Assert image type (#8845)

Author: hugovk

Tests/test_file_avif.py

@@ -14,6 +14,7 @@
 
 from PIL import (
     AvifImagePlugin,
+    GifImagePlugin,
     Image,
     ImageDraw,
     ImageFile,
@@ -240,6 +241,7 @@ def test_save_single_frame(self, tmp_path: Path) -> None:
         with Image.open("Tests/images/chi.gif") as im:
             im.save(temp_file)
         with Image.open(temp_file) as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 1
 
     def test_invalid_file(self) -> None:
@@ -598,10 +600,12 @@ def test_n_frames(self) -> None:
         """
 
         with Image.open(TEST_AVIF_FILE) as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 1
             assert not im.is_animated
 
         with Image.open("Tests/images/avif/star.avifs") as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 5
             assert im.is_animated
 
@@ -612,11 +616,13 @@ def test_write_animation_P(self, tmp_path: Path) -> None:
         """
 
         with Image.open("Tests/images/avif/star.gif") as original:
+            assert isinstance(original, GifImagePlugin.GifImageFile)
             assert original.n_frames > 1
 
             temp_file = tmp_path / "temp.avif"
             original.save(temp_file, save_all=True)
             with Image.open(temp_file) as im:
+                assert isinstance(im, AvifImagePlugin.AvifImageFile)
                 assert im.n_frames == original.n_frames
 
                 # Compare first frame in P mode to frame from original GIF
@@ -636,6 +642,7 @@ def test_write_animation_RGBA(self, tmp_path: Path) -> None:
 
         def check(temp_file: Path) -> None:
             with Image.open(temp_file) as im:
+                assert isinstance(im, AvifImagePlugin.AvifImageFile)
                 assert im.n_frames == 4
 
                 # Compare first frame to original
@@ -708,6 +715,7 @@ def test_timestamp_and_duration(self, tmp_path: Path) -> None:
             )
 
         with Image.open(temp_file) as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 5
             assert im.is_animated
 
@@ -737,6 +745,7 @@ def test_seeking(self, tmp_path: Path) -> None:
             )
 
         with Image.open(temp_file) as im:
+            assert isinstance(im, AvifImagePlugin.AvifImageFile)
             assert im.n_frames == 5
             assert im.is_animated
 

Tests/test_file_fli.py

@@ -48,13 +48,15 @@ def test_sanity() -> None:
 def test_prefix_chunk(monkeypatch: pytest.MonkeyPatch) -> None:
     monkeypatch.setattr(ImageFile, "LOAD_TRUNCATED_IMAGES", True)
     with Image.open(animated_test_file_with_prefix_chunk) as im:
+        assert isinstance(im, FliImagePlugin.FliImageFile)
         assert im.mode == "P"
         assert im.size == (320, 200)
         assert im.format == "FLI"
         assert im.info["duration"] == 171
         assert im.is_animated
 
         palette = im.getpalette()
+        assert palette is not None
         assert palette[3:6] == [255, 255, 255]
         assert palette[381:384] == [204, 204, 12]
         assert palette[765:] == [252, 0, 0]

Tests/test_file_gif.py

@@ -293,6 +293,7 @@ def test_roundtrip_save_all(tmp_path: Path) -> None:
         im.save(out, save_all=True)
 
     with Image.open(out) as reread:
+        assert isinstance(reread, GifImagePlugin.GifImageFile)
         assert reread.n_frames == 5
 
 
@@ -1374,6 +1375,7 @@ def test_palette_save_all_P(tmp_path: Path) -> None:
 
     with Image.open(out) as im:
         # Assert that the frames are correct, and each frame has the same palette
+        assert isinstance(im, GifImagePlugin.GifImageFile)
         assert_image_equal(im.convert("RGB"), frames[0].convert("RGB"))
         assert im.palette is not None
         assert im.global_palette is not None

Tests/test_file_jpeg.py

@@ -330,8 +330,10 @@ def test_exif_gps(self, tmp_path: Path) -> None:
 
         # Reading
         with Image.open("Tests/images/exif_gps.jpg") as im:
-            exif = im._getexif()
-            assert exif[gps_index] == expected_exif_gps
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
+            exif_data = im._getexif()
+            assert exif_data is not None
+            assert exif_data[gps_index] == expected_exif_gps
 
         # Writing
         f = tmp_path / "temp.jpg"
@@ -340,8 +342,10 @@ def test_exif_gps(self, tmp_path: Path) -> None:
         hopper().save(f, exif=exif)
 
         with Image.open(f) as reloaded:
-            exif = reloaded._getexif()
-            assert exif[gps_index] == expected_exif_gps
+            assert isinstance(reloaded, JpegImagePlugin.JpegImageFile)
+            exif_data = reloaded._getexif()
+            assert exif_data is not None
+            assert exif_data[gps_index] == expected_exif_gps
 
     def test_empty_exif_gps(self) -> None:
         with Image.open("Tests/images/empty_gps_ifd.jpg") as im:
@@ -368,6 +372,7 @@ def test_exif_equality(self) -> None:
         exifs = []
         for i in range(2):
             with Image.open("Tests/images/exif-200dpcm.jpg") as im:
+                assert isinstance(im, JpegImagePlugin.JpegImageFile)
                 exifs.append(im._getexif())
         assert exifs[0] == exifs[1]
 
@@ -401,13 +406,17 @@ def test_exif_rollback(self) -> None:
         }
 
         with Image.open("Tests/images/exif_gps.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             exif = im._getexif()
+        assert exif is not None
 
         for tag, value in expected_exif.items():
             assert value == exif[tag]
 
     def test_exif_gps_typeerror(self) -> None:
         with Image.open("Tests/images/exif_gps_typeerror.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
+
             # Should not raise a TypeError
             im._getexif()
 
@@ -487,7 +496,9 @@ def getsampling(
 
     def test_exif(self) -> None:
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             info = im._getexif()
+            assert info is not None
             assert info[305] == "Adobe Photoshop CS Macintosh"
 
     def test_get_child_images(self) -> None:
@@ -690,11 +701,13 @@ def test_load_16bit_qtables(self) -> None:
 
     def test_save_multiple_16bit_qtables(self) -> None:
         with Image.open("Tests/images/hopper_16bit_qtables.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             im2 = self.roundtrip(im, qtables="keep")
             assert im.quantization == im2.quantization
 
     def test_save_single_16bit_qtable(self) -> None:
         with Image.open("Tests/images/hopper_16bit_qtables.jpg") as im:
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
             im2 = self.roundtrip(im, qtables={0: im.quantization[0]})
             assert len(im2.quantization) == 1
             assert im2.quantization[0] == im.quantization[0]
@@ -898,7 +911,10 @@ def test_ifd_offset_exif(self) -> None:
         # in contrast to normal 8
         with Image.open("Tests/images/exif-ifd-offset.jpg") as im:
             # Act / Assert
-            assert im._getexif()[306] == "2017:03:13 23:03:09"
+            assert isinstance(im, JpegImagePlugin.JpegImageFile)
+            exif = im._getexif()
+            assert exif is not None
+            assert exif[306] == "2017:03:13 23:03:09"
 
     def test_multiple_exif(self) -> None:
         with Image.open("Tests/images/multiple_exif.jpg") as im:

Tests/test_file_mpo.py

@@ -120,9 +120,11 @@ def test_ignore_frame_size() -> None:
     # Ignore the different size of the second frame
     # since this is not a "Large Thumbnail" image
     with Image.open("Tests/images/ignore_frame_size.mpo") as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         assert im.size == (64, 64)
 
         im.seek(1)
+        assert im.mpinfo is not None
         assert (
             im.mpinfo[0xB002][1]["Attribute"]["MPType"]
             == "Multi-Frame Image: (Disparity)"
@@ -155,6 +157,7 @@ def test_reload_exif_after_seek() -> None:
 @pytest.mark.parametrize("test_file", test_files)
 def test_mp(test_file: str) -> None:
     with Image.open(test_file) as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         mpinfo = im._getmp()
         assert mpinfo is not None
         assert mpinfo[45056] == b"0100"
@@ -165,6 +168,7 @@ def test_mp_offset() -> None:
     # This image has been manually hexedited to have an IFD offset of 10
     # in APP2 data, in contrast to normal 8
     with Image.open("Tests/images/sugarshack_ifd_offset.mpo") as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         mpinfo = im._getmp()
         assert mpinfo is not None
         assert mpinfo[45056] == b"0100"
@@ -182,6 +186,7 @@ def test_mp_no_data() -> None:
 @pytest.mark.parametrize("test_file", test_files)
 def test_mp_attribute(test_file: str) -> None:
     with Image.open(test_file) as im:
+        assert isinstance(im, MpoImagePlugin.MpoImageFile)
         mpinfo = im._getmp()
     assert mpinfo is not None
     for frame_number, mpentry in enumerate(mpinfo[0xB002]):

Tests/test_file_png.py

@@ -671,6 +671,9 @@ def test_specify_bits(self, save_all: bool, tmp_path: Path) -> None:
         im.save(out, bits=4, save_all=save_all)
 
         with Image.open(out) as reloaded:
+            assert isinstance(reloaded, PngImagePlugin.PngImageFile)
+            assert reloaded.png is not None
+            assert reloaded.png.im_palette is not None
             assert len(reloaded.png.im_palette[1]) == 48
 
     def test_plte_length(self, tmp_path: Path) -> None:
@@ -681,6 +684,9 @@ def test_plte_length(self, tmp_path: Path) -> None:
         im.save(out)
 
         with Image.open(out) as reloaded:
+            assert isinstance(reloaded, PngImagePlugin.PngImageFile)
+            assert reloaded.png is not None
+            assert reloaded.png.im_palette is not None
             assert len(reloaded.png.im_palette[1]) == 3
 
     def test_getxmp(self) -> None:
@@ -702,13 +708,17 @@ def test_getxmp(self) -> None:
     def test_exif(self) -> None:
         # With an EXIF chunk
         with Image.open("Tests/images/exif.png") as im:
-            exif = im._getexif()
-        assert exif[274] == 1
+            assert isinstance(im, PngImagePlugin.PngImageFile)
+            exif_data = im._getexif()
+        assert exif_data is not None
+        assert exif_data[274] == 1
 
         # With an ImageMagick zTXt chunk
         with Image.open("Tests/images/exif_imagemagick.png") as im:
-            exif = im._getexif()
-            assert exif[274] == 1
+            assert isinstance(im, PngImagePlugin.PngImageFile)
+            exif_data = im._getexif()
+            assert exif_data is not None
+            assert exif_data[274] == 1
 
             # Assert that info still can be extracted
             # when the image is no longer a PngImageFile instance
@@ -717,8 +727,10 @@ def test_exif(self) -> None:
 
         # With a tEXt chunk
         with Image.open("Tests/images/exif_text.png") as im:
-            exif = im._getexif()
-        assert exif[274] == 1
+            assert isinstance(im, PngImagePlugin.PngImageFile)
+            exif_data = im._getexif()
+        assert exif_data is not None
+        assert exif_data[274] == 1
 
         # With XMP tags
         with Image.open("Tests/images/xmp_tags_orientation.png") as im:
@@ -740,8 +752,10 @@ def test_exif_save(self, tmp_path: Path) -> None:
             im.save(test_file, exif=im.getexif())
 
         with Image.open(test_file) as reloaded:
-            exif = reloaded._getexif()
-        assert exif[274] == 1
+            assert isinstance(reloaded, PngImagePlugin.PngImageFile)
+            exif_data = reloaded._getexif()
+        assert exif_data is not None
+        assert exif_data[274] == 1
 
     @mark_if_feature_version(
         pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"

Tests/test_file_webp_metadata.py

@@ -22,11 +22,13 @@
 def test_read_exif_metadata() -> None:
     file_path = "Tests/images/flower.webp"
     with Image.open(file_path) as image:
+        assert isinstance(image, WebPImagePlugin.WebPImageFile)
         assert image.format == "WEBP"
         exif_data = image.info.get("exif", None)
         assert exif_data
 
         exif = image._getexif()
+        assert exif is not None
 
         # Camera make
         assert exif[271] == "Canon"