Rework changes to be testable.

pelican/plugins/image_process/image_process.py

@@ -665,6 +665,27 @@ def process_picture(soup, img, group, settings, derivative):
             img.insert_before(s["element"])
 
 
+def try_open_image(path):
+    try:
+        i = Image.open(path)
+    except UnidentifiedImageError:
+        logger.warning(
+            "%s Source image %s is not supported by Pillow.",
+            LOG_PREFIX,
+            path,
+        )
+        return None
+    except FileNotFoundError:
+        logger.warning(
+            "%s Source image %s not found.",
+            LOG_PREFIX,
+            path,
+        )
+        return None
+
+    return i
+
+
 def process_image(image, settings):
     # Set default value for 'IMAGE_PROCESS_FORCE'.
     if "IMAGE_PROCESS_FORCE" not in settings:
@@ -686,21 +707,8 @@ def process_image(image, settings):
     ):
         logger.debug("{} Processing {} -> {}".format(LOG_PREFIX, image[0], image[1]))
 
-        try:
-            i = Image.open(image[0])
-        except UnidentifiedImageError:
-            logger.warning(
-                "%s Source image %s is not supported by Pillow.",
-                LOG_PREFIX,
-                image[0],
-            )
-            return
-        except FileNotFoundError:
-            logger.warning(
-                "%s Source image %s not found.",
-                LOG_PREFIX,
-                image[0],
-            )
+        i = try_open_image(image[0])
+        if i is None:
             return
 
         for step in image[2]:

pelican/plugins/image_process/test_image_process.py

@@ -12,7 +12,7 @@
     ExifTool,
     compute_paths,
     harvest_images_in_fragment,
-    is_img_identifiable,
+    try_open_image,
     process_image,
 )
 
@@ -118,11 +118,6 @@ def test_all_transforms(tmp_path, transform_id, transform_params, image_path):
     ],
 )
 def test_path_normalization(mocker, orig_src, orig_img, new_src, new_img):
-    # Allow non-existing images to be processed:
-    mocker.patch(
-        "pelican.plugins.image_process.image_process.is_img_identifiable",
-        lambda img_filepath: True,
-    )
     # Silence image transforms.
     process = mocker.patch("pelican.plugins.image_process.image_process.process_image")
 
@@ -439,11 +434,6 @@ def test_path_normalization(mocker, orig_src, orig_img, new_src, new_img):
     ],
 )
 def test_picture_generation(mocker, orig_tag, new_tag, call_args):
-    # Allow non-existing images to be processed:
-    mocker.patch(
-        "pelican.plugins.image_process.image_process.is_img_identifiable",
-        lambda img_filepath: True,
-    )
     process = mocker.patch("pelican.plugins.image_process.image_process.process_image")
 
     settings = get_settings(
@@ -558,19 +548,19 @@ def test_copy_exif_tags(tmp_path, image_path, copy_tags):
             assert tag not in actual_tags.keys()
 
 
-def test_is_img_identifiable():
+def test_try_open_image():
     for test_image in TEST_IMAGES:
-        assert is_img_identifiable(test_image)
+        assert try_open_image(test_image)
 
-    assert not is_img_identifiable("image/that/does/not/exist.png")
+    assert not try_open_image("image/that/does/not/exist.png")
 
-    assert not is_img_identifiable(TEST_DATA.joinpath("folded_puzzle.png"))
-    assert not is_img_identifiable(TEST_DATA.joinpath("minimal.svg"))
+    assert not try_open_image(TEST_DATA.joinpath("folded_puzzle.png"))
+    assert not try_open_image(TEST_DATA.joinpath("minimal.svg"))
 
     img = {"src": "https://upload.wikimedia.org/wikipedia/commons/3/34/Exemple.png"}
     settings = get_settings(IMAGE_PROCESS_DIR="derivatives")
     path = compute_paths(img, settings, derivative="thumb")
-    assert not is_img_identifiable(path.source)
+    assert not try_open_image(path.source)
 
 
 def generate_test_images():