| <!DOCTYPE html> |
| <meta name="viewport" content="width=device-width,initial-scale=1"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="./resources/intersection-observer-test-utils.js"></script> |
| |
| <style> |
| pre, #log { |
| position: absolute; |
| top: 0; |
| left: 200px; |
| } |
| #target { |
| width: 0px; |
| height: 0px; |
| } |
| </style> |
| |
| <div id='target'></div> |
| |
| <script> |
| var entries = []; |
| |
| runTestCycle(function() { |
| var target = document.getElementById('target'); |
| assert_true(!!target, "target exists"); |
| var observer = new IntersectionObserver(function(changes) { |
| entries = entries.concat(changes) |
| }); |
| observer.observe(target); |
| entries = entries.concat(observer.takeRecords()); |
| assert_equals(entries.length, 0, "No initial notifications."); |
| runTestCycle(step0, "First rAF should generate a notification."); |
| }, "Ensure that a zero-area target intersecting root generates a notification with intersectionRatio == 1"); |
| |
| function step0() { |
| assert_equals(entries.length, 1, "One notification."); |
| assert_equals(entries[0].intersectionRatio, 1, "intersectionRatio == 1"); |
| } |
| </script> |
