DeepExtend

/**
 * @param destination
 * @param sources
 * @returns {any}
 * @constructor
 */
export function DeepExtend (destination: any, ...sources: any[]): any {
    let isObject: Function = (object: any) => {
            return typeof object === 'object' && object !== null;
        };

    for (let source of sources) {
        for (let prop in source) {
            if (!source.hasOwnProperty(prop)) {
                continue;
            }

            if (isObject(destination[prop]) || isObject(source[prop])){
                if (!isObject(destination[prop]) || !isObject(source[prop])){
                    throw new Error('Trying to combine an object with a non-object (' + prop + ')');
                } else {
                    destination[prop] = DeepExtend(JSON.parse(JSON.stringify(destination[prop])), source[prop]);
                }
            } else {
                destination[prop] = source[prop];
            }
        }
    }

    return destination;
}