ut2/lib/merge.js

一个现代 JavaScript 实用工具库。[点击查看在线文档]。

'use strict';

var isArray = require('./isArray.js');
var isObject = require('./isObject.js');
var isObjectLike = require('./isObjectLike.js');
var isPlainObject = require('./isPlainObject.js');
var native = require('./internals/native.js');
var allKeys = require('./allKeys.js');

function baseMerge(object, source, getKeys, customizer, stack) {
    if (stack === void 0) { stack = new WeakMap(); }
    var obj = Object(object);
    if (!isObject(source) || obj === source) {
        return obj;
    }
    var keys = getKeys(source);
    var hasCustomizer = typeof customizer === 'function';
    keys.forEach(function (key) {
        var srcValue = source[key];
        var srcIsObj = isObject(srcValue);
        if (srcIsObj && stack.has(srcValue)) {
            obj[key] = srcValue;
        }
        else {
            var newValue = hasCustomizer ? customizer(obj[key], srcValue, key, obj, source) : native.nativeUndefined;
            if (newValue !== native.nativeUndefined) {
                obj[key] = newValue;
            }
            else {
                var objValue = obj[key];
                var newObjValue = void 0;
                if (srcIsObj) {
                    stack.set(srcValue, true);
                    if (isArray(srcValue)) {
                        newObjValue = isArray(objValue) ? objValue : [];
                    }
                    else if (isPlainObject(srcValue)) {
                        newObjValue = isObjectLike(objValue) ? objValue : {};
                    }
                }
                if (newObjValue) {
                    obj[key] = baseMerge(newObjValue, srcValue, getKeys, customizer, stack);
                }
                else if (srcValue !== native.nativeUndefined || !(key in obj)) {
                    obj[key] = srcValue;
                }
            }
        }
    });
    return obj;
}
function merge(object, source, customizer, getKeys) {
    if (getKeys === void 0) { getKeys = allKeys; }
    return baseMerge(object, source, getKeys, customizer);
}
merge.NOT_MERGE_ARRAYS = function (objValue, srcValue) { return (isArray(srcValue) ? srcValue : native.nativeUndefined); };

module.exports = merge;