containertiming-observe-no-paint.html (1104B)
1 <!DOCTYPE HTML> 2 <meta charset=utf-8> 3 <title>Container Timing: if no paint happens, observer is not called</title> 4 <body> 5 <style> 6 body { 7 margin: 0; 8 } 9 </style> 10 <script src="/resources/testharness.js"></script> 11 <script src="/resources/testharnessreport.js"></script> 12 <script src="/container-timing/resources/container-timing-helpers.js"></script> 13 <script src="/element-timing/resources/element-timing-helpers.js"></script> 14 <script> 15 async_test(function (t) { 16 assert_implements(window.PerformanceContainerTiming, "PerformanceContainerTiming is not implemented"); 17 const observer = new PerformanceObserver( 18 function(entryList) { 19 assert_unreached("No entry is expected with nothing to paint"); 20 } 21 ); 22 observer.observe({entryTypes: ['container']}); 23 24 finishOnElementTiming(t); 25 26 const div = document.createElement('div'); 27 div.setAttribute('containertiming', 'div_ct'); 28 document.body.appendChild(div); 29 30 addPaintingElementTimingAfterDoubleRAF(document.body); 31 }, 'Container timing did not report paints when there was nothing to paint.'); 32 </script> 33 34 </body>