add inline <img src="..." /> test

src/browser/tests/element/html/image.html

@@ -123,3 +123,36 @@
   testing.expectEqual(0, count);
 }
 </script>
+
+<img
+  id="inline-img"
+  src="https://cdn.lightpanda.io/website/assets/images/docs/hn.png"
+  onload="(() => testing.expectEqual(true, true))()"
+/>
+
+<script id="inline-on-load">
+{
+  const img = document.getElementById("inline-img");
+  testing.expectEqual(true, img.onload instanceof Function);
+  // Also call inline to double check.
+  img.onload();
+
+  // Make sure ones attached with `addEventListener` also executed.
+  testing.async(async () => {
+    const result = await new Promise(resolve => {
+      img.addEventListener("load", ({ bubbles, cancelBubble, cancelable, composed, isTrusted, target }) => {
+        testing.expectEqual(false, bubbles);
+        testing.expectEqual(false, cancelBubble);
+        testing.expectEqual(false, cancelable);
+        testing.expectEqual(false, composed);
+        testing.expectEqual(true, isTrusted);
+        testing.expectEqual(img, target);
+
+        return resolve(true);
+      });
+    });
+
+    testing.expectEqual(true, result);
+  });
+}
+</script>