| <!DOCTYPE html> |
| <title>Layout Instability: change under overflow clipping container causing shift and overflow status change at the same time</title> |
| <link rel="help" href="https://wicg.github.io/layout-instability/" /> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="resources/util.js"></script> |
| <div style="height: 100px"></div> |
| <div style="overflow: auto; width: 400px; height: 400px"> |
| <div id="resized" style="width: 600px; height: 100px; background: gray"></div> |
| <div id="shifted" style="width: 300px; height: 100px; background: blue"></div> |
| </div> |
| <script> |
| promise_test(async () => { |
| const watcher = new ScoreWatcher; |
| |
| // Wait for the initial render to complete. |
| await waitForAnimationFrames(2); |
| |
| resized.style.width = '200px'; |
| resized.style.height = '200px'; |
| |
| const expectedScore = computeExpectedScore(300 * (100 + 100), 100); |
| |
| assert_equals(watcher.score, 0); |
| await watcher.promise; |
| assert_equals(watcher.score, expectedScore); |
| |
| resized.style.width = '600px'; |
| resized.style.height = '100px'; |
| await watcher.promise; |
| assert_equals(watcher.score, expectedScore * 2); |
| }, 'Change under overflow clipping container causing shift and overflow status change at the same time'); |
| </script> |
