1 files changed, 22 insertions, 0 deletions
diff --git a/testing/web-platform/tests/largest-contentful-paint/resources/invisible-images.js b/testing/web-platform/tests/largest-contentful-paint/resources/invisible-images.js
new file mode 100644
index 0000000000..bad078e35f
--- /dev/null
+++ b/testing/web-platform/tests/largest-contentful-paint/resources/invisible-images.js
@@ -0,0 +1,22 @@
+async_test(t => {
+  assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented");
+  const observer = new PerformanceObserver(
+    t.step_func(entryList => {
+       entryList.getEntries().forEach(entry => {
+       // May receive a text entry. Ignore that entry.
+        if (!entry.url) {
+          return;
+        }
+        // The images should not have caused an entry, so fail test.
+        assert_unreached('Should not have received an entry! Received one with id '
+            + entryList.getEntries()[0].id);
+      });
+    })
+  );
+  observer.observe({type: 'largest-contentful-paint', buffered: true});
+  // Images have been added but should not cause entries to be dispatched.
+  // Wait for 500ms and end test, ensuring no entry was created.
+  t.step_timeout(() => {
+    t.done();
+  }, 500);
+}, 'Images with opacity: 0, visibility: hidden, or display: none are not observable by LargestContentfulPaint.');