test(t => {
  assert_throws(
    { name: "TypeError" },
    function () {
      new PerformanceObserver();
    },
    "PerformanceObserver constructor should throw TypeError if no argument is specified."
  );

  assert_throws(
    { name: "TypeError" },
    function () {
      new PerformanceObserver({});
    },
    "PerformanceObserver constructor should throw TypeError if the argument is not a function."
  );
}, "Test that PerformanceObserver constructor throws exception");

test(t => {
  var observer = new PerformanceObserver(() => {});

  assert_throws(
    { name: "TypeError" },
    function () {
      observer.observe();
    },
    "observe() should throw TypeError exception if no option specified."
  );

  assert_throws(
    { name: "TypeError" },
    function () {
      observer.observe({ unsupportedAttribute: "unsupported" });
    },
    "obsrve() should throw TypeError exception if the option has no 'entryTypes' attribute."
  );

  assert_equals(
    undefined,
    observer.observe({ entryTypes: [] }),
    "observe() should silently ignore empty 'entryTypes' sequence."
  );

  assert_throws(
    { name: "TypeError" },
    function () {
      observer.observe({ entryTypes: null });
    },
    "obsrve() should throw TypeError exception if 'entryTypes' attribute is null."
  );

  assert_equals(
    undefined,
    observer.observe({ entryTypes: ["invalid"] }),
    "observe() should silently ignore invalid 'entryTypes' values."
  );
}, "Test that PerformanceObserver.observe throws exception");

function promiseObserve(test, options) {
  return new Promise(resolve => {
    performance.clearMarks();
    performance.clearMeasures();

    var observer = new PerformanceObserver(list => resolve(list));
    observer.observe(options);
    test.add_cleanup(() => observer.disconnect());
  });
}

promise_test(t => {
  var promise = promiseObserve(t, { entryTypes: ["mark", "measure"] });

  performance.mark("test-start");
  performance.mark("test-end");
  performance.measure("test-measure", "test-start", "test-end");

  return promise.then(list => {
    assert_equals(
      list.getEntries().length,
      3,
      "There should be three observed entries."
    );

    var markEntries = list.getEntries().filter(entry => {
      return entry.entryType == "mark";
    });
    assert_array_equals(
      markEntries,
      performance.getEntriesByType("mark"),
      "Observed 'mark' entries should equal to entries obtained by getEntriesByType."
    );

    var measureEntries = list.getEntries().filter(entry => {
      return entry.entryType == "measure";
    });
    assert_array_equals(
      measureEntries,
      performance.getEntriesByType("measure"),
      "Observed 'measure' entries should equal to entries obtained by getEntriesByType."
    );
  });
}, "Test for user-timing with PerformanceObserver");

promise_test(t => {
  var promise = new Promise((resolve, reject) => {
    performance.clearMarks();
    performance.clearMeasures();

    var observer = new PerformanceObserver(list => reject(list));
    observer.observe({ entryTypes: ["mark", "measure"] });
    observer.disconnect();
    t.step_timeout(resolve, 100);
  });

  performance.mark("test-start");
  performance.mark("test-end");
  performance.measure("test-measure", "test-start", "test-end");

  return promise.then(
    () => {
      assert_equals(performance.getEntriesByType("mark").length, 2);
      assert_equals(performance.getEntriesByType("measure").length, 1);
    },
    list => {
      assert_unreached("Observer callback should never be called.");
    }
  );
}, "Nothing should be notified after disconnecting observer");

promise_test(t => {
  var promise = promiseObserve(t, { entryTypes: ["mark"] });

  performance.mark("test");

  return promise.then(list => {
    assert_array_equals(
      list.getEntries({ entryType: "mark" }),
      performance.getEntriesByType("mark"),
      "getEntries with entryType filter should return correct results."
    );

    assert_array_equals(
      list.getEntries({ name: "test" }),
      performance.getEntriesByName("test"),
      "getEntries with name filter should return correct results."
    );

    assert_array_equals(
      list.getEntries({ name: "test", entryType: "mark" }),
      performance.getEntriesByName("test"),
      "getEntries with name and entryType filter should return correct results."
    );

    assert_array_equals(
      list.getEntries({ name: "invalid" }),
      [],
      "getEntries with non-existent name filter should return an empty array."
    );

    assert_array_equals(
      list.getEntries({ name: "test", entryType: "measure" }),
      [],
      "getEntries with name filter and non-existent entryType should return an empty array."
    );

    assert_array_equals(
      list.getEntries({ name: "invalid", entryType: "mark" }),
      [],
      "getEntries with non-existent name and entryType filter should return an empty array."
    );

    assert_array_equals(
      list.getEntries({ initiatorType: "xmlhttprequest" }),
      [],
      "getEntries with initiatorType filter should return an empty array."
    );
  });
}, "Test for PerformanceObserverEntryList.getEntries");

promise_test(t => {
  var promise = promiseObserve(t, { entryTypes: ["mark", "measure"] });

  performance.mark("test");
  performance.measure("test-measure", "test", "test");

  return promise.then(list => {
    assert_array_equals(
      list.getEntriesByType("mark"),
      performance.getEntriesByType("mark")
    );
    assert_array_equals(
      list.getEntriesByType("measure"),
      performance.getEntriesByType("measure")
    );
  });
}, "Test for PerformanceObserverEntryList.getEntriesByType");

promise_test(t => {
  var promise = promiseObserve(t, { entryTypes: ["mark", "measure"] });

  performance.mark("test");
  performance.measure("test-measure", "test", "test");

  return promise.then(list => {
    assert_array_equals(
      list.getEntriesByName("test"),
      performance.getEntriesByName("test")
    );
    assert_array_equals(
      list.getEntriesByName("test-measure"),
      performance.getEntriesByName("test-measure")
    );
  });
}, "Test for PerformanceObserverEntryList.getEntriesByName");

promise_test(t => {
  var promise = new Promise(resolve => {
    performance.clearMarks();
    performance.clearMeasures();

    var observer = new PerformanceObserver(list => resolve(list));
    observer.observe({ entryTypes: ["mark", "measure"] });
    observer.observe({ entryTypes: ["mark", "measure"] });
    t.add_cleanup(() => observer.disconnect());
  });

  performance.mark("test-start");
  performance.mark("test-end");
  performance.measure("test-measure", "test-start", "test-end");

  return promise.then(list => {
    assert_equals(
      list.getEntries().length,
      3,
      "Observed user timing entries should have only three entries."
    );
  });
}, "Test that invoking observe method twice affects nothing");

promise_test(t => {
  var promise = new Promise(resolve => {
    performance.clearMarks();
    performance.clearMeasures();

    var observer = new PerformanceObserver(list => resolve(list));
    observer.observe({ entryTypes: ["mark", "measure"] });
    observer.observe({ entryTypes: ["mark"] });
    t.add_cleanup(() => observer.disconnect());
  });

  performance.mark("test-start");
  performance.mark("test-end");
  performance.measure("test-measure", "test-start", "test-end");

  return promise.then(list => {
    assert_equals(
      list.getEntries().length,
      2,
      "Observed user timing entries should have only two entries."
    );
  });
}, "Test that observing filter is replaced by a new filter");

promise_test(t => {
  var promise = new Promise(resolve => {
    performance.clearMarks();
    performance.clearMeasures();

    var observer = new PerformanceObserver(list => resolve(list));
    observer.observe({ entryTypes: ["mark"] });
    observer.observe({ entryTypes: ["measure"] });
    t.add_cleanup(() => observer.disconnect());
  });

  performance.mark("test-start");
  performance.mark("test-end");
  performance.measure("test-measure", "test-start", "test-end");

  return promise.then(list => {
    assert_equals(
      list.getEntries().length,
      1,
      "Observed user timing entries should have only 1 entries."
    );
  });
}, "Test that observing filter is replaced by a new filter");