如何修复TypeError：registerUser不是函数

Question

I am trying to register users and add them to a database, but when I call the registerUser function, an error gets thrown.

I have read through this article to see how I would be causing this error and I have searched through several posts on here.

I feel like I must need another set of eyes to come and help find what I'm doing wrong

Here is the code that calls the register user function ('data' is an object that is the cleaned inputs from the sign-up form)

const db  = require('./database');
const bcrypt = require('bcrypt');
const saltRounds = 10;


function hasher(data){

   bcrypt.hash(data.password, saltRounds)
      .then(function(hash) {
         data.password = hash;
         db.registerUser(data);  
      })
      .catch(e => console.error(e));
}

if I console.log(db) before registerUser is called heroku prints "{}" in the logs

and this is the register user function from database.js:

const { Client } = require('pg');
const hasher = require('../models/hash')

const client = new Client({
  connectionString: process.env.DATABASE_URL,
  ssl: true,
});

client.connect()


function registerUser(data) {

   const query = "INSERT INTO users (user_id, first_name, last_name, email, username, hash_pass) VALUES(DEFAULT, $1, $2, $3, $4, $5)";
   const values = [data.first, data.last, data.email, data.username, data.password];
   client.query(query, values)
      .then(res => console.log("stored: " + res.rows[0] + "in db"))
      .catch(e => console.error(e.stack));
}


module.exports = {
   registerUser : registerUser
};

I am getting "TypeError: db.registerUser is not a function"

Answer 1

The problem I guess is that you are importing const hasher = require('../models/hash') into database.js and const db = require('./database'); into hasher.

That circular dependency may be causing the problem.

Your exports are fine.

Answer 2

From what I can see registerUser is a standalone function, not a method of db object.

I can also see module.exports = { registerUser : registerUser }; instruction - but this doesn't give a hint to where or what is it being exported to.

I suggest you try registerUser(data); as a standalone declaration and see what happens, because obviously it is not becoming a method of db - watch your console for any error messages during the load time...

good luck