Basic psuedocode example of a signup/login flow with salt and hash

authentication.js

function signup (email, password) {
  const salt = uuid();
  const hashedPassword = hash(`${salt}${password}`);
  // this stores everything in the DB
  createUser(email, salt, hashedPassword);
}

function login (request, response) {
  // get the salt - SELECT salt FROM users 
  // WHERE email = ?, [email]
  const salt = retrieveSalt(request.email);
  const hashedPassword = hash(`${salt}${request.password}`);
  // check the database
  // SELECT id FROM users 
  // WHERE email = ? AND hashedPassword = ?,
  // [email, password]
  response.end(newJWT(tryLogin(email, hashedPassword)));
}