pigLatin.js

'use strict';

const assert = require('assert');
const readline = require('readline');
const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});


const pigLatin = (word)  => {

    let str = word;
    // Convert string to lowercase
    str = str.toString().toLowerCase();
    // Initialize array of vowels
    const vowels = ["a", "e", "i", "o", "u"];
    // Initialize vowel index to 0
    let vowelIndex = 0;
  
    if (vowels.includes(str[0])) {
      // If first letter is a vowel
      return str + "yay";
    } else {
      // If the first letter isn't a vowel i.e is a consonant
      for (let char of str) {
        // Loop through until the first vowel is found
        if (vowels.includes(char)) {
          // Store the index at which the first vowel exists
          vowelIndex = str.indexOf(char);
          break;
        }
      }
      // Compose final string
      return str.slice(vowelIndex) + str.slice(0, vowelIndex) + "ay";
    }
  }




const getPrompt = () => {
  rl.question('word ', (answer) => {
    console.log( pigLatin(answer) );
    getPrompt();
  });
}

// Tests

if (typeof describe === 'function') {

  describe('#pigLatin()', () => {
    it('should translate a simple word', () => {
      assert.equal(pigLatin('car'), 'arcay');
      assert.equal(pigLatin('dog'), 'ogday');
    });
    it('should translate a complex word', () => {
      assert.equal(pigLatin('create'), 'eatecray');
      assert.equal(pigLatin('valley'), 'alleyvay');
    });
    it('should attach "yay" if word begins with vowel', () => {
      assert.equal(pigLatin('egg'), 'eggyay');
      assert.equal(pigLatin('emission'), 'emissionyay');
    });
    it('should lowercase and trim word before translation', () => {
      assert.equal(pigLatin('HeLlO '), 'ellohay');
      assert.equal(pigLatin(' RoCkEt'), 'ocketray');
    });
  });
} else {

  getPrompt();

}