layout/style/test/test_flushing_frame.html
author Cristian Tuns <ctuns@mozilla.com>
Fri, 24 Sep 2021 14:42:22 -0400
changeset 593147 0b4005ebc9776ff43d99d1427c1a1fd2e14d9a44
parent 470294 bbdaf05c9d16b95a9bea1bf1125d69fb58aacd81
permissions -rw-r--r--
Backed out changeset dd075a074e45 (bug 1730518) for causing content crashes (bug 1732479). CLOSED TREE

<!doctype html>
<meta charset="utf-8">
<title>
  Test for bug 1545516: We don't flush layout unnecessarily on the parent
  document when the frame is already disconnected.
</title>
<link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<div id="content"></div>
<script>
  SimpleTest.waitForExplicitFinish();
  const iframe = document.createElement("iframe");
  const content = document.querySelector("#content");
  const parentUtils = SpecialPowers.getDOMWindowUtils(window);
  iframe.onload = function() {
    const win = iframe.contentWindow;
    iframe.offsetTop; // flush layout
    content.style.display = "inline"; // Dirty style with something that will reframe.

    const previousConstructCount = parentUtils.framesConstructed;
    let pagehideRan = false;
    win.addEventListener("pagehide", function() {
      pagehideRan = true;
      win.foo = win.innerWidth;
      is(parentUtils.framesConstructed, previousConstructCount, "innerWidth shouldn't have flushed parent document layout")
      win.bar = win.document.documentElement.offsetHeight;
      is(parentUtils.framesConstructed, previousConstructCount, "offsetHeight shouldn't have flushed parent document layout")
      win.baz = win.getComputedStyle(win.document.documentElement).color;
      is(parentUtils.framesConstructed, previousConstructCount, "getComputedStyle shouldn't have flushed parent document layout")
    });

    iframe.remove(); // Remove the iframe
    is(pagehideRan, true, "pagehide handler should've ran");
    is(parentUtils.framesConstructed, previousConstructCount, "Nothing should've flushed the parent document layout yet");
    content.offsetTop;
    isnot(parentUtils.framesConstructed, previousConstructCount, "We should've flushed layout now");
    SimpleTest.finish();
  };
  document.body.appendChild(iframe);
</script>