dnscms: version image URLs by file hash so media can be cached as immutable

dnscms/tests/test_image_urls.py

@@ -0,0 +1,60 @@
+import importlib
+
+from django.apps import apps
+
+from images.models import CustomImage
+from tests.conftest import CustomImageFactory
+
+backfill = importlib.import_module(
+    "images.migrations.0006_backfill_file_hash_and_size"
+).backfill_file_hash_and_size
+
+IMAGES_QUERY = "query { images { id url } }"
+
+
+def test_graphql_image_url_is_versioned_by_file_hash(db, graphql_post):
+    image = CustomImageFactory()
+    image.file_hash = "0123456789abcdef0123456789abcdef01234567"
+    image.save(update_fields=["file_hash"])
+
+    response, body = graphql_post(IMAGES_QUERY)
+
+    assert response.status_code == 200
+    assert "errors" not in body, body
+    [data] = body["data"]["images"]
+    assert data["url"].startswith("http")
+    assert data["url"].endswith(f"{image.file.url}?v=01234567")
+
+
+def test_graphql_image_url_without_file_hash_is_unversioned(db, graphql_post):
+    image = CustomImageFactory()
+    CustomImage.objects.filter(pk=image.pk).update(file_hash="")
+
+    response, body = graphql_post(IMAGES_QUERY)
+
+    assert "errors" not in body, body
+    [data] = body["data"]["images"]
+    assert data["url"].endswith(image.file.url)
+
+
+def test_backfill_sets_file_hash_and_size(db):
+    image = CustomImageFactory()
+    CustomImage.objects.filter(pk=image.pk).update(file_hash="", file_size=None)
+
+    backfill(apps, None)
+
+    image.refresh_from_db()
+    assert len(image.file_hash) == 40
+    assert image.file_size == image.file.size
+
+
+def test_backfill_skips_images_whose_file_is_missing(db):
+    image = CustomImageFactory()
+    CustomImage.objects.filter(pk=image.pk).update(file_hash="", file_size=None)
+    image.file.storage.delete(image.file.name)
+
+    backfill(apps, None)
+
+    # refresh_from_db() would read the missing file for its dimensions
+    fields = CustomImage.objects.filter(pk=image.pk).values("file_hash", "file_size")
+    assert fields.get() == {"file_hash": "", "file_size": None}