2704. To Be Or Not To Be.js

/**
 * @param {string} val
 * @return {Object}
 */
var expect = function (val) {
	return {
		toBe: function (expected) {
			if (val !== expected) {
				throw new Error("Not Equal");
			}
			return true;
		},
		notToBe: function (expected) {
			if (val === expected) {
				throw new Error("Equal");
			}
			return true;
		},
	};
};

/**
 * expect(5).toBe(5); // true
 * expect(5).notToBe(5); // throws "Equal"
 */

console.log(expect(5).toBe(5));
console.log(expect(5).notToBe(5));
// console.log(expect(5).toBe(6)); // throws "Not Equal"