53 lines
1.3 KiB
JavaScript
53 lines
1.3 KiB
JavaScript
/**
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* Clone object and all it's properties.
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* Works recursively.
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*
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* @param {Object} obj Object to clone.
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* @param {Mixed} seen For internal use only. Don't set.
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* @return {Object} The clone.
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*/
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export const clone = (obj, seen) => {
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if (typeof obj !== 'object' || obj === null) {
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return obj;
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}
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seen = seen || new Map();
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const lookup = seen.get(obj);
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if (lookup) {
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return lookup;
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}
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let newObj;
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let cloneDeep = false;
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if (!Array.isArray(obj)) {
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if (obj instanceof Date) {
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newObj = new Date(obj.getTime());
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} else if (obj instanceof RegExp) {
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newObj = new RegExp(obj);
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} else {
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const proto = Object.getPrototypeOf(obj);
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if (proto && Object.isFrozen(obj)) {
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newObj = obj;
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} else {
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newObj = Object.create(proto);
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cloneDeep = true;
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}
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}
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} else {
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newObj = [];
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cloneDeep = true;
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}
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seen.set(obj, newObj);
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if (cloneDeep) {
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const keys = Object.getOwnPropertyNames(obj);
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for (let i = 0; i < keys.length; ++i) {
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const key = keys[i];
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const descriptor = Object.getOwnPropertyDescriptor(obj, key);
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if (descriptor && (descriptor.get || descriptor.set)) {
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Object.defineProperty(newObj, key, descriptor);
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} else {
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newObj[key] = clone(obj[key], seen);
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}
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}
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}
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return newObj;
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};
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