## users/users-repository.js ####################
const users = new Map()

exports.create = user => users.set(user.username, user)
exports.read = username => users.get(username)

## users/users.js ###############################
const usersRepo = require('./users-repository')

exports.create = user =>  {
  if (!user.username || !user.email || !user.hashPassword || user.hashPassword.length < 8)
    return false

  usersRepo.create(user)
  return true
}

exports.read = username => usersRepo.read(username)

## users/users.spec.js ##########################
const assert = require('assert')
const users = require('./users')

assert(users.create({username: 'bob', email: 'example@example.com', hashPassword: 'A$%Hsdf&/F'}))

const user = users.read('bob')
assert(user)
assert.equal(user.username, 'bob')
assert.equal(user.email, 'example@example.com')
assert.equal(user.hashPassword, 'A$%Hsdf&/F')

assert(!users.create({username: 'bob', hashPassword: 'A$%Hsdf&/F'}))
assert(!users.create({username: 'bob', email: 'example@example.com', hashPassword: 'HHR$'}))

## users/index.js ###############################
const users = require('./users')
module.exports = users

## app.js #######################################
const users = require('./users')

if (!users.create({username: process.env.USERNAME, email: process.env.EMAIL, hashPassword: process.env.HASH_PASSWORD}))
  throw new Error('Invalid user\'s information')

console.log(users.read(process.env.USERNAME))