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Diffstat (limited to 'school/node_modules/deep-is/index.js')
-rw-r--r-- | school/node_modules/deep-is/index.js | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/school/node_modules/deep-is/index.js b/school/node_modules/deep-is/index.js new file mode 100644 index 0000000..506fe27 --- /dev/null +++ b/school/node_modules/deep-is/index.js @@ -0,0 +1,102 @@ +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; +} |