update tests to include desired mimebundle behaviour

Tests/test_file_jpeg.py

@@ -930,10 +930,8 @@ class TestFileJpeg:
             assert_image_similar(im, repr_jpeg, 17)
 
     def test_repr_jpeg_error(self):
-        im = hopper("F")
-
-        with pytest.raises(ValueError):
-            im._repr_jpeg_()
+        im = hopper("BGR;24")
+        assert im._repr_jpeg_() is None
 
 
 @pytest.mark.skipif(not is_win32(), reason="Windows only")

Tests/test_file_png.py

@@ -533,10 +533,8 @@ class TestFilePng:
             assert_image_equal(im, repr_png)
 
     def test_repr_png_error(self):
-        im = hopper("F")
-
-        with pytest.raises(ValueError):
-            im._repr_png_()
+        im = hopper("BGR;24")
+        assert im._repr_png_() is None
 
     def test_chunk_order(self, tmp_path):
         with Image.open("Tests/images/icc_profile.png") as im:

Tests/test_image.py

@@ -105,6 +105,69 @@ class TestImage:
         im._repr_pretty_(p, None)
         assert p.pretty_output == "<PIL.Image.Image image mode=L size=100x100>"
 
+    def test_repr_mimebundle(self):
+        im = Image.new('L', (100, 100))
+
+        # blank image should be most efficiently encoded as PNG
+        bundle = im._repr_mimebundle_()
+        with Image.open(io.BytesIO(bundle['image/png'])) as im2:
+            assert im2.format == 'PNG'
+            assert_image_equal(im, im2)
+
+        # include pointless restriction
+        bundle = im._repr_mimebundle_(exclude=['test/plain'])
+        with Image.open(io.BytesIO(bundle['image/png'])) as im2:
+            assert im2.format == 'PNG'
+            assert_image_equal(im, im2)
+
+        bundle = im._repr_mimebundle_(include=['image/png'])
+        with Image.open(io.BytesIO(bundle['image/png'])) as im2:
+            assert im2.format == 'PNG'
+            assert_image_equal(im, im2)
+
+        # force jpeg to be selected
+        bundle = im._repr_mimebundle_(include=['image/jpeg'])
+        with Image.open(io.BytesIO(bundle['image/jpeg'])) as im2:
+            assert im2.format == 'JPEG'
+            assert_image_equal(im, im2, 17)
+
+        # force jpeg to be selected in a different way
+        bundle = im._repr_mimebundle_(exclude=['image/png'])
+        with Image.open(io.BytesIO(bundle['image/jpeg'])) as im2:
+            assert im2.format == 'JPEG'
+            assert_image_equal(im, im2, 17)
+
+        # make sure higher bit depths get converted down to 8BPC with warnings
+        high = Image.new('I;16', (100, 100))
+        with pytest.warns(UserWarning):
+            bundle = high._repr_mimebundle_()
+        with Image.open(io.BytesIO(bundle['image/png'])) as im2:
+            assert im2.format == 'PNG'
+            assert_image_equal(im, im2)
+
+        high = Image.new('F', (100, 100))
+        with pytest.warns(UserWarning):
+            bundle = high._repr_mimebundle_()
+        with Image.open(io.BytesIO(bundle['image/png'])) as im2:
+            assert im2.format == 'PNG'
+            assert_image_equal(im, im2)
+
+        high = Image.new('I', (100, 100))
+        with pytest.warns(UserWarning):
+            bundle = high._repr_mimebundle_()
+        with Image.open(io.BytesIO(bundle['image/png'])) as im2:
+            assert im2.format == 'PNG'
+            assert_image_equal(im, im2)
+
+        # make sure large image gets scaled down with a warning
+        im = Image.new('L', [3000, 3000])
+        with pytest.warns(UserWarning):
+            bundle = im._repr_mimebundle_()
+
+        with Image.open(io.BytesIO(bundle['image/png'])) as im2:
+            assert im2.size == (1500, 1500)
+            assert_image_equal(im.resize(im2.size), im2)
+
     def test_open_formats(self):
         PNGFILE = "Tests/images/hopper.png"
         JPGFILE = "Tests/images/hopper.jpg"