Настройте Mocha 8, Chai 4 и Babel 7 для JavaScript TDD

Давайте посмотрим, как настроить Mocha 8, Chai 4 и Babel 7 для тестирования проблемы со строками ES6.

Для некоторых строк разной длины, если количество гласных превышает 30% длины строки, вставьте «лето» для каждого непрерывного набора (группы) гласных.

Примеры:

‘’ => ‘’
‘a’ => ‘summer’
‘ntv’ => ‘ntv’
‘bla’ => ‘blsummer’
‘blah’ => ‘blah’
‘blaahah’ => ‘blsummerhsummerh’
‘hear’ => ‘hsummerr’
‘blAhE’ => ‘blsummerhsummer’

Решение:

index.js

const newStr = ‘summer’;
const regx = /[aeiou]+/ig;
// const regx = /(a|e|i|o|u)+/ig;
// const vowels = ‘aeiou’;
// const isVowel = © => vowels.indexOf(c.toLowerCase()) > -1;
const vowelCount = (word) => {
 // const vCount = […word].reduce((count, letter) => count + (isVowel(letter)? 1:0), 0);
 // const re = /(a|e|i|o|u){1}/ig;
 const re = /[a|e|i|o|u]{1}/ig;
 return word.match(regx) ? word.match(re).length / word.length > 0.3 : false
};
const replaceVowels = (word) => word.replace(regx, newStr);
const changeStr = (word) => vowelCount(word) ? replaceVowels(word) : word;
export default changeStr;

тест\index.spec.js

import { expect } from ‘chai’;
import changeStr from ‘../index’;
describe(‘#changeStr’, () => {
 it(‘should not change empty string’, () => {
 expect(changeStr(‘’)).to.equal(‘’);
 });
it(‘should not change words with no vowels’, () => {
 expect(changeStr(‘ntv’)).to.equal(‘ntv’);
 });
it(‘should change a vowel’, () => {
 expect(changeStr(‘a’)).to.equal(‘summer’);
 });
it(‘should change consonents and a vowel’, () => {
 expect(changeStr(‘bla’)).to.equal(‘blsummer’);
 });
it(‘should not change less than 30 percent vowels’, () => {
 expect(changeStr(‘blah’)).to.equal(‘blah’);
 });
it(‘should change continuous vowels once’, () => {
 expect(changeStr(‘hear’)).to.equal(‘hsummerr’);
 });
it(‘should change multiple sets of vowels’, () => {
 expect(changeStr(‘blaahah’)).to.equal(‘blsummerhsummerh’);
 });
it(‘should change capital vowels’, () => {
 expect(changeStr(‘blAhE’)).to.equal(‘blsummerhsummer’);
 });
it(‘should error on undefined input’, () => {
 expect(() => changeStr()).to.throw();
 });
});

.babelrc

{
 “presets”: [“@babel/preset-env”]
}

.mocharc.yml

require: ‘@babel/register’

.package.json

{
 “name”: “tdd”,
 “version”: “1.0.0”,
 “main”: “index.js”,
 “scripts”: {
 “test”: “mocha”
 },
 “license”: “MIT”,
 “devDependencies”: {
 “@babel/cli”: “⁷.10.5”,
 “@babel/core”: “⁷.11.1”,
 “@babel/preset-env”: “⁷.11.0”,
 “@babel/register”: “⁷.10.5”,
 “chai”: “⁴.2.0”,
 “mocha”: “⁸.1.1”
 }
}