author ziyunfei <446240525@qq.com>
Wed, 07 Jan 2015 01:55:00 -0500
changeset 222767 3b29b9cdedfc4fa4f8b1fc9f4fda385b98905968
parent 222380 0776988aacd6201623ce747940fc7edac89e99d9
child 223165 93c6ac70dc60ec1442c97ee4d22648c3551286fe
permissions -rw-r--r--
Bug 1117350 - Part 2: Implement %TypedArray%.prototype.{reduce, reduceRight}. r=evilpie

<?xml version="1.0"?>
<?xml-stylesheet type="text/css" href="chrome://global/skin"?>
<?xml-stylesheet type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"?>
<window title="Mozilla Bug 933681"
  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"/>

  <!-- test results are displayed in the html:body -->
  <body xmlns="http://www.w3.org/1999/xhtml">
  <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=933681"
     target="_blank">Mozilla Bug 933681</a>

  <!-- test code goes here -->
  <script type="application/javascript">

  /** Test for ES constructors on Xrayed globals. **/
  const Cc = Components.classes;
  const Ci = Components.interfaces;
  const Cu = Components.utils;
  let global = Cu.getGlobalForObject.bind(Cu);

  function checkThrows(f, rgxp, msg) {
    try {
      ok(false, "Should have thrown: " + msg);
    } catch (e) {
      ok(true, "Threw as expected: " + msg);
      ok(rgxp.test(e), "Message correct: " + e);

  typedArrayClasses = ['Uint8Array', 'Int8Array', 'Uint16Array', 'Int16Array',
                       'Uint32Array', 'Int32Array', 'Float32Array', 'Float64Array',
  errorObjectClasses = ['Error', 'InternalError', 'EvalError', 'RangeError', 'ReferenceError',
                        'SyntaxError', 'TypeError', 'URIError'];
  simpleConstructors = ['Object', 'Function', 'Array', 'Boolean', 'Date', 'Number',
                        'String', 'RegExp', 'ArrayBuffer', 'WeakMap', 'Map', 'Set'].concat(typedArrayClasses)

  function go() {
    window.iwin = document.getElementById('ifr').contentWindow;

    // Test constructors that can be instantiated with zero arguments.
    for (var c of simpleConstructors) {
      ok(iwin[c], "Constructors appear: " + c);
      is(iwin[c], Cu.unwaiveXrays(iwin.wrappedJSObject[c]),
         "we end up with the appropriate constructor: " + c);
      is(Cu.unwaiveXrays(Cu.waiveXrays(new iwin[c]).constructor), iwin[c],
         "constructor property is set up right: " + c);
      let expectedProto = /Opaque/.test(new iwin[c]) ? iwin['Object'].prototype
                                                     : iwin[c].prototype;
      is(Object.getPrototypeOf(new iwin[c]), expectedProto,
         "prototype is correct: " + c);
      is(global(new iwin[c]), iwin, "Got the right global: " + c);

    // Test Object in more detail.
    var num = new iwin.Object(4);
    is(Cu.waiveXrays(num).valueOf(), 4, "primitive object construction works");
    is(global(num), iwin, "correct global for num");
    var obj = new iwin.Object();
    obj.foo = 2;
    var withProto = Cu.unwaiveXrays(Cu.waiveXrays(iwin).Object.create(obj));
    is(global(withProto), iwin, "correct global for withProto");
    is(Cu.waiveXrays(withProto).foo, 2, "Inherits properly");

    // Test Function.
    var primitiveFun = new iwin.Function('return 2');
    is(global(primitiveFun), iwin, "function construction works");
    is(primitiveFun(), 2, "basic function works");
    var doSetFoo = new iwin.Function('arg', 'arg.foo = 2;');
    is(global(doSetFoo), iwin, "function with args works");
    try {
      doSetFoo(new Object());
      ok(false, "should have thrown while setting property on object");
    } catch (e) {
      ok(!!/denied/.test(e), "Threw correctly: " + e);
    var factoryFun = new iwin.Function('return {foo: 32}');
    is(global(factoryFun), iwin, "proper global for factoryFun");
    is(factoryFun().foo, 32, "factoryFun invokable");
    is(global(factoryFun()), iwin, "minted objects live in the content scope");
    testXray('Function', factoryFun, new iwin.Function(), ['length', 'name']);
    var echoThis = new iwin.Function('return this;');
    echoThis.wrappedJSObject.bind = 42;
    var boundEchoThis = echoThis.bind(document);
    is(boundEchoThis(), document, "bind() works correctly over Xrays");
    is(global(boundEchoThis), window, "bound functions live in the caller's scope");
    ok(/return this/.test(echoThis.toSource()), 'toSource works: ' + echoThis.toSource());
    ok(/return this/.test(echoThis.toString()), 'toString works: ' + echoThis.toString());
    is(iwin.Function.prototype, Object.getPrototypeOf(echoThis), "Function.prototype works for standard classes");
    is(echoThis.prototype, undefined, "Function.prototype not visible for non standard constructors");
    iwin.eval('var foopyFunction = function namedFoopyFunction(a, b, c) {}');
    var foopyFunction = Cu.unwaiveXrays(Cu.waiveXrays(iwin).foopyFunction);
    ok(Cu.isXrayWrapper(foopyFunction), "Should be Xrays");
    is(foopyFunction.name, "namedFoopyFunction", ".name works over Xrays");
    is(foopyFunction.length, 3, ".length works over Xrays");
    ok(Object.getOwnPropertyNames(foopyFunction).indexOf('length') >= 0, "Should list length");
    ok(Object.getOwnPropertyNames(foopyFunction).indexOf('name') >= 0, "Should list name");
    ok(Object.getOwnPropertyNames(foopyFunction).indexOf('prototype') == -1, "Should not list prototype");
    ok(Object.getOwnPropertyNames(iwin.Array).indexOf('prototype') >= 0, "Should list prototype for standard constructor");

    // Test proxies.
    var targetObject = new iwin.Object();
    targetObject.foo = 9;
    var forwardingProxy = new iwin.Proxy(targetObject, new iwin.Object());
    is(global(forwardingProxy), iwin, "proxy global correct");
    is(Cu.waiveXrays(forwardingProxy).foo, 9, "forwards correctly");

    // Test eval.
    var toEval = "({a: 2, b: {foo: 'bar'}, f: function() { return window; }})";
    is(global(iwin.eval(toEval)), iwin, "eval creates objects in the correct global");
    is(iwin.eval(toEval).b.foo, 'bar', "eval-ed object looks right");
    is(Cu.waiveXrays(iwin.eval(toEval)).f(), Cu.waiveXrays(iwin), "evaled function works right");






    // We could also test DataView and Iterator here for completeness, but it's
    // more trouble than it's worth.


  // Maintain a static list of the properties that are available on each standard
  // prototype, so that we make sure to audit any new ones to make sure they're
  // Xray-safe.
  var version = Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULAppInfo).version;
  var isNightlyBuild = version.endsWith("a1");
  var isReleaseBuild = !version.contains("a");
  const jsHasSymbols = typeof Symbol === "function";
  const kIteratorSymbol = jsHasSymbols ? Symbol.iterator : "@@iterator";
  var gPrototypeProperties = {};
  gPrototypeProperties['Date'] =
    ["getTime", "getTimezoneOffset", "getYear", "getFullYear", "getUTCFullYear",
    "getMonth", "getUTCMonth", "getDate", "getUTCDate", "getDay", "getUTCDay",
    "getHours", "getUTCHours", "getMinutes", "getUTCMinutes", "getSeconds",
    "getUTCSeconds", "getMilliseconds", "getUTCMilliseconds", "setTime",
    "setYear", "setFullYear", "setUTCFullYear", "setMonth", "setUTCMonth",
    "setDate", "setUTCDate", "setHours", "setUTCHours", "setMinutes",
    "setUTCMinutes", "setSeconds", "setUTCSeconds", "setMilliseconds",
    "setUTCMilliseconds", "toUTCString", "toLocaleFormat", "toLocaleString",
    "toLocaleDateString", "toLocaleTimeString", "toDateString", "toTimeString",
    "toISOString", "toJSON", "toSource", "toString", "valueOf", "constructor",
  gPrototypeProperties['Object'] = /* __proto__ is intentionally excluded here, because
                                      the JS engine filters it out of getOwnPropertyNames */
    ["constructor", "toSource", "toString", "toLocaleString", "valueOf", "watch",
     "unwatch", "hasOwnProperty", "isPrototypeOf", "propertyIsEnumerable",
     "__defineGetter__", "__defineSetter__", "__lookupGetter__", "__lookupSetter__"];
  gPrototypeProperties['Array'] =
    ["length", "toSource", "toString", "toLocaleString", "join", "reverse", "sort", "push",
      "pop", "shift", "unshift", "splice", "concat", "slice", "lastIndexOf", "indexOf",
      "forEach", "map", "reduce", "reduceRight", "filter", "some", "every", "find",
      "findIndex", "copyWithin", "fill", kIteratorSymbol, "entries", "keys", "constructor"];
  if (isNightlyBuild) {
  for (var c of typedArrayClasses) {
    gPrototypeProperties[c] = ["constructor", "BYTES_PER_ELEMENT"];
  gPrototypeProperties['TypedArray'] =
    ["length", "buffer", "byteLength", "byteOffset", kIteratorSymbol, "subarray",
     "set", "copyWithin", "find", "findIndex", "indexOf", "lastIndexOf", "reverse",
     "join", "every", "some", "reduce", "reduceRight"];
  if (isNightlyBuild) {
  for (var c of errorObjectClasses) {
      gPrototypeProperties[c] = ["constructor", "name",
                                 // We don't actually resolve these empty data properties
                                 // onto the Xray prototypes, but we list them here to make
                                 // the test happy.
                                 "lineNumber", "columnNumber", "fileName", "message", "stack"];
  // toString and toSource only live on the parent proto (Error.prototype).

  gPrototypeProperties['Function'] =
    ["constructor", "toSource", "toString", "apply", "call", "bind",
     "isGenerator", "length", "name", "arguments", "caller"];
  gPrototypeProperties['Function'] =
    ["constructor", "toSource", "toString", "apply", "call", "bind",
     "isGenerator", "length", "name", "arguments", "caller"];

  // Sort an array that may contain symbols as well as strings.
  function sortProperties(arr) {
    function sortKey(prop) {
      return typeof prop + ":" + prop.toString();
    arr.sort((a, b) => sortKey(a) < sortKey(b) ? -1 : +1);

  // Sort all the lists so we don't need to mutate them later (or copy them
  // again to sort them).
  for (var c of Object.keys(gPrototypeProperties))

  function filterOut(array, props) {
    return array.filter(p => props.indexOf(p) == -1);

  function isTypedArrayClass(classname) {
    return typedArrayClasses.indexOf(classname) >= 0;

  function propertyIsGetter(obj, name, classname) {
    return !!Object.getOwnPropertyDescriptor(obj, name).get;

  function testProtoCallables(protoCallables, xray, xrayProto, localProto) {
    for (let name of protoCallables) {
      info("Running tests for property: " + name);
      // Test both methods and getter properties.
      function lookupCallable(obj) {
        let desc = null;
        do {
          desc = Object.getOwnPropertyDescriptor(obj, name);
          obj = Object.getPrototypeOf(obj);
        } while (!desc);
        return desc.get || desc.value;
      ok(xrayProto.hasOwnProperty(name), "proto should have the property as own");
      ok(!xray.hasOwnProperty(name), "instance should not have the property as own");
      let method = lookupCallable(xrayProto);
      is(typeof method, 'function', "Methods from Xrays are functions");
      is(global(method), window, "Methods from Xrays are local");
      ok(method instanceof Function, "instanceof works on methods from Xrays");
      is(lookupCallable(xrayProto), method, "Holder caching works properly");
      is(lookupCallable(xray), method, "Proto props resolve on the instance");
      let local = lookupCallable(localProto);
      is(method.length, local.length, "Function.length identical");
      if (method.length == 0) {
        is(method.call(xray) + "", local.call(xray) + "",
           "Xray and local method results stringify identically");

        // If invoking this method returns something non-Xrayable, the
        // stringification is going to return [object Opaque]. This happens for
        // xrayedTypedArray.buffer, for instance, since we don't have Xrays
        // to ArrayBuffers. Just check for that case.
        if (!/Opaque/.test(method.call(xray))) {
          is(method.call(xray) + "",
             lookupCallable(xray.wrappedJSObject).call(xray.wrappedJSObject) + "",
             "Xray and waived method results stringify identically");

  function testXray(classname, xray, xray2, propsToSkip) {
    propsToSkip = propsToSkip || [];
    let xrayProto = Object.getPrototypeOf(xray);
    let localProto = window[classname].prototype;
    let desiredProtoProps = Object.getOwnPropertyNames(localProto).sort();

       gPrototypeProperties[classname].filter(id => typeof id === "string").toSource(),
       "A property on the " + classname +
       " prototype has changed! You need a security audit from an XPConnect peer");
    if (jsHasSymbols) {
         gPrototypeProperties[classname].filter(id => typeof id !== "string").map(uneval).sort().toSource(),
         "A symbol-keyed property on the " + classname +
         " prototype has been changed! You need a security audit from an XPConnect peer");

    let protoProps = filterOut(desiredProtoProps, propsToSkip);
    let protoCallables = protoProps.filter(name => propertyIsGetter(localProto, name, classname) ||
                                                   typeof localProto[name] == 'function' &&
                                                   name != 'constructor');
    ok(protoCallables.length > 0, "Need something to test");
    is(xrayProto, iwin[classname].prototype, "Xray proto is correct");
    is(xrayProto, xray.__proto__, "Proto accessors agree");
    var protoProto = classname == "Object" ? null : iwin.Object.prototype;
    is(Object.getPrototypeOf(xrayProto), protoProto, "proto proto is correct");
    testProtoCallables(protoCallables, xray, xrayProto, localProto);
       protoProps.toSource(), "getOwnPropertyNames works");
    if (jsHasSymbols) {
         gPrototypeProperties[classname].filter(id => typeof id !== "string").map(uneval).sort().toSource(),
         protoProps.toSource(), "getOwnPropertySymbols works");

    is(xrayProto.constructor, iwin[classname], "constructor property works");

    xrayProto.expando = 42;
    is(xray.expando, 42, "Xrayed instances see proto expandos");
    is(xray2.expando, 42, "Xrayed instances see proto expandos");

  function testDate() {
    // toGMTString is handled oddly in the engine. We don't bother to support
    // it over Xrays.
    let propsToSkip = ['toGMTString'];

    testXray('Date', new iwin.Date(), new iwin.Date(), propsToSkip);

    // Test the self-hosted toLocaleString.
    var d = new iwin.Date();
    isnot(d.toLocaleString, Cu.unwaiveXrays(d.wrappedJSObject.toLocaleString), "Different function identities");
    is(Cu.getGlobalForObject(d.toLocaleString), window, "Xray global is correct");
    is(Cu.getGlobalForObject(d.wrappedJSObject.toLocaleString), iwin, "Underlying global is correct");
    is(d.toLocaleString('de-DE'), d.wrappedJSObject.toLocaleString('de-DE'), "Results match");

  var uniqueSymbol;

  function testObject() {
    testXray('Object', Cu.unwaiveXrays(Cu.waiveXrays(iwin).Object.create(new iwin.Object())),
             new iwin.Object(), []);

    // Construct an object full of tricky things.
    let symbolProps = '';
    if (jsHasSymbols) {
      uniqueSymbol = iwin.eval('var uniqueSymbol = Symbol("uniqueSymbol"); uniqueSymbol');
      symbolProps = `, [uniqueSymbol]: 43,
                     [Symbol.for("registrySymbolProp")]: 44`;
    var trickyObject =
      iwin.eval(`(function() {
                 var o = new Object({
                   primitiveProp: 42, objectProp: { foo: 2 },
                   xoProp: top.location, hasOwnProperty: 10,
                   get getterProp() { return 2; },
                   set setterProp(x) { },
                   get getterSetterProp() { return 3; },
                   set getterSetterProp(x) { },
                   callableProp: function() { },
                   nonXrayableProp: new WeakMap()
                 Object.defineProperty(o, "nonConfigurableGetterSetterProp",
                    { get: function() { return 5; }, set: function() {} });
                 return o;

  function testArray() {
    // The |length| property is generally very weird, especially with respect
    // to its behavior on the prototype. Array.prototype is actually an Array
    // instance, and therefore has a vestigial .length. But we don't want to
    // show that over Xrays, and generally want .length to just appear as an
    // |own| data property. So we add it to the ignore list here, and check it
    // separately.
    let propsToSkip = ['length'];
    testXray('Array', new iwin.Array(20), new iwin.Array(), propsToSkip);

    let symbolProps = '';
    if (jsHasSymbols) {
      uniqueSymbol = iwin.eval('var uniqueSymbol = Symbol("uniqueSymbol"); uniqueSymbol');
      symbolProps = `trickyArray[uniqueSymbol] = 43;
                     trickyArray[Symbol.for("registrySymbolProp")] = 44;`;
    var trickyArray =
      iwin.eval(`var trickyArray = [];
                 trickyArray.primitiveProp = 42;
                 trickyArray.objectProp = { foo: 2 };
                 trickyArray.xoProp = top.location;
                 trickyArray.hasOwnProperty = 10;
                 Object.defineProperty(trickyArray, 'getterProp', { get: function() { return 2; }});
                 Object.defineProperty(trickyArray, 'setterProp', { set: function(x) {}});
                 Object.defineProperty(trickyArray, 'getterSetterProp', { get: function() { return 3; }, set: function(x) {}, configurable: true});
                 Object.defineProperty(trickyArray, 'nonConfigurableGetterSetterProp', { get: function() { return 5; }, set: function(x) {}});
                 trickyArray.callableProp = function() {};
                 trickyArray.nonXrayableProp = new WeakMap();

    // Test indexed access.
    trickyArray.wrappedJSObject[9] = "some indexed property";
    is(trickyArray[9], "some indexed property", "indexed properties work correctly over Xrays");
    is(trickyArray.length, 10, "Length works correctly over Xrays");
    checkThrows(function() { "use strict"; delete trickyArray.length; }, /config/, "Can't delete non-configurable 'length' property");
    delete trickyArray[9];
    is(trickyArray[9], undefined, "Delete works correctly over Xrays");
    is(trickyArray.wrappedJSObject[9], undefined, "Delete works correctly over Xrays (viewed via waiver)");
    is(trickyArray.length, 10, "length doesn't change");
    trickyArray[11] = "some other indexed property";
    is(trickyArray.length, 12, "length now changes");
    is(trickyArray.wrappedJSObject[11], "some other indexed property");
    trickyArray.length = 0;
    is(trickyArray.length, 0, "Setting length works over Xray");
    is(trickyArray[11], undefined, "Setting length truncates over Xray");
    Object.defineProperty(trickyArray, 'length', { configurable: false, enumerable: false, writable: false, value: 0 });
    trickyArray[1] = "hi";
    is(trickyArray.length, 0, "Length remains non-writable");
    is(trickyArray[1], undefined, "Frozen length forbids new properties");


  // Parts of this function are kind of specific to testing Object, but we factor
  // it out so that we can re-use the trickyObject stuff on Arrays.
  function testTrickyObject(trickyObject) {

    // Make sure it looks right under the hood.
    is(trickyObject.wrappedJSObject.getterProp, 2, "Underlying object has getter");
    is(Cu.unwaiveXrays(trickyObject.wrappedJSObject.xoProp), top.location, "Underlying object has xo property");

    // Test getOwnPropertyNames.
    var expectedNames = ['objectProp', 'primitiveProp'];
    if (trickyObject instanceof iwin.Array)
       expectedNames.sort().toSource(), "getOwnPropertyNames should be filtered correctly");
    if (jsHasSymbols) {
      var expectedSymbols = [Symbol.for("registrySymbolProp"), uniqueSymbol];
         "getOwnPropertySymbols should be filtered correctly");

    // Test that cloning uses the Xray view.
    var cloned = Cu.cloneInto(trickyObject, this);
       expectedNames.sort().toSource(), "structured clone should use the Xray view");
    if (jsHasSymbols) {
         "[]", "structured cloning doesn't clone symbol-keyed properties yet");

    // Test iteration and in-place modification. Beware of 'expando', which is the property
    // we placed on the xray proto.
    var propCount = 0;
    for (let prop in trickyObject) {
      if (prop == 'primitiveProp')
        trickyObject[prop] = trickyObject[prop] - 10;
      if (prop != 'expando')
        trickyObject[prop] = trickyObject[prop];
    is(propCount, 3, "Should iterate the correct number of times");

    // Test Object.keys.
       ['objectProp', 'primitiveProp'].toSource(), "Object.keys should be filtered correctly");

    // Test getOwnPropertyDescriptor.
    is(trickyObject.primitiveProp, 32, "primitive prop works");
    is(trickyObject.objectProp.foo, 2, "object prop works");
    is(typeof trickyObject.callableProp, 'undefined', "filtering works correctly");
    is(Object.getOwnPropertyDescriptor(trickyObject, 'primitiveProp').value, 32, "getOwnPropertyDescriptor works");
    is(Object.getOwnPropertyDescriptor(trickyObject, 'xoProp'), undefined, "filtering works with getOwnPropertyDescriptor");

    // Test defineProperty.

    trickyObject.primitiveSetByXray = 'fourty two';
    is(trickyObject.primitiveSetByXray, 'fourty two', "Can set primitive correctly over Xray (ready via Xray)");
    is(trickyObject.wrappedJSObject.primitiveSetByXray, 'fourty two', "Can set primitive correctly over Xray (ready via Waiver)");

    var newContentObject = iwin.eval('new Object({prop: 99, get getterProp() { return 2; }})');
    trickyObject.objectSetByXray = newContentObject;
    is(trickyObject.objectSetByXray.prop, 99, "Can set object correctly over Xray (ready via Xray)");
    is(trickyObject.wrappedJSObject.objectSetByXray.prop, 99, "Can set object correctly over Xray (ready via Waiver)");
    checkThrows(function() { trickyObject.rejectedProp = {foo: 33}}, /cross-origin object/,
                "Should reject privileged object property definition");

    // Test JSON.stringify.
    var jsonStr = JSON.stringify(newContentObject);
    ok(/prop/.test(jsonStr), "JSON stringification should work: " + jsonStr);

    // Test deletion.
    delete newContentObject.prop;
    ok(!newContentObject.hasOwnProperty('prop'), "Deletion should work");
    ok(!newContentObject.wrappedJSObject.hasOwnProperty('prop'), "Deletion should forward");
    delete newContentObject.getterProp;
    ok(newContentObject.wrappedJSObject.hasOwnProperty('getterProp'), "Deletion be no-op for filtered property");

    // We should be able to overwrite an existing accessor prop and convert it
    // to a value prop.
    is(trickyObject.wrappedJSObject.getterSetterProp, 3, "Underlying object has getter");
    is(trickyObject.getterSetterProp, undefined, "Filtering properly over Xray");
    trickyObject.getterSetterProp = 'redefined';
    is(trickyObject.getterSetterProp, 'redefined', "Redefinition works");
    is(trickyObject.wrappedJSObject.getterSetterProp, 'redefined', "Redefinition forwards");

    // We should NOT be able to overwrite an existing non-configurable accessor
    // prop, though.
    is(trickyObject.wrappedJSObject.nonConfigurableGetterSetterProp, 5,
       "Underlying object has getter");
    is(trickyObject.nonConfigurableGetterSetterProp, undefined,
       "Filtering properly over Xray here too");
    checkThrows(function() {
	trickyObject.nonConfigurableGetterSetterProp = 'redefined';
    }, /config/, "Should throw when redefining non-configurable prop");
    is(trickyObject.nonConfigurableGetterSetterProp, undefined,
       "Redefinition should have thrown");
    is(trickyObject.wrappedJSObject.nonConfigurableGetterSetterProp, 5,
       "Redefinition really should have thrown");

    checkThrows(function() { trickyObject.hasOwnProperty = 33; }, /shadow/,
                "Should reject shadowing of pre-existing inherited properties over Xrays");

    checkThrows(function() { Object.defineProperty(trickyObject, 'rejectedProp', { get: function() {}}); },
                /accessor property/, "Should reject accessor property definition");

  function testTypedArrays() {
    // We don't invoke testXray with %TypedArray%, because that function isn't
    // set up to deal with "anonymous" dependent classes (that is, classes not
    // visible as a global property, which %TypedArray% is not), and fixing it
    // up is more trouble than it's worth.

    var typedArrayProto = Object.getPrototypeOf(Int8Array.prototype);

    var desiredInheritedProps = Object.getOwnPropertyNames(typedArrayProto).sort();
    var inheritedProps =
      filterOut(desiredInheritedProps, ["BYTES_PER_ELEMENT", "constructor"]);

    var inheritedCallables =
      inheritedProps.filter(name => (propertyIsGetter(typedArrayProto, name) ||
                                     typeof typedArrayProto[name] === "function") &&
                                    name !== "constructor");

    for (var c of typedArrayClasses) {
      var t = new iwin[c](10);
      checkThrows(function() { t[2]; }, /performant/, "direct property-wise reading of typed arrays forbidden over Xrays");
      checkThrows(function() { t[2] = 3; }, /performant/, "direct property-wise writing of typed arrays forbidden over Xrays");
      t.wrappedJSObject[2] = 3;
      is(t.wrappedJSObject[2], 3, "accessing elements over waivers works");
      t.wrappedJSObject.expando = 'hi';
      is(t.wrappedJSObject.expando, 'hi', "access expandos over waivers works");
      is(Cu.cloneInto(t, window)[2], 3, "cloneInto works");
      is(Cu.cloneInto(t, window).expando, undefined, "cloneInto does not copy expandos");
         '["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]',
         "Only indexed properties visible over Xrays");
      Object.defineProperty(t.wrappedJSObject, 'length', {value: 42});
      is(t.wrappedJSObject.length, 42, "Set tricky expando")
      is(t.length, 10, "Length accessor works over Xrays")
      is(t.byteLength, t.length * window[c].prototype.BYTES_PER_ELEMENT, "byteLength accessor works over Xrays")

      var xray = new iwin[c](0);
      var xrayTypedArrayProto = Object.getPrototypeOf(Object.getPrototypeOf(xray));
      testProtoCallables(inheritedCallables, new iwin[c](0), xrayTypedArrayProto, typedArrayProto);

  function testErrorObjects() {
    // We only invoke testXray with Error, because that function isn't set up
    // to deal with dependent classes and fixing it up is more trouble than
    // it's worth.
    testXray('Error', new iwin.Error('some error message'), new iwin.Error(),
             ['fileName', 'lineNumber', 'columnNumber', 'message', 'stack']);

    // Make sure that the dependent classes have their prototypes set up correctly.
    for (let c of errorObjectClasses.filter(x => x != "Error")) {
      var e = new iwin[c]('some message');
      is(Object.getPrototypeOf(e).name, c, "Prototype has correct name");
      is(Object.getPrototypeOf(Object.getPrototypeOf(e)), iwin.Error.prototype, "Dependent prototype set up correctly");
      is(e.name, c, "Exception name inherited correctly");

      function testProperty(name, criterion, goodReplacement, faultyReplacement) {
        ok(criterion(e[name]), name + " property is correct: " + e[name]);
        e.wrappedJSObject[name] = goodReplacement;
        is(e[name], goodReplacement, name + " property ok after replacement: " + goodReplacement);
        e.wrappedJSObject[name] = faultyReplacement;
        is(e[name], undefined, name + " property censored after suspicious replacement");
      testProperty('message', x => x == 'some message', 'some other message', 42);
      testProperty('fileName', x => /xul/.test(x), 'otherFilename.html', new iwin.Object());
      // Note - an Exception newed via Xrays is going to have an empty stack given the
      // current semantics and implementation. This tests the current behavior, but that
      // may change in bug 1036527 or similar.
      testProperty('stack', x => /^\s*$/.test(x), 'some other stack', new iwin.WeakMap());
      testProperty('columnNumber', x => x > 5 && x < 100, 99, 99.5);
      testProperty('lineNumber', x => x > 100 && x < 10000, 50, 'foo');

  <iframe id="ifr" onload="go();" src="http://example.org/tests/js/xpconnect/tests/mochitest/file_empty.html" />