Added type hints

Tests/test_features.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import io
 import re
+from typing import Callable
 
 import pytest
 
@@ -29,7 +30,7 @@ def test_version() -> None:
     # Check the correctness of the convenience function
     # and the format of version numbers
 
-    def test(name, function) -> None:
+    def test(name: str, function: Callable[[str], bool]) -> None:
         version = features.version(name)
         if not features.check(name):
             assert version is None
@@ -73,12 +74,12 @@ def test_libimagequant_version() -> None:
 
 
 @pytest.mark.parametrize("feature", features.modules)
-def test_check_modules(feature) -> None:
+def test_check_modules(feature: str) -> None:
     assert features.check_module(feature) in [True, False]
 
 
 @pytest.mark.parametrize("feature", features.codecs)
-def test_check_codecs(feature) -> None:
+def test_check_codecs(feature: str) -> None:
     assert features.check_codec(feature) in [True, False]
 
 

Tests/test_file_blp.py

@@ -71,7 +71,7 @@ def test_save(tmp_path: Path) -> None:
         "Tests/images/timeout-ef9112a065e7183fa7faa2e18929b03e44ee16bf.blp",
     ],
 )
-def test_crashes(test_file) -> None:
+def test_crashes(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with Image.open(f) as im:
             with pytest.raises(OSError):

Tests/test_file_bmp.py

@@ -16,7 +16,7 @@ from .helper import (
 
 
 def test_sanity(tmp_path: Path) -> None:
-    def roundtrip(im) -> None:
+    def roundtrip(im: Image.Image) -> None:
         outfile = str(tmp_path / "temp.bmp")
 
         im.save(outfile, "BMP")
@@ -194,7 +194,7 @@ def test_rle4() -> None:
         ("Tests/images/bmp/g/pal8rle.bmp", 1064),
     ),
 )
-def test_rle8_eof(file_name, length) -> 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:

Tests/test_file_im.py

@@ -82,7 +82,7 @@ def test_eoferror() -> None:
 
 
 @pytest.mark.parametrize("mode", ("RGB", "P", "PA"))
-def test_roundtrip(mode, tmp_path: Path) -> None:
+def test_roundtrip(mode: str, tmp_path: Path) -> None:
     out = str(tmp_path / "temp.im")
     im = hopper(mode)
     im.save(out)

Tests/test_file_pcx.py

@@ -9,7 +9,7 @@ from PIL import Image, ImageFile, PcxImagePlugin
 from .helper import assert_image_equal, hopper
 
 
-def _roundtrip(tmp_path: Path, im) -> None:
+def _roundtrip(tmp_path: Path, im: Image.Image) -> None:
     f = str(tmp_path / "temp.pcx")
     im.save(f)
     with Image.open(f) as im2:
@@ -44,7 +44,7 @@ def test_invalid_file() -> None:
 
 
 @pytest.mark.parametrize("mode", ("1", "L", "P", "RGB"))
-def test_odd(tmp_path: Path, mode) -> None:
+def test_odd(tmp_path: Path, mode: str) -> None:
     # See issue #523, odd sized images should have a stride that's even.
     # Not that ImageMagick or GIMP write PCX that way.
     # We were not handling properly.
@@ -89,7 +89,7 @@ def test_large_count(tmp_path: Path) -> None:
     _roundtrip(tmp_path, im)
 
 
-def _test_buffer_overflow(tmp_path: Path, im, size: int = 1024) -> None:
+def _test_buffer_overflow(tmp_path: Path, im: Image.Image, size: int = 1024) -> None:
     _last = ImageFile.MAXBLOCK
     ImageFile.MAXBLOCK = size
     try:

Tests/test_file_pdf.py

@@ -6,6 +6,7 @@ import os.path
 import tempfile
 import time
 from pathlib import Path
+from typing import Any, Generator
 
 import pytest
 
@@ -14,7 +15,7 @@ from PIL import Image, PdfParser, features
 from .helper import hopper, mark_if_feature_version, skip_unless_feature
 
 
-def helper_save_as_pdf(tmp_path: Path, mode, **kwargs):
+def helper_save_as_pdf(tmp_path: Path, mode: str, **kwargs: Any) -> str:
     # Arrange
     im = hopper(mode)
     outfile = str(tmp_path / ("temp_" + mode + ".pdf"))
@@ -41,13 +42,13 @@ def helper_save_as_pdf(tmp_path: Path, mode, **kwargs):
 
 
 @pytest.mark.parametrize("mode", ("L", "P", "RGB", "CMYK"))
-def test_save(tmp_path: Path, mode) -> None:
+def test_save(tmp_path: Path, mode: str) -> None:
     helper_save_as_pdf(tmp_path, mode)
 
 
 @skip_unless_feature("jpg_2000")
 @pytest.mark.parametrize("mode", ("LA", "RGBA"))
-def test_save_alpha(tmp_path: Path, mode) -> None:
+def test_save_alpha(tmp_path: Path, mode: str) -> None:
     helper_save_as_pdf(tmp_path, mode)
 
 
@@ -112,7 +113,7 @@ def test_resolution(tmp_path: Path) -> None:
         {"dpi": (75, 150), "resolution": 200},
     ),
 )
-def test_dpi(params, 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")
@@ -156,7 +157,7 @@ def test_save_all(tmp_path: Path) -> None:
         assert os.path.getsize(outfile) > 0
 
         # Test appending using a generator
-        def im_generator(ims):
+        def im_generator(ims: list[Image.Image]) -> Generator[Image.Image, None, None]:
             yield from ims
 
         im.save(outfile, save_all=True, append_images=im_generator(ims))
@@ -226,7 +227,7 @@ def test_pdf_append_fails_on_nonexistent_file() -> None:
             im.save(os.path.join(temp_dir, "nonexistent.pdf"), append=True)
 
 
-def check_pdf_pages_consistency(pdf) -> None:
+def check_pdf_pages_consistency(pdf: PdfParser.PdfParser) -> None:
     pages_info = pdf.read_indirect(pdf.pages_ref)
     assert b"Parent" not in pages_info
     assert b"Kids" in pages_info
@@ -339,7 +340,7 @@ def test_pdf_append_to_bytesio() -> None:
 @pytest.mark.timeout(1)
 @pytest.mark.skipif("PILLOW_VALGRIND_TEST" in os.environ, reason="Valgrind is slower")
 @pytest.mark.parametrize("newline", (b"\r", b"\n"))
-def test_redos(newline) -> None:
+def test_redos(newline: bytes) -> None:
     malicious = b" trailer<<>>" + newline * 3456
 
     # This particular exception isn't relevant here.

Tests/test_file_tiff.py

@@ -4,6 +4,8 @@ import os
 import warnings
 from io import BytesIO
 from pathlib import Path
+from types import ModuleType
+from typing import Generator
 
 import pytest
 
@@ -20,6 +22,7 @@ from .helper import (
     is_win32,
 )
 
+ElementTree: ModuleType | None
 try:
     from defusedxml import ElementTree
 except ImportError:
@@ -156,7 +159,7 @@ class TestFileTiff:
         "resolution_unit, dpi",
         [(None, 72.8), (2, 72.8), (3, 184.912)],
     )
-    def test_load_float_dpi(self, resolution_unit, dpi) -> None:
+    def test_load_float_dpi(self, resolution_unit: int | None, dpi: float) -> None:
         with Image.open(
             "Tests/images/hopper_float_dpi_" + str(resolution_unit) + ".tif"
         ) as im:
@@ -284,7 +287,7 @@ class TestFileTiff:
             ("Tests/images/multipage.tiff", 3),
         ),
     )
-    def test_n_frames(self, path, n_frames) -> None:
+    def test_n_frames(self, path: str, n_frames: int) -> None:
         with Image.open(path) as im:
             assert im.n_frames == n_frames
             assert im.is_animated == (n_frames != 1)
@@ -402,7 +405,7 @@ class TestFileTiff:
             assert len_before == len_after + 1
 
     @pytest.mark.parametrize("legacy_api", (False, True))
-    def test_load_byte(self, legacy_api) -> None:
+    def test_load_byte(self, legacy_api: bool) -> None:
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         data = b"abc"
         ret = ifd.load_byte(data, legacy_api)
@@ -431,7 +434,7 @@ class TestFileTiff:
             assert 0x8825 in im.tag_v2
 
     def test_exif(self, tmp_path: Path) -> None:
-        def check_exif(exif) -> None:
+        def check_exif(exif: Image.Exif) -> None:
             assert sorted(exif.keys()) == [
                 256,
                 257,
@@ -511,7 +514,7 @@ class TestFileTiff:
             assert im.getexif()[273] == (1408, 1907)
 
     @pytest.mark.parametrize("mode", ("1", "L"))
-    def test_photometric(self, mode, tmp_path: Path) -> None:
+    def test_photometric(self, mode: str, tmp_path: Path) -> None:
         filename = str(tmp_path / "temp.tif")
         im = hopper(mode)
         im.save(filename, tiffinfo={262: 0})
@@ -660,7 +663,7 @@ class TestFileTiff:
                 assert_image_equal_tofile(reloaded, infile)
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
-    def test_palette(self, mode, tmp_path: Path) -> None:
+    def test_palette(self, mode: str, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.tif")
 
         im = hopper(mode)
@@ -689,7 +692,7 @@ class TestFileTiff:
             assert reread.n_frames == 3
 
         # Test appending using a generator
-        def im_generator(ims):
+        def im_generator(ims: list[Image.Image]) -> Generator[Image.Image, None, None]:
             yield from ims
 
         mp = BytesIO()
@@ -860,7 +863,7 @@ class TestFileTiff:
         ],
     )
     @pytest.mark.timeout(2)
-    def test_oom(self, test_file) -> None:
+    def test_oom(self, test_file: str) -> None:
         with pytest.raises(UnidentifiedImageError):
             with pytest.warns(UserWarning):
                 with Image.open(test_file):

Tests/test_format_hsv.py

@@ -2,21 +2,22 @@ from __future__ import annotations
 
 import colorsys
 import itertools
+from typing import Callable
 
 from PIL import Image
 
 from .helper import assert_image_similar, hopper
 
 
-def int_to_float(i):
+def int_to_float(i: int) -> float:
     return i / 255
 
 
-def str_to_float(i):
+def str_to_float(i: str) -> float:
     return ord(i) / 255
 
 
-def tuple_to_ints(tp):
+def tuple_to_ints(tp: tuple[float, float, float]) -> tuple[int, int, int]:
     x, y, z = tp
     return int(x * 255.0), int(y * 255.0), int(z * 255.0)
 
@@ -25,7 +26,7 @@ def test_sanity() -> None:
     Image.new("HSV", (100, 100))
 
 
-def wedge():
+def wedge() -> Image.Image:
     w = Image._wedge()
     w90 = w.rotate(90)
 
@@ -49,7 +50,11 @@ def wedge():
     return img
 
 
-def to_xxx_colorsys(im, func, mode):
+def to_xxx_colorsys(
+    im: Image.Image,
+    func: Callable[[float, float, float], tuple[float, float, float]],
+    mode: str,
+) -> Image.Image:
     # convert the hard way using the library colorsys routines.
 
     (r, g, b) = im.split()
@@ -70,11 +75,11 @@ def to_xxx_colorsys(im, func, mode):
     return hsv
 
 
-def to_hsv_colorsys(im):
+def to_hsv_colorsys(im: Image.Image) -> Image.Image:
     return to_xxx_colorsys(im, colorsys.rgb_to_hsv, "HSV")
 
 
-def to_rgb_colorsys(im):
+def to_rgb_colorsys(im: Image.Image) -> Image.Image:
     return to_xxx_colorsys(im, colorsys.hsv_to_rgb, "RGB")
 
 

Tests/test_imagechops.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from typing import Callable
+
 from PIL import Image, ImageChops
 
 from .helper import assert_image_equal, hopper
@@ -387,7 +389,9 @@ def test_overlay() -> None:
 
 
 def test_logical() -> None:
-    def table(op, a, b):
+    def table(
+        op: Callable[[Image.Image, Image.Image], Image.Image], a: int, b: int
+    ) -> tuple[int, int, int, int]:
         out = []
         for x in (a, b):
             imx = Image.new("1", (1, 1), x)

Tests/test_imagedraw2.py

@@ -5,6 +5,7 @@ import os.path
 import pytest
 
 from PIL import Image, ImageDraw, ImageDraw2, features
+from PIL._typing import Coords
 
 from .helper import (
     assert_image_equal,
@@ -56,7 +57,7 @@ def test_sanity() -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_ellipse(bbox) -> None:
+def test_ellipse(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw2.Draw(im)
@@ -84,7 +85,7 @@ def test_ellipse_edge() -> None:
 
 
 @pytest.mark.parametrize("points", POINTS)
-def test_line(points) -> None:
+def test_line(points: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw2.Draw(im)
@@ -98,7 +99,7 @@ def test_line(points) -> None:
 
 
 @pytest.mark.parametrize("points", POINTS)
-def test_line_pen_as_brush(points) -> None:
+def test_line_pen_as_brush(points: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw2.Draw(im)
@@ -114,7 +115,7 @@ def test_line_pen_as_brush(points) -> None:
 
 
 @pytest.mark.parametrize("points", POINTS)
-def test_polygon(points) -> None:
+def test_polygon(points: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw2.Draw(im)
@@ -129,7 +130,7 @@ def test_polygon(points) -> None:
 
 
 @pytest.mark.parametrize("bbox", BBOX)
-def test_rectangle(bbox) -> None:
+def test_rectangle(bbox: Coords) -> None:
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw2.Draw(im)

Tests/test_imageenhance.py

@@ -22,7 +22,7 @@ def test_crash() -> None:
     ImageEnhance.Sharpness(im).enhance(0.5)
 
 
-def _half_transparent_image():
+def _half_transparent_image() -> Image.Image:
     # returns an image, half transparent, half solid
     im = hopper("RGB")
 
@@ -34,7 +34,9 @@ def _half_transparent_image():
     return im
 
 
-def _check_alpha(im, original, op, amount) -> None:
+def _check_alpha(
+    im: Image.Image, original: Image.Image, op: str, amount: float
+) -> None:
     assert im.getbands() == original.getbands()
     assert_image_equal(
         im.getchannel("A"),
@@ -44,7 +46,7 @@ def _check_alpha(im, original, op, amount) -> None:
 
 
 @pytest.mark.parametrize("op", ("Color", "Brightness", "Contrast", "Sharpness"))
-def test_alpha(op) -> None:
+def test_alpha(op: str) -> None:
     # Issue https://github.com/python-pillow/Pillow/issues/899
     # Is alpha preserved through image enhancement?
 

Tests/test_imagefile.py

@@ -31,7 +31,7 @@ SAFEBLOCK = ImageFile.SAFEBLOCK
 
 class TestImageFile:
     def test_parser(self) -> None:
-        def roundtrip(format):
+        def roundtrip(format: str) -> tuple[Image.Image, Image.Image]:
             im = hopper("L").resize((1000, 1000), Image.Resampling.NEAREST)
             if format in ("MSP", "XBM"):
                 im = im.convert("1")

Tests/test_imagefont.py

@@ -7,11 +7,13 @@ import shutil
 import sys
 from io import BytesIO
 from pathlib import Path
+from typing import BinaryIO
 
 import pytest
 from packaging.version import parse as parse_version
 
 from PIL import Image, ImageDraw, ImageFont, features
+from PIL._typing import StrOrBytesPath
 
 from .helper import (
     assert_image_equal,
@@ -47,11 +49,11 @@ def layout_engine(request):
 
 
 @pytest.fixture(scope="module")
-def font(layout_engine):
+def font(layout_engine: ImageFont.Layout) -> ImageFont.FreeTypeFont:
     return ImageFont.truetype(FONT_PATH, FONT_SIZE, layout_engine=layout_engine)
 
 
-def test_font_properties(font) -> None:
+def test_font_properties(font: ImageFont.FreeTypeFont) -> None:
     assert font.path == FONT_PATH
     assert font.size == FONT_SIZE
 
@@ -67,7 +69,9 @@ def test_font_properties(font) -> None:
     assert font_copy.path == second_font_path
 
 
-def _render(font, layout_engine):
+def _render(
+    font: StrOrBytesPath | BinaryIO, layout_engine: ImageFont.Layout
+) -> Image.Image:
     txt = "Hello World!"
     ttf = ImageFont.truetype(font, FONT_SIZE, layout_engine=layout_engine)
     ttf.getbbox(txt)
@@ -80,12 +84,12 @@ def _render(font, layout_engine):
 
 
 @pytest.mark.parametrize("font", (FONT_PATH, Path(FONT_PATH)))
-def test_font_with_name(layout_engine, font) -> None:
+def test_font_with_name(layout_engine: ImageFont.Layout, font: str | Path) -> None:
     _render(font, layout_engine)
 
 
-def test_font_with_filelike(layout_engine) -> None:
-    def _font_as_bytes():
+def test_font_with_filelike(layout_engine: ImageFont.Layout) -> None:
+    def _font_as_bytes() -> BytesIO:
         with open(FONT_PATH, "rb") as f:
             font_bytes = BytesIO(f.read())
         return font_bytes
@@ -102,12 +106,12 @@ def test_font_with_filelike(layout_engine) -> None:
     #   _render(shared_bytes)
 
 
-def test_font_with_open_file(layout_engine) -> None:
+def test_font_with_open_file(layout_engine: ImageFont.Layout) -> None:
     with open(FONT_PATH, "rb") as f:
         _render(f, layout_engine)
 
 
-def test_render_equal(layout_engine) -> None:
+def test_render_equal(layout_engine: ImageFont.Layout) -> None:
     img_path = _render(FONT_PATH, layout_engine)
     with open(FONT_PATH, "rb") as f:
         font_filelike = BytesIO(f.read())
@@ -116,7 +120,7 @@ def test_render_equal(layout_engine) -> None:
     assert_image_equal(img_path, img_filelike)
 
 
-def test_non_ascii_path(tmp_path: Path, layout_engine) -> None:
+def test_non_ascii_path(tmp_path: Path, layout_engine: ImageFont.Layout) -> None:
     tempfile = str(tmp_path / ("temp_" + chr(128) + ".ttf"))
     try:
         shutil.copy(FONT_PATH, tempfile)
@@ -126,7 +130,7 @@ def test_non_ascii_path(tmp_path: Path, layout_engine) -> None:
     ImageFont.truetype(tempfile, FONT_SIZE, layout_engine=layout_engine)
 
 
-def test_transparent_background(font) -> None:
+def test_transparent_background(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new(mode="RGBA", size=(300, 100))
     draw = ImageDraw.Draw(im)
 
@@ -140,7 +144,7 @@ def test_transparent_background(font) -> None:
     assert_image_similar_tofile(im.convert("L"), target, 0.01)
 
 
-def test_I16(font) -> None:
+def test_I16(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new(mode="I;16", size=(300, 100))
     draw = ImageDraw.Draw(im)
 
@@ -153,7 +157,7 @@ def test_I16(font) -> None:
     assert_image_similar_tofile(im.convert("L"), target, 0.01)
 
 
-def test_textbbox_equal(font) -> None:
+def test_textbbox_equal(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new(mode="RGB", size=(300, 100))
     draw = ImageDraw.Draw(im)
 
@@ -181,7 +185,13 @@ def test_textbbox_equal(font) -> None:
     ),
 )
 def test_getlength(
-    text, mode, fontname, size, layout_engine, length_basic, length_raqm
+    text: str,
+    mode: str,
+    fontname: str,
+    size: int,
+    layout_engine: ImageFont.Layout,
+    length_basic: int,
+    length_raqm: float,
 ) -> None:
     f = ImageFont.truetype("Tests/fonts/" + fontname, size, layout_engine=layout_engine)
 
@@ -207,7 +217,7 @@ def test_float_size() -> None:
     assert lengths[0] != lengths[1] != lengths[2]
 
 
-def test_render_multiline(font) -> None:
+def test_render_multiline(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new(mode="RGB", size=(300, 100))
     draw = ImageDraw.Draw(im)
     line_spacing = font.getbbox("A")[3] + 4
@@ -223,7 +233,7 @@ def test_render_multiline(font) -> None:
     assert_image_similar_tofile(im, "Tests/images/multiline_text.png", 6.2)
 
 
-def test_render_multiline_text(font) -> None:
+def test_render_multiline_text(font: ImageFont.FreeTypeFont) -> None:
     # Test that text() correctly connects to multiline_text()
     # and that align defaults to left
     im = Image.new(mode="RGB", size=(300, 100))
@@ -243,7 +253,9 @@ def test_render_multiline_text(font) -> None:
 @pytest.mark.parametrize(
     "align, ext", (("left", ""), ("center", "_center"), ("right", "_right"))
 )
-def test_render_multiline_text_align(font, align, ext) -> None:
+def test_render_multiline_text_align(
+    font: ImageFont.FreeTypeFont, align: str, ext: str
+) -> None:
     im = Image.new(mode="RGB", size=(300, 100))
     draw = ImageDraw.Draw(im)
     draw.multiline_text((0, 0), TEST_TEXT, font=font, align=align)
@@ -251,7 +263,7 @@ def test_render_multiline_text_align(font, align, ext) -> None:
     assert_image_similar_tofile(im, f"Tests/images/multiline_text{ext}.png", 0.01)
 
 
-def test_unknown_align(font) -> None:
+def test_unknown_align(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new(mode="RGB", size=(300, 100))
     draw = ImageDraw.Draw(im)
 
@@ -260,14 +272,14 @@ def test_unknown_align(font) -> None:
         draw.multiline_text((0, 0), TEST_TEXT, font=font, align="unknown")
 
 
-def test_draw_align(font) -> None:
+def test_draw_align(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new("RGB", (300, 100), "white")
     draw = ImageDraw.Draw(im)
     line = "some text"
     draw.text((100, 40), line, (0, 0, 0), font=font, align="left")
 
 
-def test_multiline_bbox(font) -> None:
+def test_multiline_bbox(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new(mode="RGB", size=(300, 100))
     draw = ImageDraw.Draw(im)
 
@@ -285,7 +297,7 @@ def test_multiline_bbox(font) -> None:
     draw.textbbox((0, 0), TEST_TEXT, font=font, spacing=4)
 
 
-def test_multiline_width(font) -> None:
+def test_multiline_width(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new(mode="RGB", size=(300, 100))
     draw = ImageDraw.Draw(im)
 
@@ -295,7 +307,7 @@ def test_multiline_width(font) -> None:
     )
 
 
-def test_multiline_spacing(font) -> None:
+def test_multiline_spacing(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new(mode="RGB", size=(300, 100))
     draw = ImageDraw.Draw(im)
     draw.multiline_text((0, 0), TEST_TEXT, font=font, spacing=10)
@@ -306,7 +318,9 @@ def test_multiline_spacing(font) -> None:
 @pytest.mark.parametrize(
     "orientation", (Image.Transpose.ROTATE_90, Image.Transpose.ROTATE_270)
 )
-def test_rotated_transposed_font(font, orientation) -> None:
+def test_rotated_transposed_font(
+    font: ImageFont.FreeTypeFont, orientation: Image.Transpose
+) -> None:
     img_gray = Image.new("L", (100, 100))
     draw = ImageDraw.Draw(img_gray)
     word = "testing"
@@ -347,7 +361,9 @@ def test_rotated_transposed_font(font, orientation) -> None:
         Image.Transpose.FLIP_TOP_BOTTOM,
     ),
 )
-def test_unrotated_transposed_font(font, orientation) -> None:
+def test_unrotated_transposed_font(
+    font: ImageFont.FreeTypeFont, orientation: Image.Transpose
+) -> None:
     img_gray = Image.new("L", (100, 100))
     draw = ImageDraw.Draw(img_gray)
     word = "testing"
@@ -382,7 +398,9 @@ def test_unrotated_transposed_font(font, orientation) -> None:
 @pytest.mark.parametrize(
     "orientation", (Image.Transpose.ROTATE_90, Image.Transpose.ROTATE_270)
 )
-def test_rotated_transposed_font_get_mask(font, orientation) -> None:
+def test_rotated_transposed_font_get_mask(
+    font: ImageFont.FreeTypeFont, orientation: Image.Transpose
+) -> None:
     # Arrange
     text = "mask this"
     transposed_font = ImageFont.TransposedFont(font, orientation=orientation)
@@ -403,7 +421,9 @@ def test_rotated_transposed_font_get_mask(font, orientation) -> None:
         Image.Transpose.FLIP_TOP_BOTTOM,
     ),
 )
-def test_unrotated_transposed_font_get_mask(font, orientation) -> None:
+def test_unrotated_transposed_font_get_mask(
+    font: ImageFont.FreeTypeFont, orientation: Image.Transpose
+) -> None:
     # Arrange
     text = "mask this"
     transposed_font = ImageFont.TransposedFont(font, orientation=orientation)
@@ -415,11 +435,11 @@ def test_unrotated_transposed_font_get_mask(font, orientation) -> None:
     assert mask.size == (108, 13)
 
 
-def test_free_type_font_get_name(font) -> None:
+def test_free_type_font_get_name(font: ImageFont.FreeTypeFont) -> None:
     assert ("FreeMono", "Regular") == font.getname()
 
 
-def test_free_type_font_get_metrics(font) -> None:
+def test_free_type_font_get_metrics(font: ImageFont.FreeTypeFont) -> None:
     ascent, descent = font.getmetrics()
 
     assert isinstance(ascent, int)
@@ -427,7 +447,7 @@ def test_free_type_font_get_metrics(font) -> None:
     assert (ascent, descent) == (16, 4)
 
 
-def test_free_type_font_get_mask(font) -> None:
+def test_free_type_font_get_mask(font: ImageFont.FreeTypeFont) -> None:
     # Arrange
     text = "mask this"
 
@@ -473,16 +493,16 @@ def test_default_font() -> None:
 
 
 @pytest.mark.parametrize("mode", (None, "1", "RGBA"))
-def test_getbbox(font, mode) -> None:
+def test_getbbox(font: ImageFont.FreeTypeFont, mode: str | None) -> None:
     assert (0, 4, 12, 16) == font.getbbox("A", mode)
 
 
-def test_getbbox_empty(font) -> None:
+def test_getbbox_empty(font: ImageFont.FreeTypeFont) -> None:
     # issue #2614, should not crash.
     assert (0, 0, 0, 0) == font.getbbox("")
 
 
-def test_render_empty(font) -> None:
+def test_render_empty(font: ImageFont.FreeTypeFont) -> None:
     # issue 2666
     im = Image.new(mode="RGB", size=(300, 100))
     target = im.copy()
@@ -492,7 +512,7 @@ def test_render_empty(font) -> None:
     assert_image_equal(im, target)
 
 
-def test_unicode_extended(layout_engine) -> None:
+def test_unicode_extended(layout_engine: ImageFont.Layout) -> None:
     # issue #3777
     text = "A\u278A\U0001F12B"
     target = "Tests/images/unicode_extended.png"
@@ -516,7 +536,7 @@ def test_unicode_extended(layout_engine) -> None:
 )
 @pytest.mark.skipif(is_win32(), reason="requires Unix or macOS")
 def test_find_font(monkeypatch, platform, font_directory) -> None:
-    def _test_fake_loading_font(path_to_fake, fontname) -> None:
+    def _test_fake_loading_font(path_to_fake: str, fontname: str) -> None:
         # Make a copy of FreeTypeFont so we can patch the original
         free_type_font = copy.deepcopy(ImageFont.FreeTypeFont)
         with monkeypatch.context() as m:
@@ -567,7 +587,7 @@ def test_find_font(monkeypatch, platform, font_directory) -> None:
     _test_fake_loading_font(font_directory + "/Duplicate.ttf", "Duplicate")
 
 
-def test_imagefont_getters(font) -> None:
+def test_imagefont_getters(font: ImageFont.FreeTypeFont) -> None:
     assert font.getmetrics() == (16, 4)
     assert font.font.ascent == 16
     assert font.font.descent == 4
@@ -588,7 +608,7 @@ def test_imagefont_getters(font) -> None:
 
 
 @pytest.mark.parametrize("stroke_width", (0, 2))
-def test_getsize_stroke(font, stroke_width) -> None:
+def test_getsize_stroke(font: ImageFont.FreeTypeFont, stroke_width: int) -> None:
     assert font.getbbox("A", stroke_width=stroke_width) == (
         0 - stroke_width,
         4 - stroke_width,
@@ -607,7 +627,7 @@ def test_complex_font_settings() -> None:
         t.getmask("абвг", language="sr")
 
 
-def test_variation_get(font) -> None:
+def test_variation_get(font: ImageFont.FreeTypeFont) -> None:
     freetype = parse_version(features.version_module("freetype2"))
     if freetype < parse_version("2.9.1"):
         with pytest.raises(NotImplementedError):
@@ -662,7 +682,7 @@ def test_variation_get(font) -> None:
     ]
 
 
-def _check_text(font, path, epsilon):
+def _check_text(font: ImageFont.FreeTypeFont, path: str, epsilon: float) -> None:
     im = Image.new("RGB", (100, 75), "white")
     d = ImageDraw.Draw(im)
     d.text((10, 10), "Text", font=font, fill="black")
@@ -677,7 +697,7 @@ def _check_text(font, path, epsilon):
             raise
 
 
-def test_variation_set_by_name(font) -> None:
+def test_variation_set_by_name(font: ImageFont.FreeTypeFont) -> None:
     freetype = parse_version(features.version_module("freetype2"))
     if freetype < parse_version("2.9.1"):
         with pytest.raises(NotImplementedError):
@@ -702,7 +722,7 @@ def test_variation_set_by_name(font) -> None:
     _check_text(font, "Tests/images/variation_tiny_name.png", 40)
 
 
-def test_variation_set_by_axes(font) -> None:
+def test_variation_set_by_axes(font: ImageFont.FreeTypeFont) -> None:
     freetype = parse_version(features.version_module("freetype2"))
     if freetype < parse_version("2.9.1"):
         with pytest.raises(NotImplementedError):
@@ -737,7 +757,9 @@ def test_variation_set_by_axes(font) -> None:
     ),
     ids=("ls", "ms", "rs", "ma", "mt", "mm", "mb", "md"),
 )
-def test_anchor(layout_engine, anchor, left, top) -> None:
+def test_anchor(
+    layout_engine: ImageFont.Layout, anchor: str, left: int, top: int
+) -> None:
     name, text = "quick", "Quick"
     path = f"Tests/images/test_anchor_{name}_{anchor}.png"
 
@@ -782,7 +804,9 @@ def test_anchor(layout_engine, anchor, left, top) -> None:
         ("md", "center"),
     ),
 )
-def test_anchor_multiline(layout_engine, anchor, align) -> None:
+def test_anchor_multiline(
+    layout_engine: ImageFont.Layout, anchor: str, align: str
+) -> None:
     target = f"Tests/images/test_anchor_multiline_{anchor}_{align}.png"
     text = "a\nlong\ntext sample"
 
@@ -800,7 +824,7 @@ def test_anchor_multiline(layout_engine, anchor, align) -> None:
     assert_image_similar_tofile(im, target, 4)
 
 
-def test_anchor_invalid(font) -> None:
+def test_anchor_invalid(font: ImageFont.FreeTypeFont) -> None:
     im = Image.new("RGB", (100, 100), "white")
     d = ImageDraw.Draw(im)
     d.font = font
@@ -826,7 +850,7 @@ def test_anchor_invalid(font) -> None:
 
 
 @pytest.mark.parametrize("bpp", (1, 2, 4, 8))
-def test_bitmap_font(layout_engine, bpp) -> None:
+def test_bitmap_font(layout_engine: ImageFont.Layout, bpp: int) -> None:
     text = "Bitmap Font"
     layout_name = ["basic", "raqm"][layout_engine]
     target = f"Tests/images/bitmap_font_{bpp}_{layout_name}.png"
@@ -843,7 +867,7 @@ def test_bitmap_font(layout_engine, bpp) -> None:
     assert_image_equal_tofile(im, target)
 
 
-def test_bitmap_font_stroke(layout_engine) -> None:
+def test_bitmap_font_stroke(layout_engine: ImageFont.Layout) -> None:
     text = "Bitmap Font"
     layout_name = ["basic", "raqm"][layout_engine]
     target = f"Tests/images/bitmap_font_stroke_{layout_name}.png"
@@ -861,7 +885,7 @@ def test_bitmap_font_stroke(layout_engine) -> None:
 
 
 @pytest.mark.parametrize("embedded_color", (False, True))
-def test_bitmap_blend(layout_engine, embedded_color) -> None:
+def test_bitmap_blend(layout_engine: ImageFont.Layout, embedded_color: bool) -> None:
     font = ImageFont.truetype(
         "Tests/fonts/EBDTTestFont.ttf", size=64, layout_engine=layout_engine
     )
@@ -873,7 +897,7 @@ def test_bitmap_blend(layout_engine, embedded_color) -> None:
     assert_image_equal_tofile(im, "Tests/images/bitmap_font_blend.png")
 
 
-def test_standard_embedded_color(layout_engine) -> None:
+def test_standard_embedded_color(layout_engine: ImageFont.Layout) -> None:
     txt = "Hello World!"
     ttf = ImageFont.truetype(FONT_PATH, 40, layout_engine=layout_engine)
     ttf.getbbox(txt)
@@ -886,7 +910,7 @@ def test_standard_embedded_color(layout_engine) -> None:
 
 
 @pytest.mark.parametrize("fontmode", ("1", "L", "RGBA"))
-def test_float_coord(layout_engine, fontmode):
+def test_float_coord(layout_engine: ImageFont.Layout, fontmode: str) -> None:
     txt = "Hello World!"
     ttf = ImageFont.truetype(FONT_PATH, 40, layout_engine=layout_engine)
 
@@ -908,7 +932,7 @@ def test_float_coord(layout_engine, fontmode):
             raise
 
 
-def test_cbdt(layout_engine) -> None:
+def test_cbdt(layout_engine: ImageFont.Layout) -> None:
     try:
         font = ImageFont.truetype(
             "Tests/fonts/CBDTTestFont.ttf", size=64, layout_engine=layout_engine
@@ -925,7 +949,7 @@ def test_cbdt(layout_engine) -> None:
         pytest.skip("freetype compiled without libpng or CBDT support")
 
 
-def test_cbdt_mask(layout_engine) -> None:
+def test_cbdt_mask(layout_engine: ImageFont.Layout) -> None:
     try:
         font = ImageFont.truetype(
             "Tests/fonts/CBDTTestFont.ttf", size=64, layout_engine=layout_engine
@@ -942,7 +966,7 @@ def test_cbdt_mask(layout_engine) -> None:
         pytest.skip("freetype compiled without libpng or CBDT support")
 
 
-def test_sbix(layout_engine) -> None:
+def test_sbix(layout_engine: ImageFont.Layout) -> None:
     try:
         font = ImageFont.truetype(
             "Tests/fonts/chromacheck-sbix.woff", size=300, layout_engine=layout_engine
@@ -959,7 +983,7 @@ def test_sbix(layout_engine) -> None:
         pytest.skip("freetype compiled without libpng or SBIX support")
 
 
-def test_sbix_mask(layout_engine) -> None:
+def test_sbix_mask(layout_engine: ImageFont.Layout) -> None:
     try:
         font = ImageFont.truetype(
             "Tests/fonts/chromacheck-sbix.woff", size=300, layout_engine=layout_engine
@@ -977,7 +1001,7 @@ def test_sbix_mask(layout_engine) -> None:
 
 
 @skip_unless_feature_version("freetype2", "2.10.0")
-def test_colr(layout_engine) -> None:
+def test_colr(layout_engine: ImageFont.Layout) -> None:
     font = ImageFont.truetype(
         "Tests/fonts/BungeeColor-Regular_colr_Windows.ttf",
         size=64,
@@ -993,7 +1017,7 @@ def test_colr(layout_engine) -> None:
 
 
 @skip_unless_feature_version("freetype2", "2.10.0")
-def test_colr_mask(layout_engine) -> None:
+def test_colr_mask(layout_engine: ImageFont.Layout) -> None:
     font = ImageFont.truetype(
         "Tests/fonts/BungeeColor-Regular_colr_Windows.ttf",
         size=64,
@@ -1008,7 +1032,7 @@ def test_colr_mask(layout_engine) -> None:
     assert_image_similar_tofile(im, "Tests/images/colr_bungee_mask.png", 22)
 
 
-def test_woff2(layout_engine) -> None:
+def test_woff2(layout_engine: ImageFont.Layout) -> None:
     try:
         font = ImageFont.truetype(
             "Tests/fonts/OpenSans.woff2",
@@ -1042,7 +1066,7 @@ def test_render_mono_size() -> None:
     assert_image_equal_tofile(im, "Tests/images/text_mono.gif")
 
 
-def test_too_many_characters(font) -> None:
+def test_too_many_characters(font: ImageFont.FreeTypeFont) -> None:
     with pytest.raises(ValueError):
         font.getlength("A" * 1_000_001)
     with pytest.raises(ValueError):
@@ -1070,7 +1094,7 @@ def test_too_many_characters(font) -> None:
         "Tests/fonts/oom-4da0210eb7081b0bf15bf16cc4c52ce02c1e1bbc.ttf",
     ],
 )
-def test_oom(test_file) -> None:
+def test_oom(test_file: str) -> None:
     with open(test_file, "rb") as f:
         font = ImageFont.truetype(BytesIO(f.read()))
         with pytest.raises(Image.DecompressionBombError):
@@ -1091,6 +1115,8 @@ def test_raqm_missing_warning(monkeypatch) -> None:
 
 
 @pytest.mark.parametrize("size", [-1, 0])
-def test_invalid_truetype_sizes_raise_valueerror(layout_engine, size) -> None:
+def test_invalid_truetype_sizes_raise_valueerror(
+    layout_engine: ImageFont.Layout, size: int
+) -> None:
     with pytest.raises(ValueError):
         ImageFont.truetype(FONT_PATH, size, layout_engine=layout_engine)

Tests/test_imageops.py

@@ -14,7 +14,7 @@ from .helper import (
 
 
 class Deformer:
-    def getmesh(self, im):
+    def getmesh(self, im: Image.Image) -> list[tuple[tuple[int, ...], tuple[int, ...]]]:
         x, y = im.size
         return [((0, 0, x, y), (0, 0, x, 0, x, y, y, 0))]
 
@@ -108,7 +108,7 @@ def test_fit_same_ratio() -> None:
 
 
 @pytest.mark.parametrize("new_size", ((256, 256), (512, 256), (256, 512)))
-def test_contain(new_size) -> None:
+def test_contain(new_size: tuple[int, int]) -> None:
     im = hopper()
     new_im = ImageOps.contain(im, new_size)
     assert new_im.size == (256, 256)
@@ -132,7 +132,7 @@ def test_contain_round() -> None:
         ("hopper.png", (256, 256)),  # square
     ),
 )
-def test_cover(image_name, expected_size) -> None:
+def test_cover(image_name: str, expected_size: tuple[int, int]) -> None:
     with Image.open("Tests/images/" + image_name) as im:
         new_im = ImageOps.cover(im, (256, 256))
         assert new_im.size == expected_size
@@ -168,7 +168,7 @@ def test_pad_round() -> None:
 
 
 @pytest.mark.parametrize("mode", ("P", "PA"))
-def test_palette(mode) -> None:
+def test_palette(mode: str) -> None:
     im = hopper(mode)
 
     # Expand
@@ -210,7 +210,7 @@ def test_scale() -> None:
 
 
 @pytest.mark.parametrize("border", (10, (1, 2, 3, 4)))
-def test_expand_palette(border) -> None:
+def test_expand_palette(border: int | tuple[int, int, int, int]) -> None:
     with Image.open("Tests/images/p_16.tga") as im:
         im_expanded = ImageOps.expand(im, border, (255, 0, 0))
 
@@ -366,7 +366,7 @@ def test_exif_transpose() -> None:
     for ext in exts:
         with Image.open("Tests/images/hopper" + ext) as base_im:
 
-            def check(orientation_im) -> None:
+            def check(orientation_im: Image.Image) -> None:
                 for im in [
                     orientation_im,
                     orientation_im.copy(),
@@ -445,7 +445,7 @@ def test_autocontrast_cutoff() -> None:
     # Test the cutoff argument of autocontrast
     with Image.open("Tests/images/bw_gradient.png") as img:
 
-        def autocontrast(cutoff):
+        def autocontrast(cutoff: int | tuple[int, int]):
             return ImageOps.autocontrast(img, cutoff).histogram()
 
         assert autocontrast(10) == autocontrast((10, 10))
@@ -486,20 +486,20 @@ def test_autocontrast_mask_real_input() -> None:
         assert result_nomask != result
         assert_tuple_approx_equal(
             ImageStat.Stat(result, mask=rect_mask).median,
-            [195, 202, 184],
+            (195, 202, 184),
             threshold=2,
             msg="autocontrast with mask pixel incorrect",
         )
         assert_tuple_approx_equal(
             ImageStat.Stat(result_nomask).median,
-            [119, 106, 79],
+            (119, 106, 79),
             threshold=2,
             msg="autocontrast without mask pixel incorrect",
         )
 
 
 def test_autocontrast_preserve_tone() -> None:
-    def autocontrast(mode, preserve_tone):
+    def autocontrast(mode: str, preserve_tone: bool) -> Image.Image:
         im = hopper(mode)
         return ImageOps.autocontrast(im, preserve_tone=preserve_tone).histogram()
 
@@ -533,7 +533,7 @@ def test_autocontrast_preserve_gradient() -> None:
 @pytest.mark.parametrize(
     "color", ((255, 255, 255), (127, 255, 0), (127, 127, 127), (0, 0, 0))
 )
-def test_autocontrast_preserve_one_color(color) -> None:
+def test_autocontrast_preserve_one_color(color: tuple[int, int, int]) -> None:
     img = Image.new("RGB", (10, 10), color)
 
     # single color images shouldn't change

Tests/test_imageops_usm.py

@@ -1,12 +1,14 @@
 from __future__ import annotations
 
+from typing import Generator
+
 import pytest
 
 from PIL import Image, ImageFilter
 
 
 @pytest.fixture
-def test_images():
+def test_images() -> Generator[dict[str, Image.Image], None, None]:
     ims = {
         "im": Image.open("Tests/images/hopper.ppm"),
         "snakes": Image.open("Tests/images/color_snakes.png"),
@@ -18,7 +20,7 @@ def test_images():
             im.close()
 
 
-def test_filter_api(test_images) -> None:
+def test_filter_api(test_images: dict[str, Image.Image]) -> None:
     im = test_images["im"]
 
     test_filter = ImageFilter.GaussianBlur(2.0)
@@ -32,7 +34,7 @@ def test_filter_api(test_images) -> None:
     assert i.size == (128, 128)
 
 
-def test_usm_formats(test_images) -> None:
+def test_usm_formats(test_images: dict[str, Image.Image]) -> None:
     im = test_images["im"]
 
     usm = ImageFilter.UnsharpMask
@@ -50,7 +52,7 @@ def test_usm_formats(test_images) -> None:
         im.convert("YCbCr").filter(usm)
 
 
-def test_blur_formats(test_images) -> None:
+def test_blur_formats(test_images: dict[str, Image.Image]) -> None:
     im = test_images["im"]
 
     blur = ImageFilter.GaussianBlur
@@ -68,7 +70,7 @@ def test_blur_formats(test_images) -> None:
         im.convert("YCbCr").filter(blur)
 
 
-def test_usm_accuracy(test_images) -> None:
+def test_usm_accuracy(test_images: dict[str, Image.Image]) -> None:
     snakes = test_images["snakes"]
 
     src = snakes.convert("RGB")
@@ -77,7 +79,7 @@ def test_usm_accuracy(test_images) -> None:
     assert i.tobytes() == src.tobytes()
 
 
-def test_blur_accuracy(test_images) -> None:
+def test_blur_accuracy(test_images: dict[str, Image.Image]) -> None:
     snakes = test_images["snakes"]
 
     i = snakes.filter(ImageFilter.GaussianBlur(0.4))

Tests/test_imagepath.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import array
 import math
 import struct
+from typing import Sequence
 
 import pytest
 
@@ -75,7 +76,9 @@ def test_path_constructors(coords) -> None:
         [[0.0, 1.0]],
     ),
 )
-def test_invalid_path_constructors(coords) -> None:
+def test_invalid_path_constructors(
+    coords: tuple[str, str] | Sequence[Sequence[int]]
+) -> None:
     # Act
     with pytest.raises(ValueError) as e:
         ImagePath.Path(coords)
@@ -93,7 +96,7 @@ def test_invalid_path_constructors(coords) -> None:
         [0, 1, 2],
     ),
 )
-def test_path_odd_number_of_coordinates(coords) -> None:
+def test_path_odd_number_of_coordinates(coords: Sequence[int]) -> None:
     # Act
     with pytest.raises(ValueError) as e:
         ImagePath.Path(coords)
@@ -111,7 +114,9 @@ def test_path_odd_number_of_coordinates(coords) -> None:
         (1, (0.0, 0.0, 0.0, 0.0)),
     ],
 )
-def test_getbbox(coords, expected) -> None:
+def test_getbbox(
+    coords: int | list[int], expected: tuple[float, float, float, float]
+) -> None:
     # Arrange
     p = ImagePath.Path(coords)
 
@@ -135,7 +140,7 @@ def test_getbbox_no_args() -> None:
         (list(range(6)), [(0.0, 3.0), (4.0, 9.0), (8.0, 15.0)]),
     ],
 )
-def test_map(coords, expected) -> None:
+def test_map(coords: int | list[int], expected: list[tuple[float, float]]) -> None:
     # Arrange
     p = ImagePath.Path(coords)