[Algorithm] Find The Vowels

// --- Directions

// Write a function that returns the number of vowels

// used in a string. Vowels are the characters 'a', 'e'

// 'i', 'o', and 'u'.

// --- Examples

// vowels('Hi There!') --> 3

// vowels('Why do you ask?') --> 4

// vowels('Why?') --> 0

function vowels(str) {
  const matchs = str.match(/[aeiou]/gi);
  return matchs ? matchs.length : 0;
}

module.exports = vowels;

　　

const vowels = require('./index');

test('Vowels is a function', () => {
  expect(typeof vowels).toEqual('function');
});

test('returns the number of vowels used', () => {
  expect(vowels('aeiou')).toEqual(5);
});

test('returns the number of vowels used when they are capitalized', () => {
  expect(vowels('AEIOU')).toEqual(5);
});

test('returns the number of vowels used', () => {
  expect(vowels('abcdefghijklmnopqrstuvwxyz')).toEqual(5);
});

test('returns the number of vowels used', () => {
  expect(vowels('bcdfghjkl')).toEqual(0);
});