1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
6 // Equality function based on isEqual in
8 // http://underscorejs.org
9 // (c) 2009-2013 Jeremy Ashkenas,
11 // and Investigative Reporters & Editors
12 // Underscore may be freely distributed under the MIT license.
14 function has(obj, key) {
15 return obj.hasOwnProperty(key);
17 function isFunction(obj) {
18 return typeof obj === 'function';
20 function isArrayBufferClass(className) {
21 return className == '[object ArrayBuffer]' ||
22 className.match(/\[object \w+\d+(Clamped)?Array\]/);
24 // Internal recursive comparison function for `isEqual`.
25 function eq(a, b, aStack, bStack) {
26 // Identical objects are equal. `0 === -0`, but they aren't identical.
27 // See the Harmony `egal` proposal:
28 // http://wiki.ecmascript.org/doku.php?id=harmony:egal.
30 return a !== 0 || 1 / a == 1 / b;
31 // A strict comparison is necessary because `null == undefined`.
32 if (a == null || b == null)
34 // Compare `[[Class]]` names.
35 var className = toString.call(a);
36 if (className != toString.call(b))
39 // Strings, numbers, dates, and booleans are compared by value.
40 case '[object String]':
41 // Primitives and their corresponding object wrappers are equivalent;
42 // thus, `"5"` is equivalent to `new String("5")`.
43 return a == String(b);
44 case '[object Number]':
45 // `NaN`s are equivalent, but non-reflexive. An `egal` comparison is
46 // performed for other numeric values.
47 return a != +a ? b != +b : (a == 0 ? 1 / a == 1 / b : a == +b);
49 case '[object Boolean]':
50 // Coerce dates and booleans to numeric primitive values. Dates are
51 // compared by their millisecond representations. Note that invalid
52 // dates with millisecond representations of `NaN` are not equivalent.
54 // RegExps are compared by their source patterns and flags.
55 case '[object RegExp]':
56 return a.source == b.source &&
57 a.global == b.global &&
58 a.multiline == b.multiline &&
59 a.ignoreCase == b.ignoreCase;
61 if (typeof a != 'object' || typeof b != 'object')
63 // Assume equality for cyclic structures. The algorithm for detecting
64 // cyclic structures is adapted from ES 5.1 section 15.12.3, abstract
66 var length = aStack.length;
68 // Linear search. Performance is inversely proportional to the number of
69 // unique nested structures.
70 if (aStack[length] == a)
71 return bStack[length] == b;
73 // Objects with different constructors are not equivalent, but `Object`s
74 // from different frames are.
75 var aCtor = a.constructor, bCtor = b.constructor;
76 if (aCtor !== bCtor && !(isFunction(aCtor) && (aCtor instanceof aCtor) &&
77 isFunction(bCtor) && (bCtor instanceof bCtor))
78 && ('constructor' in a && 'constructor' in b)) {
81 // Add the first object to the stack of traversed objects.
84 var size = 0, result = true;
85 // Recursively compare objects and arrays.
86 if (className == '[object Array]' || isArrayBufferClass(className)) {
87 // Compare array lengths to determine if a deep comparison is necessary.
89 result = size == b.length;
91 // Deep compare the contents, ignoring non-numeric properties.
93 if (!(result = eq(a[size], b[size], aStack, bStack)))
98 // Deep compare objects.
101 // Count the expected number of properties.
103 // Deep compare each member.
104 if (!(result = has(b, key) && eq(a[key], b[key], aStack, bStack)))
108 // Ensure that both objects contain the same number of properties.
111 if (has(b, key) && !(size--))
117 // Remove the first object from the stack of traversed objects.
123 function describe(subjects) {
124 var descriptions = [];
125 Object.getOwnPropertyNames(subjects).forEach(function(name) {
126 if (name === "Description")
127 descriptions.push(subjects[name]);
129 descriptions.push(name + ": " + JSON.stringify(subjects[name]));
131 return descriptions.join(" ");
136 predicates.toBe = function(actual, expected) {
138 "result": actual === expected,
139 "message": describe({
141 "Expected": expected,
146 predicates.toEqual = function(actual, expected) {
148 "result": eq(actual, expected, [], []),
149 "message": describe({
151 "Expected": expected,
156 predicates.toBeDefined = function(actual) {
158 "result": typeof actual !== "undefined",
159 "message": describe({
161 "Description": "Expected a defined value",
166 predicates.toBeUndefined = function(actual) {
167 // Recall: undefined is just a global variable. :)
169 "result": typeof actual === "undefined",
170 "message": describe({
172 "Description": "Expected an undefined value",
177 predicates.toBeNull = function(actual) {
178 // Recall: typeof null === "object".
180 "result": actual === null,
181 "message": describe({
188 predicates.toBeTruthy = function(actual) {
191 "message": describe({
193 "Description": "Expected a truthy value",
198 predicates.toBeFalsy = function(actual) {
201 "message": describe({
203 "Description": "Expected a falsy value",
208 predicates.toContain = function(actual, element) {
210 "result": (function () {
211 for (var i = 0; i < actual.length; ++i) {
212 if (eq(actual[i], element, [], []))
217 "message": describe({
224 predicates.toBeLessThan = function(actual, reference) {
226 "result": actual < reference,
227 "message": describe({
229 "Reference": reference,
234 predicates.toBeGreaterThan = function(actual, reference) {
236 "result": actual > reference,
237 "message": describe({
239 "Reference": reference,
244 predicates.toThrow = function(actual) {
246 "result": (function () {
247 if (!isFunction(actual))
256 "message": "Expected function to throw",
260 function negate(predicate) {
262 var outcome = predicate.apply(null, arguments);
263 outcome.result = !outcome.result;
268 function check(predicate) {
270 var outcome = predicate.apply(null, arguments);
273 throw outcome.message;
277 function Condition(actual) {
279 Object.getOwnPropertyNames(predicates).forEach(function(name) {
280 var bound = predicates[name].bind(null, actual);
281 this[name] = check(bound);
282 this.not[name] = check(negate(bound));
286 return function(actual) {
287 return new Condition(actual);