Parametrized test

Tests/test_file_tiff.py

@@ -84,22 +84,23 @@ def test_context_manager(self):
             with Image.open("Tests/images/multipage.tiff") as im:
                 im.load()
 
-    def test_get_child_images(self):
-        def check(ims, sizes):
-            assert len(ims) == len(sizes)
-
-            for i, im in enumerate(ims):
-                w = sizes[i]
-                expected = Image.new("RGB", (w, w), "#f00")
-                assert_image_similar(im, expected, 1)
-
-        with Image.open("Tests/images/child_ifd.tiff") as im:
+    @pytest.mark.parametrize(
+        "path, sizes",
+        (
+            ("Tests/images/hopper.tif", ()),
+            ("Tests/images/child_ifd.tiff", (16, 8)),
+            ("Tests/images/child_ifd_jpeg.tiff", (20,)),
+        ),
+    )
+    def test_get_child_images(self, path, sizes):
+        with Image.open(path) as im:
             ims = im.get_child_images()
-        check(ims, (16, 8))
 
-        with Image.open("Tests/images/child_ifd_jpeg.tiff") as im:
-            ims = im.get_child_images()
-        check(ims, (20,))
+        assert len(ims) == len(sizes)
+        for i, im in enumerate(ims):
+            w = sizes[i]
+            expected = Image.new("RGB", (w, w), "#f00")
+            assert_image_similar(im, expected, 1)
 
     def test_mac_tiff(self):
         # Read RGBa images from macOS [@PIL136]