third_party/web_platform_tests/DOMEvents/constructors.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>Event constructors</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="log"></div>
<script>
function assert_props(iface, event, defaults) {
  assert_true(event instanceof self[iface]);
  expected[iface].properties.forEach(function(p) {
    var property = p[0], value = p[defaults ? 1 : 2];
    assert_true(property in event,
                "Event " + format_value(event) + " should have a " +
                property + " property");
    assert_equals(event[property], value,
                  "The value of the " + property + " property should be " +
                  format_value(value));
  });
  if ("parent" in expected[iface]) {
    assert_props(expected[iface].parent, event, defaults);
  }
}

var EventModifierInit = [
  ["ctrlKey", false, true],
  ["shiftKey", false, true],
  ["altKey", false, true],
  ["metaKey", false, true],
];
var expected = {
  "Event": {
    "properties": [
      ["bubbles", false, true],
      ["cancelable", false, true],
    ],
  },

  "UIEvent": {
    "parent": "Event",
    "properties": [
      ["view", null, window],
      ["detail", 0, 7],
    ],
  },

  "FocusEvent": {
    "parent": "UIEvent",
    "properties": [
      ["relatedTarget", null, document],
    ],
  },

  "MouseEvent": {
    "parent": "UIEvent",
    "properties": EventModifierInit.concat([
      ["screenX", 0, 40],
      ["screenY", 0, 40],
      ["clientX", 0, 40],
      ["clientY", 0, 40],
      ["button", 0, 40],
      ["buttons", 0, 40],
      ["relatedTarget", null, document],
    ]),
  },

  "WheelEvent": {
    "parent": "MouseEvent",
    "properties": [
      ["deltaX", 0.0, 3.1],
      ["deltaY", 0.0, 3.1],
      ["deltaZ", 0.0, 3.1],
      ["deltaMode", 0, 40],
    ],
  },

  "KeyboardEvent": {
    "parent": "UIEvent",
    "properties": EventModifierInit.concat([
      ["key", "", "string"],
      ["code", "", "string"],
      ["location", 0, 7],
      ["repeat", false, true],
      ["isComposing", false, true],
      ["charCode", 0, 7],
      ["keyCode", 0, 7],
      ["which", 0, 7],
    ]),
  },

  "CompositionEvent": {
    "parent": "UIEvent",
    "properties": [
      ["data", "", "string"],
    ],
  },
};

Object.keys(expected).forEach(function(iface) {
  test(function() {
    var event = new self[iface]("type");
    assert_props(iface, event, true);
  }, iface + " constructor (no argument)");

  test(function() {
    var event = new self[iface]("type", undefined);
    assert_props(iface, event, true);
  }, iface + " constructor (undefined argument)");

  test(function() {
    var event = new self[iface]("type", null);
    assert_props(iface, event, true);
  }, iface + " constructor (null argument)");

  test(function() {
    var event = new self[iface]("type", {});
    assert_props(iface, event, true);
  }, iface + " constructor (empty argument)");

  test(function() {
    var dictionary = {};
    expected[iface].properties.forEach(function(p) {
      var property = p[0], value = p[1];
      dictionary[property] = value;
    });
    var event = new self[iface]("type", dictionary);
    assert_props(iface, event, true);
  }, iface + " constructor (argument with default values)");

  test(function() {
    function fill_in(iface, dictionary) {
      if ("parent" in expected[iface]) {
        fill_in(expected[iface].parent, dictionary)
      }
      expected[iface].properties.forEach(function(p) {
        var property = p[0], value = p[2];
        dictionary[property] = value;
      });
    }

    var dictionary = {};
    fill_in(iface, dictionary);

    var event = new self[iface]("type", dictionary);
    assert_props(iface, event, false);
  }, iface + " constructor (argument with non-default values)");
});

test(function () {
  assert_throws(new TypeError(), function() {
    new UIEvent("x", { view: 7 })
  });
}, "UIEvent constructor (view argument with wrong type)")
</script>