files/tests/test_utils.py

@@ -1,3 +1,6 @@
+from unittest.mock import patch, ANY
+from pathlib import Path
+
 from django.test import TestCase
 
 from files.utils import (
@@ -5,8 +8,12 @@ from files.utils import (
     find_exact_path,
     find_path_by_name,
     get_thumbnail_upload_to,
+    make_thumbnails,
 )
 
+# Reusing test files from the extensions app
+TEST_FILES_DIR = Path(__file__).resolve().parent.parent.parent / 'extensions' / 'tests' / 'files'
+
 
 class UtilsTest(TestCase):
     manifest = 'blender_manifest.toml'
@@ -112,3 +119,26 @@ class UtilsTest(TestCase):
         ):
             with self.subTest(file_hash=file_hash, kwargs=kwargs):
                 self.assertEqual(get_thumbnail_upload_to(file_hash, **kwargs), expected)
+
+    @patch('files.utils.resize_image')
+    def test_make_thumbnails(self, mock_resize_image):
+        self.assertEqual(
+            {
+                'l': {'path': 'thumbnails/fo/foobar_1920x1080.png', 'size': (1920, 1080)},
+                's': {'path': 'thumbnails/fo/foobar_640x360.png', 'size': (640, 360)},
+            },
+            make_thumbnails(TEST_FILES_DIR / 'test_preview_image_0001.png', 'foobar'),
+        )
+
+        self.assertEqual(len(mock_resize_image.mock_calls), 2)
+        for expected_size in ((1920, 1080), (640, 360)):
+            with self.subTest(expected_size=expected_size):
+                mock_resize_image.assert_any_call(
+                    ANY,
+                    expected_size,
+                    ANY,
+                    output_format='PNG',
+                    quality=83,
+                    optimize=True,
+                    progressive=True,
+                )

files/utils.py

@@ -225,7 +225,7 @@ def resize_image(image: Image, size: tuple, output, output_format: str = 'PNG',
     source_image.save(output, output_format, **output_params)
 
 
-def make_thumbnails(file_path: str, file_hash: str, output_format: str = THUMBNAIL_FORMAT) -> list:
+def make_thumbnails(file_path: str, file_hash: str, output_format: str = THUMBNAIL_FORMAT) -> dict:
     """Generate thumbnail files for given file and a predefined list of dimensions.
 
     Resulting thumbnail paths a derived from the given file hash and thumbnail sizes.