Test markdown image lazy loading extensions

articles/markdown.py

@@ -11,14 +11,16 @@ from markdown.inlinepatterns import (
 class LazyImageInlineProcessor(ImageInlineProcessor):
     def handleMatch(self, m, data):
         el, match_start, index = super().handleMatch(m, data)
-        el.set("loading", "lazy")
+        if el is not None:
+            el.set("loading", "lazy")
         return el, match_start, index
 
 
 class LazyImageReferenceInlineProcessor(ImageReferenceInlineProcessor):
     def makeTag(self, href, title, text):
         el = super().makeTag(href, title, text)
-        el.set("loading", "lazy")
+        if el is not None:
+            el.set("loading", "lazy")
         return el
 
 

articles/tests/conftest.py

@@ -19,7 +19,13 @@ def published_article(author: User) -> Article:
         author=author,
         published_at=timezone.now(),
         slug="some-article-slug",
-        content="## some article markdown\n\n[an article link](https://article.com)",
+        content=(
+            "## some article markdown\n\n"
+            "[an article link](https://article.com)\n"
+            "![an image](https://article.com)\n"
+            "![a referenced image][1]\n\n"
+            "[1]: https://example.com/image.png"
+        ),
     )
 
 

articles/tests/test_html_views.py

@@ -117,3 +117,11 @@ def test_logged_in_user_doesnt_have_plausible(client: Client, author: User, sett
     res = client.get(reverse("articles-list"))
     content = res.content.decode("utf-8")
     assert "https://plausible.augendre.info/js/plausible.js" not in content
+
+
+@pytest.mark.django_db
+def test_image_is_lazy(client: Client, published_article: Article):
+    res = client.get(reverse("article-detail", kwargs={"slug": published_article.slug}))
+    assert res.status_code == 200
+    content = res.content.decode("utf-8")
+    assert content.count('loading="lazy"') == 2