Error when post data to serve express using hash bcrypt to hash password

Question

I try to write a Api using express and sequelize. I'm writing create user function and use bcrypt to hash password.

 const createNewUser = (data) => {
  return new Promise(async (resolve, reject) => {
    try {
      let check = await checkUserEmail(data.email)
      if (check === true) {
        resolve({
          errcode: 1,
          errMessage: 'Your email is already exist!',
        })
      }
      let hashPassWordFromBcrypt = await hashUserPassWord(data.passWord)
  

      await db.User.create({
        email: data.email,
        passWord: hashPassWordFromBcrypt,
        firstName: data.firstName,
        lastName: data.lastName,
        address: data.address,
        phoneNumber: data.phoneNumber,
        gender: data.gender === '1' ? true : false,
        roleId: data.roleId,
      })
     resolve({
       errcode: 0,
       errMessage: 'OK',
     })
} catch (error) {
  reject(error)
}

}) }

const salt = bcrypt.genSaltSync(10)

const hashUserPassWord = (password) => {
  return new Promise(async (resolve, reject) => {
    try {
      let hashPassWord = await bcrypt.hashSync(password, salt)
      resolve(hashPassWord)
    } catch (error) {
      reject(error)
    }
  })
}

const checkUserEmail = (email) => {
  return new Promise(async (resolve, reject) => {
    try {
      const user = await db.User.findOne({ where: { email } })
      if (user) {
        resolve(true)
      }
      resolve(false)
    } catch (e) {
      reject(e)
    }
  })
}

I use postman to test. The problem is when I send data with a email already exist .The response: errCode: 1 and errMasege: Your email is already exist but a new user created with same email . But if I post a request with a already exist email and without passWord , no new User created. Help me. Thanks.

Answer 1

A resolve or reject statement does not exit the promise executor function. You should write

if (check === true) {
  return resolve({
    errcode: 1,
    errMessage: 'Your email is already exist!',
  })
}

otherwise the db.User.create operation will be carried out afterwards.

(Your code

if (user) {
  resolve(true)
}
resolve(false)

also seems to assume that resolve exits the executor function. But in this particular case, it does not matter, because resolve(false) has no effect if the promise has already resolved to true .)