MutationObserver-callback-tricky.html

Enable keyboard shortcuts

This WPT test may be referenced by the following Test IDs:
- /dom/nodes/MutationObserver-callback-tricky.html - WPT Dashboard Interop Dashboard

<!doctype html>

<meta charset=utf-8>

<title>Certain actions within the callback does not lead to infinite loop</title>

<script src=/resources/testharness.js></script>

<script src=/resources/testharnessreport.js></script>

<body>

<script>

  "use strict";

  promise_test(() => {

    let called = 0;

    const div1 = document.createElement("div");

    document.body.appendChild(div1);

    const m = new MutationObserver(() => {

      called++;

      const div2 = document.createElement("div");

      document.body.appendChild(div2);

      m.observe(div2, { attributes: true });

});

    m.observe(div1, { attributes: true });

    div1.setAttribute("data-test", "test");

    return Promise.resolve().then(() => {

      assert_equals(called, 1, "times callback called");

});

  }, "Calling observe in callback should not lead to more calls");

  promise_test(() => {

    let called = 0;

    const div1 = document.createElement("div");

    document.body.appendChild(div1);

    const m = new MutationObserver(() => {

      called++;

      m.disconnect();

      m.observe(div1, { attributes: true });

});

    m.observe(div1, { attributes: true });

    div1.setAttribute("data-test", "test");

    return Promise.resolve().then(() => {

      assert_equals(called, 1, "times callback called");

});

  }, "Disconnect and re-observe in callback should not lead to more calls");

</script>