<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Values: Viewport units are computed correctly after font load.</title>
<link rel="author"  title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
<link rel="author"  title="Mozilla" href="https://mozilla.org">
<link rel="help" href="https://www.w3.org/TR/css-values-3/#viewport-relative-lengths">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1620359">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<iframe width=300 height=300 scrolling=no srcdoc=""></iframe>
<script>
let t = async_test("Viewport units are correctly updated after resize even if a font load has happened before");
let iframe = document.querySelector("iframe");
onload = t.step_func(function() {
  let doc = iframe.contentDocument;
  let win = iframe.contentWindow;
  doc.body.innerHTML = `
    <div style="width: 100vw; height: 100vh; background: green"></div>
  `;
  let div = doc.querySelector("div");
  let oldWidth = win.getComputedStyle(div).width;
  let oldHeight = win.getComputedStyle(div).height;
  assert_equals(oldWidth, win.innerWidth + "px", "Should fill the viewport");
  assert_equals(oldHeight, win.innerHeight + "px", "Should fill the viewport");
  let link = doc.createElement("link");
  link.rel = "stylesheet";
  link.href = "/fonts/ahem.css";
  link.onload = t.step_func(function() {
    iframe.width = 400;
    win.requestAnimationFrame(t.step_func(function() {
      win.requestAnimationFrame(t.step_func_done(function() {
        let newWidth = win.getComputedStyle(div).width;
        let newHeight = win.getComputedStyle(div).height;
        assert_equals(newWidth, win.innerWidth + "px", "Should fill the viewport");
        assert_equals(newHeight, win.innerHeight + "px", "Should fill the viewport");
        assert_equals(newHeight, oldHeight, "Height shouldn't have changed");
        assert_not_equals(newWidth, oldWidth, "Width should have changed");
      }));
    }));
  });
  doc.body.appendChild(link);
});
</script>
