The Tor Browser: js/src/tests/supporting/testBuiltInObject.js@6474c204b198 (annotated)

js/src/tests/supporting/testBuiltInObject.js@6474c204b198 (annotated)

js/src/tests/supporting/testBuiltInObject.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // Copyright 2012 Mozilla Corporation. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
 /**
  * @description Tests that obj meets the requirements for built-in objects
  *     defined by the introduction of chapter 15 of the ECMAScript Language Specification.
  * @param {Object} obj the object to be tested.
  * @param {boolean} isFunction whether the specification describes obj as a function.
  * @param {boolean} isConstructor whether the specification describes obj as a constructor.
  * @param {String[]} properties an array with the names of the built-in properties of obj,
  *     excluding length, prototype, or properties with non-default attributes.
  * @param {number} length for functions only: the length specified for the function
  *     or derived from the argument list.
  * @author Norbert Lindenberg
  */
 function testBuiltInObject(obj, isFunction, isConstructor, properties, length) {
     if (obj === undefined) {
         $ERROR("Object being tested is undefined.");
     }
     var objString = Object.prototype.toString.call(obj);
     if (isFunction) {
         if (objString !== "[object Function]") {
             $ERROR("The [[Class]] internal property of a built-in function must be " +
                     "\"Function\", but toString() returns " + objString);
         }
     } else {
         if (objString !== "[object Object]") {
             $ERROR("The [[Class]] internal property of a built-in non-function object must be " +
                     "\"Object\", but toString() returns " + objString);
         }
     }
     if (!Object.isExtensible(obj)) {
         $ERROR("Built-in objects must be extensible.");
     }
     if (isFunction && Object.getPrototypeOf(obj) !== Function.prototype) {
         $ERROR("Built-in functions must have Function.prototype as their prototype.");
     }
     if (isConstructor && Object.getPrototypeOf(obj.prototype) !== Object.prototype) {
         $ERROR("Built-in prototype objects must have Object.prototype as their prototype.");
     }
     // verification of the absence of the [[Construct]] internal property has
     // been moved to the end of the test
     // verification of the absence of the prototype property has
     // been moved to the end of the test
     if (isFunction) {
         if (typeof obj.length !== "number" || obj.length !== Math.floor(obj.length)) {
             $ERROR("Built-in functions must have a length property with an integer value.");
         }
         if (obj.length !== length) {
             $ERROR("Function's length property doesn't have specified value; expected " +
                 length + ", got " + obj.length + ".");
         }
         var desc = Object.getOwnPropertyDescriptor(obj, "length");
         if (desc.writable) {
             $ERROR("The length property of a built-in function must not be writable.");
         }
         if (desc.enumerable) {
             $ERROR("The length property of a built-in function must not be enumerable.");
         }
         if (desc.configurable) {
             $ERROR("The length property of a built-in function must not be configurable.");
         }
     }
     properties.forEach(function(prop) {
         var desc = Object.getOwnPropertyDescriptor(obj, prop);
         if (desc === undefined) {
             $ERROR("Missing property " + prop + ".");
         }
         // accessor properties don't have writable attribute
         if (desc.hasOwnProperty("writable") && !desc.writable) {
             $ERROR("The " + prop + " property of this built-in function must be writable.");
         }
         if (desc.enumerable) {
             $ERROR("The " + prop + " property of this built-in function must not be enumerable.");
         }
         if (!desc.configurable) {
             $ERROR("The " + prop + " property of this built-in function must be configurable.");
         }
     });
     // The remaining sections have been moved to the end of the test because
     // unbound non-constructor functions written in JavaScript cannot possibly
     // pass them, and we still want to test JavaScript implementations as much
     // as possible.
     var exception;
     if (isFunction && !isConstructor) {
         // this is not a complete test for the presence of [[Construct]]:
         // if it's absent, the exception must be thrown, but it may also
         // be thrown if it's present and just has preconditions related to
         // arguments or the this value that this statement doesn't meet.
         try {
             /*jshint newcap:false*/
             var instance = new obj();
         } catch (e) {
             exception = e;
         }
         if (exception === undefined || exception.name !== "TypeError") {
             $ERROR("Built-in functions that aren't constructors must throw TypeError when " +
                 "used in a \"new\" statement.");
         }
     }
     if (isFunction && !isConstructor && obj.hasOwnProperty("prototype")) {
         $ERROR("Built-in functions that aren't constructors must not have a prototype property.");
     }
     // passed the complete test!
     return true;
 }