Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1685 insertions, 0 deletions

diff --git a/dom/imptests/idlharness.js b/dom/imptests/idlharness.js
new file mode 100644
index 0000000000..b49e7dec4c
--- /dev/null
+++ b/dom/imptests/idlharness.js
@@ -0,0 +1,1685 @@
+/*
+Distributed under both the W3C Test Suite License [1] and the W3C
+3-clause BSD License [2]. To contribute to a W3C Test Suite, see the
+policies and contribution forms [3].
+
+[1] http://www.w3.org/Consortium/Legal/2008/04-testsuite-license
+[2] http://www.w3.org/Consortium/Legal/2008/03-bsd-license
+[3] http://www.w3.org/2004/10/27-testcases
+*/
+
+/* For user documentation see docs/idlharness.md */
+
+/**
+ * Notes for people who want to edit this file (not just use it as a library):
+ *
+ * Most of the interesting stuff happens in the derived classes of IdlObject,
+ * especially IdlInterface.  The entry point for all IdlObjects is .test(),
+ * which is called by IdlArray.test().  An IdlObject is conceptually just
+ * "thing we want to run tests on", and an IdlArray is an array of IdlObjects
+ * with some additional data thrown in.
+ *
+ * The object model is based on what WebIDLParser.js produces, which is in turn
+ * based on its pegjs grammar.  If you want to figure out what properties an
+ * object will have from WebIDLParser.js, the best way is to look at the
+ * grammar:
+ *
+ *   https://github.com/darobin/webidl.js/blob/master/lib/grammar.peg
+ *
+ * So for instance:
+ *
+ *   // interface definition
+ *   interface
+ *       =   extAttrs:extendedAttributeList? S? "interface" S name:identifier w herit:ifInheritance? w "{" w mem:ifMember* w "}" w ";" w
+ *           { return { type: "interface", name: name, inheritance: herit, members: mem, extAttrs: extAttrs }; }
+ *
+ * This means that an "interface" object will have a .type property equal to
+ * the string "interface", a .name property equal to the identifier that the
+ * parser found, an .inheritance property equal to either null or the result of
+ * the "ifInheritance" production found elsewhere in the grammar, and so on.
+ * After each grammatical production is a JavaScript function in curly braces
+ * that gets called with suitable arguments and returns some JavaScript value.
+ *
+ * (Note that the version of WebIDLParser.js we use might sometimes be
+ * out-of-date or forked.)
+ *
+ * The members and methods of the classes defined by this file are all at least
+ * briefly documented, hopefully.
+ */
+(function(){
+"use strict";
+/// Helpers ///
+function constValue (cnt) {
+    if (cnt.type === "null") return null;
+    if (cnt.type === "NaN") return NaN;
+    if (cnt.type === "Infinity") return cnt.negative ? -Infinity : Infinity;
+    return cnt.value;
+}
+
+function minOverloadLength(overloads) {
+    if (!overloads.length) {
+        return 0;
+    }
+
+    return overloads.map(function(attr) {
+        return attr.arguments ? attr.arguments.filter(function(arg) {
+            return !arg.optional && !arg.variadic;
+        }).length : 0;
+    })
+    .reduce(function(m, n) { return Math.min(m, n); });
+}
+
+/// IdlArray ///
+// Entry point
+self.IdlArray = function()
+//@{
+{
+    /**
+     * A map from strings to the corresponding named IdlObject, such as
+     * IdlInterface or IdlException.  These are the things that test() will run
+     * tests on.
+     */
+    this.members = {};
+
+    /**
+     * A map from strings to arrays of strings.  The keys are interface or
+     * exception names, and are expected to also exist as keys in this.members
+     * (otherwise they'll be ignored).  This is populated by add_objects() --
+     * see documentation at the start of the file.  The actual tests will be
+     * run by calling this.members[name].test_object(obj) for each obj in
+     * this.objects[name].  obj is a string that will be eval'd to produce a
+     * JavaScript value, which is supposed to be an object implementing the
+     * given IdlObject (interface, exception, etc.).
+     */
+    this.objects = {};
+
+    /**
+     * When adding multiple collections of IDLs one at a time, an earlier one
+     * might contain a partial interface or implements statement that depends
+     * on a later one.  Save these up and handle them right before we run
+     * tests.
+     *
+     * .partials is simply an array of objects from WebIDLParser.js'
+     * "partialinterface" production.  .implements maps strings to arrays of
+     * strings, such that
+     *
+     *   A implements B;
+     *   A implements C;
+     *   D implements E;
+     *
+     * results in { A: ["B", "C"], D: ["E"] }.
+     */
+    this.partials = [];
+    this["implements"] = {};
+};
+
+//@}
+IdlArray.prototype.add_idls = function(raw_idls)
+//@{
+{
+    /** Entry point.  See documentation at beginning of file. */
+    this.internal_add_idls(WebIDL2.parse(raw_idls));
+};
+
+//@}
+IdlArray.prototype.add_untested_idls = function(raw_idls)
+//@{
+{
+    /** Entry point.  See documentation at beginning of file. */
+    var parsed_idls = WebIDL2.parse(raw_idls);
+    for (var i = 0; i < parsed_idls.length; i++)
+    {
+        parsed_idls[i].untested = true;
+        if ("members" in parsed_idls[i])
+        {
+            for (var j = 0; j < parsed_idls[i].members.length; j++)
+            {
+                parsed_idls[i].members[j].untested = true;
+            }
+        }
+    }
+    this.internal_add_idls(parsed_idls);
+};
+
+//@}
+IdlArray.prototype.internal_add_idls = function(parsed_idls)
+//@{
+{
+    /**
+     * Internal helper called by add_idls() and add_untested_idls().
+     * parsed_idls is an array of objects that come from WebIDLParser.js's
+     * "definitions" production.  The add_untested_idls() entry point
+     * additionally sets an .untested property on each object (and its
+     * .members) so that they'll be skipped by test() -- they'll only be
+     * used for base interfaces of tested interfaces, return types, etc.
+     */
+    parsed_idls.forEach(parsed_idl => {
+        if (parsed_idl.type == "interface" && parsed_idl.partial)
+        {
+            this.partials.push(parsed_idl);
+            return;
+        }
+
+        if (parsed_idl.type == "implements")
+        {
+            if (!(parsed_idl.target in this["implements"]))
+            {
+                this["implements"][parsed_idl.target] = [];
+            }
+            this["implements"][parsed_idl.target].push(parsed_idl["implements"]);
+            return;
+        }
+
+        parsed_idl.array = this;
+        if (parsed_idl.name in this.members)
+        {
+            throw "Duplicate identifier " + parsed_idl.name;
+        }
+        switch(parsed_idl.type)
+        {
+        case "interface":
+            this.members[parsed_idl.name] =
+                new IdlInterface(parsed_idl, /* is_callback = */ false);
+            break;
+
+        case "dictionary":
+            // Nothing to test, but we need the dictionary info around for type
+            // checks
+            this.members[parsed_idl.name] = new IdlDictionary(parsed_idl);
+            break;
+
+        case "typedef":
+            this.members[parsed_idl.name] = new IdlTypedef(parsed_idl);
+            break;
+
+        case "callback":
+            // TODO
+            console.log("callback not yet supported");
+            break;
+
+        case "enum":
+            this.members[parsed_idl.name] = new IdlEnum(parsed_idl);
+            break;
+
+        case "callback interface":
+            this.members[parsed_idl.name] =
+                new IdlInterface(parsed_idl, /* is_callback = */ true);
+            break;
+
+        default:
+            throw parsed_idl.name + ": " + parsed_idl.type + " not yet supported";
+        }
+    });
+};
+
+//@}
+IdlArray.prototype.add_objects = function(dict)
+//@{
+{
+    /** Entry point.  See documentation at beginning of file. */
+    for (var k in dict)
+    {
+        if (k in this.objects)
+        {
+            this.objects[k] = this.objects[k].concat(dict[k]);
+        }
+        else
+        {
+            this.objects[k] = dict[k];
+        }
+    }
+};
+
+//@}
+IdlArray.prototype.prevent_multiple_testing = function(name)
+//@{
+{
+    /** Entry point.  See documentation at beginning of file. */
+    this.members[name].prevent_multiple_testing = true;
+};
+
+//@}
+IdlArray.prototype.recursively_get_implements = function(interface_name)
+//@{
+{
+    /**
+     * Helper function for test().  Returns an array of things that implement
+     * interface_name, so if the IDL contains
+     *
+     *   A implements B;
+     *   B implements C;
+     *   B implements D;
+     *
+     * then recursively_get_implements("A") should return ["B", "C", "D"].
+     */
+    var ret = this["implements"][interface_name];
+    if (ret === undefined)
+    {
+        return [];
+    }
+    for (var i = 0; i < this["implements"][interface_name].length; i++)
+    {
+        ret = ret.concat(this.recursively_get_implements(ret[i]));
+        if (ret.indexOf(ret[i]) != ret.lastIndexOf(ret[i]))
+        {
+            throw "Circular implements statements involving " + ret[i];
+        }
+    }
+    return ret;
+};
+
+//@}
+IdlArray.prototype.test = function()
+//@{
+{
+    /** Entry point.  See documentation at beginning of file. */
+
+    // First merge in all the partial interfaces and implements statements we
+    // encountered.
+    this.partials.forEach(parsed_idl => {
+        if (!(parsed_idl.name in this.members)
+        || !(this.members[parsed_idl.name] instanceof IdlInterface))
+        {
+            throw "Partial interface " + parsed_idl.name + " with no original interface";
+        }
+        if (parsed_idl.extAttrs)
+        {
+            parsed_idl.extAttrs.forEach(extAttr => {
+                this.members[parsed_idl.name].extAttrs.push(extAttr);
+            });
+        }
+        parsed_idl.members.forEach(member => {
+            this.members[parsed_idl.name].members.push(new IdlInterfaceMember(member));
+        });
+    });
+    this.partials = [];
+
+    for (var lhs in this["implements"])
+    {
+        this.recursively_get_implements(lhs).forEach(rhs => {
+            var errStr = lhs + " implements " + rhs + ", but ";
+            if (!(lhs in this.members)) throw errStr + lhs + " is undefined.";
+            if (!(this.members[lhs] instanceof IdlInterface)) throw errStr + lhs + " is not an interface.";
+            if (!(rhs in this.members)) throw errStr + rhs + " is undefined.";
+            if (!(this.members[rhs] instanceof IdlInterface)) throw errStr + rhs + " is not an interface.";
+            this.members[rhs].members.forEach(member => {
+                this.members[lhs].members.push(new IdlInterfaceMember(member));
+            });
+        });
+    }
+    this["implements"] = {};
+
+    // Now run test() on every member, and test_object() for every object.
+    for (var name in this.members)
+    {
+        this.members[name].test();
+        if (name in this.objects)
+        {
+            this.objects[name].forEach(str => {
+                this.members[name].test_object(str);
+            });
+        }
+    }
+};
+
+//@}
+IdlArray.prototype.assert_type_is = function(value, type)
+//@{
+{
+    /**
+     * Helper function that tests that value is an instance of type according
+     * to the rules of WebIDL.  value is any JavaScript value, and type is an
+     * object produced by WebIDLParser.js' "type" production.  That production
+     * is fairly elaborate due to the complexity of WebIDL's types, so it's
+     * best to look at the grammar to figure out what properties it might have.
+     */
+    if (type.idlType == "any")
+    {
+        // No assertions to make
+        return;
+    }
+
+    if (type.nullable && value === null)
+    {
+        // This is fine
+        return;
+    }
+
+    if (type.array)
+    {
+        // TODO: not supported yet
+        return;
+    }
+
+    if (type.sequence)
+    {
+        assert_true(Array.isArray(value), "is not array");
+        if (!value.length)
+        {
+            // Nothing we can do.
+            return;
+        }
+        this.assert_type_is(value[0], type.idlType.idlType);
+        return;
+    }
+
+    type = type.idlType;
+
+    switch(type)
+    {
+        case "void":
+            assert_equals(value, undefined);
+            return;
+
+        case "boolean":
+            assert_equals(typeof value, "boolean");
+            return;
+
+        case "byte":
+            assert_equals(typeof value, "number");
+            assert_equals(value, Math.floor(value), "not an integer");
+            assert_true(-128 <= value && value <= 127, "byte " + value + " not in range [-128, 127]");
+            return;
+
+        case "octet":
+            assert_equals(typeof value, "number");
+            assert_equals(value, Math.floor(value), "not an integer");
+            assert_true(0 <= value && value <= 255, "octet " + value + " not in range [0, 255]");
+            return;
+
+        case "short":
+            assert_equals(typeof value, "number");
+            assert_equals(value, Math.floor(value), "not an integer");
+            assert_true(-32768 <= value && value <= 32767, "short " + value + " not in range [-32768, 32767]");
+            return;
+
+        case "unsigned short":
+            assert_equals(typeof value, "number");
+            assert_equals(value, Math.floor(value), "not an integer");
+            assert_true(0 <= value && value <= 65535, "unsigned short " + value + " not in range [0, 65535]");
+            return;
+
+        case "long":
+            assert_equals(typeof value, "number");
+            assert_equals(value, Math.floor(value), "not an integer");
+            assert_true(-2147483648 <= value && value <= 2147483647, "long " + value + " not in range [-2147483648, 2147483647]");
+            return;
+
+        case "unsigned long":
+            assert_equals(typeof value, "number");
+            assert_equals(value, Math.floor(value), "not an integer");
+            assert_true(0 <= value && value <= 4294967295, "unsigned long " + value + " not in range [0, 4294967295]");
+            return;
+
+        case "long long":
+            assert_equals(typeof value, "number");
+            return;
+
+        case "unsigned long long":
+        case "EpochTimeStamp":
+        case "DOMTimeStamp":
+            assert_equals(typeof value, "number");
+            assert_true(0 <= value, "unsigned long long is negative");
+            return;
+
+        case "float":
+        case "double":
+        case "DOMHighResTimeStamp":
+        case "unrestricted float":
+        case "unrestricted double":
+            // TODO: distinguish these cases
+            assert_equals(typeof value, "number");
+            return;
+
+        case "DOMString":
+        case "ByteString":
+        case "USVString":
+            // TODO: https://github.com/w3c/testharness.js/issues/92
+            assert_equals(typeof value, "string");
+            return;
+
+        case "object":
+            assert_true(typeof value == "object" || typeof value == "function", "wrong type: not object or function");
+            return;
+    }
+
+    if (!(type in this.members))
+    {
+        throw "Unrecognized type " + type;
+    }
+
+    if (this.members[type] instanceof IdlInterface)
+    {
+        // We don't want to run the full
+        // IdlInterface.prototype.test_instance_of, because that could result
+        // in an infinite loop.  TODO: This means we don't have tests for
+        // NoInterfaceObject interfaces, and we also can't test objects that
+        // come from another self.
+        assert_true(typeof value == "object" || typeof value == "function", "wrong type: not object or function");
+        if (value instanceof Object
+        && !this.members[type].has_extended_attribute("NoInterfaceObject")
+        && type in self)
+        {
+            assert_true(value instanceof self[type], "not instanceof " + type);
+        }
+    }
+    else if (this.members[type] instanceof IdlEnum)
+    {
+        assert_equals(typeof value, "string");
+    }
+    else if (this.members[type] instanceof IdlDictionary)
+    {
+        // TODO: Test when we actually have something to test this on
+    }
+    else if (this.members[type] instanceof IdlTypedef)
+    {
+        // TODO: Test when we actually have something to test this on
+    }
+    else
+    {
+        throw "Type " + type + " isn't an interface or dictionary";
+    }
+};
+//@}
+
+/// IdlObject ///
+function IdlObject() {}
+IdlObject.prototype.test = function()
+//@{
+{
+    /**
+     * By default, this does nothing, so no actual tests are run for IdlObjects
+     * that don't define any (e.g., IdlDictionary at the time of this writing).
+     */
+};
+
+//@}
+IdlObject.prototype.has_extended_attribute = function(name)
+//@{
+{
+    /**
+     * This is only meaningful for things that support extended attributes,
+     * such as interfaces, exceptions, and members.
+     */
+    return this.extAttrs.some(function(o)
+    {
+        return o.name == name;
+    });
+};
+
+//@}
+
+/// IdlDictionary ///
+// Used for IdlArray.prototype.assert_type_is
+function IdlDictionary(obj)
+//@{
+{
+    /**
+     * obj is an object produced by the WebIDLParser.js "dictionary"
+     * production.
+     */
+
+    /** Self-explanatory. */
+    this.name = obj.name;
+
+    /** An array of objects produced by the "dictionaryMember" production. */
+    this.members = obj.members;
+
+    /**
+     * The name (as a string) of the dictionary type we inherit from, or null
+     * if there is none.
+     */
+    this.base = obj.inheritance;
+}
+
+//@}
+IdlDictionary.prototype = Object.create(IdlObject.prototype);
+
+/// IdlInterface ///
+function IdlInterface(obj, is_callback) {
+    /**
+     * obj is an object produced by the WebIDLParser.js "exception" or
+     * "interface" production, as appropriate.
+     */
+
+    /** Self-explanatory. */
+    this.name = obj.name;
+
+    /** A back-reference to our IdlArray. */
+    this.array = obj.array;
+
+    /**
+     * An indicator of whether we should run tests on the (exception) interface
+     * object and (exception) interface prototype object.  Tests on members are
+     * controlled by .untested on each member, not this.
+     */
+    this.untested = obj.untested;
+
+    /** An array of objects produced by the "ExtAttr" production. */
+    this.extAttrs = obj.extAttrs;
+
+    /** An array of IdlInterfaceMembers. */
+    this.members = obj.members.map(function(m){return new IdlInterfaceMember(m); });
+    if (this.has_extended_attribute("Unforgeable")) {
+        this.members
+            .filter(function(m) { return !m["static"] && (m.type == "attribute" || m.type == "operation"); })
+            .forEach(function(m) { return m.isUnforgeable = true; });
+    }
+
+    /**
+     * The name (as a string) of the type we inherit from, or null if there is
+     * none.
+     */
+    this.base = obj.inheritance;
+
+    this._is_callback = is_callback;
+}
+IdlInterface.prototype = Object.create(IdlObject.prototype);
+IdlInterface.prototype.is_callback = function()
+//@{
+{
+    return this._is_callback;
+};
+//@}
+
+IdlInterface.prototype.has_constants = function()
+//@{
+{
+    return this.members.some(function(member) {
+        return member.type === "const";
+    });
+};
+//@}
+
+IdlInterface.prototype.is_global = function()
+//@{
+{
+    return this.extAttrs.some(function(attribute) {
+        return attribute.name === "Global" ||
+               attribute.name === "PrimaryGlobal";
+    });
+};
+//@}
+
+IdlInterface.prototype.test = function()
+//@{
+{
+    if (this.has_extended_attribute("NoInterfaceObject"))
+    {
+        // No tests to do without an instance.  TODO: We should still be able
+        // to run tests on the prototype object, if we obtain one through some
+        // other means.
+        return;
+    }
+
+    if (!this.untested)
+    {
+        // First test things to do with the exception/interface object and
+        // exception/interface prototype object.
+        this.test_self();
+    }
+    // Then test things to do with its members (constants, fields, attributes,
+    // operations, . . .).  These are run even if .untested is true, because
+    // members might themselves be marked as .untested.  This might happen to
+    // interfaces if the interface itself is untested but a partial interface
+    // that extends it is tested -- then the interface itself and its initial
+    // members will be marked as untested, but the members added by the partial
+    // interface are still tested.
+    this.test_members();
+};
+//@}
+
+IdlInterface.prototype.test_self = function()
+//@{
+{
+    test(() => {
+        // This function tests WebIDL as of 2015-01-13.
+        // TODO: Consider [Exposed].
+
+        // "For every interface that is exposed in a given ECMAScript global
+        // environment and:
+        // * is a callback interface that has constants declared on it, or
+        // * is a non-callback interface that is not declared with the
+        //   [NoInterfaceObject] extended attribute,
+        // a corresponding property MUST exist on the ECMAScript global object.
+        // The name of the property is the identifier of the interface, and its
+        // value is an object called the interface object.
+        // The property has the attributes { [[Writable]]: true,
+        // [[Enumerable]]: false, [[Configurable]]: true }."
+        if (this.is_callback() && !this.has_constants()) {
+            return;
+        }
+
+        // TODO: Should we test here that the property is actually writable
+        // etc., or trust getOwnPropertyDescriptor?
+        assert_own_property(self, this.name,
+                            "self does not have own property " + format_value(this.name));
+        var desc = Object.getOwnPropertyDescriptor(self, this.name);
+        assert_false("get" in desc, "self's property " + format_value(this.name) + " has getter");
+        assert_false("set" in desc, "self's property " + format_value(this.name) + " has setter");
+        assert_true(desc.writable, "self's property " + format_value(this.name) + " is not writable");
+        assert_false(desc.enumerable, "self's property " + format_value(this.name) + " is enumerable");
+        assert_true(desc.configurable, "self's property " + format_value(this.name) + " is not configurable");
+
+        if (this.is_callback()) {
+            // "The internal [[Prototype]] property of an interface object for
+            // a callback interface MUST be the Object.prototype object."
+            assert_equals(Object.getPrototypeOf(self[this.name]), Object.prototype,
+                          "prototype of self's property " + format_value(this.name) + " is not Object.prototype");
+
+            return;
+        }
+
+        // "The interface object for a given non-callback interface is a
+        // function object."
+        // "If an object is defined to be a function object, then it has
+        // characteristics as follows:"
+
+        // Its [[Prototype]] internal property is otherwise specified (see
+        // below).
+
+        // "* Its [[Get]] internal property is set as described in ECMA-262
+        //    section 9.1.8."
+        // Not much to test for this.
+
+        // "* Its [[Construct]] internal property is set as described in
+        //    ECMA-262 section 19.2.2.3."
+        // Tested below if no constructor is defined.  TODO: test constructors
+        // if defined.
+
+        // "* Its @@hasInstance property is set as described in ECMA-262
+        //    section 19.2.3.8, unless otherwise specified."
+        // TODO
+
+        // ES6 (rev 30) 19.1.3.6:
+        // "Else, if O has a [[Call]] internal method, then let builtinTag be
+        // "Function"."
+        assert_class_string(self[this.name], "Function", "class string of " + this.name);
+
+        // "The [[Prototype]] internal property of an interface object for a
+        // non-callback interface is determined as follows:"
+        var prototype = Object.getPrototypeOf(self[this.name]);
+        if (this.base) {
+            // "* If the interface inherits from some other interface, the
+            //    value of [[Prototype]] is the interface object for that other
+            //    interface."
+            var has_interface_object =
+                !this.array
+                     .members[this.base]
+                     .has_extended_attribute("NoInterfaceObject");
+            if (has_interface_object) {
+                assert_own_property(self, this.base,
+                                    'should inherit from ' + this.base +
+                                    ', but self has no such property');
+                assert_equals(prototype, self[this.base],
+                              'prototype of ' + this.name + ' is not ' +
+                              this.base);
+            }
+        } else {
+            // "If the interface doesn't inherit from any other interface, the
+            // value of [[Prototype]] is %FunctionPrototype% ([ECMA-262],
+            // section 6.1.7.4)."
+            assert_equals(prototype, Function.prototype,
+                          "prototype of self's property " + format_value(this.name) + " is not Function.prototype");
+        }
+
+        if (!this.has_extended_attribute("Constructor")) {
+            // "The internal [[Call]] method of the interface object behaves as
+            // follows . . .
+            //
+            // "If I was not declared with a [Constructor] extended attribute,
+            // then throw a TypeError."
+            assert_throws(new TypeError(), () => {
+                self[this.name]();
+            }, "interface object didn't throw TypeError when called as a function");
+            assert_throws(new TypeError(), () => {
+                new self[this.name]();
+            }, "interface object didn't throw TypeError when called as a constructor");
+        }
+    }, this.name + " interface: existence and properties of interface object");
+
+    if (!this.is_callback()) {
+        test(() => {
+            // This function tests WebIDL as of 2014-10-25.
+            // https://heycam.github.io/webidl/#es-interface-call
+
+            assert_own_property(self, this.name,
+                                "self does not have own property " + format_value(this.name));
+
+            // "Interface objects for non-callback interfaces MUST have a
+            // property named “length” with attributes { [[Writable]]: false,
+            // [[Enumerable]]: false, [[Configurable]]: true } whose value is
+            // a Number."
+            assert_own_property(self[this.name], "length");
+            var desc = Object.getOwnPropertyDescriptor(self[this.name], "length");
+            assert_false("get" in desc, this.name + ".length has getter");
+            assert_false("set" in desc, this.name + ".length has setter");
+            assert_false(desc.writable, this.name + ".length is writable");
+            assert_false(desc.enumerable, this.name + ".length is enumerable");
+            assert_true(desc.configurable, this.name + ".length is not configurable");
+
+            var constructors = this.extAttrs
+                .filter(function(attr) { return attr.name == "Constructor"; });
+            var expected_length = minOverloadLength(constructors);
+            assert_equals(self[this.name].length, expected_length, "wrong value for " + this.name + ".length");
+        }, this.name + " interface object length");
+    }
+
+    // TODO: Test named constructors if I find any interfaces that have them.
+
+    test(() => {
+        // This function tests WebIDL as of 2015-01-21.
+        // https://heycam.github.io/webidl/#interface-object
+
+        if (this.is_callback() && !this.has_constants()) {
+            return;
+        }
+
+        assert_own_property(self, this.name,
+                            "self does not have own property " + format_value(this.name));
+
+        if (this.is_callback()) {
+            assert_false("prototype" in self[this.name],
+                         this.name + ' should not have a "prototype" property');
+            return;
+        }
+
+        // "An interface object for a non-callback interface must have a
+        // property named “prototype” with attributes { [[Writable]]: false,
+        // [[Enumerable]]: false, [[Configurable]]: false } whose value is an
+        // object called the interface prototype object. This object has
+        // properties that correspond to the regular attributes and regular
+        // operations defined on the interface, and is described in more detail
+        // in section 4.5.4 below."
+        assert_own_property(self[this.name], "prototype",
+                            'interface "' + this.name + '" does not have own property "prototype"');
+        var desc = Object.getOwnPropertyDescriptor(self[this.name], "prototype");
+        assert_false("get" in desc, this.name + ".prototype has getter");
+        assert_false("set" in desc, this.name + ".prototype has setter");
+        assert_false(desc.writable, this.name + ".prototype is writable");
+        assert_false(desc.enumerable, this.name + ".prototype is enumerable");
+        assert_false(desc.configurable, this.name + ".prototype is configurable");
+
+        // Next, test that the [[Prototype]] of the interface prototype object
+        // is correct. (This is made somewhat difficult by the existence of
+        // [NoInterfaceObject].)
+        // TODO: Aryeh thinks there's at least other place in this file where
+        //       we try to figure out if an interface prototype object is
+        //       correct. Consolidate that code.
+
+        // "The interface prototype object for a given interface A must have an
+        // internal [[Prototype]] property whose value is returned from the
+        // following steps:
+        // "If A is declared with the [Global] or [PrimaryGlobal] extended
+        // attribute, and A supports named properties, then return the named
+        // properties object for A, as defined in section 4.5.5 below.
+        // "Otherwise, if A is declared to inherit from another interface, then
+        // return the interface prototype object for the inherited interface.
+        // "Otherwise, if A is declared with the [ArrayClass] extended
+        // attribute, then return %ArrayPrototype% ([ECMA-262], section
+        // 6.1.7.4).
+        // "Otherwise, return %ObjectPrototype% ([ECMA-262], section 6.1.7.4).
+        // ([ECMA-262], section 15.2.4).
+        if (this.name === "Window") {
+            assert_class_string(Object.getPrototypeOf(self[this.name].prototype),
+                                'WindowProperties',
+                                'Class name for prototype of Window' +
+                                '.prototype is not "WindowProperties"');
+        } else {
+            var inherit_interface, inherit_interface_has_interface_object;
+            if (this.base) {
+                inherit_interface = this.base;
+                inherit_interface_has_interface_object =
+                    !this.array
+                         .members[inherit_interface]
+                         .has_extended_attribute("NoInterfaceObject");
+            } else if (this.has_extended_attribute('ArrayClass')) {
+                inherit_interface = 'Array';
+                inherit_interface_has_interface_object = true;
+            } else {
+                inherit_interface = 'Object';
+                inherit_interface_has_interface_object = true;
+            }
+            if (inherit_interface_has_interface_object) {
+                assert_own_property(self, inherit_interface,
+                                    'should inherit from ' + inherit_interface + ', but self has no such property');
+                assert_own_property(self[inherit_interface], 'prototype',
+                                    'should inherit from ' + inherit_interface + ', but that object has no "prototype" property');
+                assert_equals(Object.getPrototypeOf(self[this.name].prototype),
+                              self[inherit_interface].prototype,
+                              'prototype of ' + this.name + '.prototype is not ' + inherit_interface + '.prototype');
+            } else {
+                // We can't test that we get the correct object, because this is the
+                // only way to get our hands on it. We only test that its class
+                // string, at least, is correct.
+                assert_class_string(Object.getPrototypeOf(self[this.name].prototype),
+                                    inherit_interface + 'Prototype',
+                                    'Class name for prototype of ' + this.name +
+                                    '.prototype is not "' + inherit_interface + 'Prototype"');
+            }
+        }
+
+        // "The class string of an interface prototype object is the
+        // concatenation of the interface’s identifier and the string
+        // “Prototype”."
+        assert_class_string(self[this.name].prototype, this.name + "Prototype",
+                            "class string of " + this.name + ".prototype");
+        // String() should end up calling {}.toString if nothing defines a
+        // stringifier.
+        if (!this.has_stringifier()) {
+            assert_equals(String(self[this.name].prototype), "[object " + this.name + "Prototype]",
+                    "String(" + this.name + ".prototype)");
+        }
+    }, this.name + " interface: existence and properties of interface prototype object");
+
+    test(() => {
+        if (this.is_callback() && !this.has_constants()) {
+            return;
+        }
+
+        assert_own_property(self, this.name,
+                            "self does not have own property " + format_value(this.name));
+
+        if (this.is_callback()) {
+            assert_false("prototype" in self[this.name],
+                         this.name + ' should not have a "prototype" property');
+            return;
+        }
+
+        assert_own_property(self[this.name], "prototype",
+                            'interface "' + this.name + '" does not have own property "prototype"');
+
+        // "If the [NoInterfaceObject] extended attribute was not specified on
+        // the interface, then the interface prototype object must also have a
+        // property named “constructor” with attributes { [[Writable]]: true,
+        // [[Enumerable]]: false, [[Configurable]]: true } whose value is a
+        // reference to the interface object for the interface."
+        assert_own_property(self[this.name].prototype, "constructor",
+                            this.name + '.prototype does not have own property "constructor"');
+        var desc = Object.getOwnPropertyDescriptor(self[this.name].prototype, "constructor");
+        assert_false("get" in desc, this.name + ".prototype.constructor has getter");
+        assert_false("set" in desc, this.name + ".prototype.constructor has setter");
+        assert_true(desc.writable, this.name + ".prototype.constructor is not writable");
+        assert_false(desc.enumerable, this.name + ".prototype.constructor is enumerable");
+        assert_true(desc.configurable, this.name + ".prototype.constructor in not configurable");
+        assert_equals(self[this.name].prototype.constructor, self[this.name],
+                      this.name + '.prototype.constructor is not the same object as ' + this.name);
+    }, this.name + ' interface: existence and properties of interface prototype object\'s "constructor" property');
+};
+
+//@}
+IdlInterface.prototype.test_member_const = function(member)
+//@{
+{
+    test(() => {
+        if (this.is_callback() && !this.has_constants()) {
+            return;
+        }
+
+        assert_own_property(self, this.name,
+                            "self does not have own property " + format_value(this.name));
+
+        // "For each constant defined on an interface A, there must be
+        // a corresponding property on the interface object, if it
+        // exists."
+        assert_own_property(self[this.name], member.name);
+        // "The value of the property is that which is obtained by
+        // converting the constant’s IDL value to an ECMAScript
+        // value."
+        assert_equals(self[this.name][member.name], constValue(member.value),
+                      "property has wrong value");
+        // "The property has attributes { [[Writable]]: false,
+        // [[Enumerable]]: true, [[Configurable]]: false }."
+        var desc = Object.getOwnPropertyDescriptor(self[this.name], member.name);
+        assert_false("get" in desc, "property has getter");
+        assert_false("set" in desc, "property has setter");
+        assert_false(desc.writable, "property is writable");
+        assert_true(desc.enumerable, "property is not enumerable");
+        assert_false(desc.configurable, "property is configurable");
+    }, this.name + " interface: constant " + member.name + " on interface object");
+    // "In addition, a property with the same characteristics must
+    // exist on the interface prototype object."
+    test(() => {
+        if (this.is_callback() && !this.has_constants()) {
+            return;
+        }
+
+        assert_own_property(self, this.name,
+                            "self does not have own property " + format_value(this.name));
+
+        if (this.is_callback()) {
+            assert_false("prototype" in self[this.name],
+                         this.name + ' should not have a "prototype" property');
+            return;
+        }
+
+        assert_own_property(self[this.name], "prototype",
+                            'interface "' + this.name + '" does not have own property "prototype"');
+
+        assert_own_property(self[this.name].prototype, member.name);
+        assert_equals(self[this.name].prototype[member.name], constValue(member.value),
+                      "property has wrong value");
+        var desc = Object.getOwnPropertyDescriptor(self[this.name], member.name);
+        assert_false("get" in desc, "property has getter");
+        assert_false("set" in desc, "property has setter");
+        assert_false(desc.writable, "property is writable");
+        assert_true(desc.enumerable, "property is not enumerable");
+        assert_false(desc.configurable, "property is configurable");
+    }, this.name + " interface: constant " + member.name + " on interface prototype object");
+};
+
+
+//@}
+IdlInterface.prototype.test_member_attribute = function(member)
+//@{
+{
+    test(() => {
+        if (this.is_callback() && !this.has_constants()) {
+            return;
+        }
+
+        assert_own_property(self, this.name,
+                            "self does not have own property " + format_value(this.name));
+        assert_own_property(self[this.name], "prototype",
+                            'interface "' + this.name + '" does not have own property "prototype"');
+
+        if (member["static"]) {
+            assert_own_property(self[this.name], member.name,
+                "The interface object must have a property " +
+                format_value(member.name));
+        } else if (this.is_global()) {
+            assert_own_property(self, member.name,
+                "The global object must have a property " +
+                format_value(member.name));
+            assert_false(member.name in self[this.name].prototype,
+                "The prototype object must not have a property " +
+                format_value(member.name));
+
+            // Try/catch around the get here, since it can legitimately throw.
+            // If it does, we obviously can't check for equality with direct
+            // invocation of the getter.
+            var gotValue;
+            var propVal;
+            try {
+                propVal = self[member.name];
+                gotValue = true;
+            } catch (e) {
+                gotValue = false;
+            }
+            if (gotValue) {
+                var getter = Object.getOwnPropertyDescriptor(self, member.name).get;
+                assert_equals(typeof(getter), "function",
+                              format_value(member.name) + " must have a getter");
+                assert_equals(propVal, getter.call(undefined),
+                              "Gets on a global should not require an explicit this");
+            }
+            this.do_interface_attribute_asserts(self, member);
+        } else {
+            assert_true(member.name in self[this.name].prototype,
+                "The prototype object must have a property " +
+                format_value(member.name));
+
+            if (!member.has_extended_attribute("LenientThis")) {
+                assert_throws(new TypeError(), () => {
+                    self[this.name].prototype[member.name];
+                }, "getting property on prototype object must throw TypeError");
+            } else {
+                assert_equals(self[this.name].prototype[member.name], undefined,
+                              "getting property on prototype object must return undefined");
+            }
+            this.do_interface_attribute_asserts(self[this.name].prototype, member);
+        }
+    }, this.name + " interface: attribute " + member.name);
+};
+
+//@}
+IdlInterface.prototype.test_member_operation = function(member)
+//@{
+{
+    test(() => {
+        if (this.is_callback() && !this.has_constants()) {
+            return;
+        }
+
+        assert_own_property(self, this.name,
+                            "self does not have own property " + format_value(this.name));
+
+        if (this.is_callback()) {
+            assert_false("prototype" in self[this.name],
+                         this.name + ' should not have a "prototype" property');
+            return;
+        }
+
+        assert_own_property(self[this.name], "prototype",
+                            'interface "' + this.name + '" does not have own property "prototype"');
+
+        // "For each unique identifier of an operation defined on the
+        // interface, there must be a corresponding property on the
+        // interface prototype object (if it is a regular operation) or
+        // the interface object (if it is a static operation), unless
+        // the effective overload set for that identifier and operation
+        // and with an argument count of 0 (for the ECMAScript language
+        // binding) has no entries."
+        //
+        var memberHolderObject;
+        if (member["static"]) {
+            assert_own_property(self[this.name], member.name,
+                    "interface object missing static operation");
+            memberHolderObject = self[this.name];
+        } else if (this.is_global()) {
+            assert_own_property(self, member.name,
+                    "global object missing non-static operation");
+            memberHolderObject = self;
+        } else {
+            assert_own_property(self[this.name].prototype, member.name,
+                    "interface prototype object missing non-static operation");
+            memberHolderObject = self[this.name].prototype;
+        }
+
+        this.do_member_operation_asserts(memberHolderObject, member);
+    }, this.name + " interface: operation " + member.name +
+    "(" + member.arguments.map(function(m) { return m.idlType.idlType; }) +
+    ")");
+};
+
+//@}
+IdlInterface.prototype.do_member_operation_asserts = function(memberHolderObject, member)
+//@{
+{
+    var operationUnforgeable = member.isUnforgeable;
+    var desc = Object.getOwnPropertyDescriptor(memberHolderObject, member.name);
+    // "The property has attributes { [[Writable]]: B,
+    // [[Enumerable]]: true, [[Configurable]]: B }, where B is false if the
+    // operation is unforgeable on the interface, and true otherwise".
+    assert_false("get" in desc, "property has getter");
+    assert_false("set" in desc, "property has setter");
+    assert_equals(desc.writable, !operationUnforgeable,
+                  "property should be writable if and only if not unforgeable");
+    assert_true(desc.enumerable, "property is not enumerable");
+    assert_equals(desc.configurable, !operationUnforgeable,
+                  "property should be configurable if and only if not unforgeable");
+    // "The value of the property is a Function object whose
+    // behavior is as follows . . ."
+    assert_equals(typeof memberHolderObject[member.name], "function",
+                  "property must be a function");
+    // "The value of the Function object’s “length” property is
+    // a Number determined as follows:
+    // ". . .
+    // "Return the length of the shortest argument list of the
+    // entries in S."
+    assert_equals(memberHolderObject[member.name].length,
+        minOverloadLength(this.members.filter(function(m) {
+            return m.type == "operation" && m.name == member.name;
+        })),
+        "property has wrong .length");
+
+    // Make some suitable arguments
+    var args = member.arguments.map(function(arg) {
+        return create_suitable_object(arg.idlType);
+    });
+
+    // "Let O be a value determined as follows:
+    // ". . .
+    // "Otherwise, throw a TypeError."
+    // This should be hit if the operation is not static, there is
+    // no [ImplicitThis] attribute, and the this value is null.
+    //
+    // TODO: We currently ignore the [ImplicitThis] case.  Except we manually
+    // check for globals, since otherwise we'll invoke window.close().  And we
+    // have to skip this test for anything that on the proto chain of "self",
+    // since that does in fact have implicit-this behavior.
+    if (!member["static"]) {
+        if (!this.is_global() &&
+            memberHolderObject[member.name] != self[member.name])
+        {
+            assert_throws(new TypeError(), function() {
+                memberHolderObject[member.name].apply(null, args);
+            }, "calling operation with this = null didn't throw TypeError");
+        }
+
+        // ". . . If O is not null and is also not a platform object
+        // that implements interface I, throw a TypeError."
+        //
+        // TODO: Test a platform object that implements some other
+        // interface.  (Have to be sure to get inheritance right.)
+        assert_throws(new TypeError(), function() {
+            memberHolderObject[member.name].apply({}, args);
+        }, "calling operation with this = {} didn't throw TypeError");
+    }
+}
+
+//@}
+IdlInterface.prototype.test_member_stringifier = function(member)
+//@{
+{
+    test(() => {
+        if (this.is_callback() && !this.has_constants()) {
+            return;
+        }
+
+        assert_own_property(self, this.name,
+                            "self does not have own property " + format_value(this.name));
+
+        if (this.is_callback()) {
+            assert_false("prototype" in self[this.name],
+                         this.name + ' should not have a "prototype" property');
+            return;
+        }
+
+        assert_own_property(self[this.name], "prototype",
+                            'interface "' + this.name + '" does not have own property "prototype"');
+
+        // ". . . the property exists on the interface prototype object."
+        var interfacePrototypeObject = self[this.name].prototype;
+        assert_own_property(self[this.name].prototype, "toString",
+                "interface prototype object missing non-static operation");
+
+        var stringifierUnforgeable = member.isUnforgeable;
+        var desc = Object.getOwnPropertyDescriptor(interfacePrototypeObject, "toString");
+        // "The property has attributes { [[Writable]]: B,
+        // [[Enumerable]]: true, [[Configurable]]: B }, where B is false if the
+        // stringifier is unforgeable on the interface, and true otherwise."
+        assert_false("get" in desc, "property has getter");
+        assert_false("set" in desc, "property has setter");
+        assert_equals(desc.writable, !stringifierUnforgeable,
+                      "property should be writable if and only if not unforgeable");
+        assert_true(desc.enumerable, "property is not enumerable");
+        assert_equals(desc.configurable, !stringifierUnforgeable,
+                      "property should be configurable if and only if not unforgeable");
+        // "The value of the property is a Function object, which behaves as
+        // follows . . ."
+        assert_equals(typeof interfacePrototypeObject.toString, "function",
+                      "property must be a function");
+        // "The value of the Function object’s “length” property is the Number
+        // value 0."
+        assert_equals(interfacePrototypeObject.toString.length, 0,
+            "property has wrong .length");
+
+        // "Let O be the result of calling ToObject on the this value."
+        assert_throws(new TypeError(), function() {
+            self[this.name].prototype.toString.apply(null, []);
+        }, "calling stringifier with this = null didn't throw TypeError");
+
+        // "If O is not an object that implements the interface on which the
+        // stringifier was declared, then throw a TypeError."
+        //
+        // TODO: Test a platform object that implements some other
+        // interface.  (Have to be sure to get inheritance right.)
+        assert_throws(new TypeError(), function() {
+            self[this.name].prototype.toString.apply({}, []);
+        }, "calling stringifier with this = {} didn't throw TypeError");
+    }, this.name + " interface: stringifier");
+};
+
+//@}
+IdlInterface.prototype.test_members = function()
+//@{
+{
+    for (var i = 0; i < this.members.length; i++)
+    {
+        var member = this.members[i];
+        if (member.untested) {
+            continue;
+        }
+
+        switch (member.type) {
+        case "const":
+            this.test_member_const(member);
+            break;
+
+        case "attribute":
+            // For unforgeable attributes, we do the checks in
+            // test_interface_of instead.
+            if (!member.isUnforgeable)
+            {
+                this.test_member_attribute(member);
+            }
+            break;
+
+        case "operation":
+            // TODO: Need to correctly handle multiple operations with the same
+            // identifier.
+            // For unforgeable operations, we do the checks in
+            // test_interface_of instead.
+            if (member.name) {
+                if (!member.isUnforgeable)
+                {
+                    this.test_member_operation(member);
+                }
+            } else if (member.stringifier) {
+                this.test_member_stringifier(member);
+            }
+            break;
+
+        default:
+            // TODO: check more member types.
+            break;
+        }
+    }
+};
+
+//@}
+IdlInterface.prototype.test_object = function(desc)
+//@{
+{
+    var obj, exception = null;
+    try
+    {
+        obj = eval(desc);
+    }
+    catch(e)
+    {
+        exception = e;
+    }
+
+    // TODO: WebIDLParser doesn't currently support named legacycallers, so I'm
+    // not sure what those would look like in the AST
+    var expected_typeof = this.members.some(function(member)
+    {
+        return member.legacycaller
+            || ("idlType" in member && member.idlType.legacycaller)
+            || ("idlType" in member && typeof member.idlType == "object"
+            && "idlType" in member.idlType && member.idlType.idlType == "legacycaller");
+    }) ? "function" : "object";
+
+    this.test_primary_interface_of(desc, obj, exception, expected_typeof);
+    var current_interface = this;
+    while (current_interface)
+    {
+        if (!(current_interface.name in this.array.members))
+        {
+            throw "Interface " + current_interface.name + " not found (inherited by " + this.name + ")";
+        }
+        if (current_interface.prevent_multiple_testing && current_interface.already_tested)
+        {
+            return;
+        }
+        current_interface.test_interface_of(desc, obj, exception, expected_typeof);
+        current_interface = this.array.members[current_interface.base];
+    }
+};
+
+//@}
+IdlInterface.prototype.test_primary_interface_of = function(desc, obj, exception, expected_typeof)
+//@{
+{
+    // We can't easily test that its prototype is correct if there's no
+    // interface object, or the object is from a different global environment
+    // (not instanceof Object).  TODO: test in this case that its prototype at
+    // least looks correct, even if we can't test that it's actually correct.
+    if (!this.has_extended_attribute("NoInterfaceObject")
+    && (typeof obj != expected_typeof || obj instanceof Object))
+    {
+        test(() => {
+            assert_equals(exception, null, "Unexpected exception when evaluating object");
+            assert_equals(typeof obj, expected_typeof, "wrong typeof object");
+            assert_own_property(self, this.name,
+                                "self does not have own property " + format_value(this.name));
+            assert_own_property(self[this.name], "prototype",
+                                'interface "' + this.name + '" does not have own property "prototype"');
+
+            // "The value of the internal [[Prototype]] property of the
+            // platform object is the interface prototype object of the primary
+            // interface from the platform object’s associated global
+            // environment."
+            assert_equals(Object.getPrototypeOf(obj),
+                          self[this.name].prototype,
+                          desc + "'s prototype is not " + this.name + ".prototype");
+        }, this.name + " must be primary interface of " + desc);
+    }
+
+    // "The class string of a platform object that implements one or more
+    // interfaces must be the identifier of the primary interface of the
+    // platform object."
+    test(() => {
+        assert_equals(exception, null, "Unexpected exception when evaluating object");
+        assert_equals(typeof obj, expected_typeof, "wrong typeof object");
+        assert_class_string(obj, this.name, "class string of " + desc);
+        if (!this.has_stringifier())
+        {
+            assert_equals(String(obj), "[object " + this.name + "]", "String(" + desc + ")");
+        }
+    }, "Stringification of " + desc);
+};
+
+//@}
+IdlInterface.prototype.test_interface_of = function(desc, obj, exception, expected_typeof)
+//@{
+{
+    // TODO: Indexed and named properties, more checks on interface members
+    this.already_tested = true;
+
+    for (var i = 0; i < this.members.length; i++)
+    {
+        var member = this.members[i];
+        if (member.type == "attribute" && member.isUnforgeable)
+        {
+            test(() => {
+                assert_equals(exception, null, "Unexpected exception when evaluating object");
+                assert_equals(typeof obj, expected_typeof, "wrong typeof object");
+                this.do_interface_attribute_asserts(obj, member);
+            }, this.name + " interface: " + desc + ' must have own property "' + member.name + '"');
+        }
+        else if (member.type == "operation" &&
+                 member.name &&
+                 member.isUnforgeable)
+        {
+            test(() => {
+                assert_equals(exception, null, "Unexpected exception when evaluating object");
+                assert_equals(typeof obj, expected_typeof, "wrong typeof object");
+                assert_own_property(obj, member.name,
+                                    "Doesn't have the unforgeable operation property");
+                this.do_member_operation_asserts(obj, member);
+            }, this.name + " interface: " + desc + ' must have own property "' + member.name + '"');
+        }
+        else if ((member.type == "const"
+        || member.type == "attribute"
+        || member.type == "operation")
+        && member.name)
+        {
+            test(() => {
+                assert_equals(exception, null, "Unexpected exception when evaluating object");
+                assert_equals(typeof obj, expected_typeof, "wrong typeof object");
+                if (!member["static"]) {
+                    if (!this.is_global()) {
+                        assert_inherits(obj, member.name);
+                    } else {
+                        assert_own_property(obj, member.name);
+                    }
+
+                    if (member.type == "const")
+                    {
+                        assert_equals(obj[member.name], constValue(member.value));
+                    }
+                    if (member.type == "attribute")
+                    {
+                        // Attributes are accessor properties, so they might
+                        // legitimately throw an exception rather than returning
+                        // anything.
+                        var property, thrown = false;
+                        try
+                        {
+                            property = obj[member.name];
+                        }
+                        catch (e)
+                        {
+                            thrown = true;
+                        }
+                        if (!thrown)
+                        {
+                            this.array.assert_type_is(property, member.idlType);
+                        }
+                    }
+                    if (member.type == "operation")
+                    {
+                        assert_equals(typeof obj[member.name], "function");
+                    }
+                }
+            }, this.name + " interface: " + desc + ' must inherit property "' + member.name + '" with the proper type (' + i + ')');
+        }
+        // TODO: This is wrong if there are multiple operations with the same
+        // identifier.
+        // TODO: Test passing arguments of the wrong type.
+        if (member.type == "operation" && member.name && member.arguments.length)
+        {
+            test(() => {
+                assert_equals(exception, null, "Unexpected exception when evaluating object");
+                assert_equals(typeof obj, expected_typeof, "wrong typeof object");
+                if (!member["static"]) {
+                    if (!this.is_global() && !member.isUnforgeable) {
+                        assert_inherits(obj, member.name);
+                    } else {
+                        assert_own_property(obj, member.name);
+                    }
+                }
+                else
+                {
+                    assert_false(member.name in obj);
+                }
+
+                var minLength = minOverloadLength(this.members.filter(function(m) {
+                    return m.type == "operation" && m.name == member.name;
+                }));
+                var args = [];
+                for (var i = 0; i < minLength; i++) {
+                    assert_throws(new TypeError(), () => {
+                        obj[member.name].apply(obj, args);
+                    }, "Called with " + i + " arguments");
+
+                    args.push(create_suitable_object(member.arguments[i].idlType));
+                }
+            }, this.name + " interface: calling " + member.name +
+            "(" + member.arguments.map(function(m) { return m.idlType.idlType; }) +
+            ") on " + desc + " with too few arguments must throw TypeError");
+        }
+    }
+};
+
+//@}
+IdlInterface.prototype.has_stringifier = function()
+//@{
+{
+    if (this.members.some(function(member) { return member.stringifier; })) {
+        return true;
+    }
+    if (this.base &&
+        this.array.members[this.base].has_stringifier()) {
+        return true;
+    }
+    return false;
+};
+
+//@}
+IdlInterface.prototype.do_interface_attribute_asserts = function(obj, member)
+//@{
+{
+    // This function tests WebIDL as of 2015-01-27.
+    // TODO: Consider [Exposed].
+
+    // This is called by test_member_attribute() with the prototype as obj if
+    // it is not a global, and the global otherwise, and by test_interface_of()
+    // with the object as obj.
+
+    // "For each exposed attribute of the interface, whether it was declared on
+    // the interface itself or one of its consequential interfaces, there MUST
+    // exist a corresponding property. The characteristics of this property are
+    // as follows:"
+
+    // "The name of the property is the identifier of the attribute."
+    assert_own_property(obj, member.name);
+
+    // "The property has attributes { [[Get]]: G, [[Set]]: S, [[Enumerable]]:
+    // true, [[Configurable]]: configurable }, where:
+    // "configurable is false if the attribute was declared with the
+    // [Unforgeable] extended attribute and true otherwise;
+    // "G is the attribute getter, defined below; and
+    // "S is the attribute setter, also defined below."
+    var desc = Object.getOwnPropertyDescriptor(obj, member.name);
+    assert_false("value" in desc, 'property descriptor has value but is supposed to be accessor');
+    assert_false("writable" in desc, 'property descriptor has "writable" field but is supposed to be accessor');
+    assert_true(desc.enumerable, "property is not enumerable");
+    if (member.isUnforgeable)
+    {
+        assert_false(desc.configurable, "[Unforgeable] property must not be configurable");
+    }
+    else
+    {
+        assert_true(desc.configurable, "property must be configurable");
+    }
+
+
+    // "The attribute getter is a Function object whose behavior when invoked
+    // is as follows:"
+    assert_equals(typeof desc.get, "function", "getter must be Function");
+
+    // "If the attribute is a regular attribute, then:"
+    if (!member["static"]) {
+        // "If O is not a platform object that implements I, then:
+        // "If the attribute was specified with the [LenientThis] extended
+        // attribute, then return undefined.
+        // "Otherwise, throw a TypeError."
+        if (!member.has_extended_attribute("LenientThis")) {
+            assert_throws(new TypeError(), () => {
+                desc.get.call({});
+            }, "calling getter on wrong object type must throw TypeError");
+        } else {
+            assert_equals(desc.get.call({}), undefined,
+                          "calling getter on wrong object type must return undefined");
+        }
+    }
+
+    // "The value of the Function object’s “length” property is the Number
+    // value 0."
+    assert_equals(desc.get.length, 0, "getter length must be 0");
+
+
+    // TODO: Test calling setter on the interface prototype (should throw
+    // TypeError in most cases).
+    if (member.readonly
+    && !member.has_extended_attribute("PutForwards")
+    && !member.has_extended_attribute("Replaceable"))
+    {
+        // "The attribute setter is undefined if the attribute is declared
+        // readonly and has neither a [PutForwards] nor a [Replaceable]
+        // extended attribute declared on it."
+        assert_equals(desc.set, undefined, "setter must be undefined for readonly attributes");
+    }
+    else
+    {
+        // "Otherwise, it is a Function object whose behavior when
+        // invoked is as follows:"
+        assert_equals(typeof desc.set, "function", "setter must be function for PutForwards, Replaceable, or non-readonly attributes");
+
+        // "If the attribute is a regular attribute, then:"
+        if (!member["static"]) {
+            // "If /validThis/ is false and the attribute was not specified
+            // with the [LenientThis] extended attribute, then throw a
+            // TypeError."
+            // "If the attribute is declared with a [Replaceable] extended
+            // attribute, then: ..."
+            // "If validThis is false, then return."
+            if (!member.has_extended_attribute("LenientThis")) {
+                assert_throws(new TypeError(), () => {
+                    desc.set.call({});
+                }, "calling setter on wrong object type must throw TypeError");
+            } else {
+                assert_equals(desc.set.call({}), undefined,
+                              "calling setter on wrong object type must return undefined");
+            }
+        }
+
+        // "The value of the Function object’s “length” property is the Number
+        // value 1."
+        assert_equals(desc.set.length, 1, "setter length must be 1");
+    }
+}
+//@}
+
+/// IdlInterfaceMember ///
+function IdlInterfaceMember(obj)
+//@{
+{
+    /**
+     * obj is an object produced by the WebIDLParser.js "ifMember" production.
+     * We just forward all properties to this object without modification,
+     * except for special extAttrs handling.
+     */
+    for (var k in obj)
+    {
+        this[k] = obj[k];
+    }
+    if (!("extAttrs" in this))
+    {
+        this.extAttrs = [];
+    }
+
+    this.isUnforgeable = this.has_extended_attribute("Unforgeable");
+}
+
+//@}
+IdlInterfaceMember.prototype = Object.create(IdlObject.prototype);
+
+/// Internal helper functions ///
+function create_suitable_object(type)
+//@{
+{
+    /**
+     * type is an object produced by the WebIDLParser.js "type" production.  We
+     * return a JavaScript value that matches the type, if we can figure out
+     * how.
+     */
+    if (type.nullable)
+    {
+        return null;
+    }
+    switch (type.idlType)
+    {
+        case "any":
+        case "boolean":
+            return true;
+
+        case "byte": case "octet": case "short": case "unsigned short":
+        case "long": case "unsigned long": case "long long":
+        case "unsigned long long": case "float": case "double":
+        case "unrestricted float": case "unrestricted double":
+            return 7;
+
+        case "DOMString":
+        case "ByteString":
+        case "USVString":
+            return "foo";
+
+        case "object":
+            return {a: "b"};
+
+        case "Node":
+            return document.createTextNode("abc");
+    }
+    return null;
+}
+//@}
+
+/// IdlEnum ///
+// Used for IdlArray.prototype.assert_type_is
+function IdlEnum(obj)
+//@{
+{
+    /**
+     * obj is an object produced by the WebIDLParser.js "dictionary"
+     * production.
+     */
+
+    /** Self-explanatory. */
+    this.name = obj.name;
+
+    /** An array of values produced by the "enum" production. */
+    this.values = obj.values;
+
+}
+//@}
+
+IdlEnum.prototype = Object.create(IdlObject.prototype);
+
+/// IdlTypedef ///
+// Used for IdlArray.prototype.assert_type_is
+function IdlTypedef(obj)
+//@{
+{
+    /**
+     * obj is an object produced by the WebIDLParser.js "typedef"
+     * production.
+     */
+
+    /** Self-explanatory. */
+    this.name = obj.name;
+
+    /** An array of values produced by the "typedef" production. */
+    this.values = obj.values;
+
+}
+//@}
+
+IdlTypedef.prototype = Object.create(IdlObject.prototype);
+
+}());
+// vim: set expandtab shiftwidth=4 tabstop=4 foldmarker=@{,@} foldmethod=marker: