fixed-position-move.html (900B)
1 <!DOCTYPE html> 2 <title>Layout Instability: movement of fixed position</title> 3 <link rel="help" href="https://wicg.github.io/layout-instability/" /> 4 <script src="/resources/testharness.js"></script> 5 <script src="/resources/testharnessreport.js"></script> 6 <script src="resources/util.js"></script> 7 <div id="target" style="position: fixed; top: 100px; width: 300px; height: 200px; background: yellow"> 8 </div> 9 <script> 10 promise_test(async () => { 11 const watcher = new ScoreWatcher; 12 13 // Wait for the initial render to complete. 14 await waitForAnimationFrames(2); 15 16 // Modify the position of the div. 17 target.style.top = '200px'; 18 19 const expectedScore = computeExpectedScore(300 * (200 + 100), 100); 20 21 // Observer fires after the frame is painted. 22 assert_equals(watcher.score, 0); 23 await watcher.promise; 24 assert_equals(watcher.score, expectedScore); 25 }, 'Movement of fixed position'); 26 27 </script>