Add match parameter to pytest.warns() (#9038)

Author: radarhere

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.11.12
+    rev: v0.12.0
     hooks:
       - id: ruff-check
         args: [--exit-non-zero-on-fix]
@@ -11,7 +11,7 @@ repos:
       - id: black
 
   - repo: https://github.com/PyCQA/bandit
-    rev: 1.8.3
+    rev: 1.8.5
     hooks:
     - id: bandit
       args: [--severity-level=high]
@@ -24,7 +24,7 @@ repos:
         exclude: (Makefile$|\.bat$|\.cmake$|\.eps$|\.fits$|\.gd$|\.opt$)
 
   - repo: https://github.com/pre-commit/mirrors-clang-format
-    rev: v20.1.5
+    rev: v20.1.6
     hooks:
       - id: clang-format
         types: [c]
@@ -51,7 +51,7 @@ repos:
         exclude: ^.github/.*TEMPLATE|^Tests/(fonts|images)/
 
   - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.33.0
+    rev: 0.33.1
     hooks:
       - id: check-github-workflows
       - id: check-readthedocs

Tests/helper.py

@@ -272,7 +272,7 @@ def _cached_hopper(mode: str) -> Image.Image:
     else:
         im = hopper()
     if mode.startswith("BGR;"):
-        with pytest.warns(DeprecationWarning):
+        with pytest.warns(DeprecationWarning, match="BGR;"):
             im = im.convert(mode)
     else:
         try:

Tests/test_core_resources.py

@@ -188,5 +188,5 @@ def test_units(self) -> None:
         ),
     )
     def test_warnings(self, var: dict[str, str]) -> None:
-        with pytest.warns(UserWarning):
+        with pytest.warns(UserWarning, match=list(var)[0]):
             Image._apply_env_variables(var)

Tests/test_features.py

@@ -19,7 +19,7 @@ def test_check() -> None:
         assert features.check_codec(codec) == features.check(codec)
     for feature in features.features:
         if "webp" in feature:
-            with pytest.warns(DeprecationWarning):
+            with pytest.warns(DeprecationWarning, match="webp"):
                 assert features.check_feature(feature) == features.check(feature)
         else:
             assert features.check_feature(feature) == features.check(feature)
@@ -49,24 +49,24 @@ def test(name: str, function: Callable[[str], str | None]) -> None:
         test(codec, features.version_codec)
     for feature in features.features:
         if "webp" in feature:
-            with pytest.warns(DeprecationWarning):
+            with pytest.warns(DeprecationWarning, match="webp"):
                 test(feature, features.version_feature)
         else:
             test(feature, features.version_feature)
 
 
 def test_webp_transparency() -> None:
-    with pytest.warns(DeprecationWarning):
+    with pytest.warns(DeprecationWarning, match="transp_webp"):
         assert (features.check("transp_webp") or False) == features.check_module("webp")
 
 
 def test_webp_mux() -> None:
-    with pytest.warns(DeprecationWarning):
+    with pytest.warns(DeprecationWarning, match="webp_mux"):
         assert (features.check("webp_mux") or False) == features.check_module("webp")
 
 
 def test_webp_anim() -> None:
-    with pytest.warns(DeprecationWarning):
+    with pytest.warns(DeprecationWarning, match="webp_anim"):
         assert (features.check("webp_anim") or False) == features.check_module("webp")
 
 
@@ -95,10 +95,9 @@ def test_check_codecs(feature: str) -> None:
 
 
 def test_check_warns_on_nonexistent() -> None:
-    with pytest.warns(UserWarning) as cm:
+    with pytest.warns(UserWarning, match="Unknown feature 'typo'."):
         has_feature = features.check("typo")
     assert has_feature is False
-    assert str(cm[-1].message) == "Unknown feature 'typo'."
 
 
 def test_supported_modules() -> None:

Tests/test_file_apng.py

@@ -303,11 +303,11 @@ def test_apng_chunk_errors() -> None:
         assert isinstance(im, PngImagePlugin.PngImageFile)
         assert not im.is_animated
 
-    with pytest.warns(UserWarning):
-        with Image.open("Tests/images/apng/chunk_multi_actl.png") as im:
-            im.load()
-        assert isinstance(im, PngImagePlugin.PngImageFile)
-        assert not im.is_animated
+    with pytest.warns(UserWarning, match="Invalid APNG"):
+        im = Image.open("Tests/images/apng/chunk_multi_actl.png")
+    assert isinstance(im, PngImagePlugin.PngImageFile)
+    assert not im.is_animated
+    im.close()
 
     with Image.open("Tests/images/apng/chunk_actl_after_idat.png") as im:
         assert isinstance(im, PngImagePlugin.PngImageFile)
@@ -330,18 +330,20 @@ def test_apng_chunk_errors() -> None:
 
 
 def test_apng_syntax_errors() -> None:
-    with pytest.warns(UserWarning):
-        with Image.open("Tests/images/apng/syntax_num_frames_zero.png") as im:
-            assert isinstance(im, PngImagePlugin.PngImageFile)
-            assert not im.is_animated
-            with pytest.raises(OSError):
-                im.load()
+    with pytest.warns(UserWarning, match="Invalid APNG"):
+        im = Image.open("Tests/images/apng/syntax_num_frames_zero.png")
+    assert isinstance(im, PngImagePlugin.PngImageFile)
+    assert not im.is_animated
+    with pytest.raises(OSError):
+        im.load()
+    im.close()
 
-    with pytest.warns(UserWarning):
-        with Image.open("Tests/images/apng/syntax_num_frames_zero_default.png") as im:
-            assert isinstance(im, PngImagePlugin.PngImageFile)
-            assert not im.is_animated
-            im.load()
+    with pytest.warns(UserWarning, match="Invalid APNG"):
+        im = Image.open("Tests/images/apng/syntax_num_frames_zero_default.png")
+    assert isinstance(im, PngImagePlugin.PngImageFile)
+    assert not im.is_animated
+    im.load()
+    im.close()
 
     # we can handle this case gracefully
     with Image.open("Tests/images/apng/syntax_num_frames_low.png") as im:
@@ -354,11 +356,12 @@ def test_apng_syntax_errors() -> None:
             im.seek(im.n_frames - 1)
             im.load()
 
-    with pytest.warns(UserWarning):
-        with Image.open("Tests/images/apng/syntax_num_frames_invalid.png") as im:
-            assert isinstance(im, PngImagePlugin.PngImageFile)
-            assert not im.is_animated
-            im.load()
+    with pytest.warns(UserWarning, match="Invalid APNG"):
+        im = Image.open("Tests/images/apng/syntax_num_frames_invalid.png")
+    assert isinstance(im, PngImagePlugin.PngImageFile)
+    assert not im.is_animated
+    im.load()
+    im.close()
 
 
 @pytest.mark.parametrize(

Tests/test_file_avif.py

@@ -77,8 +77,8 @@ class TestUnsupportedAvif:
     def test_unsupported(self, monkeypatch: pytest.MonkeyPatch) -> None:
         monkeypatch.setattr(AvifImagePlugin, "SUPPORTED", False)
 
-        with pytest.warns(UserWarning):
-            with pytest.raises(UnidentifiedImageError):
+        with pytest.raises(UnidentifiedImageError):
+            with pytest.warns(UserWarning, match="AVIF support not installed"):
                 with Image.open(TEST_AVIF_FILE):
                     pass
 

Tests/test_file_gif.py

@@ -1232,7 +1232,9 @@ def test_removed_transparency(tmp_path: Path) -> None:
         im.putpixel((x, 0), (x, 0, 0))
 
     im.info["transparency"] = (255, 255, 255)
-    with pytest.warns(UserWarning):
+    with pytest.warns(
+        UserWarning, match="Couldn't allocate palette entry for transparency"
+    ):
         im.save(out)
 
     with Image.open(out) as reloaded:
@@ -1254,7 +1256,7 @@ def test_rgb_transparency(tmp_path: Path) -> None:
     im = Image.new("RGB", (1, 1))
     im.info["transparency"] = b""
     ims = [Image.new("RGB", (1, 1))]
-    with pytest.warns(UserWarning):
+    with pytest.warns(UserWarning, match="should be converted to RGBA images"):
         im.save(out, save_all=True, append_images=ims)
 
     with Image.open(out) as reloaded:

Tests/test_file_icns.py

@@ -95,7 +95,9 @@ def test_sizes() -> None:
         for w, h, r in im.info["sizes"]:
             wr = w * r
             hr = h * r
-            with pytest.warns(DeprecationWarning):
+            with pytest.warns(
+                DeprecationWarning, match=r"Setting size to \(width, height, scale\)"
+            ):
                 im.size = (w, h, r)
             im.load()
             assert im.mode == "RGBA"

Tests/test_file_ico.py

@@ -234,7 +234,7 @@ def test_save_append_images(tmp_path: Path) -> None:
 def test_unexpected_size() -> None:
     # This image has been manually hexedited to state that it is 16x32
     # while the image within is still 16x16
-    with pytest.warns(UserWarning):
+    with pytest.warns(UserWarning, match="Image was not the expected size"):
         with Image.open("Tests/images/hopper_unexpected.ico") as im:
             assert im.size == (16, 16)
 

Tests/test_file_iptc.py

@@ -102,7 +102,7 @@ def test_i() -> None:
     c = b"a"
 
     # Act
-    with pytest.warns(DeprecationWarning):
+    with pytest.warns(DeprecationWarning, match="IptcImagePlugin.i"):
         ret = IptcImagePlugin.i(c)
 
     # Assert
@@ -117,13 +117,13 @@ def test_dump(monkeypatch: pytest.MonkeyPatch) -> None:
     monkeypatch.setattr(sys, "stdout", mystdout)
 
     # Act
-    with pytest.warns(DeprecationWarning):
+    with pytest.warns(DeprecationWarning, match="IptcImagePlugin.dump"):
         IptcImagePlugin.dump(c)
 
     # Assert
     assert mystdout.getvalue() == "61 62 63 \n"
 
 
 def test_pad_deprecation() -> None:
-    with pytest.warns(DeprecationWarning):
+    with pytest.warns(DeprecationWarning, match="IptcImagePlugin.PAD"):
         assert IptcImagePlugin.PAD == b"\0\0\0\0"