dynamoose/dist/utils/deep_copy.js

Dynamoose is a modeling tool for Amazon's DynamoDB (inspired by Mongoose)

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
function deep_copy(obj, refs = new Set()) {
    let copy;
    // Handle Date
    if (obj instanceof Date) {
        copy = new Date();
        copy.setTime(obj.getTime());
        return copy;
    }
    // Handle Array
    if (obj instanceof Array) {
        copy = obj.map((i) => deep_copy(i, refs));
        return copy;
    }
    // Handle Set
    if (obj instanceof Set) {
        copy = new Set(obj);
        return copy;
    }
    // Handle Map
    if (obj instanceof Map) {
        copy = new Map(obj);
        return copy;
    }
    // Handle Buffer
    if (obj instanceof Buffer) {
        copy = Buffer.from(obj);
        return copy;
    }
    // Handle Uint8Array
    if (obj instanceof Uint8Array) {
        copy = new Uint8Array(obj);
        return copy;
    }
    if (obj instanceof Function) {
        // This is not technically correct, but required for unit test purposes. We currently have a unit test that passes in a function where it shouldn't. So in order to handle this case we need to do something here. Ideally we would clone the function somehow to create a copy of it. But that is lower priority for now.
        return obj;
    }
    // Handle Object
    if (obj instanceof Object) {
        refs.add(obj);
        if (obj.constructor !== Object) {
            copy = Object.assign(Object.create(Object.getPrototypeOf(obj)), obj);
        }
        else {
            copy = {};
        }
        for (const attr in obj) {
            if (Object.prototype.hasOwnProperty.call(obj, attr)) {
                const value = obj[attr];
                const isObjValue = typeof value === "object" && !Array.isArray(value) && value !== null;
                if (isObjValue) {
                    const isCircular = refs.has(value);
                    // Omit circular property from copy
                    if (isCircular)
                        continue;
                    refs.add(value);
                }
                copy[attr] = deep_copy(value, refs);
            }
        }
        return copy;
    }
    return obj;
}
exports.default = deep_copy;