testing/web-platform/tests/element-timing/toJSON.html

   1 <!DOCTYPE HTML>
   2 <meta charset=utf-8>
   3 <title>Element Timing: toJSON</title>
   4 <body>
   5 <script src="/resources/testharness.js"></script>
   6 <script src="/resources/testharnessreport.js"></script>
   7 <script src="resources/element-timing-helpers.js"></script>
   8 <img elementtiming='img' src="resources/square100.png"/>
   9 <script>
  10   async_test(function (t) {
  11     assert_precondition(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented");
  12     const observer = new PerformanceObserver(
  13       t.step_func_done(function(entryList) {
  14         assert_equals(entryList.getEntries().length, 1);
  15         const entry = entryList.getEntries()[0];
  16         assert_equals(typeof(entry.toJSON), 'function');
  17         const json = entry.toJSON();
  18         assert_equals(typeof(json), 'object');
  19         const keys = [
  20           // PerformanceEntry
  21           'name',
  22           'entryType',
  23           'startTime',
  24           'duration',
  25           // PerformanceElementTiming
  26           'renderTime',
  27           'loadTime',
  28           'intersectionRect',
  29           'identifier',
  30           'naturalWidth',
  31           'naturalHeight',
  32           'id',
  33           'element',
  34           'url',
  35         ];
  36         for (const key of keys) {
  37           assert_equals(json[key], entry[key],
  38             'PerformanceElementTiming ${key} entry does not match its toJSON value');
  39         }
  40       })
  41     );
  42     observer.observe({type: 'element', buffered: true});
  43   }, 'Test toJSON() in PerformanceElementTiming.');
  44 </script>
  45 </body>