1 files changed, 81 insertions, 0 deletions
diff --git a/testing/web-platform/tests/long-animation-frame/tentative/loaf-first-ui-event.html b/testing/web-platform/tests/long-animation-frame/tentative/loaf-first-ui-event.html
new file mode 100644
index 0000000000..7e32010189
--- /dev/null
+++ b/testing/web-platform/tests/long-animation-frame/tentative/loaf-first-ui-event.html
@@ -0,0 +1,81 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Long Animation Frame Timing: first UI Event</title>
+<meta name="timeout" content="long">
+<script src=/resources/testdriver.js></script>
+<script src=/resources/testdriver-actions.js></script>
+<script src=/resources/testdriver-vendor.js></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/utils.js"></script>
+
+<body>
+<h1>Long Animation Frame: First UI Event</h1>
+<div id="log"></div>
+<script>
+
+promise_test(async t => {
+  const button = document.createElement("button");
+  button.innerText = "Click";
+  document.body.appendChild(button);
+  t.add_cleanup(() => button.remove());
+  const eventPromise = new Promise(resolve => button.addEventListener("click", event => {
+    busy_wait();
+    resolve(event);
+  }));
+  const entryPromise = expect_long_frame_with_script(() => {
+    test_driver.click(button);
+  }, s => s.invoker === "BUTTON.onclick", t);
+  await new Promise(resolve => t.step_timeout(resolve, 0));
+  const event = await eventPromise;
+  const [entry] = await entryPromise;
+  assert_equals(entry.firstUIEventTimestamp, event.timeStamp);
+}, "LoAF should expose firstUIEventTimestamp for click events");
+
+promise_test(async t => {
+  const button = document.createElement("button");
+  button.innerText = "Hover";
+  document.body.appendChild(button);
+  t.add_cleanup(() => button.remove());
+  let expectedTimestamp = null;
+  const entryPromise = expect_long_frame_with_script(async () => {
+    const eventPromise = new Promise(resolve => button.addEventListener("pointermove", event => {
+      busy_wait();
+      expectedTimestamp = event.timeStamp;
+      resolve();
+    }));
+
+    const actions = new test_driver.Actions()
+       .pointerMove(0, 0, {origin: button})
+       .pointerDown()
+       .pointerUp();
+    await actions.send();
+    await eventPromise;
+  }, (script, entry) =>
+      script.invoker === "BUTTON.onpointermove" &&
+      entry.firstUIEventTimestamp === expectedTimestamp, t);
+}, "LoAF should expose firstUIEventTimestamp for pointermove events");
+
+promise_test(async t => {
+  const button = document.createElement("button");
+  button.innerText = "Click";
+  document.body.appendChild(button);
+  t.add_cleanup(() => button.remove());
+  let firstUIEventTimestamp = null;
+  const eventPromise = new Promise(resolve => button.addEventListener("click", event => {
+    if (firstUIEventTimestamp)
+      resolve(event);
+    else {
+      firstUIEventTimestamp = event.timeStamp;
+      busy_wait();
+    }
+  }));
+  const entryPromise = expect_long_frame_with_script(() => {
+    test_driver.click(button);
+    test_driver.click(button);
+  }, s => s.invoker === "BUTTON.onclick", t);
+  const [event, [entry]] = await Promise.all([eventPromise, entryPromise]);
+  assert_equals(entry.firstUIEventTimestamp, firstUIEventTimestamp);
+}, "firstUIEventTimestamp doesn't have to come from a long script");
+</script>
+</body>