/
deep_equal.js
112 lines (97 loc) · 3.7 KB
/
deep_equal.js
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// Forked from the node.js assert module, partly because it's not
// exposed as a boolean-returning function, and I needed to extend it
// to use any equals() method available.
module.exports = _deepEqual;
function _deepEqual(actual, expected) {
// 7.1. All identical values are equivalent, as determined by ===.
if (actual === expected) {
return true;
} else if (Buffer.isBuffer(actual) && Buffer.isBuffer(expected)) {
if (actual.length != expected.length) return false;
for (var i = 0; i < actual.length; i++) {
if (actual[i] !== expected[i]) return false;
}
return true;
// 7.2. If the expected value is a Date object, the actual value is
// equivalent if it is also a Date object that refers to the same time.
} else if (actual instanceof Date && expected instanceof Date) {
return actual.getTime() === expected.getTime();
// 7.3 If the expected value is a RegExp object, the actual value is
// equivalent if it is also a RegExp object with the same source and
// properties (`global`, `multiline`, `lastIndex`, `ignoreCase`).
} else if (actual instanceof RegExp && expected instanceof RegExp) {
return actual.source === expected.source &&
actual.global === expected.global &&
actual.multiline === expected.multiline &&
actual.lastIndex === expected.lastIndex &&
actual.ignoreCase === expected.ignoreCase;
// 7.4. 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;
// 7.5. In case the expected object has an equals function,
// use that to determine equality.
} else if ( expected && typeof(expected.equals) == 'function') {
return expected.equals(actual);
// 7.6 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 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)
var lea = ka.length;
var leb = kb.length;
if (lea != leb) {
debugger
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;
}