utils.js

const { validationResult, check } = require('express-validator');
const { User } = require('./db/models/user');

const asyncHandler = (handler) => (req, res, next) => handler(req, res, next).catch(next);

const validateEmailAndPassword = [
  check("email")
    .exists({ checkFalsy: true })
    .isEmail()
    .withMessage("Please provide a valid email."),
  check("password")
    .exists({ checkFalsy: true })
    .withMessage("Please provide a password.")
];

const handleValidationErrors = (req, res, next) => {
  const validationErrors = validationResult(req);

  if (!validationErrors.isEmpty()) {
    const errors = validationErrors.array().map((error) => error.msg);

    const err = Error("Bad request.");
    err.status = 400;
    err.title = "Bad request.";
    err.errors = errors;
    res.status(400).json({ err });
  }
  next();
};

const emailNotUnique = async (email) => {
  const emails = await User.findAll().map((user) => user = user.email);
  return emails.includes(email);
};


module.exports = {
  asyncHandler,
  handleValidationErrors,
  emailNotUnique,
  validateEmailAndPassword
}