Add a test for fullscreen for the A/B/A case

mfreed7 · chromium-wpt-export-bot · commit ebc90b12bbca · 2023-05-03T10:03:51.000-07:00
See the discussion at [1] for more context. This test requests fullscreen on A, then B, then A, where A and B are sibling divs. All three requests should succeed, but at the end, B should be left topmost (and the fullscreen element) but both A and B should be in the top layer. [1] whatwg/fullscreen#223 Change-Id: I3f35dda5b9eb1bc24201616bb5bb4949d20fd170
diff --git a/fullscreen/api/fullscreen-reordering.html b/fullscreen/api/fullscreen-reordering.html
@@ -0,0 +1,63 @@
+<!DOCTYPE html>
+<title>Re-requesting fullscreen doesn't fail but doesn't change order</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="../trusted-click.js"></script>
+
+<div class="elements">
+  <div id="A">Element A</div>
+  <div id="B">Element B</div>
+</div>
+
+<style>
+  .elements>div {
+    width:200px;
+    height:200px;
+  }
+  #A { background: blue; }
+  #B { background: green; }
+  }
+</style>
+
+<script>
+function isTopLayer(el) {
+  return getComputedStyle(el, '::backdrop').right !== 'auto';
+}
+
+promise_test(async (t) => {
+  t.add_cleanup(async () => {
+    if (document.fullscreenElement)
+      await document.exitFullscreen();
+  });
+  document.onfullscreenerror = t.unreached_func('fullscreenerror should not happen');
+  const A = document.getElementById('A');
+  const B = document.getElementById('B');
+  assert_true(!isTopLayer(A) && !isTopLayer(B));
+  await trusted_click(document.body);
+  await A.requestFullscreen();
+  assert_equals(document.fullscreenElement,A,'first A request');
+  assert_true(isTopLayer(A),'A top layer');
+  await trusted_click(A);
+  await B.requestFullscreen();
+  assert_equals(document.fullscreenElement,B,'B request');
+  assert_true(isTopLayer(B),'B top layer');
+  assert_true(isTopLayer(A),'A still top layer');
+  await trusted_click(B);
+  await A.requestFullscreen();
+  assert_true(isTopLayer(A),'A is still top layer');
+  assert_true(isTopLayer(B),'B is still top layer');
+  assert_equals(document.fullscreenElement,B,'B is still the fullscreen element');
+  assert_equals(document.elementFromPoint(10,10),B,'B should be topmost');
+
+  await document.exitFullscreen();
+  assert_equals(document.fullscreenElement,A,'A goes back to being the fullscreen element');
+  assert_true(isTopLayer(A),'A is still top layer');
+  assert_false(isTopLayer(B),'B is no longer top layer');
+  await document.exitFullscreen();
+  assert_equals(document.fullscreenElement,null,'Both closed');
+  assert_false(isTopLayer(A),'A is no longer top layer');
+  assert_false(isTopLayer(B),'B is no longer top layer');
+}, 'Requesting fullscreen on A, then B, then A doesn\'t throw, but leaves B topmost');
+</script>
