Check if variable is empty on javascript

empty.js

/**
 * Is empty
 * @param x
 * @returns {boolean}
 */
export const isEmpty = (x) => {
	// Generic
	if (typeof x !== "boolean" && !x) {
		return true;
	}
	// Strings
	if (typeof x === "string") {
		x = x.replace(/^\s+|\s+$|\s+(?=\s)/g, "");
		return x === "";
	}
	// Nulls and undefined
	if (x == null) {
		return true;
	}
	// Arrays
	if (Array.isArray(x) && x.length === 0) {
		return true;
	}
	// Functions
	if (Object.prototype.toString.call(x).indexOf("Function") > -1) {
		let m = x.toString().match(/{([\s\S]*)}/m)[1];
		let body = m.replace(/^\s*\/\/.*$/gm, "");
		return isEmpty(body);
	}
	// Objects
	if (typeof x === "object") {
		if (Object.keys(x).length === 0) {
			return true;
		}
		for (let key in x) {
			if (x.hasOwnProperty(key) && !isEmpty(x[key])) {
				return false;
			}
		}
		return true;
	}

	return false;
}