apollo-utilities/lib/util/mergeDeep.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var tslib_1 = require("tslib");
var hasOwnProperty = Object.prototype.hasOwnProperty;
function mergeDeep() {
    var sources = [];
    for (var _i = 0; _i < arguments.length; _i++) {
        sources[_i] = arguments[_i];
    }
    return mergeDeepArray(sources);
}
exports.mergeDeep = mergeDeep;
function mergeDeepArray(sources) {
    var target = sources[0] || {};
    var count = sources.length;
    if (count > 1) {
        var pastCopies = [];
        target = shallowCopyForMerge(target, pastCopies);
        for (var i = 1; i < count; ++i) {
            target = mergeHelper(target, sources[i], pastCopies);
        }
    }
    return target;
}
exports.mergeDeepArray = mergeDeepArray;
function isObject(obj) {
    return obj !== null && typeof obj === 'object';
}
function mergeHelper(target, source, pastCopies) {
    if (isObject(source) && isObject(target)) {
        if (Object.isExtensible && !Object.isExtensible(target)) {
            target = shallowCopyForMerge(target, pastCopies);
        }
        Object.keys(source).forEach(function (sourceKey) {
            var sourceValue = source[sourceKey];
            if (hasOwnProperty.call(target, sourceKey)) {
                var targetValue = target[sourceKey];
                if (sourceValue !== targetValue) {
                    target[sourceKey] = mergeHelper(shallowCopyForMerge(targetValue, pastCopies), sourceValue, pastCopies);
                }
            }
            else {
                target[sourceKey] = sourceValue;
            }
        });
        return target;
    }
    return source;
}
function shallowCopyForMerge(value, pastCopies) {
    if (value !== null &&
        typeof value === 'object' &&
        pastCopies.indexOf(value) < 0) {
        if (Array.isArray(value)) {
            value = value.slice(0);
        }
        else {
            value = tslib_1.__assign({ __proto__: Object.getPrototypeOf(value) }, value);
        }
        pastCopies.push(value);
    }
    return value;
}
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