ("1", "L"))
     def test_photometric(self, mode: str, tmp_path: Path) -> None:
-        filename = str(tmp_path / "temp.tif")
+        filename = tmp_path / "temp.tif"
         im = hopper(mode)
         im.save(filename, tiffinfo={262: 0})
         with Image.open(filename) as reloaded:
+            assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
             assert reloaded.tag_v2[262] == 0
             assert_image_equal(im, reloaded)
 
@@ -612,9 +644,11 @@ class TestFileTiff:
 
     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")
+        filename = tmp_path / "temp.tif"
         hopper("RGB").save(filename, "TIFF", **kwargs)
         with Image.open(filename) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
+
             # legacy interface
             assert im.tag[X_RESOLUTION][0][0] == 72
             assert im.tag[Y_RESOLUTION][0][0] == 36
@@ -630,14 +664,14 @@ class TestFileTiff:
         with Image.open(infile) as im:
             assert im.getpixel((0, 0)) == pixel_value
 
-            tmpfile = str(tmp_path / "temp.tif")
+            tmpfile = tmp_path / "temp.tif"
             im.save(tmpfile)
 
             assert_image_equal_tofile(im, tmpfile)
 
     def test_iptc(self, tmp_path: Path) -> None:
         # Do not preserve IPTC_NAA_CHUNK by default if type is LONG
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         with Image.open("Tests/images/hopper.tif") as im:
             im.load()
             assert isinstance(im, TiffImagePlugin.TiffImageFile)
@@ -652,7 +686,7 @@ class TestFileTiff:
             assert 33723 not in im.tag_v2
 
     def test_rowsperstrip(self, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         im = hopper()
         im.save(outfile, tiffinfo={278: 256})
 
@@ -701,9 +735,10 @@ class TestFileTiff:
     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 isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im._planar_configuration == 2
 
-            outfile = str(tmp_path / "temp.tif")
+            outfile = tmp_path / "temp.tif"
             im.save(outfile)
 
             with Image.open(outfile) as reloaded:
@@ -718,7 +753,7 @@ class TestFileTiff:
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
     def test_palette(self, mode: str, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
 
         im = hopper(mode)
         im.save(outfile)
@@ -733,6 +768,7 @@ class TestFileTiff:
 
         mp.seek(0, os.SEEK_SET)
         with Image.open(mp) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im.n_frames == 3
 
         # Test appending images
@@ -743,6 +779,7 @@ class TestFileTiff:
 
         mp.seek(0, os.SEEK_SET)
         with Image.open(mp) as reread:
+            assert isinstance(reread, TiffImagePlugin.TiffImageFile)
             assert reread.n_frames == 3
 
         # Test appending using a generator
@@ -754,6 +791,7 @@ class TestFileTiff:
 
         mp.seek(0, os.SEEK_SET)
         with Image.open(mp) as reread:
+            assert isinstance(reread, TiffImagePlugin.TiffImageFile)
             assert reread.n_frames == 3
 
     def test_fixoffsets(self) -> None:
@@ -812,7 +850,7 @@ class TestFileTiff:
         im.info["icc_profile"] = "Dummy value"
 
         # Try save-load round trip to make sure both handle icc_profile.
-        tmpfile = str(tmp_path / "temp.tif")
+        tmpfile = tmp_path / "temp.tif"
         im.save(tmpfile, "TIFF", compression="raw")
         with Image.open(tmpfile) as reloaded:
             assert b"Dummy value" == reloaded.info["icc_profile"]
@@ -821,7 +859,7 @@ class TestFileTiff:
         im = hopper()
         assert "icc_profile" not in im.info
 
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
         icc_profile = b"Dummy value"
         im.save(outfile, icc_profile=icc_profile)
 
@@ -832,11 +870,11 @@ class TestFileTiff:
         with Image.open("Tests/images/hopper.bmp") as im:
             assert im.info["compression"] == 0
 
-            outfile = str(tmp_path / "temp.tif")
+            outfile = tmp_path / "temp.tif"
             im.save(outfile)
 
     def test_discard_icc_profile(self, tmp_path: Path) -> None:
-        outfile = str(tmp_path / "temp.tif")
+        outfile = tmp_path / "temp.tif"
 
         with Image.open("Tests/images/icc_profile.png") as im:
             assert "icc_profile" in im.info
@@ -864,6 +902,7 @@ class TestFileTiff:
 
     def test_get_photoshop_blocks(self) -> None:
         with Image.open("Tests/images/lab.tif") as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert list(im.get_photoshop_blocks().keys()) == [
                 1061,
                 1002,
@@ -889,7 +928,7 @@ class TestFileTiff:
             ]
 
     def test_tiff_chunks(self, tmp_path: Path) -> None:
-        tmpfile = str(tmp_path / "temp.tif")
+        tmpfile = tmp_path / "temp.tif"
 
         im = hopper()
         with open(tmpfile, "wb") as fp:
@@ -911,7 +950,7 @@ class TestFileTiff:
 
     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")
+        tmpfile = tmp_path / "temp.tif"
 
         with Image.open("Tests/images/uint16_1_4660.tif") as im:
             im.save(tmpfile)
@@ -923,7 +962,7 @@ class TestFileTiff:
         assert fp.closed
 
     def test_close_on_load_nonexclusive(self, tmp_path: Path) -> None:
-        tmpfile = str(tmp_path / "temp.tif")
+        tmpfile = tmp_path / "temp.tif"
 
         with Image.open("Tests/images/uint16_1_4660.tif") as im:
             im.save(tmpfile)
@@ -950,7 +989,7 @@ class TestFileTiff:
             with pytest.raises(OSError):
                 im.load()
 
-    @pytest.mark.timeout(6)
+    @timeout_unless_slower_valgrind(6)
     @pytest.mark.filterwarnings("ignore:Truncated File Read")
     def test_timeout(self, monkeypatch: pytest.MonkeyPatch) -> None:
         with Image.open("Tests/images/timeout-6646305047838720") as im:
@@ -963,7 +1002,7 @@ class TestFileTiff:
             "Tests/images/oom-225817ca0f8c663be7ab4b9e717b02c661e66834.tif",
         ],
     )
-    @pytest.mark.timeout(2)
+    @timeout_unless_slower_valgrind(2)
     def test_oom(self, test_file: str) -> None:
         with pytest.raises(UnidentifiedImageError):
             with pytest.warns(UserWarning):
@@ -974,7 +1013,7 @@ class TestFileTiff:
 @pytest.mark.skipif(not is_win32(), reason="Windows only")
 class TestFileTiffW32:
     def test_fd_leak(self, tmp_path: Path) -> None:
-        tmpfile = str(tmp_path / "temp.tif")
+        tmpfile = tmp_path / "temp.tif"
 
         # this is an mmaped file.
         with Image.open("Tests/images/uint16_1_4660.tif") as im:

Tests/test_file_tiff_metadata.py

@@ -56,11 +56,12 @@ def test_rt_metadata(tmp_path: Path) -> None:
 
     info[ImageDescription] = text_data
 
-    f = str(tmp_path / "temp.tif")
+    f = tmp_path / "temp.tif"
 
     img.save(f, tiffinfo=info)
 
     with Image.open(f) as loaded:
+        assert isinstance(loaded, TiffImagePlugin.TiffImageFile)
         assert loaded.tag[ImageJMetaDataByteCounts] == (len(bin_data),)
         assert loaded.tag_v2[ImageJMetaDataByteCounts] == (len(bin_data),)
 
@@ -80,12 +81,14 @@ def test_rt_metadata(tmp_path: Path) -> None:
     info[ImageJMetaDataByteCounts] = (8, len(bin_data) - 8)
     img.save(f, tiffinfo=info)
     with Image.open(f) as loaded:
+        assert isinstance(loaded, TiffImagePlugin.TiffImageFile)
         assert loaded.tag[ImageJMetaDataByteCounts] == (8, len(bin_data) - 8)
         assert loaded.tag_v2[ImageJMetaDataByteCounts] == (8, len(bin_data) - 8)
 
 
 def test_read_metadata() -> None:
     with Image.open("Tests/images/hopper_g4.tif") as img:
+        assert isinstance(img, TiffImagePlugin.TiffImageFile)
         assert {
             "YResolution": IFDRational(4294967295, 113653537),
             "PlanarConfiguration": 1,
@@ -128,13 +131,15 @@ def test_read_metadata() -> None:
 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")
+        assert isinstance(img, TiffImagePlugin.TiffImageFile)
+        f = tmp_path / "temp.tiff"
         del img.tag[278]
         img.save(f, tiffinfo=img.tag)
 
         original = img.tag_v2.named()
 
     with Image.open(f) as loaded:
+        assert isinstance(loaded, TiffImagePlugin.TiffImageFile)
         reloaded = loaded.tag_v2.named()
 
     ignored = ["StripByteCounts", "RowsPerStrip", "PageNumber", "StripOffsets"]
@@ -163,8 +168,9 @@ def test_write_metadata(tmp_path: Path) -> None:
 
 
 def test_change_stripbytecounts_tag_type(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     with Image.open("Tests/images/hopper.tif") as im:
+        assert isinstance(im, TiffImagePlugin.TiffImageFile)
         info = im.tag_v2
         del info[278]
 
@@ -178,6 +184,7 @@ def test_change_stripbytecounts_tag_type(tmp_path: Path) -> None:
         im.save(out, tiffinfo=info)
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert reloaded.tag_v2.tagtype[TiffImagePlugin.STRIPBYTECOUNTS] == TiffTags.LONG
 
 
@@ -210,7 +217,7 @@ def test_no_duplicate_50741_tag() -> None:
 
 
 def test_iptc(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     with Image.open("Tests/images/hopper.Lab.tif") as im:
         im.save(out)
 
@@ -227,10 +234,11 @@ def test_writing_other_types_to_ascii(
     info[271] = value
 
     im = hopper()
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info)
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert reloaded.tag_v2[271] == expected
 
 
@@ -244,10 +252,11 @@ def test_writing_other_types_to_bytes(value: int | IFDRational, tmp_path: Path)
 
     info[700] = value
 
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info)
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert reloaded.tag_v2[700] == b"\x01"
 
 
@@ -263,10 +272,11 @@ def test_writing_other_types_to_undefined(
 
     info[33723] = value
 
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info)
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert reloaded.tag_v2[33723] == b"1"
 
 
@@ -296,7 +306,7 @@ def test_empty_metadata() -> None:
 
 def test_iccprofile(tmp_path: Path) -> None:
     # https://github.com/python-pillow/Pillow/issues/1462
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     with Image.open("Tests/images/hopper.iccprofile.tif") as im:
         im.save(out)
 
@@ -311,19 +321,20 @@ def test_iccprofile_binary() -> None:
     # but probably won't be able to save it.
 
     with Image.open("Tests/images/hopper.iccprofile_binary.tif") as im:
+        assert isinstance(im, TiffImagePlugin.TiffImageFile)
         assert im.tag_v2.tagtype[34675] == 1
         assert im.info["icc_profile"]
 
 
 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")
+        outfile = tmp_path / "temp.png"
         im.save(outfile)
 
 
 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")
+        outfile = tmp_path / "temp.png"
         im.save(outfile)
 
 
@@ -332,10 +343,11 @@ def test_exif_div_zero(tmp_path: Path) -> None:
     info = TiffImagePlugin.ImageFileDirectory_v2()
     info[41988] = TiffImagePlugin.IFDRational(0, 0)
 
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info, compression="raw")
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert 0 == reloaded.tag_v2[41988].numerator
         assert 0 == reloaded.tag_v2[41988].denominator
 
@@ -351,10 +363,11 @@ def test_ifd_unsigned_rational(tmp_path: Path) -> None:
 
     info[41493] = TiffImagePlugin.IFDRational(numerator, 1)
 
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info, compression="raw")
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert max_long == reloaded.tag_v2[41493].numerator
         assert 1 == reloaded.tag_v2[41493].denominator
 
@@ -363,10 +376,11 @@ def test_ifd_unsigned_rational(tmp_path: Path) -> None:
 
     info[41493] = TiffImagePlugin.IFDRational(numerator, 1)
 
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info, compression="raw")
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert max_long == reloaded.tag_v2[41493].numerator
         assert 1 == reloaded.tag_v2[41493].denominator
 
@@ -381,10 +395,11 @@ def test_ifd_signed_rational(tmp_path: Path) -> None:
 
     info[37380] = TiffImagePlugin.IFDRational(numerator, denominator)
 
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info, compression="raw")
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert numerator == reloaded.tag_v2[37380].numerator
         assert denominator == reloaded.tag_v2[37380].denominator
 
@@ -393,10 +408,11 @@ def test_ifd_signed_rational(tmp_path: Path) -> None:
 
     info[37380] = TiffImagePlugin.IFDRational(numerator, denominator)
 
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info, compression="raw")
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert numerator == reloaded.tag_v2[37380].numerator
         assert denominator == reloaded.tag_v2[37380].denominator
 
@@ -406,10 +422,11 @@ def test_ifd_signed_rational(tmp_path: Path) -> None:
 
     info[37380] = TiffImagePlugin.IFDRational(numerator, denominator)
 
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info, compression="raw")
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert 2**31 - 1 == reloaded.tag_v2[37380].numerator
         assert -1 == reloaded.tag_v2[37380].denominator
 
@@ -420,10 +437,11 @@ def test_ifd_signed_long(tmp_path: Path) -> None:
 
     info[37000] = -60000
 
-    out = str(tmp_path / "temp.tiff")
+    out = tmp_path / "temp.tiff"
     im.save(out, tiffinfo=info, compression="raw")
 
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert reloaded.tag_v2[37000] == -60000
 
 
@@ -444,11 +462,13 @@ def test_empty_values() -> None:
 
 def test_photoshop_info(tmp_path: Path) -> None:
     with Image.open("Tests/images/issue_2278.tif") as im:
+        assert isinstance(im, TiffImagePlugin.TiffImageFile)
         assert len(im.tag_v2[34377]) == 70
         assert isinstance(im.tag_v2[34377], bytes)
-        out = str(tmp_path / "temp.tiff")
+        out = tmp_path / "temp.tiff"
         im.save(out)
     with Image.open(out) as reloaded:
+        assert isinstance(reloaded, TiffImagePlugin.TiffImageFile)
         assert len(reloaded.tag_v2[34377]) == 70
         assert isinstance(reloaded.tag_v2[34377], bytes)
 
@@ -480,7 +500,7 @@ def test_tag_group_data() -> None:
 
 
 def test_empty_subifd(tmp_path: Path) -> None:
-    out = str(tmp_path / "temp.jpg")
+    out = tmp_path / "temp.jpg"
 
     im = hopper()
     exif = im.getexif()

Tests/test_file_webp_alpha.py

@@ -42,7 +42,7 @@ def test_write_lossless_rgb(tmp_path: Path) -> None:
     Does it have the bits we expect?
     """
 
-    temp_file = str(tmp_path / "temp.webp")
+    temp_file = tmp_path / "temp.webp"
     # temp_file = "temp.webp"
 
     pil_image = hopper("RGBA")
@@ -71,7 +71,7 @@ def test_write_rgba(tmp_path: Path) -> None:
     Does it have the bits we expect?
     """
 
-    temp_file = str(tmp_path / "temp.webp")
+    temp_file = tmp_path / "temp.webp"
 
     pil_image = Image.new("RGBA", (10, 10), (255, 0, 0, 20))
     pil_image.save(temp_file)
@@ -104,7 +104,7 @@ def test_keep_rgb_values_when_transparent(tmp_path: Path) -> None:
     half_transparent_image.putalpha(new_alpha)
 
     # save with transparent area preserved
-    temp_file = str(tmp_path / "temp.webp")
+    temp_file = tmp_path / "temp.webp"
     half_transparent_image.save(temp_file, exact=True, lossless=True)
 
     with Image.open(temp_file) as reloaded:
@@ -123,7 +123,7 @@ def test_write_unsupported_mode_PA(tmp_path: Path) -> None:
     should work, and be similar to the original file.
     """
 
-    temp_file = str(tmp_path / "temp.webp")
+    temp_file = tmp_path / "temp.webp"
     file_path = "Tests/images/transparent.gif"
     with Image.open(file_path) as im:
         im.save(temp_file)
@@ -142,10 +142,10 @@ def test_write_unsupported_mode_PA(tmp_path: Path) -> None:
 
 def test_alpha_quality(tmp_path: Path) -> None:
     with Image.open("Tests/images/transparent.png") as im:
-        out = str(tmp_path / "temp.webp")
+        out = tmp_path / "temp.webp"
         im.save(out)
 
-        out_quality = str(tmp_path / "quality.webp")
+        out_quality = tmp_path / "quality.webp"
         im.save(out_quality, alpha_quality=50)
         with Image.open(out) as reloaded:
             with Image.open(out_quality) as reloaded_quality:

Tests/test_file_webp_animated.py

@@ -6,7 +6,7 @@ from pathlib import Path
 import pytest
 from packaging.version import parse as parse_version
 
-from PIL import Image, features
+from PIL import GifImagePlugin, Image, WebPImagePlugin, features
 
 from .helper import (
     assert_image_equal,
@@ -22,10 +22,12 @@ 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:
+        assert isinstance(im, WebPImagePlugin.WebPImageFile)
         assert im.n_frames == 1
         assert not im.is_animated
 
     with Image.open("Tests/images/iss634.webp") as im:
+        assert isinstance(im, WebPImagePlugin.WebPImageFile)
         assert im.n_frames == 42
         assert im.is_animated
 
@@ -37,11 +39,13 @@ def test_write_animation_L(tmp_path: Path) -> None:
     """
 
     with Image.open("Tests/images/iss634.gif") as orig:
+        assert isinstance(orig, GifImagePlugin.GifImageFile)
         assert orig.n_frames > 1
 
-        temp_file = str(tmp_path / "temp.webp")
+        temp_file = tmp_path / "temp.webp"
         orig.save(temp_file, save_all=True)
         with Image.open(temp_file) as im:
+            assert isinstance(im, WebPImagePlugin.WebPImageFile)
             assert im.n_frames == orig.n_frames
 
             # Compare first and last frames to the original animated GIF
@@ -67,8 +71,9 @@ def test_write_animation_RGB(tmp_path: Path) -> None:
     are visually similar to the originals.
     """
 
-    def check(temp_file: str) -> None:
+    def check(temp_file: Path) -> None:
         with Image.open(temp_file) as im:
+            assert isinstance(im, WebPImagePlugin.WebPImageFile)
             assert im.n_frames == 2
 
             # Compare first frame to original
@@ -87,7 +92,7 @@ def test_write_animation_RGB(tmp_path: Path) -> None:
 
     with Image.open("Tests/images/anim_frame1.webp") as frame1:
         with Image.open("Tests/images/anim_frame2.webp") as frame2:
-            temp_file1 = str(tmp_path / "temp.webp")
+            temp_file1 = tmp_path / "temp.webp"
             frame1.copy().save(
                 temp_file1, save_all=True, append_images=[frame2], lossless=True
             )
@@ -99,7 +104,7 @@ def test_write_animation_RGB(tmp_path: Path) -> None:
             ) -> Generator[Image.Image, None, None]:
                 yield from ims
 
-            temp_file2 = str(tmp_path / "temp_generator.webp")
+            temp_file2 = tmp_path / "temp_generator.webp"
             frame1.copy().save(
                 temp_file2,
                 save_all=True,
@@ -116,7 +121,7 @@ def test_timestamp_and_duration(tmp_path: Path) -> None:
     """
 
     durations = [0, 10, 20, 30, 40]
-    temp_file = str(tmp_path / "temp.webp")
+    temp_file = tmp_path / "temp.webp"
     with Image.open("Tests/images/anim_frame1.webp") as frame1:
         with Image.open("Tests/images/anim_frame2.webp") as frame2:
             frame1.save(
@@ -127,6 +132,7 @@ def test_timestamp_and_duration(tmp_path: Path) -> None:
             )
 
     with Image.open(temp_file) as im:
+        assert isinstance(im, WebPImagePlugin.WebPImageFile)
         assert im.n_frames == 5
         assert im.is_animated
 
@@ -141,7 +147,7 @@ def test_timestamp_and_duration(tmp_path: Path) -> None:
 
 
 def test_float_duration(tmp_path: Path) -> None:
-    temp_file = str(tmp_path / "temp.webp")
+    temp_file = tmp_path / "temp.webp"
     with Image.open("Tests/images/iss634.apng") as im:
         assert im.info["duration"] == 70.0
 
@@ -159,7 +165,7 @@ def test_seeking(tmp_path: Path) -> None:
     """
 
     dur = 33
-    temp_file = str(tmp_path / "temp.webp")
+    temp_file = tmp_path / "temp.webp"
     with Image.open("Tests/images/anim_frame1.webp") as frame1:
         with Image.open("Tests/images/anim_frame2.webp") as frame2:
             frame1.save(
@@ -170,6 +176,7 @@ def test_seeking(tmp_path: Path) -> None:
             )
 
     with Image.open(temp_file) as im:
+        assert isinstance(im, WebPImagePlugin.WebPImageFile)
         assert im.n_frames == 5
         assert im.is_animated
 
@@ -196,10 +203,10 @@ def test_alpha_quality(tmp_path: Path) -> None:
     with Image.open("Tests/images/transparent.png") as im:
         first_frame = Image.new("L", im.size)
 
-        out = str(tmp_path / "temp.webp")
+        out = tmp_path / "temp.webp"
         first_frame.save(out, save_all=True, append_images=[im])
 
-        out_quality = str(tmp_path / "quality.webp")
+        out_quality = tmp_path / "quality.webp"
         first_frame.save(
             out_quality, save_all=True, append_images=[im], alpha_quality=50
         )

Tests/test_file_webp_lossless.py

@@ -13,7 +13,7 @@ RGB_MODE = "RGB"
 
 
 def test_write_lossless_rgb(tmp_path: Path) -> None:
-    temp_file = str(tmp_path / "temp.webp")
+    temp_file = tmp_path / "temp.webp"
 
     hopper(RGB_MODE).save(temp_file, lossless=True)
 

Tests/test_file_webp_metadata.py

@@ -6,7 +6,7 @@ from types import ModuleType
 
 import pytest
 
-from PIL import Image
+from PIL import Image, WebPImagePlugin
 
 from .helper import mark_if_feature_version, skip_unless_feature
 
@@ -110,6 +110,7 @@ def test_read_no_exif() -> None:
 
     test_buffer.seek(0)
     with Image.open(test_buffer) as webp_image:
+        assert isinstance(webp_image, WebPImagePlugin.WebPImageFile)
         assert not webp_image._getexif()
 
 
@@ -146,7 +147,7 @@ def test_write_animated_metadata(tmp_path: Path) -> None:
     exif_data = b"<exif_data>"
     xmp_data = b"<xmp_data>"
 
-    temp_file = str(tmp_path / "temp.webp")
+    temp_file = tmp_path / "temp.webp"
     with Image.open("Tests/images/anim_frame1.webp") as frame1:
         with Image.open("Tests/images/anim_frame2.webp") as frame2:
             frame1.save(

Tests/test_file_wmf.py

@@ -8,7 +8,7 @@ import pytest
 
 from PIL import Image, ImageFile, WmfImagePlugin
 
-from .helper import assert_image_similar_tofile, hopper
+from .helper import assert_image_equal_tofile, assert_image_similar_tofile, hopper
 
 
 def test_load_raw() -> None:
@@ -44,6 +44,15 @@ def test_load_zero_inch() -> None:
             pass
 
 
+def test_render() -> None:
+    with open("Tests/images/drawing.emf", "rb") as fp:
+        data = fp.read()
+    b = BytesIO(data[:808] + b"\x00" + data[809:])
+    with Image.open(b) as im:
+        if hasattr(Image.core, "drawwmf"):
+            assert_image_equal_tofile(im, "Tests/images/drawing.emf")
+
+
 def test_register_handler(tmp_path: Path) -> None:
     class TestHandler(ImageFile.StubHandler):
         methodCalled = False
@@ -59,7 +68,7 @@ def test_register_handler(tmp_path: Path) -> None:
     WmfImagePlugin.register_handler(handler)
 
     im = hopper()
-    tmpfile = str(tmp_path / "temp.wmf")
+    tmpfile = tmp_path / "temp.wmf"
     im.save(tmpfile)
     assert handler.methodCalled
 
@@ -80,6 +89,7 @@ def test_load_float_dpi() -> None:
 
 def test_load_set_dpi() -> None:
     with Image.open("Tests/images/drawing.wmf") as im:
+        assert isinstance(im, WmfImagePlugin.WmfStubImageFile)
         assert im.size == (82, 82)
 
         if hasattr(Image.core, "drawwmf"):
@@ -88,11 +98,27 @@ def test_load_set_dpi() -> None:
 
             assert_image_similar_tofile(im, "Tests/images/drawing_wmf_ref_144.png", 2.1)
 
+    with Image.open("Tests/images/drawing.emf") as im:
+        assert im.size == (1625, 1625)
+
+        if not hasattr(Image.core, "drawwmf"):
+            return
+        assert isinstance(im, WmfImagePlugin.WmfStubImageFile)
+        im.load(im.info["dpi"])
+        assert im.size == (1625, 1625)
+
+    with Image.open("Tests/images/drawing.emf") as im:
+        assert isinstance(im, WmfImagePlugin.WmfStubImageFile)
+        im.load((72, 144))
+        assert im.size == (82, 164)
+
+        assert_image_equal_tofile(im, "Tests/images/drawing_emf_ref_72_144.png")
+
 
 @pytest.mark.parametrize("ext", (".wmf", ".emf"))
 def test_save(ext: str, tmp_path: Path) -> None:
     im = hopper()
 
-    tmpfile = str(tmp_path / ("temp" + ext))
+    tmpfile = tmp_path / ("temp" + ext)
     with pytest.raises(OSError):
         im.save(tmpfile)

Tests/test_file_xbm.py

@@ -73,7 +73,7 @@ def test_invalid_file() -> None:
 
 def test_save_wrong_mode(tmp_path: Path) -> None:
     im = hopper()
-    out = str(tmp_path / "temp.xbm")
+    out = tmp_path / "temp.xbm"
 
     with pytest.raises(OSError):
         im.save(out)
@@ -81,7 +81,7 @@ def test_save_wrong_mode(tmp_path: Path) -> None:
 
 def test_hotspot(tmp_path: Path) -> None:
     im = hopper("1")
-    out = str(tmp_path / "temp.xbm")
+    out = tmp_path / "temp.xbm"
 
     hotspot = (0, 7)
     im.save(out, hotspot=hotspot)

Tests/test_file_xpm.py

@@ -30,6 +30,7 @@ def test_invalid_file() -> None:
 def test_load_read() -> None:
     # Arrange
     with Image.open(TEST_FILE) as im:
+        assert isinstance(im, XpmImagePlugin.XpmImageFile)
         dummy_bytes = 1
 
         # Act

Tests/test_image.py

@@ -34,6 +34,7 @@ from .helper import (
     is_win32,
     mark_if_feature_version,
     skip_unless_feature,
+    timeout_unless_slower_valgrind,
 )
 
 ElementTree: ModuleType | None
@@ -175,6 +176,13 @@ class TestImage:
             with Image.open(io.StringIO()):  # type: ignore[arg-type]
                 pass
 
+    def test_string(self, tmp_path: Path) -> None:
+        out = str(tmp_path / "temp.png")
+        im = hopper()
+        im.save(out)
+        with Image.open(out) as reloaded:
+            assert_image_equal(im, reloaded)
+
     def test_pathlib(self, tmp_path: Path) -> None:
         with Image.open(Path("Tests/images/multipage-mmap.tiff")) as im:
             assert im.mode == "P"
@@ -187,14 +195,13 @@ class TestImage:
             for ext in (".jpg", ".jp2"):
                 if ext == ".jp2" and not features.check_codec("jpg_2000"):
                     pytest.skip("jpg_2000 not available")
-                temp_file = str(tmp_path / ("temp." + ext))
+                im.save(tmp_path / ("temp." + ext))
-                im.save(Path(temp_file))
 
     def test_fp_name(self, tmp_path: Path) -> None:
-        temp_file = str(tmp_path / "temp.jpg")
+        temp_file = tmp_path / "temp.jpg"
 
         class FP(io.BytesIO):
-            name: str
+            name: Path
 
             if sys.version_info >= (3, 12):
                 from collections.abc import Buffer
@@ -224,10 +231,10 @@ class TestImage:
                 assert_image_similar(im, reloaded, 20)
 
     def test_unknown_extension(self, tmp_path: Path) -> None:
-        im = hopper()
+        temp_file = tmp_path / "temp.unknown"
-        temp_file = str(tmp_path / "temp.unknown")
+        with hopper() as im:
-        with pytest.raises(ValueError):
+            with pytest.raises(ValueError):
-            im.save(temp_file)
+                im.save(temp_file)
 
     def test_internals(self) -> None:
         im = Image.new("L", (100, 100))
@@ -245,13 +252,22 @@ class TestImage:
         reason="Test requires opening an mmaped file for writing",
     )
     def test_readonly_save(self, tmp_path: Path) -> None:
-        temp_file = str(tmp_path / "temp.bmp")
+        temp_file = tmp_path / "temp.bmp"
         shutil.copy("Tests/images/rgb32bf-rgba.bmp", temp_file)
 
         with Image.open(temp_file) as im:
             assert im.readonly
             im.save(temp_file)
 
+    def test_save_without_changing_readonly(self, tmp_path: Path) -> None:
+        temp_file = tmp_path / "temp.bmp"
+
+        with Image.open("Tests/images/rgb32bf-rgba.bmp") as im:
+            assert im.readonly
+
+            im.save(temp_file)
+            assert im.readonly
+
     def test_dump(self, tmp_path: Path) -> None:
         im = Image.new("L", (10, 10))
         im._dump(str(tmp_path / "temp_L.ppm"))
@@ -557,10 +573,7 @@ class TestImage:
         i = Image.new("RGB", [1, 1])
         assert isinstance(i.size, tuple)
 
-    @pytest.mark.timeout(0.75)
+    @timeout_unless_slower_valgrind(0.75)
-    @pytest.mark.skipif(
-        "PILLOW_VALGRIND_TEST" in os.environ, reason="Valgrind is slower"
-    )
     @pytest.mark.parametrize("size", ((0, 100000000), (100000000, 0)))
     def test_empty_image(self, size: tuple[int, int]) -> None:
         Image.new("RGB", size)
@@ -658,6 +671,7 @@ class TestImage:
         im_remapped = im.remap_palette(list(range(256)))
         assert_image_equal(im, im_remapped)
         assert im.palette is not None
+        assert im_remapped.palette is not None
         assert im.palette.palette == im_remapped.palette.palette
 
         # Test illegal image mode
@@ -728,7 +742,7 @@ class TestImage:
         # https://github.com/python-pillow/Pillow/issues/835
         # Arrange
         test_file = "Tests/images/hopper.png"
-        temp_file = str(tmp_path / "temp.jpg")
+        temp_file = tmp_path / "temp.jpg"
 
         # Act/Assert
         with Image.open(test_file) as im:
@@ -738,7 +752,7 @@ class TestImage:
                 im.save(temp_file)
 
     def test_no_new_file_on_error(self, tmp_path: Path) -> None:
-        temp_file = str(tmp_path / "temp.jpg")
+        temp_file = tmp_path / "temp.jpg"
 
         im = Image.new("RGB", (0, 0))
         with pytest.raises(ValueError):
@@ -805,7 +819,7 @@ class TestImage:
             assert exif[296] == 2
             assert exif[11] == "gThumb 3.0.1"
 
-            out = str(tmp_path / "temp.jpg")
+            out = tmp_path / "temp.jpg"
             exif[258] = 8
             del exif[274]
             del exif[282]
@@ -827,7 +841,7 @@ class TestImage:
             assert exif[274] == 1
             assert exif[305] == "Adobe Photoshop CC 2017 (Macintosh)"
 
-            out = str(tmp_path / "temp.jpg")
+            out = tmp_path / "temp.jpg"
             exif[258] = 8
             del exif[306]
             exif[274] = 455
@@ -846,7 +860,7 @@ class TestImage:
             exif = im.getexif()
             assert exif == {}
 
-            out = str(tmp_path / "temp.webp")
+            out = tmp_path / "temp.webp"
             exif[258] = 8
             exif[40963] = 455
             exif[305] = "Pillow test"
@@ -868,7 +882,7 @@ class TestImage:
             exif = im.getexif()
             assert exif == {274: 1}
 
-            out = str(tmp_path / "temp.png")
+            out = tmp_path / "temp.png"
             exif[258] = 8
             del exif[274]
             exif[40963] = 455

Tests/test_image_convert.py

@@ -118,7 +118,7 @@ def test_trns_p(tmp_path: Path) -> None:
     im = hopper("P")
     im.info["transparency"] = 0
 
-    f = str(tmp_path / "temp.png")
+    f = tmp_path / "temp.png"
 
     im_l = im.convert("L")
     assert im_l.info["transparency"] == 0
@@ -154,7 +154,7 @@ def test_trns_l(tmp_path: Path) -> None:
     im = hopper("L")
     im.info["transparency"] = 128
 
-    f = str(tmp_path / "temp.png")
+    f = tmp_path / "temp.png"
 
     im_la = im.convert("LA")
     assert "transparency" not in im_la.info
@@ -177,7 +177,7 @@ def test_trns_RGB(tmp_path: Path) -> None:
     im = hopper("RGB")
     im.info["transparency"] = im.getpixel((0, 0))
 
-    f = str(tmp_path / "temp.png")
+    f = tmp_path / "temp.png"
 
     im_l = im.convert("L")
     assert im_l.info["transparency"] == im_l.getpixel((0, 0))  # undone

Tests/test_image_resample.py

@@ -462,7 +462,7 @@ class TestCoreResampleBox:
         im.resize((32, 32), resample, (20, 20, 20, 100))
         im.resize((32, 32), resample, (20, 20, 100, 20))
 
-        with pytest.raises(TypeError, match="must be sequence of length 4"):
+        with pytest.raises(TypeError, match="must be (sequence|tuple) of length 4"):
             im.resize((32, 32), resample, (im.width, im.height))  # type: ignore[arg-type]
 
         with pytest.raises(ValueError, match="can't be negative"):

Tests/test_image_resize.py

@@ -171,7 +171,7 @@ class TestImagingCoreResize:
         # platforms. So if a future Pillow change requires that the test file
         # be updated, that is okay.
         im = hopper().resize((64, 64))
-        temp_file = str(tmp_path / "temp.gif")
+        temp_file = tmp_path / "temp.gif"
         im.save(temp_file)
 
         with Image.open(temp_file) as reloaded:

Tests/test_image_split.py

@@ -45,9 +45,9 @@ def test_split_merge(mode: str) -> None:
 
 def test_split_open(tmp_path: Path) -> None:
     if features.check("zlib"):
-        test_file = str(tmp_path / "temp.png")
+        test_file = tmp_path / "temp.png"
     else:
-        test_file = str(tmp_path / "temp.pcx")
+        test_file = tmp_path / "temp.pcx"
 
     def split_open(mode: str) -> int:
         hopper(mode).save(test_file)

Tests/test_imagedraw.py

@@ -1704,7 +1704,7 @@ def test_discontiguous_corners_polygon() -> None:
         BLACK,
     )
     expected = os.path.join(IMAGES_PATH, "discontiguous_corners_polygon.png")
-    assert_image_similar_tofile(img, expected, 1)
+    assert_image_equal_tofile(img, expected)
 
 
 def test_polygon2() -> None:

Tests/test_imagefile.py

@@ -131,6 +131,26 @@ class TestImageFile:
 
         assert_image_equal(im1, im2)
 
+    def test_tile_size(self) -> None:
+        with open("Tests/images/hopper.tif", "rb") as im_fp:
+            data = im_fp.read()
+
+        reads = []
+
+        class FP(BytesIO):
+            def read(self, size: int | None = None) -> bytes:
+                reads.append(size)
+                return super().read(size)
+
+        fp = FP(data)
+        with Image.open(fp) as im:
+            assert len(im.tile) == 7
+
+            im.load()
+
+        # Despite multiple tiles, assert only one tile caused a read of maxblock size
+        assert reads.count(im.decodermaxblock) == 1
+
     def test_raise_oserror(self) -> None:
         with pytest.warns(DeprecationWarning):
             with pytest.raises(OSError):

Tests/test_imagefont.py

@@ -124,7 +124,7 @@ def test_render_equal(layout_engine: ImageFont.Layout) -> None:
 
 
 def test_non_ascii_path(tmp_path: Path, layout_engine: ImageFont.Layout) -> None:
-    tempfile = str(tmp_path / ("temp_" + chr(128) + ".ttf"))
+    tempfile = tmp_path / ("temp_" + chr(128) + ".ttf")
     try:
         shutil.copy(FONT_PATH, tempfile)
     except UnicodeEncodeError:

Tests/test_imagefontpil.py

@@ -7,7 +7,7 @@ import pytest
 
 from PIL import Image, ImageDraw, ImageFont, _util, features
 
-from .helper import assert_image_equal_tofile
+from .helper import assert_image_equal_tofile, timeout_unless_slower_valgrind
 
 fonts = [ImageFont.load_default_imagefont()]
 if not features.check_module("freetype2"):
@@ -72,7 +72,7 @@ def test_decompression_bomb() -> None:
         font.getmask("A" * 1_000_000)
 
 
-@pytest.mark.timeout(4)
+@timeout_unless_slower_valgrind(4)
 def test_oom() -> None:
     glyph = struct.pack(
         ">hhhhhhhhhh", 1, 0, -32767, -32767, 32767, 32767, -32767, -32767, 32767, 32767