Random Number Generator in TypeScript: Jest Unit Test

RandomGenerator.test.ts

import { Crypto } from '@peculiar/webcrypto';
import RandomGenerator from '@/crypto/RandomGenerator';

Object.defineProperty(window, 'crypto', {
  value: new Crypto(),
});

test('Random generator returns a 16 byte random sequence', () => {
  const randomBytes1 = RandomGenerator.generateRandomBytes(16);
  const randomBytes2 = RandomGenerator.generateRandomBytes(16);

  expect(randomBytes1).toBeInstanceOf(Uint8Array);
  expect(randomBytes1.length).toEqual(16);

  expect(randomBytes2).toBeInstanceOf(Uint8Array);
  expect(randomBytes2.length).toEqual(16);

  expect(randomBytes1).not.toEqual(randomBytes2);
});

test('Random number generator returns a number between the given range', () => {
  const min = 0;
  const max = 7;
  const randomNumber = RandomGenerator.generateRandomNumber(min, max);

  expect(randomNumber).toBeGreaterThanOrEqual(min);
  expect(randomNumber).toBeLessThanOrEqual(max);
});