| <!DOCTYPE HTML> |
| <meta charset=utf-8> |
| <title>Layout Instability: toJSON</title> |
| <body> |
| <style> |
| #myDiv { position: relative; width: 300px; height: 100px; } |
| </style> |
| <div id='myDiv'></div> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="resources/util.js"></script> |
| <script> |
| async_test(async function(t) { |
| assert_precondition(window.LayoutShift, 'LayoutShift entries are not supported'); |
| // Wait for the initial render to complete. |
| await waitForAnimationFrames(2); |
| |
| const observer = new PerformanceObserver( |
| t.step_func_done(function(entryList) { |
| const entry = entryList.getEntries()[0]; |
| assert_equals(typeof(entry.toJSON), 'function'); |
| const json = entry.toJSON(); |
| assert_equals(typeof(json), 'object'); |
| const keys = [ |
| // PerformanceEntry |
| 'name', |
| 'entryType', |
| 'startTime', |
| 'duration', |
| // LayoutShift |
| 'value', |
| 'hadRecentInput', |
| 'lastInputTime', |
| ]; |
| for (const key of keys) { |
| assert_equals(json[key], entry[key], |
| 'LayoutShift ${key} entry does not match its toJSON value'); |
| } |
| }) |
| ); |
| observer.observe({type: 'layout-shift'}); |
| document.getElementById('myDiv').style = "top: 60px"; |
| }, 'Test toJSON() in LayoutShift.'); |
| </script> |
| </body> |
