# 2704. To Be Or Not To Be

## Description

Write a function expect that helps developers test their code. It should take in any value val and return an object with the following two functions.

• toBe(val) accepts another value and returns true if the two values === each other. If they are not equal, it should throw an error "Not Equal".
• notToBe(val) accepts another value and returns true if the two values !== each other. If they are equal, it should throw an error "Equal".

Example 1:

Input: func = () => expect(5).toBe(5)
Output: {"value": true}
Explanation: 5 === 5 so this expression returns true.


Example 2:

Input: func = () => expect(5).toBe(null)
Output: {"error": "Not Equal"}
Explanation: 5 !== null so this expression throw the error "Not Equal".


Example 3:

Input: func = () => expect(5).notToBe(null)
Output: {"value": true}
Explanation: 5 !== null so this expression returns true.


## Solutions

• type ToBeOrNotToBe = {
toBe: (val: any) => boolean;
notToBe: (val: any) => boolean;
};

function expect(val: any): ToBeOrNotToBe {
return {
toBe: (toBeVal: any) => {
if (val !== toBeVal) {
throw new Error('Not Equal');
}
return true;
},
notToBe: (notToBeVal: any) => {
if (val === notToBeVal) {
throw new Error('Equal');
}
return true;
},
};
}

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


• /**
* @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"
*/