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