1 files changed, 53 insertions, 0 deletions
diff --git a/testing/web-platform/tests/fenced-frame/intersection-observer.https.html b/testing/web-platform/tests/fenced-frame/intersection-observer.https.html
new file mode 100644
index 0000000000..592e7c127f
--- /dev/null
+++ b/testing/web-platform/tests/fenced-frame/intersection-observer.https.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<title>Test Intersection Observer in fenced frame</title>
+<script src="/common/rendering-utils.js"></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/utils.js"></script>
+<script src="resources/utils.js"></script>
+<script src="/common/utils.js"></script>
+<style>
+fencedframe {
+  width: 100px;
+  height: 100px;
+  position: fixed;
+  top: 0px;
+  left: 0px;
+  border: unset;
+}
+</style>
+
+<body>
+<script>
+promise_test(async (t) => {
+  // first entry after observe.
+  const io_entry_on_registration = token();
+  // entry after transform.
+  const io_entry_on_transform = token();
+  // entry with clip.
+  const io_entry_on_clip = token();
+
+  const frame = attachFencedFrame(generateURL(
+    "resources/frame-with-intersection-observer.html",
+    [io_entry_on_registration, io_entry_on_transform, io_entry_on_clip]));
+
+  let result = await nextValueFromServer(io_entry_on_registration);
+  assert_equals(result, "0,0,100,100,true",
+    "Subscribing to IO dispatches a notification");
+
+  // Apply a transform to the fencedframe and ensure it gets applied to the
+  // intersectionRect.
+  frame.style.transform = 'translate(-10px, -20px)';
+  result = await nextValueFromServer(io_entry_on_transform);
+  assert_equals(result, "10,20,90,80,true",
+    "Transform applies to intersection rect");
+
+  // Now add a clip to the fencedframe which should clip the intersectionRect.
+  frame.style.clipPath = 'inset(10px)';
+  result = await nextValueFromServer(io_entry_on_clip);
+  assert_equals(result, "10,20,80,70,false", "Clip applies to intersection rect");
+}, 'Intersection Observer Test');
+
+</script>
+</body>
+</html>