| <!DOCTYPE html> |
| <meta name="viewport" content="width=device-width,initial-scale=1"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| |
| <style> |
| #target { |
| width: 100px; |
| height: 100px; |
| background-color: green; |
| } |
| </style> |
| |
| <div id="target"></div> |
| |
| <script> |
| var target = document.getElementById("target"); |
| async_test((t) => { |
| var observer = new IntersectionObserver(t.step_func_done((entries) => { |
| var rootBounds = entries[0].rootBounds; |
| assert_equals(rootBounds.left, 0); |
| assert_equals(rootBounds.right, document.documentElement.clientWidth); |
| assert_equals(rootBounds.top, 0); |
| assert_equals(rootBounds.bottom, document.documentElement.clientHeight); |
| observer.disconnect(); |
| }), { rootMargin: "" }); |
| observer.observe(document.getElementById("target")); |
| }, "An empty rootMargin string is interpreted as a margin of size zero"); |
| </script> |
