FHC-Core/public/js/composables/ObjectUtils.js

export default {
	/**
	* Performs a deep merge of objects and returns new object. Does not modify
	* objects (immutable) and merges arrays via concatenation.
	*
	* @param {...object} objects - Objects to merge
	* @returns {object} New object with merged key/values
	*/
	mergeDeep(...objects) {
		const isObject = obj => obj && typeof obj === 'object';
		
		return objects.reduce((prev, obj) => {
			Object.keys(obj).forEach(key => {
				const pVal = prev[key];
				const oVal = obj[key];
				
				if (Array.isArray(pVal) && Array.isArray(oVal)) {
					prev[key] = pVal.concat(...oVal);
				}
				else if (isObject(pVal) && isObject(oVal)) {
					prev[key] = this.mergeDeep(pVal, oVal);
				}
				else {
					prev[key] = oVal;
				}
			});
			
			return prev;
		}, {});
	}
}