| <!DOCTYPE html> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-anchoring-1/"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| body { height: 1000px } |
| div { height: 100px } |
| </style> |
| <div id="block1">abc</div> |
| <div id="block2">def</div> |
| <script> |
| // This test verifies that reading window.scrollY forces any pending scroll |
| // anchoring adjustment to occur before computing the return value. |
| async_test((t) => { |
| scrollTo(0, 150); |
| requestAnimationFrame(() => { |
| step_timeout(() => { |
| // Queue scroll anchoring adjustment. |
| document.querySelector("#block1").style.height = "200px"; |
| |
| // Reading scrollY should force both the layout and the adjustment to |
| // occur synchronously. |
| var y = scrollY; |
| |
| assert_equals(y, 250); |
| t.done(); |
| }, 0); |
| }); |
| }, 'Reading scroll position forces scroll anchoring adjustment.'); |
| </script> |
