| <!doctype html> |
| <meta name="viewport" content="width=device-width,initial-scale=1"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <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://w3c.github.io/IntersectionObserver/#dom-intersectionobserver-rootmargin"> |
| <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1553673"> |
| <style> |
| html { width: 100vw; height: 100vh } |
| </style> |
| <script> |
| const t = async_test("IntersectionObserver root margin cannot end up with negative rect (and thus non-intersecting) due to rounding"); |
| |
| let remainingTests = 100; |
| |
| // This is just a best-effort test to catch issues. |
| for (let i = 0; i < 100; ++i) { |
| let offset = i / 100; |
| let observer; |
| observer = new IntersectionObserver(t.step_func(function(entries) { |
| assert_equals(entries.length, 1); |
| assert_equals(entries[0].target, document.documentElement); |
| assert_true(entries[0].isIntersecting, "should be intersecting at " + offset); |
| if (!--remainingTests) |
| t.done(); |
| observer.disconnect(); |
| }), { rootMargin: `${-100 * (1 - offset)}% 0px ${-100 * offset}%` }); |
| observer.observe(document.documentElement); |
| } |
| </script> |
