| var pSlice = Array.prototype.slice; | |
| var Object_keys = typeof Object.keys === 'function' | |
|     ? Object.keys | |
|     : function (obj) { | |
|         var keys = []; | |
|         for (var key in obj) keys.push(key); | |
|         return keys; | |
|     } | |
| ; | |
| 
 | |
| var deepEqual = module.exports = function (actual, expected) { | |
|   // enforce Object.is +0 !== -0 | |
|   if (actual === 0 && expected === 0) { | |
|     return areZerosEqual(actual, expected); | |
| 
 | |
|   // 7.1. All identical values are equivalent, as determined by ===. | |
|   } else if (actual === expected) { | |
|     return true; | |
| 
 | |
|   } else if (actual instanceof Date && expected instanceof Date) { | |
|     return actual.getTime() === expected.getTime(); | |
| 
 | |
|   } else if (isNumberNaN(actual)) { | |
|     return isNumberNaN(expected); | |
| 
 | |
|   // 7.3. Other pairs that do not both pass typeof value == 'object', | |
|   // equivalence is determined by ==. | |
|   } else if (typeof actual != 'object' && typeof expected != 'object') { | |
|     return actual == expected; | |
| 
 | |
|   // 7.4. For all other Object pairs, including Array objects, equivalence is | |
|   // determined by having the same number of owned properties (as verified | |
|   // with Object.prototype.hasOwnProperty.call), the same set of keys | |
|   // (although not necessarily the same order), equivalent values for every | |
|   // corresponding key, and an identical 'prototype' property. Note: this | |
|   // accounts for both named and indexed properties on Arrays. | |
|   } else { | |
|     return objEquiv(actual, expected); | |
|   } | |
| }; | |
| 
 | |
| function isUndefinedOrNull(value) { | |
|   return value === null || value === undefined; | |
| } | |
| 
 | |
| function isArguments(object) { | |
|   return Object.prototype.toString.call(object) == '[object Arguments]'; | |
| } | |
| 
 | |
| function isNumberNaN(value) { | |
|   // NaN === NaN -> false | |
|   return typeof value == 'number' && value !== value; | |
| } | |
| 
 | |
| function areZerosEqual(zeroA, zeroB) { | |
|   // (1 / +0|0) -> Infinity, but (1 / -0) -> -Infinity and (Infinity !== -Infinity) | |
|   return (1 / zeroA) === (1 / zeroB); | |
| } | |
| 
 | |
| function objEquiv(a, b) { | |
|   if (isUndefinedOrNull(a) || isUndefinedOrNull(b)) | |
|     return false; | |
| 
 | |
|   // an identical 'prototype' property. | |
|   if (a.prototype !== b.prototype) return false; | |
|   //~~~I've managed to break Object.keys through screwy arguments passing. | |
|   //   Converting to array solves the problem. | |
|   if (isArguments(a)) { | |
|     if (!isArguments(b)) { | |
|       return false; | |
|     } | |
|     a = pSlice.call(a); | |
|     b = pSlice.call(b); | |
|     return deepEqual(a, b); | |
|   } | |
|   try { | |
|     var ka = Object_keys(a), | |
|         kb = Object_keys(b), | |
|         key, i; | |
|   } catch (e) {//happens when one is a string literal and the other isn't | |
|     return false; | |
|   } | |
|   // having the same number of owned properties (keys incorporates | |
|   // hasOwnProperty) | |
|   if (ka.length != kb.length) | |
|     return false; | |
|   //the same set of keys (although not necessarily the same order), | |
|   ka.sort(); | |
|   kb.sort(); | |
|   //~~~cheap key test | |
|   for (i = ka.length - 1; i >= 0; i--) { | |
|     if (ka[i] != kb[i]) | |
|       return false; | |
|   } | |
|   //equivalent values for every corresponding key, and | |
|   //~~~possibly expensive deep test | |
|   for (i = ka.length - 1; i >= 0; i--) { | |
|     key = ka[i]; | |
|     if (!deepEqual(a[key], b[key])) return false; | |
|   } | |
|   return true; | |
| }
 |