Added type hints

Tests/check_imaging_leaks.py

@@ -23,7 +23,10 @@ def _get_mem_usage() -> float:
 
 
 def _test_leak(
-    min_iterations: int, max_iterations: int, fn: Callable[..., None], *args: Any
+    min_iterations: int,
+    max_iterations: int,
+    fn: Callable[..., Image.Image | None],
+    *args: Any,
 ) -> None:
     mem_limit = None
     for i in range(max_iterations):

Tests/check_png_dos.py

@@ -17,6 +17,7 @@ def test_ignore_dos_text() -> None:
     finally:
         ImageFile.LOAD_TRUNCATED_IMAGES = False
 
+    assert isinstance(im, PngImagePlugin.PngImageFile)
     for s in im.text.values():
         assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
 
@@ -32,6 +33,7 @@ def test_dos_text() -> None:
         assert msg, "Decompressed Data Too Large"
         return
 
+    assert isinstance(im, PngImagePlugin.PngImageFile)
     for s in im.text.values():
         assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
 
@@ -57,6 +59,7 @@ def test_dos_total_memory() -> None:
         return
 
     total_len = 0
+    assert isinstance(im2, PngImagePlugin.PngImageFile)
     for txt in im2.text.values():
         total_len += len(txt)
     assert total_len < 64 * 1024 * 1024, "Total text chunks greater than 64M"

Tests/helper.py

@@ -351,7 +351,7 @@ def is_mingw() -> bool:
 
 
 class CachedProperty:
-    def __init__(self, func: Callable[[Any], None]) -> None:
+    def __init__(self, func: Callable[[Any], Any]) -> None:
         self.func = func
 
     def __get__(self, instance: Any, cls: type[Any] | None = None) -> Any:

Tests/test_file_container.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from typing import Literal
+
 import pytest
 
 from PIL import ContainerIO, Image
@@ -22,14 +24,14 @@ def test_isatty() -> None:
 
 
 @pytest.mark.parametrize(
-    "mode, expected_value",
+    "mode, expected_position",
     (
         (0, 33),
         (1, 66),
         (2, 100),
     ),
 )
-def test_seek_mode(mode: int, expected_value: int) -> None:
+def test_seek_mode(mode: Literal[0, 1, 2], expected_position: int) -> None:
     # Arrange
     with open(TEST_FILE, "rb") as fh:
         container = ContainerIO.ContainerIO(fh, 22, 100)
@@ -39,7 +41,7 @@ def test_seek_mode(mode: int, expected_value: int) -> None:
         container.seek(33, mode)
 
         # Assert
-        assert container.tell() == expected_value
+        assert container.tell() == expected_position
 
 
 @pytest.mark.parametrize("bytesmode", (True, False))

Tests/test_file_jpeg.py

@@ -6,7 +6,7 @@ import warnings
 from io import BytesIO
 from pathlib import Path
 from types import ModuleType
-from typing import Any
+from typing import Any, cast
 
 import pytest
 
@@ -45,14 +45,20 @@ TEST_FILE = "Tests/images/hopper.jpg"
 
 @skip_unless_feature("jpg")
 class TestFileJpeg:
-    def roundtrip(self, im: Image.Image, **options: Any) -> Image.Image:
+    def roundtrip_with_bytes(
+        self, im: Image.Image, **options: Any
+    ) -> tuple[JpegImagePlugin.JpegImageFile, int]:
         out = BytesIO()
         im.save(out, "JPEG", **options)
         test_bytes = out.tell()
         out.seek(0)
-        im = Image.open(out)
-        im.bytes = test_bytes  # for testing only
-        return im
+        reloaded = cast(JpegImagePlugin.JpegImageFile, Image.open(out))
+        return reloaded, test_bytes
+
+    def roundtrip(
+        self, im: Image.Image, **options: Any
+    ) -> JpegImagePlugin.JpegImageFile:
+        return self.roundtrip_with_bytes(im, **options)[0]
 
     def gen_random_image(self, size: tuple[int, int], mode: str = "RGB") -> Image.Image:
         """Generates a very hard to compress file
@@ -246,13 +252,13 @@ class TestFileJpeg:
             im.save(f, progressive=True, quality=94, exif=b" " * 43668)
 
     def test_optimize(self) -> None:
-        im1 = self.roundtrip(hopper())
-        im2 = self.roundtrip(hopper(), optimize=0)
-        im3 = self.roundtrip(hopper(), optimize=1)
+        im1, im1_bytes = self.roundtrip_with_bytes(hopper())
+        im2, im2_bytes = self.roundtrip_with_bytes(hopper(), optimize=0)
+        im3, im3_bytes = self.roundtrip_with_bytes(hopper(), optimize=1)
         assert_image_equal(im1, im2)
         assert_image_equal(im1, im3)
-        assert im1.bytes >= im2.bytes
-        assert im1.bytes >= im3.bytes
+        assert im1_bytes >= im2_bytes
+        assert im1_bytes >= im3_bytes
 
     def test_optimize_large_buffer(self, tmp_path: Path) -> None:
         # https://github.com/python-pillow/Pillow/issues/148
@@ -262,15 +268,15 @@ class TestFileJpeg:
         im.save(f, format="JPEG", optimize=True)
 
     def test_progressive(self) -> None:
-        im1 = self.roundtrip(hopper())
+        im1, im1_bytes = self.roundtrip_with_bytes(hopper())
         im2 = self.roundtrip(hopper(), progressive=False)
-        im3 = self.roundtrip(hopper(), progressive=True)
+        im3, im3_bytes = self.roundtrip_with_bytes(hopper(), progressive=True)
         assert not im1.info.get("progressive")
         assert not im2.info.get("progressive")
         assert im3.info.get("progressive")
 
         assert_image_equal(im1, im3)
-        assert im1.bytes >= im3.bytes
+        assert im1_bytes >= im3_bytes
 
     def test_progressive_large_buffer(self, tmp_path: Path) -> None:
         f = str(tmp_path / "temp.jpg")
@@ -341,6 +347,7 @@ class TestFileJpeg:
             assert exif.get_ifd(0x8825) == {}
 
             transposed = ImageOps.exif_transpose(im)
+        assert transposed is not None
         exif = transposed.getexif()
         assert exif.get_ifd(0x8825) == {}
 
@@ -419,14 +426,14 @@ class TestFileJpeg:
         assert im3.info.get("progression")
 
     def test_quality(self) -> None:
-        im1 = self.roundtrip(hopper())
-        im2 = self.roundtrip(hopper(), quality=50)
+        im1, im1_bytes = self.roundtrip_with_bytes(hopper())
+        im2, im2_bytes = self.roundtrip_with_bytes(hopper(), quality=50)
         assert_image(im1, im2.mode, im2.size)
-        assert im1.bytes >= im2.bytes
+        assert im1_bytes >= im2_bytes
 
-        im3 = self.roundtrip(hopper(), quality=0)
+        im3, im3_bytes = self.roundtrip_with_bytes(hopper(), quality=0)
         assert_image(im1, im3.mode, im3.size)
-        assert im2.bytes > im3.bytes
+        assert im2_bytes > im3_bytes
 
     def test_smooth(self) -> None:
         im1 = self.roundtrip(hopper())

Tests/test_file_jpeg2k.py

@@ -40,10 +40,8 @@ test_card.load()
 def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
     out = BytesIO()
     im.save(out, "JPEG2000", **options)
-    test_bytes = out.tell()
     out.seek(0)
     with Image.open(out) as im:
-        im.bytes = test_bytes  # for testing only
         im.load()
     return im
 
@@ -77,7 +75,9 @@ def test_invalid_file() -> None:
 def test_bytesio() -> None:
     with open("Tests/images/test-card-lossless.jp2", "rb") as f:
         data = BytesIO(f.read())
-    assert_image_similar_tofile(test_card, data, 1.0e-3)
+    with Image.open(data) as im:
+        im.load()
+        assert_image_similar(im, test_card, 1.0e-3)
 
 
 # These two test pre-written JPEG 2000 files that were not written with
@@ -340,6 +340,7 @@ def test_parser_feed() -> None:
     p.feed(data)
 
     # Assert
+    assert p.image is not None
     assert p.image.size == (640, 480)
 
 

Tests/test_file_libtiff.py

@@ -27,7 +27,7 @@ from .helper import (
 
 @skip_unless_feature("libtiff")
 class LibTiffTestCase:
-    def _assert_noerr(self, tmp_path: Path, im: Image.Image) -> None:
+    def _assert_noerr(self, tmp_path: Path, im: TiffImagePlugin.TiffImageFile) -> None:
         """Helper tests that assert basic sanity about the g4 tiff reading"""
         # 1 bit
         assert im.mode == "1"
@@ -524,7 +524,8 @@ class TestFileLibTiff(LibTiffTestCase):
             im.save(out, compression=compression)
 
     def test_fp_leak(self) -> None:
-        im = Image.open("Tests/images/hopper_g4_500.tif")
+        im: Image.Image | None = Image.open("Tests/images/hopper_g4_500.tif")
+        assert im is not None
         fn = im.fp.fileno()
 
         os.fstat(fn)
@@ -716,6 +717,7 @@ class TestFileLibTiff(LibTiffTestCase):
                 f.write(src.read())
 
         im = Image.open(tmpfile)
+        assert isinstance(im, TiffImagePlugin.TiffImageFile)
         im.n_frames
         im.close()
         # Should not raise PermissionError.
@@ -1097,6 +1099,7 @@ class TestFileLibTiff(LibTiffTestCase):
 
         with Image.open(out) as im:
             # Assert that there are multiple strips
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert len(im.tag_v2[STRIPOFFSETS]) > 1
 
     @pytest.mark.parametrize("argument", (True, False))
@@ -1113,6 +1116,7 @@ class TestFileLibTiff(LibTiffTestCase):
             im.save(out, **arguments)
 
             with Image.open(out) as im:
+                assert isinstance(im, TiffImagePlugin.TiffImageFile)
                 assert len(im.tag_v2[STRIPOFFSETS]) == 1
         finally:
             TiffImagePlugin.STRIP_SIZE = 65536

Tests/test_file_mpo.py

@@ -2,11 +2,11 @@ from __future__ import annotations
 
 import warnings
 from io import BytesIO
-from typing import Any
+from typing import Any, cast
 
 import pytest
 
-from PIL import Image
+from PIL import Image, MpoImagePlugin
 
 from .helper import (
     assert_image_equal,
@@ -20,14 +20,11 @@ test_files = ["Tests/images/sugarshack.mpo", "Tests/images/frozenpond.mpo"]
 pytestmark = skip_unless_feature("jpg")
 
 
-def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
+def roundtrip(im: Image.Image, **options: Any) -> MpoImagePlugin.MpoImageFile:
     out = BytesIO()
     im.save(out, "MPO", **options)
-    test_bytes = out.tell()
     out.seek(0)
-    im = Image.open(out)
-    im.bytes = test_bytes  # for testing only
-    return im
+    return cast(MpoImagePlugin.MpoImageFile, Image.open(out))
 
 
 @pytest.mark.parametrize("test_file", test_files)

Tests/test_file_png.py

@@ -7,7 +7,7 @@ import zlib
 from io import BytesIO
 from pathlib import Path
 from types import ModuleType
-from typing import Any
+from typing import Any, cast
 
 import pytest
 
@@ -59,11 +59,11 @@ def load(data: bytes) -> Image.Image:
     return Image.open(BytesIO(data))
 
 
-def roundtrip(im: Image.Image, **options: Any) -> Image.Image:
+def roundtrip(im: Image.Image, **options: Any) -> PngImagePlugin.PngImageFile:
     out = BytesIO()
     im.save(out, "PNG", **options)
     out.seek(0)
-    return Image.open(out)
+    return cast(PngImagePlugin.PngImageFile, Image.open(out))
 
 
 @skip_unless_feature("zlib")

Tests/test_file_spider.py

@@ -9,7 +9,7 @@ import pytest
 
 from PIL import Image, ImageSequence, SpiderImagePlugin
 
-from .helper import assert_image_equal_tofile, hopper, is_pypy
+from .helper import assert_image_equal, hopper, is_pypy
 
 TEST_FILE = "Tests/images/hopper.spider"
 
@@ -152,7 +152,7 @@ def test_nonstack_dos() -> None:
             assert i <= 1, "Non-stack DOS file test failed"
 
 
-# for issue #4093
+# for issue #4093s
 def test_odd_size() -> None:
     data = BytesIO()
     width = 100
@@ -160,4 +160,5 @@ def test_odd_size() -> None:
     im.save(data, format="SPIDER")
 
     data.seek(0)
-    assert_image_equal_tofile(im, data)
+    with Image.open(data) as im2:
+        assert_image_equal(im, im2)

Tests/test_file_tiff.py

@@ -623,6 +623,7 @@ class TestFileTiff:
         im.save(outfile, tiffinfo={278: 256})
 
         with Image.open(outfile) as im:
+            assert isinstance(im, TiffImagePlugin.TiffImageFile)
             assert im.tag_v2[278] == 256
 
     def test_strip_raw(self) -> None:

Tests/test_image.py

@@ -138,13 +138,13 @@ class TestImage:
         assert im.height == 2
 
         with pytest.raises(AttributeError):
-            im.size = (3, 4)
+            im.size = (3, 4)  # type: ignore[misc]
 
     def test_set_mode(self) -> None:
         im = Image.new("RGB", (1, 1))
 
         with pytest.raises(AttributeError):
-            im.mode = "P"
+            im.mode = "P"  # type: ignore[misc]
 
     def test_invalid_image(self) -> None:
         im = io.BytesIO(b"")

Tests/test_image_access.py

@@ -14,6 +14,7 @@ from .helper import assert_image_equal, hopper, is_win32
 
 # CFFI imports pycparser which doesn't support PYTHONOPTIMIZE=2
 # https://github.com/eliben/pycparser/pull/198#issuecomment-317001670
+cffi: ModuleType | None
 if os.environ.get("PYTHONOPTIMIZE") == "2":
     cffi = None
 else:

Tests/test_image_fromqimage.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import warnings
-from typing import Generator
 
 import pytest
 
@@ -17,17 +16,14 @@ pytestmark = pytest.mark.skipif(
     not ImageQt.qt_is_installed, reason="Qt bindings are not installed"
 )
 
-
-@pytest.fixture
-def test_images() -> Generator[Image.Image, None, None]:
-    ims = [
+ims = [
     hopper(),
     Image.open("Tests/images/transparent.png"),
     Image.open("Tests/images/7x13.png"),
-    ]
-    try:
-        yield ims
-    finally:
+]
+
+
+def teardown_module() -> None:
     for im in ims:
         im.close()
 
@@ -44,26 +40,26 @@ def roundtrip(expected: Image.Image) -> None:
         assert_image_equal(result, expected.convert("RGB"))
 
 
-def test_sanity_1(test_images: Generator[Image.Image, None, None]) -> None:
-    for im in test_images:
+def test_sanity_1() -> None:
+    for im in ims:
         roundtrip(im.convert("1"))
 
 
-def test_sanity_rgb(test_images: Generator[Image.Image, None, None]) -> None:
-    for im in test_images:
+def test_sanity_rgb() -> None:
+    for im in ims:
         roundtrip(im.convert("RGB"))
 
 
-def test_sanity_rgba(test_images: Generator[Image.Image, None, None]) -> None:
-    for im in test_images:
+def test_sanity_rgba() -> None:
+    for im in ims:
         roundtrip(im.convert("RGBA"))
 
 
-def test_sanity_l(test_images: Generator[Image.Image, None, None]) -> None:
-    for im in test_images:
+def test_sanity_l() -> None:
+    for im in ims:
         roundtrip(im.convert("L"))
 
 
-def test_sanity_p(test_images: Generator[Image.Image, None, None]) -> None:
-    for im in test_images:
+def test_sanity_p() -> None:
+    for im in ims:
         roundtrip(im.convert("P"))

Tests/test_image_paste.py

@@ -32,7 +32,7 @@ class TestImagingPaste:
     def assert_9points_paste(
         self,
         im: Image.Image,
-        im2: Image.Image,
+        im2: Image.Image | str | tuple[int, ...],
         mask: Image.Image,
         expected: list[tuple[int, int, int, int]],
     ) -> None:

Tests/test_image_resample.py

@@ -237,7 +237,7 @@ class TestCoreResampleConsistency:
         im = Image.new(mode, (512, 9), fill)
         return im.resize((9, 512), Image.Resampling.LANCZOS), im.load()[0, 0]
 
-    def run_case(self, case: tuple[Image.Image, Image.Image]) -> None:
+    def run_case(self, case: tuple[Image.Image, int | tuple[int, ...]]) -> None:
         channel, color = case
         px = channel.load()
         for x in range(channel.size[0]):

Tests/test_image_resize.py

@@ -154,7 +154,7 @@ class TestImagingCoreResize:
 
     def test_unknown_filter(self) -> None:
         with pytest.raises(ValueError):
-            self.resize(hopper(), (10, 10), 9)
+            self.resize(hopper(), (10, 10), 9)  # type: ignore[arg-type]
 
     def test_cross_platform(self, tmp_path: Path) -> None:
         # This test is intended for only check for consistent behaviour across

Tests/test_imagemorph.py

@@ -73,15 +73,16 @@ def test_lut(op: str) -> None:
 
 
 def test_no_operator_loaded() -> None:
+    im = Image.new("L", (1, 1))
     mop = ImageMorph.MorphOp()
     with pytest.raises(Exception) as e:
-        mop.apply(None)
+        mop.apply(im)
     assert str(e.value) == "No operator loaded"
     with pytest.raises(Exception) as e:
-        mop.match(None)
+        mop.match(im)
     assert str(e.value) == "No operator loaded"
     with pytest.raises(Exception) as e:
-        mop.save_lut(None)
+        mop.save_lut("")
     assert str(e.value) == "No operator loaded"
 
 

Tests/test_imageops.py

@@ -13,8 +13,12 @@ from .helper import (
 )
 
 
-class Deformer:
-    def getmesh(self, im: Image.Image) -> list[tuple[tuple[int, ...], tuple[int, ...]]]:
+class Deformer(ImageOps.SupportsGetMesh):
+    def getmesh(
+        self, im: Image.Image
+    ) -> list[
+        tuple[tuple[int, int, int, int], tuple[int, int, int, int, int, int, int, int]]
+    ]:
         x, y = im.size
         return [((0, 0, x, y), (0, 0, x, 0, x, y, y, 0))]
 
@@ -376,6 +380,7 @@ def test_exif_transpose() -> None:
                     else:
                         original_exif = im.info["exif"]
                     transposed_im = ImageOps.exif_transpose(im)
+                    assert transposed_im is not None
                     assert_image_similar(base_im, transposed_im, 17)
                     if orientation_im is base_im:
                         assert "exif" not in im.info
@@ -387,6 +392,7 @@ def test_exif_transpose() -> None:
 
                     # Repeat the operation to test that it does not keep transposing
                     transposed_im2 = ImageOps.exif_transpose(transposed_im)
+                    assert transposed_im2 is not None
                     assert_image_equal(transposed_im2, transposed_im)
 
             check(base_im)
@@ -402,6 +408,7 @@ def test_exif_transpose() -> None:
             assert im.getexif()[0x0112] == 3
 
             transposed_im = ImageOps.exif_transpose(im)
+            assert transposed_im is not None
             assert 0x0112 not in transposed_im.getexif()
 
             transposed_im._reload_exif()
@@ -414,12 +421,14 @@ def test_exif_transpose() -> None:
         assert im.getexif()[0x0112] == 3
 
         transposed_im = ImageOps.exif_transpose(im)
+        assert transposed_im is not None
         assert 0x0112 not in transposed_im.getexif()
 
     # Orientation set directly on Image.Exif
     im = hopper()
     im.getexif()[0x0112] = 3
     transposed_im = ImageOps.exif_transpose(im)
+    assert transposed_im is not None
     assert 0x0112 not in transposed_im.getexif()
 
 
@@ -499,7 +508,7 @@ def test_autocontrast_mask_real_input() -> None:
 
 
 def test_autocontrast_preserve_tone() -> None:
-    def autocontrast(mode: str, preserve_tone: bool) -> Image.Image:
+    def autocontrast(mode: str, preserve_tone: bool) -> list[int]:
         im = hopper(mode)
         return ImageOps.autocontrast(im, preserve_tone=preserve_tone).histogram()
 

Tests/test_imageops_usm.py

@@ -28,8 +28,8 @@ def test_filter_api(test_images: dict[str, Image.Image]) -> None:
     assert i.mode == "RGB"
     assert i.size == (128, 128)
 
-    test_filter = ImageFilter.UnsharpMask(2.0, 125, 8)
-    i = im.filter(test_filter)
+    test_filter2 = ImageFilter.UnsharpMask(2.0, 125, 8)
+    i = im.filter(test_filter2)
     assert i.mode == "RGB"
     assert i.size == (128, 128)
 

Tests/test_imagesequence.py

@@ -26,7 +26,7 @@ def test_sanity(tmp_path: Path) -> None:
     assert index == 1
 
     with pytest.raises(AttributeError):
-        ImageSequence.Iterator(0)
+        ImageSequence.Iterator(0)  # type: ignore[arg-type]
 
 
 def test_iterator() -> None:
@@ -72,6 +72,7 @@ def test_consecutive() -> None:
         for frame in ImageSequence.Iterator(im):
             if first_frame is None:
                 first_frame = frame.copy()
+        assert first_frame is not None
         for frame in ImageSequence.Iterator(im):
             assert_image_equal(frame, first_frame)
             break

Tests/test_imageshow.py

@@ -68,10 +68,11 @@ def test_show_without_viewers() -> None:
 def test_viewer() -> None:
     viewer = ImageShow.Viewer()
 
-    assert viewer.get_format(None) is None
+    im = Image.new("L", (1, 1))
+    assert viewer.get_format(im) is None
 
     with pytest.raises(NotImplementedError):
-        viewer.get_command(None)
+        viewer.get_command("")
 
 
 @pytest.mark.parametrize("viewer", ImageShow._viewers)

Tests/test_mode_i16.py

@@ -78,7 +78,7 @@ def test_basic(tmp_path: Path, mode: str) -> None:
 
 
 def test_tobytes() -> None:
-    def tobytes(mode: str) -> Image.Image:
+    def tobytes(mode: str) -> bytes:
         return Image.new(mode, (1, 1), 1).tobytes()
 
     order = 1 if Image._ENDIAN == "<" else -1

Tests/test_tiff_crashes.py

@@ -47,9 +47,8 @@ def test_tiff_crashes(test_file: str) -> None:
         with Image.open(test_file) as im:
             im.load()
     except FileNotFoundError:
-        if not on_ci():
-            pytest.skip("test image not found")
-            return
+        if on_ci():
             raise
+        pytest.skip("test image not found")
     except OSError:
         pass

src/PIL/EpsImagePlugin.py

@@ -38,7 +38,7 @@ from ._deprecate import deprecate
 split = re.compile(r"^%%([^:]*):[ \t]*(.*)[ \t]*$")
 field = re.compile(r"^%[%!\w]([^:]*)[ \t]*$")
 
-gs_binary = None
+gs_binary: str | bool | None = None
 gs_windows_binary = None
 
 

src/PIL/Image.py

@@ -75,7 +75,7 @@ class DecompressionBombError(Exception):
 
 
 # Limit to around a quarter gigabyte for a 24-bit (3 bpp) image
-MAX_IMAGE_PIXELS = int(1024 * 1024 * 1024 // 4 // 3)
+MAX_IMAGE_PIXELS: int | None = int(1024 * 1024 * 1024 // 4 // 3)
 
 
 try:

src/PIL/ImageFile.py

@@ -384,7 +384,7 @@ class Parser:
     """
 
     incremental = None
-    image = None
+    image: Image.Image | None = None
     data = None
     decoder = None
     offset = 0