| <!DOCTYPE html> |
| <title>Layout Instability: no shift for adding/removing position:fixed</title> |
| <link rel="help" href="https://wicg.github.io/layout-instability/" /> |
| <div id="target" style="width: 100px; height: 100px; background: green; |
| position: absolute; top: 200px"></div> |
| <div style="height: 2000px"></div> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="resources/util.js"></script> |
| <script> |
| |
| promise_test(async () => { |
| const watcher = new ScoreWatcher; |
| |
| // Wait for the initial render to complete. |
| await waitForAnimationFrames(2); |
| |
| window.scrollTo(0, 1000); |
| target.style.position = 'fixed'; |
| target.style.top = 0; |
| |
| await waitForAnimationFrames(3); |
| assert_equals(watcher.score, 0); |
| |
| window.scrollTo(0, 100); |
| target.style.position = 'absolute'; |
| target.style.top = '200px'; |
| |
| await waitForAnimationFrames(3); |
| assert_equals(watcher.score, 0); |
| }, "No shift for adding/removing position:fixed."); |
| |
| </script> |
| |
| |
