test_weakRefs_collected_wrapper.html

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<!DOCTYPE HTML>

<html>

  <head>

    <meta charset="utf-8">

    <title>Test WeakRefs with DOM wrappers that get cycle collected</title>

    <script src="/tests/SimpleTest/SimpleTest.js"></script>

    <script type="application/javascript">

      let weakrefs = [];

      function go() {

        SimpleTest.waitForExplicitFinish();

        // 1. nsISupports-derived object.

        let doc = document.implementation.createHTMLDocument();

        weakrefs.push(new WeakRef(doc));

        // 2. non-nsISupports-derived object.

        let buffer = new AudioBuffer({length: 1, sampleRate: 8000});

        weakrefs.push(new WeakRef(buffer));

        // 3. nsISupports non-wrapper-cached object.

        let image = new ImageData(1, 1);

        weakrefs.push(new WeakRef(image));

        // 4. non-nsISupports non-wrapper-cached object.

        let iterator = document.fonts.values();

        weakrefs.push(new WeakRef(iterator));

        for (let wr of weakrefs) {

          isnot(wr.deref(), undefined, "Check that live wrapper is returned");

        // setTimeout will call its callback in a new task.

        setTimeout(task2, 0);

      function task2() {

        // Trigger a GC and CC to collect the DOM objects, but no GC to

        // collect the wrappers.

        SpecialPowers.DOMWindowUtils.garbageCollect();

        SpecialPowers.DOMWindowUtils.cycleCollect();

        for (let wr of weakrefs) {

          is(wr.deref(), undefined, "Check that stale wrapper is not exposed");

        SimpleTest.finish();

    </script>

  </head>

  <body onload="go()"></body>

</html>