Parametrized tests

Tests/test_features.py

@@ -70,13 +70,13 @@ def test_libimagequant_version():
     assert re.search(r"\d+\.\d+\.\d+$", features.version("libimagequant"))
 
 
-def test_check_modules():
+@pytest.mark.parametrize("feature", features.modules)
-    for feature in features.modules:
+def test_check_modules(feature):
     assert features.check_module(feature) in [True, False]
 
 
-def test_check_codecs():
+@pytest.mark.parametrize("feature", features.codecs)
-    for feature in features.codecs:
+def test_check_codecs(feature):
     assert features.check_codec(feature) in [True, False]
 
 

Tests/test_file_apng.py

@@ -39,13 +39,12 @@ def test_apng_basic():
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
 
-def test_apng_fdat():
+@pytest.mark.parametrize(
-    with Image.open("Tests/images/apng/split_fdat.png") as im:
+    "filename",
-        im.seek(im.n_frames - 1)
+    ("Tests/images/apng/split_fdat.png", "Tests/images/apng/split_fdat_zero_chunk.png"),
-        assert im.getpixel((0, 0)) == (0, 255, 0, 255)
+)
-        assert im.getpixel((64, 32)) == (0, 255, 0, 255)
+def test_apng_fdat(filename):
-
+    with Image.open(filename) as im:
-    with Image.open("Tests/images/apng/split_fdat_zero_chunk.png") as im:
         im.seek(im.n_frames - 1)
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)

Tests/test_file_eps.py

@@ -195,22 +195,20 @@ def test_render_scale2():
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
-def test_resize():
+@pytest.mark.parametrize("filename", (FILE1, FILE2, "Tests/images/illu10_preview.eps"))
-    files = [FILE1, FILE2, "Tests/images/illu10_preview.eps"]
+def test_resize(filename):
-    for fn in files:
+    with Image.open(filename) as im:
-        with Image.open(fn) as im:
         new_size = (100, 100)
         im = im.resize(new_size)
         assert im.size == new_size
 
 
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
-def test_thumbnail():
+@pytest.mark.parametrize("filename", (FILE1, FILE2))
+def test_thumbnail(filename):
     # Issue #619
     # Arrange
-    files = [FILE1, FILE2]
+    with Image.open(filename) as im:
-    for fn in files:
-        with Image.open(FILE1) as im:
         new_size = (100, 100)
         im.thumbnail(new_size)
         assert max(im.size) == max(new_size)
@@ -258,18 +256,17 @@ def test_readline(tmp_path):
         _test_readline_file_psfile(s, ending)
 
 
-def test_open_eps():
+@pytest.mark.parametrize(
-    # https://github.com/python-pillow/Pillow/issues/1104
+    "filename",
-    # Arrange
+    (
-    FILES = [
         "Tests/images/illu10_no_preview.eps",
         "Tests/images/illu10_preview.eps",
         "Tests/images/illuCS6_no_preview.eps",
         "Tests/images/illuCS6_preview.eps",
-    ]
+    ),
-
+)
-    # Act / Assert
+def test_open_eps(filename):
-    for filename in FILES:
+    # https://github.com/python-pillow/Pillow/issues/1104
     with Image.open(filename) as img:
         assert img.mode == "RGB"
 

Tests/test_file_gif.py

@@ -793,8 +793,10 @@ def test_identical_frames(tmp_path):
         assert reread.info["duration"] == 4500
 
 
-def test_identical_frames_to_single_frame(tmp_path):
+@pytest.mark.parametrize(
-    for duration in ([1000, 1500, 2000, 4000], (1000, 1500, 2000, 4000), 8500):
+    "duration", ([1000, 1500, 2000, 4000], (1000, 1500, 2000, 4000), 8500)
+)
+def test_identical_frames_to_single_frame(duration, tmp_path):
     out = str(tmp_path / "temp.gif")
     im_list = [
         Image.new("L", (100, 100), "#000"),
@@ -802,9 +804,7 @@ def test_identical_frames_to_single_frame(tmp_path):
         Image.new("L", (100, 100), "#000"),
     ]
 
-        im_list[0].save(
+    im_list[0].save(out, save_all=True, append_images=im_list[1:], duration=duration)
-            out, save_all=True, append_images=im_list[1:], duration=duration
-        )
     with Image.open(out) as reread:
         # Assert that all frames were combined
         assert reread.n_frames == 1

Tests/test_file_jpeg.py

@@ -150,9 +150,23 @@ class TestFileJpeg:
             assert not im1.info.get("icc_profile")
             assert im2.info.get("icc_profile")
 
-    def test_icc_big(self):
+    @pytest.mark.parametrize(
+        "n",
+        (
+            0,
+            1,
+            3,
+            4,
+            5,
+            65533 - 14,  # full JPEG marker block
+            65533 - 14 + 1,  # full block plus one byte
+            ImageFile.MAXBLOCK,  # full buffer block
+            ImageFile.MAXBLOCK + 1,  # full buffer block plus one byte
+            ImageFile.MAXBLOCK * 4 + 3,  # large block
+        ),
+    )
+    def test_icc_big(self, n):
         # Make sure that the "extra" support handles large blocks
-        def test(n):
         # The ICC APP marker can store 65519 bytes per marker, so
         # using a 4-byte test code should allow us to detect out of
         # order issues.
@@ -161,17 +175,6 @@ class TestFileJpeg:
         im1 = self.roundtrip(hopper(), icc_profile=icc_profile)
         assert im1.info.get("icc_profile") == (icc_profile or None)
 
-        test(0)
-        test(1)
-        test(3)
-        test(4)
-        test(5)
-        test(65533 - 14)  # full JPEG marker block
-        test(65533 - 14 + 1)  # full block plus one byte
-        test(ImageFile.MAXBLOCK)  # full buffer block
-        test(ImageFile.MAXBLOCK + 1)  # full buffer block plus one byte
-        test(ImageFile.MAXBLOCK * 4 + 3)  # large block
-
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
     )
@@ -649,16 +652,16 @@ class TestFileJpeg:
             # Assert
             assert im.format == "JPEG"
 
-    def test_save_correct_modes(self):
+    @pytest.mark.parametrize("mode", ("1", "L", "RGB", "RGBX", "CMYK", "YCbCr"))
+    def test_save_correct_modes(self, mode):
         out = BytesIO()
-        for mode in ["1", "L", "RGB", "RGBX", "CMYK", "YCbCr"]:
         img = Image.new(mode, (20, 20))
         img.save(out, "JPEG")
 
-    def test_save_wrong_modes(self):
+    @pytest.mark.parametrize("mode", ("LA", "La", "RGBA", "RGBa", "P"))
+    def test_save_wrong_modes(self, mode):
         # ref https://github.com/python-pillow/Pillow/issues/2005
         out = BytesIO()
-        for mode in ["LA", "La", "RGBA", "RGBa", "P"]:
         img = Image.new(mode, (20, 20))
         with pytest.raises(OSError):
             img.save(out, "JPEG")

Tests/test_file_jpeg2k.py

@@ -126,8 +126,8 @@ def test_prog_res_rt():
     assert_image_equal(im, test_card)
 
 
-def test_default_num_resolutions():
+@pytest.mark.parametrize("num_resolutions", range(2, 6))
-    for num_resolutions in range(2, 6):
+def test_default_num_resolutions(num_resolutions):
     d = 1 << (num_resolutions - 1)
     im = test_card.resize((d - 1, d - 1))
     with pytest.raises(OSError):
@@ -266,14 +266,11 @@ def test_rgba():
             assert jp2.mode == "RGBA"
 
 
-def test_16bit_monochrome_has_correct_mode():
+@pytest.mark.parametrize("ext", (".j2k", ".jp2"))
-    with Image.open("Tests/images/16bit.cropped.j2k") as j2k:
+def test_16bit_monochrome_has_correct_mode(ext):
-        j2k.load()
+    with Image.open("Tests/images/16bit.cropped" + ext) as im:
-        assert j2k.mode == "I;16"
+        im.load()
-
+        assert im.mode == "I;16"
-    with Image.open("Tests/images/16bit.cropped.jp2") as jp2:
-        jp2.load()
-        assert jp2.mode == "I;16"
 
 
 def test_16bit_monochrome_jp2_like_tiff():

Tests/test_file_libtiff.py

@@ -509,7 +509,8 @@ class TestFileLibTiff(LibTiffTestCase):
             # colormap/palette tag
             assert len(reloaded.tag_v2[320]) == 768
 
-    def xtest_bw_compression_w_rgb(self, tmp_path):
+    @pytest.mark.parametrize("compression", ("tiff_ccitt", "group3", "group4"))
+    def xtest_bw_compression_w_rgb(self, compression, tmp_path):
         """This test passes, but when running all tests causes a failure due
         to output on stderr from the error thrown by libtiff. We need to
         capture that but not now"""
@@ -518,11 +519,7 @@ class TestFileLibTiff(LibTiffTestCase):
         out = str(tmp_path / "temp.tif")
 
         with pytest.raises(OSError):
-            im.save(out, compression="tiff_ccitt")
+            im.save(out, compression=compression)
-        with pytest.raises(OSError):
-            im.save(out, compression="group3")
-        with pytest.raises(OSError):
-            im.save(out, compression="group4")
 
     def test_fp_leak(self):
         im = Image.open("Tests/images/hopper_g4_500.tif")

Tests/test_file_palm.py

@@ -63,19 +63,7 @@ def test_p_mode(tmp_path):
     roundtrip(tmp_path, mode)
 
 
-def test_l_oserror(tmp_path):
+@pytest.mark.parametrize("mode", ("L", "RGB"))
-    # Arrange
+def test_oserror(tmp_path, mode):
-    mode = "L"
-
-    # Act / Assert
-    with pytest.raises(OSError):
-        helper_save_as_palm(tmp_path, mode)
-
-
-def test_rgb_oserror(tmp_path):
-    # Arrange
-    mode = "RGB"
-
-    # Act / Assert
     with pytest.raises(OSError):
         helper_save_as_palm(tmp_path, mode)

Tests/test_file_pcx.py

@@ -39,11 +39,11 @@ def test_invalid_file():
         PcxImagePlugin.PcxImageFile(invalid_file)
 
 
-def test_odd(tmp_path):
+@pytest.mark.parametrize("mode", ("1", "L", "P", "RGB"))
+def test_odd(tmp_path, mode):
     # 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.
-    for mode in ("1", "L", "P", "RGB"):
     # larger, odd sized images are better here to ensure that
     # we handle interrupted scan lines properly.
     _roundtrip(tmp_path, hopper(mode).resize((511, 511)))

Tests/test_file_pdf.py

@@ -37,6 +37,11 @@ def helper_save_as_pdf(tmp_path, mode, **kwargs):
     return outfile
 
 
+@pytest.mark.parametrize("mode", ("L", "P", "RGB", "CMYK"))
+def test_save(tmp_path, mode):
+    helper_save_as_pdf(tmp_path, mode)
+
+
 @pytest.mark.valgrind_known_error(reason="Temporary skip")
 def test_monochrome(tmp_path):
     # Arrange
@@ -47,38 +52,6 @@ def test_monochrome(tmp_path):
     assert os.path.getsize(outfile) < (5000 if features.check("libtiff") else 15000)
 
 
-def test_greyscale(tmp_path):
-    # Arrange
-    mode = "L"
-
-    # Act / Assert
-    helper_save_as_pdf(tmp_path, mode)
-
-
-def test_rgb(tmp_path):
-    # Arrange
-    mode = "RGB"
-
-    # Act / Assert
-    helper_save_as_pdf(tmp_path, mode)
-
-
-def test_p_mode(tmp_path):
-    # Arrange
-    mode = "P"
-
-    # Act / Assert
-    helper_save_as_pdf(tmp_path, mode)
-
-
-def test_cmyk_mode(tmp_path):
-    # Arrange
-    mode = "CMYK"
-
-    # Act / Assert
-    helper_save_as_pdf(tmp_path, mode)
-
-
 def test_unsupported_mode(tmp_path):
     im = hopper("LA")
     outfile = str(tmp_path / "temp_LA.pdf")

Tests/test_file_tiff.py

@@ -311,11 +311,14 @@ class TestFileTiff:
             with Image.open("Tests/images/hopper_unknown_pixel_mode.tif"):
                 pass
 
-    def test_n_frames(self):
+    @pytest.mark.parametrize(
-        for path, n_frames in [
+        "path, n_frames",
-            ["Tests/images/multipage-lastframe.tif", 1],
+        (
-            ["Tests/images/multipage.tiff", 3],
+            ("Tests/images/multipage-lastframe.tif", 1),
-        ]:
+            ("Tests/images/multipage.tiff", 3),
+        ),
+    )
+    def test_n_frames(self, path, n_frames):
         with Image.open(path) as im:
             assert im.n_frames == n_frames
             assert im.is_animated == (n_frames != 1)
@@ -434,8 +437,8 @@ class TestFileTiff:
             len_after = len(dict(im.ifd))
             assert len_before == len_after + 1
 
-    def test_load_byte(self):
+    @pytest.mark.parametrize("legacy_api", (False, True))
-        for legacy_api in [False, True]:
+    def test_load_byte(self, legacy_api):
         ifd = TiffImagePlugin.ImageFileDirectory_v2()
         data = b"abc"
         ret = ifd.load_byte(data, legacy_api)
@@ -685,8 +688,8 @@ class TestFileTiff:
             with Image.open(outfile) as reloaded:
                 assert_image_equal_tofile(reloaded, infile)
 
-    def test_palette(self, tmp_path):
+    @pytest.mark.parametrize("mode", ("P", "PA"))
-        def roundtrip(mode):
+    def test_palette(self, mode, tmp_path):
         outfile = str(tmp_path / "temp.tif")
 
         im = hopper(mode)
@@ -695,9 +698,6 @@ class TestFileTiff:
         with Image.open(outfile) as reloaded:
             assert_image_equal(im.convert("RGB"), reloaded.convert("RGB"))
 
-        for mode in ["P", "PA"]:
-            roundtrip(mode)
-
     def test_tiff_save_all(self):
         mp = BytesIO()
         with Image.open("Tests/images/multipage.tiff") as im:

Tests/test_font_pcf_charsets.py

@@ -1,5 +1,7 @@
 import os
 
+import pytest
+
 from PIL import FontFile, Image, ImageDraw, ImageFont, PcfFontFile
 
 from .helper import (
@@ -59,23 +61,13 @@ def save_font(request, tmp_path, encoding):
     return tempname
 
 
-def _test_sanity(request, tmp_path, encoding):
+@pytest.mark.parametrize("encoding", ("iso8859-1", "iso8859-2", "cp1250"))
+def test_sanity(request, tmp_path, encoding):
     save_font(request, tmp_path, encoding)
 
 
-def test_sanity_iso8859_1(request, tmp_path):
+@pytest.mark.parametrize("encoding", ("iso8859-1", "iso8859-2", "cp1250"))
-    _test_sanity(request, tmp_path, "iso8859-1")
+def test_draw(request, tmp_path, encoding):
-
-
-def test_sanity_iso8859_2(request, tmp_path):
-    _test_sanity(request, tmp_path, "iso8859-2")
-
-
-def test_sanity_cp1250(request, tmp_path):
-    _test_sanity(request, tmp_path, "cp1250")
-
-
-def _test_draw(request, tmp_path, encoding):
     tempname = save_font(request, tmp_path, encoding)
     font = ImageFont.load(tempname)
     im = Image.new("L", (150, 30), "white")
@@ -85,19 +77,8 @@ def _test_draw(request, tmp_path, encoding):
     assert_image_similar_tofile(im, charsets[encoding]["image1"], 0)
 
 
-def test_draw_iso8859_1(request, tmp_path):
+@pytest.mark.parametrize("encoding", ("iso8859-1", "iso8859-2", "cp1250"))
-    _test_draw(request, tmp_path, "iso8859-1")
+def test_textsize(request, tmp_path, encoding):
-
-
-def test_draw_iso8859_2(request, tmp_path):
-    _test_draw(request, tmp_path, "iso8859-2")
-
-
-def test_draw_cp1250(request, tmp_path):
-    _test_draw(request, tmp_path, "cp1250")
-
-
-def _test_textsize(request, tmp_path, encoding):
     tempname = save_font(request, tmp_path, encoding)
     font = ImageFont.load(tempname)
     for i in range(255):
@@ -112,15 +93,3 @@ def _test_textsize(request, tmp_path, encoding):
         msg = message[: i + 1]
         assert font.getlength(msg) == len(msg) * 10
         assert font.getbbox(msg) == (0, 0, len(msg) * 10, 20)
-
-
-def test_textsize_iso8859_1(request, tmp_path):
-    _test_textsize(request, tmp_path, "iso8859-1")
-
-
-def test_textsize_iso8859_2(request, tmp_path):
-    _test_textsize(request, tmp_path, "iso8859-2")
-
-
-def test_textsize_cp1250(request, tmp_path):
-    _test_textsize(request, tmp_path, "cp1250")

Tests/test_image_reduce.py

@@ -196,9 +196,9 @@ def assert_compare_images(a, b, max_average_diff, max_diff=255):
         )
 
 
-def test_mode_L():
+@pytest.mark.parametrize("factor", remarkable_factors)
+def test_mode_L(factor):
     im = get_image("L")
-    for factor in remarkable_factors:
     compare_reduce_with_reference(im, factor)
     compare_reduce_with_box(im, factor)
 

Tests/test_image_resample.py

@@ -554,11 +554,13 @@ class TestCoreResampleBox:
                 # check that the difference at least that much
                 assert_image_similar(res, im.crop(box), 20, f">>> {size} {box}")
 
-    def test_skip_horizontal(self):
+    @pytest.mark.parametrize(
+        "flt", (Image.Resampling.NEAREST, Image.Resampling.BICUBIC)
+    )
+    def test_skip_horizontal(self, flt):
         # Can skip resize for one dimension
         im = hopper()
 
-        for flt in [Image.Resampling.NEAREST, Image.Resampling.BICUBIC]:
         for size, box in [
             ((40, 50), (0, 0, 40, 90)),
             ((40, 50), (0, 20, 40, 90)),
@@ -575,11 +577,13 @@ class TestCoreResampleBox:
                 f">>> {size} {box} {flt}",
             )
 
-    def test_skip_vertical(self):
+    @pytest.mark.parametrize(
+        "flt", (Image.Resampling.NEAREST, Image.Resampling.BICUBIC)
+    )
+    def test_skip_vertical(self, flt):
         # Can skip resize for one dimension
         im = hopper()
 
-        for flt in [Image.Resampling.NEAREST, Image.Resampling.BICUBIC]:
         for size, box in [
             ((40, 50), (0, 0, 90, 50)),
             ((40, 50), (20, 0, 90, 50)),

Tests/test_image_split.py

@@ -1,3 +1,5 @@
+import pytest
+
 from PIL import Image, features
 
 from .helper import assert_image_equal, hopper
@@ -29,19 +31,12 @@ def test_split():
     assert split("YCbCr") == [("L", 128, 128), ("L", 128, 128), ("L", 128, 128)]
 
 
-def test_split_merge():
+@pytest.mark.parametrize(
-    def split_merge(mode):
+    "mode", ("1", "L", "I", "F", "P", "RGB", "RGBA", "CMYK", "YCbCr")
-        return Image.merge(mode, hopper(mode).split())
+)
-
+def test_split_merge(mode):
-    assert_image_equal(hopper("1"), split_merge("1"))
+    expected = Image.merge(mode, hopper(mode).split())
-    assert_image_equal(hopper("L"), split_merge("L"))
+    assert_image_equal(hopper(mode), expected)
-    assert_image_equal(hopper("I"), split_merge("I"))
-    assert_image_equal(hopper("F"), split_merge("F"))
-    assert_image_equal(hopper("P"), split_merge("P"))
-    assert_image_equal(hopper("RGB"), split_merge("RGB"))
-    assert_image_equal(hopper("RGBA"), split_merge("RGBA"))
-    assert_image_equal(hopper("CMYK"), split_merge("CMYK"))
-    assert_image_equal(hopper("YCbCr"), split_merge("YCbCr"))
 
 
 def test_split_open(tmp_path):

Tests/test_imagedraw.py

@@ -64,7 +64,9 @@ def test_mode_mismatch():
         ImageDraw.ImageDraw(im, mode="L")
 
 
-def helper_arc(bbox, start, end):
+@pytest.mark.parametrize("bbox", (BBOX1, BBOX2))
+@pytest.mark.parametrize("start, end", ((0, 180), (0.5, 180.4)))
+def test_arc(bbox, start, end):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -76,16 +78,6 @@ def helper_arc(bbox, start, end):
     assert_image_similar_tofile(im, "Tests/images/imagedraw_arc.png", 1)
 
 
-def test_arc1():
-    helper_arc(BBOX1, 0, 180)
-    helper_arc(BBOX1, 0.5, 180.4)
-
-
-def test_arc2():
-    helper_arc(BBOX2, 0, 180)
-    helper_arc(BBOX2, 0.5, 180.4)
-
-
 def test_arc_end_le_start():
     # Arrange
     im = Image.new("RGB", (W, H))
@@ -192,29 +184,21 @@ def test_bitmap():
     assert_image_equal_tofile(im, "Tests/images/imagedraw_bitmap.png")
 
 
-def helper_chord(mode, bbox, start, end):
+@pytest.mark.parametrize("mode", ("RGB", "L"))
+@pytest.mark.parametrize("bbox", (BBOX1, BBOX2))
+def test_chord(mode, bbox):
     # Arrange
     im = Image.new(mode, (W, H))
     draw = ImageDraw.Draw(im)
     expected = f"Tests/images/imagedraw_chord_{mode}.png"
 
     # Act
-    draw.chord(bbox, start, end, fill="red", outline="yellow")
+    draw.chord(bbox, 0, 180, fill="red", outline="yellow")
 
     # Assert
     assert_image_similar_tofile(im, expected, 1)
 
 
-def test_chord1():
-    for mode in ["RGB", "L"]:
-        helper_chord(mode, BBOX1, 0, 180)
-
-
-def test_chord2():
-    for mode in ["RGB", "L"]:
-        helper_chord(mode, BBOX2, 0, 180)
-
-
 def test_chord_width():
     # Arrange
     im = Image.new("RGB", (W, H))
@@ -263,7 +247,9 @@ def test_chord_too_fat():
     assert_image_equal_tofile(im, "Tests/images/imagedraw_chord_too_fat.png")
 
 
-def helper_ellipse(mode, bbox):
+@pytest.mark.parametrize("mode", ("RGB", "L"))
+@pytest.mark.parametrize("bbox", (BBOX1, BBOX2))
+def test_ellipse(mode, bbox):
     # Arrange
     im = Image.new(mode, (W, H))
     draw = ImageDraw.Draw(im)
@@ -276,16 +262,6 @@ def helper_ellipse(mode, bbox):
     assert_image_similar_tofile(im, expected, 1)
 
 
-def test_ellipse1():
-    for mode in ["RGB", "L"]:
-        helper_ellipse(mode, BBOX1)
-
-
-def test_ellipse2():
-    for mode in ["RGB", "L"]:
-        helper_ellipse(mode, BBOX2)
-
-
 def test_ellipse_translucent():
     # Arrange
     im = Image.new("RGB", (W, H))
@@ -405,7 +381,8 @@ def test_ellipse_various_sizes_filled():
     )
 
 
-def helper_line(points):
+@pytest.mark.parametrize("points", (POINTS1, POINTS2))
+def test_line(points):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -417,14 +394,6 @@ def helper_line(points):
     assert_image_equal_tofile(im, "Tests/images/imagedraw_line.png")
 
 
-def test_line1():
-    helper_line(POINTS1)
-
-
-def test_line2():
-    helper_line(POINTS2)
-
-
 def test_shape1():
     # Arrange
     im = Image.new("RGB", (100, 100), "white")
@@ -484,7 +453,9 @@ def test_transform():
     assert_image_equal(im, expected)
 
 
-def helper_pieslice(bbox, start, end):
+@pytest.mark.parametrize("bbox", (BBOX1, BBOX2))
+@pytest.mark.parametrize("start, end", ((-92, 46), (-92.2, 46.2)))
+def test_pieslice(bbox, start, end):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -496,16 +467,6 @@ def helper_pieslice(bbox, start, end):
     assert_image_similar_tofile(im, "Tests/images/imagedraw_pieslice.png", 1)
 
 
-def test_pieslice1():
-    helper_pieslice(BBOX1, -92, 46)
-    helper_pieslice(BBOX1, -92.2, 46.2)
-
-
-def test_pieslice2():
-    helper_pieslice(BBOX2, -92, 46)
-    helper_pieslice(BBOX2, -92.2, 46.2)
-
-
 def test_pieslice_width():
     # Arrange
     im = Image.new("RGB", (W, H))
@@ -585,7 +546,8 @@ def test_pieslice_no_spikes():
     assert_image_equal(im, im_pre_erase)
 
 
-def helper_point(points):
+@pytest.mark.parametrize("points", (POINTS1, POINTS2))
+def test_point(points):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -597,15 +559,8 @@ def helper_point(points):
     assert_image_equal_tofile(im, "Tests/images/imagedraw_point.png")
 
 
-def test_point1():
+@pytest.mark.parametrize("points", (POINTS1, POINTS2))
-    helper_point(POINTS1)
+def test_polygon(points):
-
-
-def test_point2():
-    helper_point(POINTS2)
-
-
-def helper_polygon(points):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -617,14 +572,6 @@ def helper_polygon(points):
     assert_image_equal_tofile(im, "Tests/images/imagedraw_polygon.png")
 
 
-def test_polygon1():
-    helper_polygon(POINTS1)
-
-
-def test_polygon2():
-    helper_polygon(POINTS2)
-
-
 @pytest.mark.parametrize("mode", ("RGB", "L"))
 def test_polygon_kite(mode):
     # Test drawing lines of different gradients (dx>dy, dy>dx) and
@@ -682,7 +629,8 @@ def test_polygon_translucent():
     assert_image_equal_tofile(im, expected)
 
 
-def helper_rectangle(bbox):
+@pytest.mark.parametrize("bbox", (BBOX1, BBOX2))
+def test_rectangle(bbox):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
@@ -694,14 +642,6 @@ def helper_rectangle(bbox):
     assert_image_equal_tofile(im, "Tests/images/imagedraw_rectangle.png")
 
 
-def test_rectangle1():
-    helper_rectangle(BBOX1)
-
-
-def test_rectangle2():
-    helper_rectangle(BBOX2)
-
-
 def test_big_rectangle():
     # Test drawing a rectangle bigger than the image
     # Arrange
@@ -1503,7 +1443,7 @@ def test_discontiguous_corners_polygon():
     assert_image_similar_tofile(img, expected, 1)
 
 
-def test_polygon():
+def test_polygon2():
     im = Image.new("RGB", (W, H))
     draw = ImageDraw.Draw(im)
     draw.polygon([(18, 30), (19, 31), (18, 30), (85, 30), (60, 72)], "red")

Tests/test_imagedraw2.py

@@ -52,27 +52,19 @@ def test_sanity():
     draw.line(list(range(10)), pen)
 
 
-def helper_ellipse(mode, bbox):
+@pytest.mark.parametrize("bbox", (BBOX1, BBOX2))
+def test_ellipse(bbox):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw2.Draw(im)
     pen = ImageDraw2.Pen("blue", width=2)
     brush = ImageDraw2.Brush("green")
-    expected = f"Tests/images/imagedraw_ellipse_{mode}.png"
 
     # Act
     draw.ellipse(bbox, pen, brush)
 
     # Assert
-    assert_image_similar_tofile(im, expected, 1)
+    assert_image_similar_tofile(im, "Tests/images/imagedraw_ellipse_RGB.png", 1)
-
-
-def test_ellipse1():
-    helper_ellipse("RGB", BBOX1)
-
-
-def test_ellipse2():
-    helper_ellipse("RGB", BBOX2)
 
 
 def test_ellipse_edge():
@@ -88,7 +80,8 @@ def test_ellipse_edge():
     assert_image_similar_tofile(im, "Tests/images/imagedraw_ellipse_edge.png", 1)
 
 
-def helper_line(points):
+@pytest.mark.parametrize("points", (POINTS1, POINTS2))
+def test_line(points):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw2.Draw(im)
@@ -101,14 +94,6 @@ def helper_line(points):
     assert_image_equal_tofile(im, "Tests/images/imagedraw_line.png")
 
 
-def test_line1_pen():
-    helper_line(POINTS1)
-
-
-def test_line2_pen():
-    helper_line(POINTS2)
-
-
 def test_line_pen_as_brush():
     # Arrange
     im = Image.new("RGB", (W, H))
@@ -124,7 +109,8 @@ def test_line_pen_as_brush():
     assert_image_equal_tofile(im, "Tests/images/imagedraw_line.png")
 
 
-def helper_polygon(points):
+@pytest.mark.parametrize("points", (POINTS1, POINTS2))
+def test_polygon(points):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw2.Draw(im)
@@ -138,15 +124,8 @@ def helper_polygon(points):
     assert_image_equal_tofile(im, "Tests/images/imagedraw_polygon.png")
 
 
-def test_polygon1():
+@pytest.mark.parametrize("bbox", (BBOX1, BBOX2))
-    helper_polygon(POINTS1)
+def test_rectangle(bbox):
-
-
-def test_polygon2():
-    helper_polygon(POINTS2)
-
-
-def helper_rectangle(bbox):
     # Arrange
     im = Image.new("RGB", (W, H))
     draw = ImageDraw2.Draw(im)
@@ -160,14 +139,6 @@ def helper_rectangle(bbox):
     assert_image_equal_tofile(im, "Tests/images/imagedraw_rectangle.png")
 
 
-def test_rectangle1():
-    helper_rectangle(BBOX1)
-
-
-def test_rectangle2():
-    helper_rectangle(BBOX2)
-
-
 def test_big_rectangle():
     # Test drawing a rectangle bigger than the image
     # Arrange

Tests/test_imageenhance.py

@@ -1,3 +1,5 @@
+import pytest
+
 from PIL import Image, ImageEnhance
 
 from .helper import assert_image_equal, hopper
@@ -39,13 +41,13 @@ def _check_alpha(im, original, op, amount):
     )
 
 
-def test_alpha():
+@pytest.mark.parametrize("op", ("Color", "Brightness", "Contrast", "Sharpness"))
+def test_alpha(op):
     # Issue https://github.com/python-pillow/Pillow/issues/899
     # Is alpha preserved through image enhancement?
 
     original = _half_transparent_image()
 
-    for op in ["Color", "Brightness", "Contrast", "Sharpness"]:
     for amount in [0, 0.5, 1.0]:
         _check_alpha(
             getattr(ImageEnhance, op)(original).enhance(amount),

Tests/test_imagefont.py

@@ -632,8 +632,8 @@ def test_imagefont_getters(font):
     assert len(log) == 11
 
 
-def test_getsize_stroke(font):
+@pytest.mark.parametrize("stroke_width", (0, 2))
-    for stroke_width in [0, 2]:
+def test_getsize_stroke(font, stroke_width):
     assert font.getbbox("A", stroke_width=stroke_width) == (
         0 - stroke_width,
         4 - stroke_width,

Tests/test_imagemorph.py

@@ -65,8 +65,10 @@ def create_lut():
 
 
 # create_lut()
-def test_lut():
+@pytest.mark.parametrize(
-    for op in ("corner", "dilation4", "dilation8", "erosion4", "erosion8", "edge"):
+    "op", ("corner", "dilation4", "dilation8", "erosion4", "erosion8", "edge")
+)
+def test_lut(op):
     lb = ImageMorph.LutBuilder(op_name=op)
     assert lb.get_lut() is None
 

Tests/test_imageshow.py

@@ -45,8 +45,8 @@ def test_viewer_show(order):
     not on_ci() or is_win32(),
     reason="Only run on CIs; hangs on Windows CIs",
 )
-def test_show():
+@pytest.mark.parametrize("mode", ("1", "I;16", "LA", "RGB", "RGBA"))
-    for mode in ("1", "I;16", "LA", "RGB", "RGBA"):
+def test_show(mode):
     im = hopper(mode)
     assert ImageShow.show(im)
 
@@ -70,8 +70,8 @@ def test_viewer():
         viewer.get_command(None)
 
 
-def test_viewers():
+@pytest.mark.parametrize("viewer", ImageShow._viewers)
-    for viewer in ImageShow._viewers:
+def test_viewers(viewer):
     try:
         viewer.get_command("test.jpg")
     except NotImplementedError:
@@ -95,9 +95,9 @@ def test_ipythonviewer():
     not on_ci() or is_win32(),
     reason="Only run on CIs; hangs on Windows CIs",
 )
-def test_file_deprecated(tmp_path):
+@pytest.mark.parametrize("viewer", ImageShow._viewers)
+def test_file_deprecated(tmp_path, viewer):
     f = str(tmp_path / "temp.jpg")
-    for viewer in ImageShow._viewers:
     hopper().save(f)
     with pytest.warns(DeprecationWarning):
         try:

Tests/test_imagetk.py

@@ -54,8 +54,8 @@ def test_kw():
     assert im is None
 
 
-def test_photoimage():
+@pytest.mark.parametrize("mode", TK_MODES)
-    for mode in TK_MODES:
+def test_photoimage(mode):
     # test as image:
     im = hopper(mode)
 
@@ -76,9 +76,9 @@ def test_photoimage_apply_transparency():
         assert_image_equal(reloaded, im.convert("RGBA"))
 
 
-def test_photoimage_blank():
+@pytest.mark.parametrize("mode", TK_MODES)
+def test_photoimage_blank(mode):
     # test a image using mode/size:
-    for mode in TK_MODES:
     im_tk = ImageTk.PhotoImage(mode, (100, 100))
 
     assert im_tk.width() == 100

Tests/test_mode_i16.py

@@ -1,3 +1,5 @@
+import pytest
+
 from PIL import Image
 
 from .helper import hopper
@@ -20,12 +22,11 @@ def verify(im1):
             ), f"got {repr(p1)} from mode {im1.mode} at {xy}, expected {repr(p2)}"
 
 
-def test_basic(tmp_path):
+@pytest.mark.parametrize("mode", ("L", "I;16", "I;16B", "I;16L", "I"))
+def test_basic(tmp_path, mode):
     # PIL 1.1 has limited support for 16-bit image data.  Check that
     # create/copy/transform and save works as expected.
 
-    def basic(mode):
-
     im_in = original.convert(mode)
     verify(im_in)
 
@@ -72,14 +73,6 @@ def test_basic(tmp_path):
     im_in.putpixel((0, 0), 512)
     assert im_in.getpixel((0, 0)) == min(512, maximum)
 
-    basic("L")
-
-    basic("I;16")
-    basic("I;16B")
-    basic("I;16L")
-
-    basic("I")
-
 
 def test_tobytes():
     def tobytes(mode):

Tests/test_numpy.py

@@ -137,19 +137,9 @@ def test_save_tiff_uint16():
     assert img_px[0, 0] == pixel_value
 
 
-def test_to_array():
+@pytest.mark.parametrize(
-    def _to_array(mode, dtype):
+    "mode, dtype",
-        img = hopper(mode)
+    (
-
-        # Resize to non-square
-        img = img.crop((3, 0, 124, 127))
-        assert img.size == (121, 127)
-
-        np_img = numpy.array(img)
-        _test_img_equals_nparray(img, np_img)
-        assert np_img.dtype == dtype
-
-    modes = [
         ("L", numpy.uint8),
         ("I", numpy.int32),
         ("F", numpy.float32),
@@ -163,10 +153,18 @@ def test_to_array():
         ("I;16B", ">u2"),
         ("I;16L", "<u2"),
         ("HSV", numpy.uint8),
-    ]
+    ),
+)
+def test_to_array(mode, dtype):
+    img = hopper(mode)
 
-    for mode in modes:
+    # Resize to non-square
-        _to_array(*mode)
+    img = img.crop((3, 0, 124, 127))
+    assert img.size == (121, 127)
+
+    np_img = numpy.array(img)
+    _test_img_equals_nparray(img, np_img)
+    assert np_img.dtype == dtype
 
 
 def test_point_lut():

Tests/test_pickle.py

@@ -60,9 +60,9 @@ def helper_pickle_string(pickle, protocol, test_file, mode):
         ("Tests/images/itxt_chunks.png", None),
     ],
 )
-def test_pickle_image(tmp_path, test_file, test_mode):
+@pytest.mark.parametrize("protocol", range(0, pickle.HIGHEST_PROTOCOL + 1))
+def test_pickle_image(tmp_path, test_file, test_mode, protocol):
     # Act / Assert
-    for protocol in range(0, pickle.HIGHEST_PROTOCOL + 1):
     helper_pickle_string(pickle, protocol, test_file, test_mode)
     helper_pickle_file(tmp_path, pickle, protocol, test_file, test_mode)