testing/web-platform/tests/performance-timeline/po-observe.html

   1 <!DOCTYPE HTML>
   2 <meta charset=utf-8>
   3 <title>PerformanceObservers: PerformanceObserverInit.buffered</title>
   4 <meta name="timeout" content="long">
   5 <script src="/resources/testharness.js"></script>
   6 <script src="/resources/testharnessreport.js"></script>
   7 <script src="performanceobservers.js"></script>
   8 <h1>PerformanceObservers: PerformanceObserverInit.buffered</h1>
   9 <p>
  10 PerformanceObserverInit.buffered should retrieve previously buffered entries
  11 </p>
  12 <div id="log"></div>
  13 <script>
  14   async_test(function (t) {
  15     function initTest() {
  16       new PerformanceObserver(function (entryList, observer) {
  17         entryList.getEntries().forEach(function(entry) {
  18           if (shouldExclude(entry)) {
  19             return;
  20           }
  21
  22           observedEntries.push(entry);
  23           if (observedEntries.length === entryTypes.length) {
  24             observer.disconnect();
  25             runTest();
  26           }
  27         });
  28       }).observe({entryTypes});
  29
  30       // creates a `resource` entry
  31       var img = document.createElement("img");
  32       img.src = "./resources/square.png";
  33       document.body.appendChild(img);
  34
  35       performance.mark("markName"); // creates a `mark` entry
  36       performance.measure("measureName"); // creates a `measure` entry
  37     }
  38     function shouldExclude(entry) {
  39       // exclude all `resource` entries that aren't for "square.png"
  40       return entry.entryType === "resource" &&
  41              entry.name.indexOf("square.png") === -1;
  42     }
  43     function runTest() {
  44       // this PerformanceObserver is a nop because we've already been notified about all of our `entryTypes`
  45       var po_nop = new PerformanceObserver(function (entryList, observer) {
  46         if (entryList.getEntries().find(function(entry) {
  47           return !shouldExclude(entry);
  48         })) {
  49           assert_unreached("this PerformanceObserver callback should never be called");
  50         }
  51       });
  52       po_nop.observe({
  53         entryTypes,
  54         buffered: false
  55       });
  56
  57       // this PerformanceObserver should be notified about the previously
  58       // buffered mark entry only
  59       const bufferedEntries = [];
  60       new PerformanceObserver(function (entryList, observer) {
  61         entryList.getEntries().forEach(function(entry) {
  62           if (shouldExclude(entry)) {
  63             return;
  64           }
  65
  66           bufferedEntries.push(entry);
  67           if (bufferedEntries.length === 1) {
  68             observer.disconnect();
  69             po_nop.disconnect();
  70             for (i = 0; i < bufferedEntries.length; i++) {
  71               assert_equals(bufferedEntries[i].entryType, "mark")
  72             }
  73             t.done();
  74           }
  75         });
  76       }).observe({
  77         type: "mark",
  78         buffered: true
  79       });
  80     }
  81
  82     const entryTypes = ["navigation", "resource", "mark", "measure"];
  83     const observedEntries = [];
  84     initTest();
  85   }, "PerformanceObserverInit.buffered should retrieve previously buffered entries");
  86
  87 </script>