Let’s use the createUser() helper function in our routes. We’ll add the logic to create users in a POST request to "/register".

Since we’re working with promises, we can create an asynchronous route handler by using async/await:

app.post("/register", async (req, res) => { ... })

We’ll retrieve the user data from req.body and await as we call our helper function to create the new user:

app.post("/register", async (req, res) => {
  const { username, password } = req.body;
  // imported helper function: 
  // db.users.createUser
  const newUser = await db.users.createUser({ username, password });

If a newUser is successfully created, we send a status code of 201 and a json response back to the client:

app.post("/register", async (req, res) => {
  const { username, password } = req.body;
  const newUser = await db.users.createUser({ username, password });
  if (newUser) {
    res.status(201).json({
      msg: "Insert Success Message Here",
      insertDataHere
    });
  }

Lastly, we want to handle potential errors that might occur. In an else statement we can return a status code of 500 indicating that there was a relevant error message:

app.post("/register", async (req, res) => {
  const { username, password } = req.body;
  const newUser = await db.users.createUser({ username, password });
  if (newUser) {
    res.status(201).json({
      msg: "Insert Success Message Here",
      insertDataHere
    });
  } else {
    res.status(500).json({ msg: "Insert Failure Message Here" });
  }

NOTE: In a real development environment, passwords would be hashed whenever a new user registers.

With the route completed, users will now be able to register and log in!