Created
April 20, 2020 06:50
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| const diff = (() => { | |
| const toString = Function.prototype.toString; | |
| const objectString = toString.call(Object); | |
| return function diff(a, b, opts) { | |
| opts = { | |
| printShallow: false, | |
| ...opts, | |
| }; | |
| return diffValues(a, b, '$', opts); | |
| } | |
| function diffValues(a, b, path, opts) { | |
| if (a === b) { | |
| return []; | |
| } | |
| let childResults; | |
| if (Array.isArray(a) && Array.isArray(b)) { | |
| childResults = diffArrays(a, b, path, opts); | |
| } else if (isPlainObject(a) && isPlainObject(b)) { | |
| childResults = diffObjects(a, b, path, opts); | |
| } | |
| const results = []; | |
| if (!childResults || opts.printShallow) { | |
| results.push({ | |
| path, | |
| a, | |
| b | |
| }); | |
| } | |
| if (childResults) { | |
| results.push(...childResults); | |
| } | |
| return results; | |
| } | |
| function diffObjects(a, b, path, opts) { | |
| const results = []; | |
| const keys = [...new Set([...Object.keys(a), ...Object.keys(b)])]; | |
| const n = keys.length; | |
| let i = -1; | |
| while (++i < n) { | |
| const k = keys[i]; | |
| results.push(...diffValues(a[k], b[k], addToPath(path, k), opts)); | |
| } | |
| return results; | |
| } | |
| function diffArrays(a, b, path, opts) { | |
| const aLen = a.length; | |
| const bLen = b.length; | |
| let n = aLen | |
| if (aLen < bLen) { | |
| [a, b] = [b, a]; | |
| n = bLen | |
| } | |
| let i = -1; | |
| const results = []; | |
| while (++i < n) { | |
| results.push(...diffValues(a[i], b[i], addToPath(path, i), opts)); | |
| } | |
| return results; | |
| } | |
| function addToPath(path, key) { | |
| return path + '.' + key; | |
| } | |
| function isPlainObject(v) { | |
| if (!v || Array.isArray(v) || typeof v !== 'object') { | |
| return false; | |
| } | |
| const proto = Object.getPrototypeOf(v); | |
| return !proto || toString.call(proto.constructor) === objectString; | |
| } | |
| })(); |
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