Added type hints

Tests/check_fli_overflow.py

@@ -4,7 +4,7 @@ from PIL import Image
 TEST_FILE = "Tests/images/fli_overflow.fli"
 
 
-def test_fli_overflow():
+def test_fli_overflow() -> None:
     # this should not crash with a malloc error or access violation
     with Image.open(TEST_FILE) as im:
         im.load()

Tests/check_imaging_leaks.py

@@ -2,6 +2,8 @@
 from __future__ import annotations
 import pytest
 
+from typing import Any, Callable
+
 from PIL import Image
 
 from .helper import is_win32
@@ -12,31 +14,34 @@ max_iterations = 10000
 pytestmark = pytest.mark.skipif(is_win32(), reason="requires Unix or macOS")
 
 
-def _get_mem_usage():
+def _get_mem_usage() -> float:
     from resource import RUSAGE_SELF, getpagesize, getrusage
 
     mem = getrusage(RUSAGE_SELF).ru_maxrss
     return mem * getpagesize() / 1024 / 1024
 
 
-def _test_leak(min_iterations, max_iterations, fn, *args, **kwargs):
+def _test_leak(
+    min_iterations: int, max_iterations: int, fn: Callable[..., None], *args: Any
+) -> None:
     mem_limit = None
     for i in range(max_iterations):
-        fn(*args, **kwargs)
+        fn(*args)
         mem = _get_mem_usage()
         if i < min_iterations:
             mem_limit = mem + 1
             continue
         msg = f"memory usage limit exceeded after {i + 1} iterations"
+        assert mem_limit is not None
         assert mem <= mem_limit, msg
 
 
-def test_leak_putdata():
+def test_leak_putdata() -> None:
     im = Image.new("RGB", (25, 25))
     _test_leak(min_iterations, max_iterations, im.putdata, im.getdata())
 
 
-def test_leak_getlist():
+def test_leak_getlist() -> None:
     im = Image.new("P", (25, 25))
     _test_leak(
         min_iterations,

Tests/check_j2k_leaks.py

@@ -19,7 +19,7 @@ pytestmark = [
 ]
 
 
-def test_leak_load():
+def test_leak_load() -> None:
     from resource import RLIMIT_AS, RLIMIT_STACK, setrlimit
 
     setrlimit(RLIMIT_STACK, (stack_size, stack_size))
@@ -29,7 +29,7 @@ def test_leak_load():
             im.load()
 
 
-def test_leak_save():
+def test_leak_save() -> None:
     from resource import RLIMIT_AS, RLIMIT_STACK, setrlimit
 
     setrlimit(RLIMIT_STACK, (stack_size, stack_size))

Tests/check_j2k_overflow.py

@@ -1,10 +1,11 @@
 from __future__ import annotations
+from pathlib import PosixPath
 import pytest
 
 from PIL import Image
 
 
-def test_j2k_overflow(tmp_path):
+def test_j2k_overflow(tmp_path: PosixPath) -> None:
     im = Image.new("RGBA", (1024, 131584))
     target = str(tmp_path / "temp.jpc")
     with pytest.raises(OSError):

Tests/check_jpeg_leaks.py

@@ -110,14 +110,14 @@ standard_chrominance_qtable = (
         [standard_l_qtable, standard_chrominance_qtable],
     ),
 )
-def test_qtables_leak(qtables):
+def test_qtables_leak(qtables: tuple[tuple[int, ...]] | list[tuple[int, ...]]) -> None:
     im = hopper("RGB")
     for _ in range(iterations):
         test_output = BytesIO()
         im.save(test_output, "JPEG", qtables=qtables)
 
 
-def test_exif_leak():
+def test_exif_leak() -> None:
     """
     pre patch:
 
@@ -180,7 +180,7 @@ def test_exif_leak():
         im.save(test_output, "JPEG", exif=exif)
 
 
-def test_base_save():
+def test_base_save() -> None:
     """
     base case:
         MB

Tests/check_large_memory.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
+from pathlib import PosixPath
 import sys
+from types import ModuleType
 
 import pytest
 
@@ -15,6 +17,7 @@ from PIL import Image
 # 2.7 and 3.2.
 
 
+numpy: ModuleType | None
 try:
     import numpy
 except ImportError:
@@ -27,23 +30,24 @@ XDIM = 48000
 pytestmark = pytest.mark.skipif(sys.maxsize <= 2**32, reason="requires 64-bit system")
 
 
-def _write_png(tmp_path, xdim, ydim):
+def _write_png(tmp_path: PosixPath, xdim: int, ydim: int) -> None:
     f = str(tmp_path / "temp.png")
     im = Image.new("L", (xdim, ydim), 0)
     im.save(f)
 
 
-def test_large(tmp_path):
+def test_large(tmp_path: PosixPath) -> None:
     """succeeded prepatch"""
     _write_png(tmp_path, XDIM, YDIM)
 
 
-def test_2gpx(tmp_path):
+def test_2gpx(tmp_path: PosixPath) -> None:
     """failed prepatch"""
     _write_png(tmp_path, XDIM, XDIM)
 
 
 @pytest.mark.skipif(numpy is None, reason="Numpy is not installed")
-def test_size_greater_than_int():
+def test_size_greater_than_int() -> None:
+    assert numpy is not None
     arr = numpy.ndarray(shape=(16394, 16394))
     Image.fromarray(arr)

Tests/check_large_memory_numpy.py

@@ -1,4 +1,5 @@
 from __future__ import annotations
+from pathlib import PosixPath
 import sys
 
 import pytest
@@ -23,7 +24,7 @@ XDIM = 48000
 pytestmark = pytest.mark.skipif(sys.maxsize <= 2**32, reason="requires 64-bit system")
 
 
-def _write_png(tmp_path, xdim, ydim):
+def _write_png(tmp_path: PosixPath, xdim: int, ydim: int) -> None:
     dtype = np.uint8
     a = np.zeros((xdim, ydim), dtype=dtype)
     f = str(tmp_path / "temp.png")
@@ -31,11 +32,11 @@ def _write_png(tmp_path, xdim, ydim):
     im.save(f)
 
 
-def test_large(tmp_path):
+def test_large(tmp_path: PosixPath) -> None:
     """succeeded prepatch"""
     _write_png(tmp_path, XDIM, YDIM)
 
 
-def test_2gpx(tmp_path):
+def test_2gpx(tmp_path: PosixPath) -> None:
     """failed prepatch"""
     _write_png(tmp_path, XDIM, XDIM)

Tests/check_libtiff_segfault.py

@@ -6,7 +6,7 @@ from PIL import Image
 TEST_FILE = "Tests/images/libtiff_segfault.tif"
 
 
-def test_libtiff_segfault():
+def test_libtiff_segfault() -> None:
     """This test should not segfault. It will on Pillow <= 3.1.0 and
     libtiff >= 4.0.0
     """

Tests/check_png_dos.py

@@ -7,7 +7,7 @@ from PIL import Image, ImageFile, PngImagePlugin
 TEST_FILE = "Tests/images/png_decompression_dos.png"
 
 
-def test_ignore_dos_text():
+def test_ignore_dos_text() -> None:
     ImageFile.LOAD_TRUNCATED_IMAGES = True
 
     try:
@@ -23,7 +23,7 @@ def test_ignore_dos_text():
         assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
 
 
-def test_dos_text():
+def test_dos_text() -> None:
     try:
         im = Image.open(TEST_FILE)
         im.load()
@@ -35,7 +35,7 @@ def test_dos_text():
         assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
 
 
-def test_dos_total_memory():
+def test_dos_total_memory() -> None:
     im = Image.new("L", (1, 1))
     compressed_data = zlib.compress(b"a" * 1024 * 1023)
 
@@ -52,7 +52,7 @@ def test_dos_total_memory():
     try:
         im2 = Image.open(b)
     except ValueError as msg:
-        assert "Too much memory" in msg
+        assert "Too much memory" in str(msg)
         return
 
     total_len = 0

Tests/check_wheel.py

@@ -4,7 +4,7 @@ import sys
 from PIL import features
 
 
-def test_wheel_modules():
+def test_wheel_modules() -> None:
     expected_modules = {"pil", "tkinter", "freetype2", "littlecms2", "webp"}
 
     # tkinter is not available in cibuildwheel installed CPython on Windows
@@ -18,13 +18,13 @@ def test_wheel_modules():
     assert set(features.get_supported_modules()) == expected_modules
 
 
-def test_wheel_codecs():
+def test_wheel_codecs() -> None:
     expected_codecs = {"jpg", "jpg_2000", "zlib", "libtiff"}
 
     assert set(features.get_supported_codecs()) == expected_codecs
 
 
-def test_wheel_features():
+def test_wheel_features() -> None:
     expected_features = {
         "webp_anim",
         "webp_mux",

Tests/helper.py

@@ -238,7 +238,7 @@ def tostring(im, string_format, **options):
     return out.getvalue()
 
 
-def hopper(mode=None, cache={}):
+def hopper(mode: str | None = None, cache: dict[str, Image.Image] = {}) -> Image.Image:
     if mode is None:
         # Always return fresh not-yet-loaded version of image.
         # Operations on not-yet-loaded images is separate class of errors
@@ -323,7 +323,7 @@ def is_ppc64le():
     return platform.machine() == "ppc64le"
 
 
-def is_win32():
+def is_win32() -> bool:
     return sys.platform.startswith("win32")