firebase-admin/lib/utils/deep-copy.js

/*! firebase-admin v10.0.0 */
"use strict";
/*!
 * @license
 * Copyright 2017 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.deepExtend = exports.deepCopy = void 0;
/**
 * Returns a deep copy of an object or array.
 *
 * @param value - The object or array to deep copy.
 * @returns A deep copy of the provided object or array.
 */
function deepCopy(value) {
    return deepExtend(undefined, value);
}
exports.deepCopy = deepCopy;
/**
 * Copies properties from source to target (recursively allows extension of objects and arrays).
 * Scalar values in the target are over-written. If target is undefined, an object of the
 * appropriate type will be created (and returned).
 *
 * We recursively copy all child properties of plain objects in the source - so that namespace-like
 * objects are merged.
 *
 * Note that the target can be a function, in which case the properties in the source object are
 * copied onto it as static properties of the function.
 *
 * @param target - The value which is being extended.
 * @param source - The value whose properties are extending the target.
 * @returns The target value.
 */
function deepExtend(target, source) {
    if (!(source instanceof Object)) {
        return source;
    }
    switch (source.constructor) {
        case Date: {
            // Treat Dates like scalars; if the target date object had any child
            // properties - they will be lost!
            var dateValue = source;
            return new Date(dateValue.getTime());
        }
        case Object:
            if (target === undefined) {
                target = {};
            }
            break;
        case Array:
            // Always copy the array source and overwrite the target.
            target = [];
            break;
        default:
            // Not a plain Object - treat it as a scalar.
            return source;
    }
    for (var prop in source) {
        if (!Object.prototype.hasOwnProperty.call(source, prop)) {
            continue;
        }
        target[prop] = deepExtend(target[prop], source[prop]);
    }
    return target;
}
exports.deepExtend = deepExtend;