From cdc498e6f3b2060906ca14fe9b9187e0a93a1613 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Wed, 7 Feb 2024 19:16:28 +1100
Subject: [PATCH 1/2] Added type hints

---
 Tests/test_color_lut.py      |  4 ++-
 Tests/test_file_eps.py       | 32 ++++++++++----------
 Tests/test_file_jpeg.py      | 35 +++++++++++-----------
 Tests/test_file_jpeg2k.py    | 21 ++++++-------
 Tests/test_file_libtiff.py   | 38 +++++++++++++-----------
 Tests/test_file_png.py       | 15 +++++-----
 Tests/test_image_paste.py    | 41 +++++++++++++++-----------
 Tests/test_image_reduce.py   | 43 +++++++++++++++------------
 Tests/test_image_resample.py | 57 ++++++++++++++++++++----------------
 Tests/test_imagemath.py      |  8 ++---
 10 files changed, 160 insertions(+), 134 deletions(-)

diff --git a/Tests/test_color_lut.py b/Tests/test_color_lut.py
index e6c8d7819a6..2bb1b57d482 100644
--- a/Tests/test_color_lut.py
+++ b/Tests/test_color_lut.py
@@ -15,7 +15,9 @@
 
 
 class TestColorLut3DCoreAPI:
-    def generate_identity_table(self, channels, size):
+    def generate_identity_table(
+        self, channels: int, size: int | tuple[int, int, int]
+    ) -> tuple[int, int, int, int, list[float]]:
         if isinstance(size, tuple):
             size_1d, size_2d, size_3d = size
         else:
diff --git a/Tests/test_file_eps.py b/Tests/test_file_eps.py
index 06f927c7bb2..00f5f39e8c8 100644
--- a/Tests/test_file_eps.py
+++ b/Tests/test_file_eps.py
@@ -84,7 +84,7 @@
     ("filename", "size"), ((FILE1, (460, 352)), (FILE2, (360, 252)))
 )
 @pytest.mark.parametrize("scale", (1, 2))
-def test_sanity(filename, size, scale) -> None:
+def test_sanity(filename: str, size: tuple[int, int], scale: int) -> None:
     expected_size = tuple(s * scale for s in size)
     with Image.open(filename) as image:
         image.load(scale=scale)
@@ -129,28 +129,28 @@ def test_binary_header_only() -> None:
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_missing_version_comment(prefix) -> None:
+def test_missing_version_comment(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_without_version))
     with pytest.raises(SyntaxError):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_missing_boundingbox_comment(prefix) -> None:
+def test_missing_boundingbox_comment(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_without_boundingbox))
     with pytest.raises(SyntaxError, match='EPS header missing "%%BoundingBox" comment'):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_invalid_boundingbox_comment(prefix) -> None:
+def test_invalid_boundingbox_comment(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_invalid_boundingbox))
     with pytest.raises(OSError, match="cannot determine EPS bounding box"):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_invalid_boundingbox_comment_valid_imagedata_comment(prefix) -> None:
+def test_invalid_boundingbox_comment_valid_imagedata_comment(prefix: bytes) -> None:
     data = io.BytesIO(
         prefix + b"\n".join(simple_eps_file_with_invalid_boundingbox_valid_imagedata)
     )
@@ -161,21 +161,21 @@ def test_invalid_boundingbox_comment_valid_imagedata_comment(prefix) -> None:
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_ascii_comment_too_long(prefix) -> None:
+def test_ascii_comment_too_long(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_long_ascii_comment))
     with pytest.raises(SyntaxError, match="not an EPS file"):
         EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_long_binary_data(prefix) -> None:
+def test_long_binary_data(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_long_binary_data))
     EpsImagePlugin.EpsImageFile(data)
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @pytest.mark.parametrize("prefix", (b"", simple_binary_header))
-def test_load_long_binary_data(prefix) -> None:
+def test_load_long_binary_data(prefix: bytes) -> None:
     data = io.BytesIO(prefix + b"\n".join(simple_eps_file_with_long_binary_data))
     with Image.open(data) as img:
         img.load()
@@ -305,7 +305,7 @@ def test_render_scale2() -> None:
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @pytest.mark.parametrize("filename", (FILE1, FILE2, "Tests/images/illu10_preview.eps"))
-def test_resize(filename) -> None:
+def test_resize(filename: str) -> None:
     with Image.open(filename) as im:
         new_size = (100, 100)
         im = im.resize(new_size)
@@ -314,7 +314,7 @@ def test_resize(filename) -> None:
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 @pytest.mark.parametrize("filename", (FILE1, FILE2))
-def test_thumbnail(filename) -> None:
+def test_thumbnail(filename: str) -> None:
     # Issue #619
     with Image.open(filename) as im:
         new_size = (100, 100)
@@ -335,7 +335,7 @@ def test_readline_psfile(tmp_path: Path) -> None:
     line_endings = ["\r\n", "\n", "\n\r", "\r"]
     strings = ["something", "else", "baz", "bif"]
 
-    def _test_readline(t, ending) -> None:
+    def _test_readline(t: EpsImagePlugin.PSFile, ending: str) -> None:
         ending = "Failure with line ending: %s" % (
             "".join("%s" % ord(s) for s in ending)
         )
@@ -344,13 +344,13 @@ def _test_readline(t, ending) -> None:
         assert t.readline().strip("\r\n") == "baz", ending
         assert t.readline().strip("\r\n") == "bif", ending
 
-    def _test_readline_io_psfile(test_string, ending) -> None:
+    def _test_readline_io_psfile(test_string: str, ending: str) -> None:
         f = io.BytesIO(test_string.encode("latin-1"))
         with pytest.warns(DeprecationWarning):
             t = EpsImagePlugin.PSFile(f)
         _test_readline(t, ending)
 
-    def _test_readline_file_psfile(test_string, ending) -> None:
+    def _test_readline_file_psfile(test_string: str, ending: str) -> None:
         f = str(tmp_path / "temp.txt")
         with open(f, "wb") as w:
             w.write(test_string.encode("latin-1"))
@@ -376,7 +376,7 @@ def test_psfile_deprecation() -> None:
     "line_ending",
     (b"\r\n", b"\n", b"\n\r", b"\r"),
 )
-def test_readline(prefix, line_ending) -> None:
+def test_readline(prefix: bytes, line_ending: bytes) -> None:
     simple_file = prefix + line_ending.join(simple_eps_file_with_comments)
     data = io.BytesIO(simple_file)
     test_file = EpsImagePlugin.EpsImageFile(data)
@@ -394,7 +394,7 @@ def test_readline(prefix, line_ending) -> None:
         "Tests/images/illuCS6_preview.eps",
     ),
 )
-def test_open_eps(filename) -> None:
+def test_open_eps(filename: str) -> None:
     # https://github.com/python-pillow/Pillow/issues/1104
     with Image.open(filename) as img:
         assert img.mode == "RGB"
@@ -417,7 +417,7 @@ def test_emptyline() -> None:
     "test_file",
     ["Tests/images/timeout-d675703545fee17acab56e5fec644c19979175de.eps"],
 )
-def test_timeout(test_file) -> None:
+def test_timeout(test_file: str) -> None:
     with open(test_file, "rb") as f:
         with pytest.raises(Image.UnidentifiedImageError):
             with Image.open(f):
diff --git a/Tests/test_file_jpeg.py b/Tests/test_file_jpeg.py
index ff278d4c1bf..6b0662e0be3 100644
--- a/Tests/test_file_jpeg.py
+++ b/Tests/test_file_jpeg.py
@@ -5,6 +5,7 @@
 import warnings
 from io import BytesIO
 from pathlib import Path
+from typing import Any
 
 import pytest
 
@@ -42,7 +43,7 @@
 
 @skip_unless_feature("jpg")
 class TestFileJpeg:
-    def roundtrip(self, im, **options):
+    def roundtrip(self, im: Image.Image, **options: Any) -> Image.Image:
         out = BytesIO()
         im.save(out, "JPEG", **options)
         test_bytes = out.tell()
@@ -51,7 +52,7 @@ def roundtrip(self, im, **options):
         im.bytes = test_bytes  # for testing only
         return im
 
-    def gen_random_image(self, size, mode: str = "RGB"):
+    def gen_random_image(self, size: tuple[int, int], mode: str = "RGB") -> Image.Image:
         """Generates a very hard to compress file
         :param size: tuple
         :param mode: optional image mode
@@ -71,7 +72,7 @@ def test_sanity(self) -> None:
             assert im.get_format_mimetype() == "image/jpeg"
 
     @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
-    def test_zero(self, size, tmp_path: Path) -> None:
+    def test_zero(self, size: tuple[int, int], tmp_path: Path) -> None:
         f = str(tmp_path / "temp.jpg")
         im = Image.new("RGB", size)
         with pytest.raises(ValueError):
@@ -108,13 +109,11 @@ def test_comment_write(self) -> None:
                     assert "comment" not in reloaded.info
 
             # Test that a comment argument overrides the default comment
-            for comment in ("Test comment text", b"Text comment text"):
+            for comment in ("Test comment text", b"Test comment text"):
                 out = BytesIO()
                 im.save(out, format="JPEG", comment=comment)
                 with Image.open(out) as reloaded:
-                    if not isinstance(comment, bytes):
-                        comment = comment.encode()
-                    assert reloaded.info["comment"] == comment
+                    assert reloaded.info["comment"] == b"Test comment text"
 
     def test_cmyk(self) -> None:
         # Test CMYK handling.  Thanks to Tim and Charlie for test data,
@@ -145,7 +144,7 @@ def test_cmyk(self) -> None:
             assert k > 0.9
 
     def test_rgb(self) -> None:
-        def getchannels(im):
+        def getchannels(im: Image.Image) -> tuple[int, int, int]:
             return tuple(v[0] for v in im.layer)
 
         im = hopper()
@@ -161,8 +160,8 @@ def getchannels(im):
         "test_image_path",
         [TEST_FILE, "Tests/images/pil_sample_cmyk.jpg"],
     )
-    def test_dpi(self, test_image_path) -> None:
-        def test(xdpi, ydpi=None):
+    def test_dpi(self, test_image_path: str) -> None:
+        def test(xdpi: int, ydpi: int | None = None):
             with Image.open(test_image_path) as im:
                 im = self.roundtrip(im, dpi=(xdpi, ydpi or xdpi))
             return im.info.get("dpi")
@@ -207,7 +206,7 @@ def test_icc(self, tmp_path: Path) -> None:
             ImageFile.MAXBLOCK * 4 + 3,  # large block
         ),
     )
-    def test_icc_big(self, n) -> None:
+    def test_icc_big(self, n: int) -> None:
         # Make sure that the "extra" support handles large blocks
         # The ICC APP marker can store 65519 bytes per marker, so
         # using a 4-byte test code should allow us to detect out of
@@ -433,7 +432,7 @@ def test_smooth(self) -> None:
         assert_image(im1, im2.mode, im2.size)
 
     def test_subsampling(self) -> None:
-        def getsampling(im):
+        def getsampling(im: Image.Image):
             layer = im.layer
             return layer[0][1:3] + layer[1][1:3] + layer[2][1:3]
 
@@ -530,7 +529,7 @@ def test_truncated_jpeg_throws_oserror(self) -> None:
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
     def test_qtables(self, tmp_path: Path) -> None:
-        def _n_qtables_helper(n, test_file) -> None:
+        def _n_qtables_helper(n: int, test_file: str) -> None:
             with Image.open(test_file) as im:
                 f = str(tmp_path / "temp.jpg")
                 im.save(f, qtables=[[n] * 64] * n)
@@ -666,7 +665,7 @@ def test_save_low_quality_baseline_qtables(self) -> None:
         "blocks, rows, markers",
         ((0, 0, 0), (1, 0, 15), (3, 0, 5), (8, 0, 1), (0, 1, 3), (0, 2, 1)),
     )
-    def test_restart_markers(self, blocks, rows, markers) -> None:
+    def test_restart_markers(self, blocks: int, rows: int, markers: int) -> None:
         im = Image.new("RGB", (32, 32))  # 16 MCUs
         out = BytesIO()
         im.save(
@@ -724,13 +723,13 @@ def test_bad_mpo_header(self) -> None:
             assert im.format == "JPEG"
 
     @pytest.mark.parametrize("mode", ("1", "L", "RGB", "RGBX", "CMYK", "YCbCr"))
-    def test_save_correct_modes(self, mode) -> None:
+    def test_save_correct_modes(self, mode: str) -> None:
         out = BytesIO()
         img = Image.new(mode, (20, 20))
         img.save(out, "JPEG")
 
     @pytest.mark.parametrize("mode", ("LA", "La", "RGBA", "RGBa", "P"))
-    def test_save_wrong_modes(self, mode) -> None:
+    def test_save_wrong_modes(self, mode: str) -> None:
         # ref https://github.com/python-pillow/Pillow/issues/2005
         out = BytesIO()
         img = Image.new(mode, (20, 20))
@@ -982,12 +981,12 @@ def test_eof(self) -> None:
         # Even though this decoder never says that it is finished
         # the image should still end when there is no new data
         class InfiniteMockPyDecoder(ImageFile.PyDecoder):
-            def decode(self, buffer):
+            def decode(self, buffer: bytes) -> tuple[int, int]:
                 return 0, 0
 
         decoder = InfiniteMockPyDecoder(None)
 
-        def closure(mode, *args):
+        def closure(mode: str, *args) -> InfiniteMockPyDecoder:
             decoder.__init__(mode, *args)
             return decoder
 
diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index e3f1fa8fde1..fab19e2eab4 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -4,6 +4,7 @@
 import re
 from io import BytesIO
 from pathlib import Path
+from typing import Any
 
 import pytest
 
@@ -36,7 +37,7 @@
 # 'Not enough memory to handle tile data'
 
 
-def roundtrip(im, **options):
+def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
     out = BytesIO()
     im.save(out, "JPEG2000", **options)
     test_bytes = out.tell()
@@ -138,7 +139,7 @@ def test_prog_res_rt() -> None:
 
 
 @pytest.mark.parametrize("num_resolutions", range(2, 6))
-def test_default_num_resolutions(num_resolutions) -> None:
+def test_default_num_resolutions(num_resolutions: int) -> None:
     d = 1 << (num_resolutions - 1)
     im = test_card.resize((d - 1, d - 1))
     with pytest.raises(OSError):
@@ -198,9 +199,9 @@ def test_layers_type(tmp_path: Path) -> None:
     for quality_layers in [[100, 50, 10], (100, 50, 10), None]:
         test_card.save(outfile, quality_layers=quality_layers)
 
-    for quality_layers in ["quality_layers", ("100", "50", "10")]:
+    for quality_layers_str in ["quality_layers", ("100", "50", "10")]:
         with pytest.raises(ValueError):
-            test_card.save(outfile, quality_layers=quality_layers)
+            test_card.save(outfile, quality_layers=quality_layers_str)
 
 
 def test_layers() -> None:
@@ -233,7 +234,7 @@ def test_layers() -> None:
         ("foo.jp2", {"no_jp2": False}, 4, b"jP"),
     ),
 )
-def test_no_jp2(name, args, offset, data) -> None:
+def test_no_jp2(name: str, args: dict[str, bool], offset: int, data: bytes) -> None:
     out = BytesIO()
     if name:
         out.name = name
@@ -278,7 +279,7 @@ def test_sgnd(tmp_path: Path) -> None:
 
 
 @pytest.mark.parametrize("ext", (".j2k", ".jp2"))
-def test_rgba(ext) -> None:
+def test_rgba(ext: str) -> None:
     # Arrange
     with Image.open("Tests/images/rgb_trns_ycbc" + ext) as im:
         # Act
@@ -289,7 +290,7 @@ def test_rgba(ext) -> None:
 
 
 @pytest.mark.parametrize("ext", (".j2k", ".jp2"))
-def test_16bit_monochrome_has_correct_mode(ext) -> None:
+def test_16bit_monochrome_has_correct_mode(ext: str) -> None:
     with Image.open("Tests/images/16bit.cropped" + ext) as im:
         im.load()
         assert im.mode == "I;16"
@@ -346,12 +347,12 @@ def test_parser_feed() -> None:
     not os.path.exists(EXTRA_DIR), reason="Extra image files not installed"
 )
 @pytest.mark.parametrize("name", ("subsampling_1", "subsampling_2", "zoo1", "zoo2"))
-def test_subsampling_decode(name) -> None:
+def test_subsampling_decode(name: str) -> None:
     test = f"{EXTRA_DIR}/{name}.jp2"
     reference = f"{EXTRA_DIR}/{name}.ppm"
 
     with Image.open(test) as im:
-        epsilon = 3  # for YCbCr images
+        epsilon = 3.0  # for YCbCr images
         with Image.open(reference) as im2:
             width, height = im2.size
             if name[-1] == "2":
@@ -400,7 +401,7 @@ def test_save_comment() -> None:
         "Tests/images/crash-d2c93af851d3ab9a19e34503626368b2ecde9c03.j2k",
     ],
 )
-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:
             # Valgrind should not complain here
diff --git a/Tests/test_file_libtiff.py b/Tests/test_file_libtiff.py
index 1386034e5a3..0994d99040e 100644
--- a/Tests/test_file_libtiff.py
+++ b/Tests/test_file_libtiff.py
@@ -27,7 +27,7 @@
 
 @skip_unless_feature("libtiff")
 class LibTiffTestCase:
-    def _assert_noerr(self, tmp_path: Path, im) -> None:
+    def _assert_noerr(self, tmp_path: Path, im: Image.Image) -> None:
         """Helper tests that assert basic sanity about the g4 tiff reading"""
         # 1 bit
         assert im.mode == "1"
@@ -140,7 +140,7 @@ def test_adobe_deflate_tiff(self) -> None:
             assert_image_equal_tofile(im, "Tests/images/tiff_adobe_deflate.png")
 
     @pytest.mark.parametrize("legacy_api", (False, True))
-    def test_write_metadata(self, legacy_api, tmp_path: Path) -> None:
+    def test_write_metadata(self, legacy_api: bool, tmp_path: Path) -> None:
         """Test metadata writing through libtiff"""
         f = str(tmp_path / "temp.tiff")
         with Image.open("Tests/images/hopper_g4.tif") as img:
@@ -243,7 +243,7 @@ def test_additional_metadata(self, tmp_path: Path) -> None:
         TiffImagePlugin.WRITE_LIBTIFF = False
 
     def test_custom_metadata(self, tmp_path: Path) -> None:
-        tc = namedtuple("test_case", "value,type,supported_by_default")
+        tc = namedtuple("tc", "value,type,supported_by_default")
         custom = {
             37000 + k: v
             for k, v in enumerate(
@@ -284,7 +284,9 @@ def test_custom_metadata(self, tmp_path: Path) -> None:
         for libtiff in libtiffs:
             TiffImagePlugin.WRITE_LIBTIFF = libtiff
 
-            def check_tags(tiffinfo) -> None:
+            def check_tags(
+                tiffinfo: TiffImagePlugin.ImageFileDirectory_v2 | dict[int, str]
+            ) -> None:
                 im = hopper()
 
                 out = str(tmp_path / "temp.tif")
@@ -502,7 +504,7 @@ def test_cmyk_save(self, tmp_path: Path) -> None:
         assert_image_equal_tofile(im, out)
 
     @pytest.mark.parametrize("im", (hopper("P"), Image.new("P", (1, 1), "#000")))
-    def test_palette_save(self, im, tmp_path: Path) -> None:
+    def test_palette_save(self, im: Image.Image, tmp_path: Path) -> None:
         out = str(tmp_path / "temp.tif")
 
         TiffImagePlugin.WRITE_LIBTIFF = True
@@ -514,7 +516,7 @@ def test_palette_save(self, im, tmp_path: Path) -> None:
             assert len(reloaded.tag_v2[320]) == 768
 
     @pytest.mark.parametrize("compression", ("tiff_ccitt", "group3", "group4"))
-    def test_bw_compression_w_rgb(self, compression, tmp_path: Path) -> None:
+    def test_bw_compression_w_rgb(self, compression: str, tmp_path: Path) -> None:
         im = hopper("RGB")
         out = str(tmp_path / "temp.tif")
 
@@ -647,7 +649,7 @@ def test_save_bytesio(self) -> None:
         # Generate test image
         pilim = hopper()
 
-        def save_bytesio(compression=None) -> None:
+        def save_bytesio(compression: str | None = None) -> None:
             buffer_io = io.BytesIO()
             pilim.save(buffer_io, format="tiff", compression=compression)
             buffer_io.seek(0)
@@ -731,7 +733,7 @@ def test_read_icc(self) -> None:
         assert icc == icc_libtiff
 
     def test_write_icc(self, tmp_path: Path) -> None:
-        def check_write(libtiff) -> None:
+        def check_write(libtiff: bool) -> None:
             TiffImagePlugin.WRITE_LIBTIFF = libtiff
 
             with Image.open("Tests/images/hopper.iccprofile.tif") as img:
@@ -837,7 +839,7 @@ def test_sampleformat_write(self, tmp_path: Path) -> None:
             assert reloaded.mode == "F"
             assert reloaded.getexif()[SAMPLEFORMAT] == 3
 
-    def test_lzma(self, capfd):
+    def test_lzma(self, capfd: pytest.CaptureFixture[str]) -> None:
         try:
             with Image.open("Tests/images/hopper_lzma.tif") as im:
                 assert im.mode == "RGB"
@@ -853,7 +855,7 @@ def test_lzma(self, capfd):
             sys.stderr.write(captured.err)
             raise
 
-    def test_webp(self, capfd):
+    def test_webp(self, capfd: pytest.CaptureFixture[str]) -> None:
         try:
             with Image.open("Tests/images/hopper_webp.tif") as im:
                 assert im.mode == "RGB"
@@ -971,7 +973,7 @@ def test_strip_planar_16bit_RGBa(self) -> None:
             assert_image_equal_tofile(im, "Tests/images/tiff_16bit_RGBa_target.png")
 
     @pytest.mark.parametrize("compression", (None, "jpeg"))
-    def test_block_tile_tags(self, compression, tmp_path: Path) -> None:
+    def test_block_tile_tags(self, compression: str | None, tmp_path: Path) -> None:
         im = hopper()
         out = str(tmp_path / "temp.tif")
 
@@ -1020,7 +1022,9 @@ def test_open_missing_samplesperpixel(self) -> None:
             ),
         ],
     )
-    def test_wrong_bits_per_sample(self, file_name, mode, size, tile) -> None:
+    def test_wrong_bits_per_sample(
+        self, file_name: str, mode: str, size: tuple[int, int], tile
+    ) -> None:
         with Image.open("Tests/images/" + file_name) as im:
             assert im.mode == mode
             assert im.size == size
@@ -1086,7 +1090,7 @@ def test_realloc_overflow(self) -> None:
         TiffImagePlugin.READ_LIBTIFF = False
 
     @pytest.mark.parametrize("compression", ("tiff_adobe_deflate", "jpeg"))
-    def test_save_multistrip(self, compression, tmp_path: Path) -> None:
+    def test_save_multistrip(self, compression: str, tmp_path: Path) -> None:
         im = hopper("RGB").resize((256, 256))
         out = str(tmp_path / "temp.tif")
         im.save(out, compression=compression)
@@ -1096,14 +1100,14 @@ def test_save_multistrip(self, compression, tmp_path: Path) -> None:
             assert len(im.tag_v2[STRIPOFFSETS]) > 1
 
     @pytest.mark.parametrize("argument", (True, False))
-    def test_save_single_strip(self, argument, tmp_path: Path) -> None:
+    def test_save_single_strip(self, argument: bool, tmp_path: Path) -> None:
         im = hopper("RGB").resize((256, 256))
         out = str(tmp_path / "temp.tif")
 
         if not argument:
             TiffImagePlugin.STRIP_SIZE = 2**18
         try:
-            arguments = {"compression": "tiff_adobe_deflate"}
+            arguments: dict[str, str | int] = {"compression": "tiff_adobe_deflate"}
             if argument:
                 arguments["strip_size"] = 2**18
             im.save(out, **arguments)
@@ -1114,7 +1118,7 @@ def test_save_single_strip(self, argument, tmp_path: Path) -> None:
             TiffImagePlugin.STRIP_SIZE = 65536
 
     @pytest.mark.parametrize("compression", ("tiff_adobe_deflate", None))
-    def test_save_zero(self, compression, tmp_path: Path) -> 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")
         with pytest.raises(SystemError):
@@ -1134,7 +1138,7 @@ def test_save_many_compressed(self, tmp_path: Path) -> None:
             ("Tests/images/child_ifd_jpeg.tiff", (20,)),
         ),
     )
-    def test_get_child_images(self, path, sizes) -> None:
+    def test_get_child_images(self, path: str, sizes: tuple[int, ...]) -> None:
         with Image.open(path) as im:
             ims = im.get_child_images()
 
diff --git a/Tests/test_file_png.py b/Tests/test_file_png.py
index 0f1d96365ea..d4a63431647 100644
--- a/Tests/test_file_png.py
+++ b/Tests/test_file_png.py
@@ -6,6 +6,7 @@
 import zlib
 from io import BytesIO
 from pathlib import Path
+from typing import Any
 
 import pytest
 
@@ -36,7 +37,7 @@
 MAGIC = PngImagePlugin._MAGIC
 
 
-def chunk(cid, *data):
+def chunk(cid: bytes, *data: bytes) -> bytes:
     test_file = BytesIO()
     PngImagePlugin.putchunk(*(test_file, cid) + data)
     return test_file.getvalue()
@@ -52,11 +53,11 @@ def chunk(cid, *data):
 TAIL = IDAT + IEND
 
 
-def load(data):
+def load(data: bytes) -> Image.Image:
     return Image.open(BytesIO(data))
 
 
-def roundtrip(im, **options):
+def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
     out = BytesIO()
     im.save(out, "PNG", **options)
     out.seek(0)
@@ -65,7 +66,7 @@ def roundtrip(im, **options):
 
 @skip_unless_feature("zlib")
 class TestFilePng:
-    def get_chunks(self, filename):
+    def get_chunks(self, filename: str) -> list[bytes]:
         chunks = []
         with open(filename, "rb") as fp:
             fp.read(8)
@@ -436,7 +437,7 @@ def test_nonunicode_text(self) -> None:
     def test_unicode_text(self) -> None:
         # Check preservation of non-ASCII characters
 
-        def rt_text(value) -> None:
+        def rt_text(value: str) -> None:
             im = Image.new("RGB", (32, 32))
             info = PngImagePlugin.PngInfo()
             info.add_text("Text", value)
@@ -636,7 +637,7 @@ def test_padded_idat(self) -> None:
     @pytest.mark.parametrize(
         "cid", (b"IHDR", b"sRGB", b"pHYs", b"acTL", b"fcTL", b"fdAT")
     )
-    def test_truncated_chunks(self, cid) -> None:
+    def test_truncated_chunks(self, cid: bytes) -> None:
         fp = BytesIO()
         with PngImagePlugin.PngStream(fp) as png:
             with pytest.raises(ValueError):
@@ -755,7 +756,7 @@ def test_seek(self) -> None:
                 im.seek(1)
 
     @pytest.mark.parametrize("buffer", (True, False))
-    def test_save_stdout(self, buffer) -> None:
+    def test_save_stdout(self, buffer: bool) -> None:
         old_stdout = sys.stdout
 
         if buffer:
diff --git a/Tests/test_image_paste.py b/Tests/test_image_paste.py
index 34a2f8f3db5..c4d7a5dd254 100644
--- a/Tests/test_image_paste.py
+++ b/Tests/test_image_paste.py
@@ -11,10 +11,9 @@ class TestImagingPaste:
     masks = {}
     size = 128
 
-    def assert_9points_image(self, im, expected) -> None:
-        expected = [
-            point[0] if im.mode == "L" else point[: len(im.mode)] for point in expected
-        ]
+    def assert_9points_image(
+        self, im: Image.Image, expected: list[tuple[int, int, int, int]]
+    ) -> None:
         px = im.load()
         actual = [
             px[0, 0],
@@ -27,9 +26,17 @@ def assert_9points_image(self, im, expected) -> None:
             px[self.size // 2, self.size - 1],
             px[self.size - 1, self.size - 1],
         ]
-        assert actual == expected
+        assert actual == [
+            point[0] if im.mode == "L" else point[: len(im.mode)] for point in expected
+        ]
 
-    def assert_9points_paste(self, im, im2, mask, expected) -> None:
+    def assert_9points_paste(
+        self,
+        im: Image.Image,
+        im2: Image.Image,
+        mask: Image.Image,
+        expected: list[tuple[int, int, int, int]],
+    ) -> None:
         im3 = im.copy()
         im3.paste(im2, (0, 0), mask)
         self.assert_9points_image(im3, expected)
@@ -106,7 +113,7 @@ def gradient_RGBa(self):
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_solid(self, mode) -> None:
+    def test_image_solid(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "red")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -116,7 +123,7 @@ def test_image_solid(self, mode) -> None:
         assert_image_equal(im, im2)
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_1(self, mode) -> None:
+    def test_image_mask_1(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -138,7 +145,7 @@ def test_image_mask_1(self, mode) -> None:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_L(self, mode) -> None:
+    def test_image_mask_L(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -160,7 +167,7 @@ def test_image_mask_L(self, mode) -> None:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_LA(self, mode) -> None:
+    def test_image_mask_LA(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -182,7 +189,7 @@ def test_image_mask_LA(self, mode) -> None:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_RGBA(self, mode) -> None:
+    def test_image_mask_RGBA(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -204,7 +211,7 @@ def test_image_mask_RGBA(self, mode) -> None:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_image_mask_RGBa(self, mode) -> None:
+    def test_image_mask_RGBa(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "white")
         im2 = getattr(self, "gradient_" + mode)
 
@@ -226,7 +233,7 @@ def test_image_mask_RGBa(self, mode) -> None:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_solid(self, mode) -> None:
+    def test_color_solid(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), "black")
 
         rect = (12, 23, 128 + 12, 128 + 23)
@@ -239,7 +246,7 @@ def test_color_solid(self, mode) -> None:
             assert sum(head[:255]) == 0
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_mask_1(self, mode) -> None:
+    def test_color_mask_1(self, mode: str) -> None:
         im = Image.new(mode, (200, 200), (50, 60, 70, 80)[: len(mode)])
         color = (10, 20, 30, 40)[: len(mode)]
 
@@ -261,7 +268,7 @@ def test_color_mask_1(self, mode) -> None:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_mask_L(self, mode) -> None:
+    def test_color_mask_L(self, mode: str) -> None:
         im = getattr(self, "gradient_" + mode).copy()
         color = "white"
 
@@ -283,7 +290,7 @@ def test_color_mask_L(self, mode) -> None:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_mask_RGBA(self, mode) -> None:
+    def test_color_mask_RGBA(self, mode: str) -> None:
         im = getattr(self, "gradient_" + mode).copy()
         color = "white"
 
@@ -305,7 +312,7 @@ def test_color_mask_RGBA(self, mode) -> None:
         )
 
     @pytest.mark.parametrize("mode", ["RGBA", "RGB", "L"])
-    def test_color_mask_RGBa(self, mode) -> None:
+    def test_color_mask_RGBa(self, mode: str) -> None:
         im = getattr(self, "gradient_" + mode).copy()
         color = "white"
 
diff --git a/Tests/test_image_reduce.py b/Tests/test_image_reduce.py
index c29830a7e5f..33b33d6b7fc 100644
--- a/Tests/test_image_reduce.py
+++ b/Tests/test_image_reduce.py
@@ -48,7 +48,7 @@
         ((1, 3), (10, 4)),
     ),
 )
-def test_args_factor(size, expected) -> None:
+def test_args_factor(size: int | tuple[int, int], expected: tuple[int, int]) -> None:
     im = Image.new("L", (10, 10))
     assert expected == im.reduce(size).size
 
@@ -56,7 +56,7 @@ def test_args_factor(size, expected) -> None:
 @pytest.mark.parametrize(
     "size, expected_error", ((0, ValueError), (2.0, TypeError), ((0, 10), ValueError))
 )
-def test_args_factor_error(size, expected_error) -> None:
+def test_args_factor_error(size: float | tuple[int, int], expected_error) -> None:
     im = Image.new("L", (10, 10))
     with pytest.raises(expected_error):
         im.reduce(size)
@@ -69,7 +69,7 @@ def test_args_factor_error(size, expected_error) -> None:
         ((5, 5, 6, 6), (1, 1)),
     ),
 )
-def test_args_box(size, expected) -> None:
+def test_args_box(size: tuple[int, int, int, int], expected: tuple[int, int]) -> None:
     im = Image.new("L", (10, 10))
     assert expected == im.reduce(2, size).size
 
@@ -86,20 +86,20 @@ def test_args_box(size, expected) -> None:
         ((5, 0, 5, 10), ValueError),
     ),
 )
-def test_args_box_error(size, expected_error) -> None:
+def test_args_box_error(size: str | tuple[int, int, int, int], expected_error) -> None:
     im = Image.new("L", (10, 10))
     with pytest.raises(expected_error):
         im.reduce(2, size).size
 
 
 @pytest.mark.parametrize("mode", ("P", "1", "I;16"))
-def test_unsupported_modes(mode) -> None:
+def test_unsupported_modes(mode: str) -> None:
     im = Image.new("P", (10, 10))
     with pytest.raises(ValueError):
         im.reduce(3)
 
 
-def get_image(mode):
+def get_image(mode: str) -> Image.Image:
     mode_info = ImageMode.getmode(mode)
     if mode_info.basetype == "L":
         bands = [gradients_image]
@@ -119,7 +119,7 @@ def get_image(mode):
     return im.crop((0, 0, im.width, im.height - 5))
 
 
-def compare_reduce_with_box(im, factor) -> None:
+def compare_reduce_with_box(im: Image.Image, factor: int | tuple[int, int]) -> None:
     box = (11, 13, 146, 164)
     reduced = im.reduce(factor, box=box)
     reference = im.crop(box).reduce(factor)
@@ -127,7 +127,10 @@ def compare_reduce_with_box(im, factor) -> None:
 
 
 def compare_reduce_with_reference(
-    im, factor, average_diff: float = 0.4, max_diff: int = 1
+    im: Image.Image,
+    factor: int | tuple[int, int],
+    average_diff: float = 0.4,
+    max_diff: int = 1,
 ) -> None:
     """Image.reduce() should look very similar to Image.resize(BOX).
 
@@ -173,7 +176,9 @@ def compare_reduce_with_reference(
     assert_compare_images(reduced, reference, average_diff, max_diff)
 
 
-def assert_compare_images(a, b, max_average_diff, max_diff: int = 255) -> None:
+def assert_compare_images(
+    a: Image.Image, b: Image.Image, max_average_diff: float, max_diff: int = 255
+) -> None:
     assert a.mode == b.mode, f"got mode {repr(a.mode)}, expected {repr(b.mode)}"
     assert a.size == b.size, f"got size {repr(a.size)}, expected {repr(b.size)}"
 
@@ -201,20 +206,20 @@ def assert_compare_images(a, b, max_average_diff, max_diff: int = 255) -> None:
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_L(factor) -> None:
+def test_mode_L(factor: int | tuple[int, int]) -> None:
     im = get_image("L")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_LA(factor) -> None:
+def test_mode_LA(factor: int | tuple[int, int]) -> None:
     im = get_image("LA")
     compare_reduce_with_reference(im, factor, 0.8, 5)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_LA_opaque(factor) -> None:
+def test_mode_LA_opaque(factor: int | tuple[int, int]) -> None:
     im = get_image("LA")
     # With opaque alpha, an error should be way smaller.
     im.putalpha(Image.new("L", im.size, 255))
@@ -223,27 +228,27 @@ def test_mode_LA_opaque(factor) -> None:
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_La(factor) -> None:
+def test_mode_La(factor: int | tuple[int, int]) -> None:
     im = get_image("La")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_RGB(factor) -> None:
+def test_mode_RGB(factor: int | tuple[int, int]) -> None:
     im = get_image("RGB")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_RGBA(factor) -> None:
+def test_mode_RGBA(factor: int | tuple[int, int]) -> None:
     im = get_image("RGBA")
     compare_reduce_with_reference(im, factor, 0.8, 5)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_RGBA_opaque(factor) -> None:
+def test_mode_RGBA_opaque(factor: int | tuple[int, int]) -> None:
     im = get_image("RGBA")
     # With opaque alpha, an error should be way smaller.
     im.putalpha(Image.new("L", im.size, 255))
@@ -252,21 +257,21 @@ def test_mode_RGBA_opaque(factor) -> None:
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_RGBa(factor) -> None:
+def test_mode_RGBa(factor: int | tuple[int, int]) -> None:
     im = get_image("RGBa")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_I(factor) -> None:
+def test_mode_I(factor: int | tuple[int, int]) -> None:
     im = get_image("I")
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 
 
 @pytest.mark.parametrize("factor", remarkable_factors)
-def test_mode_F(factor) -> None:
+def test_mode_F(factor: int | tuple[int, int]) -> None:
     im = get_image("F")
     compare_reduce_with_reference(im, factor, 0, 0)
     compare_reduce_with_box(im, factor)
diff --git a/Tests/test_image_resample.py b/Tests/test_image_resample.py
index f4c9eb0e6fa..f3ec12c053b 100644
--- a/Tests/test_image_resample.py
+++ b/Tests/test_image_resample.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from contextlib import contextmanager
+from typing import Generator
 
 import pytest
 
@@ -51,7 +52,7 @@ def test_modify_after_resizing(self) -> None:
 
 
 class TestImagingCoreResampleAccuracy:
-    def make_case(self, mode, size, color):
+    def make_case(self, mode: str, size: tuple[int, int], color: int) -> Image.Image:
         """Makes a sample image with two dark and two bright squares.
         For example:
         e0 e0 1f 1f
@@ -66,7 +67,7 @@ def make_case(self, mode, size, color):
 
         return Image.merge(mode, [case] * len(mode))
 
-    def make_sample(self, data, size):
+    def make_sample(self, data: str, size: tuple[int, int]) -> Image.Image:
         """Restores a sample image from given data string which contains
         hex-encoded pixels from the top left fourth of a sample.
         """
@@ -83,7 +84,7 @@ def make_sample(self, data, size):
                 s_px[size[0] - x - 1, y] = 255 - val
         return sample
 
-    def check_case(self, case, sample) -> None:
+    def check_case(self, case: Image.Image, sample: Image.Image) -> None:
         s_px = sample.load()
         c_px = case.load()
         for y in range(case.size[1]):
@@ -95,7 +96,7 @@ def check_case(self, case, sample) -> None:
                     )
                     assert s_px[x, y] == c_px[x, y], message
 
-    def serialize_image(self, image):
+    def serialize_image(self, image: Image.Image) -> str:
         s_px = image.load()
         return "\n".join(
             " ".join(f"{s_px[x, y]:02x}" for x in range(image.size[0]))
@@ -103,7 +104,7 @@ def serialize_image(self, image):
         )
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_box(self, mode) -> None:
+    def test_reduce_box(self, mode: str) -> None:
         case = self.make_case(mode, (8, 8), 0xE1)
         case = case.resize((4, 4), Image.Resampling.BOX)
         # fmt: off
@@ -114,7 +115,7 @@ def test_reduce_box(self, mode) -> None:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_bilinear(self, mode) -> None:
+    def test_reduce_bilinear(self, mode: str) -> None:
         case = self.make_case(mode, (8, 8), 0xE1)
         case = case.resize((4, 4), Image.Resampling.BILINEAR)
         # fmt: off
@@ -125,7 +126,7 @@ def test_reduce_bilinear(self, mode) -> None:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_hamming(self, mode) -> None:
+    def test_reduce_hamming(self, mode: str) -> None:
         case = self.make_case(mode, (8, 8), 0xE1)
         case = case.resize((4, 4), Image.Resampling.HAMMING)
         # fmt: off
@@ -136,7 +137,7 @@ def test_reduce_hamming(self, mode) -> None:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_bicubic(self, mode) -> None:
+    def test_reduce_bicubic(self, mode: str) -> None:
         case = self.make_case(mode, (12, 12), 0xE1)
         case = case.resize((6, 6), Image.Resampling.BICUBIC)
         # fmt: off
@@ -148,7 +149,7 @@ def test_reduce_bicubic(self, mode) -> None:
             self.check_case(channel, self.make_sample(data, (6, 6)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_reduce_lanczos(self, mode) -> None:
+    def test_reduce_lanczos(self, mode: str) -> None:
         case = self.make_case(mode, (16, 16), 0xE1)
         case = case.resize((8, 8), Image.Resampling.LANCZOS)
         # fmt: off
@@ -161,7 +162,7 @@ def test_reduce_lanczos(self, mode) -> None:
             self.check_case(channel, self.make_sample(data, (8, 8)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_box(self, mode) -> None:
+    def test_enlarge_box(self, mode: str) -> None:
         case = self.make_case(mode, (2, 2), 0xE1)
         case = case.resize((4, 4), Image.Resampling.BOX)
         # fmt: off
@@ -172,7 +173,7 @@ def test_enlarge_box(self, mode) -> None:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_bilinear(self, mode) -> None:
+    def test_enlarge_bilinear(self, mode: str) -> None:
         case = self.make_case(mode, (2, 2), 0xE1)
         case = case.resize((4, 4), Image.Resampling.BILINEAR)
         # fmt: off
@@ -183,7 +184,7 @@ def test_enlarge_bilinear(self, mode) -> None:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_hamming(self, mode) -> None:
+    def test_enlarge_hamming(self, mode: str) -> None:
         case = self.make_case(mode, (2, 2), 0xE1)
         case = case.resize((4, 4), Image.Resampling.HAMMING)
         # fmt: off
@@ -194,7 +195,7 @@ def test_enlarge_hamming(self, mode) -> None:
             self.check_case(channel, self.make_sample(data, (4, 4)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_bicubic(self, mode) -> None:
+    def test_enlarge_bicubic(self, mode: str) -> None:
         case = self.make_case(mode, (4, 4), 0xE1)
         case = case.resize((8, 8), Image.Resampling.BICUBIC)
         # fmt: off
@@ -207,7 +208,7 @@ def test_enlarge_bicubic(self, mode) -> None:
             self.check_case(channel, self.make_sample(data, (8, 8)))
 
     @pytest.mark.parametrize("mode", ("RGBX", "RGB", "La", "L"))
-    def test_enlarge_lanczos(self, mode) -> None:
+    def test_enlarge_lanczos(self, mode: str) -> None:
         case = self.make_case(mode, (6, 6), 0xE1)
         case = case.resize((12, 12), Image.Resampling.LANCZOS)
         data = (
@@ -230,7 +231,7 @@ def test_box_filter_correct_range(self) -> None:
 
 
 class TestCoreResampleConsistency:
-    def make_case(self, mode, fill):
+    def make_case(self, mode: str, fill: tuple[int, int, int] | float):
         im = Image.new(mode, (512, 9), fill)
         return im.resize((9, 512), Image.Resampling.LANCZOS), im.load()[0, 0]
 
@@ -265,7 +266,7 @@ def test_32f(self) -> None:
 
 
 class TestCoreResampleAlphaCorrect:
-    def make_levels_case(self, mode):
+    def make_levels_case(self, mode: str) -> Image.Image:
         i = Image.new(mode, (256, 16))
         px = i.load()
         for y in range(i.size[1]):
@@ -275,7 +276,7 @@ def make_levels_case(self, mode):
                 px[x, y] = tuple(pix)
         return i
 
-    def run_levels_case(self, i) -> None:
+    def run_levels_case(self, i: Image.Image) -> None:
         px = i.load()
         for y in range(i.size[1]):
             used_colors = {px[x, y][0] for x in range(i.size[0])}
@@ -302,7 +303,9 @@ def test_levels_la(self) -> None:
         self.run_levels_case(case.resize((512, 32), Image.Resampling.BICUBIC))
         self.run_levels_case(case.resize((512, 32), Image.Resampling.LANCZOS))
 
-    def make_dirty_case(self, mode, clean_pixel, dirty_pixel):
+    def make_dirty_case(
+        self, mode: str, clean_pixel: tuple[int, ...], dirty_pixel: tuple[int, ...]
+    ) -> Image.Image:
         i = Image.new(mode, (64, 64), dirty_pixel)
         px = i.load()
         xdiv4 = i.size[0] // 4
@@ -312,7 +315,7 @@ def make_dirty_case(self, mode, clean_pixel, dirty_pixel):
                 px[x + xdiv4, y + ydiv4] = clean_pixel
         return i
 
-    def run_dirty_case(self, i, clean_pixel) -> None:
+    def run_dirty_case(self, i: Image.Image, clean_pixel: tuple[int, ...]) -> None:
         px = i.load()
         for y in range(i.size[1]):
             for x in range(i.size[0]):
@@ -432,7 +435,7 @@ class TestCoreResampleBox:
             Image.Resampling.LANCZOS,
         ),
     )
-    def test_wrong_arguments(self, resample) -> None:
+    def test_wrong_arguments(self, resample: Image.Resampling) -> None:
         im = hopper()
         im.resize((32, 32), resample, (0, 0, im.width, im.height))
         im.resize((32, 32), resample, (20, 20, im.width, im.height))
@@ -459,8 +462,12 @@ def test_wrong_arguments(self, resample) -> None:
         with pytest.raises(ValueError, match="can't exceed"):
             im.resize((32, 32), resample, (0, 0, im.width, im.height + 1))
 
-    def resize_tiled(self, im, dst_size, xtiles, ytiles):
-        def split_range(size, tiles):
+    def resize_tiled(
+        self, im: Image.Image, dst_size: tuple[int, int], xtiles: int, ytiles: int
+    ) -> Image.Image:
+        def split_range(
+            size: int, tiles: int
+        ) -> Generator[tuple[int, int], None, None]:
             scale = size / tiles
             for i in range(tiles):
                 yield int(round(scale * i)), int(round(scale * (i + 1)))
@@ -518,7 +525,7 @@ def test_subsample(self) -> None:
     @pytest.mark.parametrize(
         "resample", (Image.Resampling.NEAREST, Image.Resampling.BILINEAR)
     )
-    def test_formats(self, mode, resample) -> None:
+    def test_formats(self, mode: str, resample: Image.Resampling) -> None:
         im = hopper(mode)
         box = (20, 20, im.size[0] - 20, im.size[1] - 20)
         with_box = im.resize((32, 32), resample, box)
@@ -558,7 +565,7 @@ def test_no_passthrough(self) -> None:
     @pytest.mark.parametrize(
         "flt", (Image.Resampling.NEAREST, Image.Resampling.BICUBIC)
     )
-    def test_skip_horizontal(self, flt) -> None:
+    def test_skip_horizontal(self, flt: Image.Resampling) -> None:
         # Can skip resize for one dimension
         im = hopper()
 
@@ -581,7 +588,7 @@ def test_skip_horizontal(self, flt) -> None:
     @pytest.mark.parametrize(
         "flt", (Image.Resampling.NEAREST, Image.Resampling.BICUBIC)
     )
-    def test_skip_vertical(self, flt) -> None:
+    def test_skip_vertical(self, flt: Image.Resampling) -> None:
         # Can skip resize for one dimension
         im = hopper()
 
diff --git a/Tests/test_imagemath.py b/Tests/test_imagemath.py
index ea6e80f1ee7..b65ea874063 100644
--- a/Tests/test_imagemath.py
+++ b/Tests/test_imagemath.py
@@ -5,11 +5,11 @@
 from PIL import Image, ImageMath
 
 
-def pixel(im):
-    if hasattr(im, "im"):
-        return f"{im.mode} {repr(im.getpixel((0, 0)))}"
+def pixel(im: Image.Image | int) -> str | int:
     if isinstance(im, int):
         return int(im)  # hack to deal with booleans
+    else:
+        return f"{im.mode} {repr(im.getpixel((0, 0)))}"
 
 
 A = Image.new("L", (1, 1), 1)
@@ -60,7 +60,7 @@ def test_ops() -> None:
         "(lambda: (lambda: exec('pass'))())()",
     ),
 )
-def test_prevent_exec(expression) -> None:
+def test_prevent_exec(expression: str) -> None:
     with pytest.raises(ValueError):
         ImageMath.eval(expression)
 

From 463c36821136652a05517a4db810a265d25c9b0c Mon Sep 17 00:00:00 2001
From: Andrew Murray <3112309+radarhere@users.noreply.github.com>
Date: Wed, 7 Feb 2024 21:02:34 +1100
Subject: [PATCH 2/2] Simplified code

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
---
 Tests/test_imagemath.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Tests/test_imagemath.py b/Tests/test_imagemath.py
index b65ea874063..a21e2307d5f 100644
--- a/Tests/test_imagemath.py
+++ b/Tests/test_imagemath.py
@@ -8,8 +8,8 @@
 def pixel(im: Image.Image | int) -> str | int:
     if isinstance(im, int):
         return int(im)  # hack to deal with booleans
-    else:
-        return f"{im.mode} {repr(im.getpixel((0, 0)))}"
+
+    return f"{im.mode} {repr(im.getpixel((0, 0)))}"
 
 
 A = Image.new("L", (1, 1), 1)