47 lines
1.2 KiB
JavaScript
47 lines
1.2 KiB
JavaScript
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var clone = require('./clone');
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module.exports = merge;
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function typesMatch(a, b) {
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return (typeof a === typeof b) && (Array.isArray(a) === Array.isArray(b));
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}
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/**
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* A deep merge of the source based on the target.
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* @param {Object} source [description]
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* @param {Object} target [description]
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* @return {Object} [description]
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*/
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function merge(source, target, result) {
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if (result === undefined) {
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result = clone(source);
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}
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// merge missing values from the target to the source
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Object.getOwnPropertyNames(target).forEach(function (key) {
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if (source[key] === undefined) {
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result[key] = target[key];
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}
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});
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Object.getOwnPropertyNames(source).forEach(function (key) {
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var value = source[key];
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if (target[key] && typesMatch(value, target[key])) {
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// merge empty values
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if (value === '') {
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result[key] = target[key];
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}
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if (Array.isArray(value)) {
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if (value.length === 0 && target[key].length) {
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result[key] = target[key].slice(0);
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}
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} else if (typeof value === 'object') {
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result[key] = merge(value, target[key]);
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}
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}
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});
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return result;
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}
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