import { checkVowels } from './CheckVowels' describe('Test the checkVowels function', () => { it('expect throws on use wrong param', () => { expect(() => checkVowels(0)).toThrow() }) it('count the vowels in a string', () => { const value = 'Mad World' const countVowels = checkVowels(value) expect(countVowels).toBe(2) }) })