Nodejs errors cause postman to hang on loading screen

Question

I'm new to Node and am working on an app and using SQL for the first time in it as well. I successfully GET request objects from the database but am having trouble with the POST request. With my current code I can POST to the database if my request body falls within the parameters I set, but if they don't I get nothing returned.

I'm using Postman to check my work and when I set a faulty request body, the error message doesn't return and Postman keeps loading and the "sending request" message stays on the screen.

Here is my router function:

router.post('/', checkAccountPayload, async (req, res, next) => {
  try {
    const data = await Account.create(req.body);
    res.status(201).json(data);
  } catch (err) {
    next(err)
  }
})

my model function:

const create = async account => {
  let [id] = await db('accounts').insert(account);
  return getById(id);
}

my middleware function:

exports.checkAccountPayload = (req, res, next) => {
  const error = { status: 400 }
  if (req.body.name === undefined || req.body.budget === undefined) {
    error.message = "name and budget are required"
  } else if (req.body.name.trim().length < 3 || req.body.name.trim().length > 100) {
    error.message = "name of account must be between 3 and 100"
  } else if (typeof req.body.budget !== 'number' || isNaN(req.body.budget)) {
    error.message = "budget of account must be a number"
  } else if (req.body.budget < 0 || req.body.budget > 1000000) {
    error.message = "budget of account is too large or too small"
  }

  if (error.message) {
    next(error)
    console.log(error);
  } else {
    next()
  }
}

When I console.log the error inside the if statement with the "next(error)" I get the error logged, so I know the message is getting passed. I also added console.logs to the router and model functions and those DON'T pop up.

Any help on how I can fix my code would be appreciated

Answer 1

You have created an error object, but express doesn't know it is an error. You need to create an error object like this and pass or just throw an error:

exports.checkAccountPayload = (req, res, next) => {
  const error = new Error();
  if (req.body.name === undefined || req.body.budget === undefined) {
    error.message = "name and budget are required"
  } else if (req.body.name.trim().length < 3 || req.body.name.trim().length > 100) {
    error.message = "name of account must be between 3 and 100"
  } else if (typeof req.body.budget !== 'number' || isNaN(req.body.budget)) {
    error.message = "budget of account must be a number"
  } else if (req.body.budget < 0 || req.body.budget > 1000000) {
    error.message = "budget of account is too large or too small"
  }

  if (error.message) {
    // next(error) it will pass it to next middleware
    throw new Error('Account Validation failed', {cause: error});
  } else {
    next()
  }
}

Also, check your terminal error messages if any unhandled error occurs your server won't be able to send the response and the client will wait until request is time out.

Answer 2

I ended up making the code work properly by getting rid of the error object and replacing error.message with a res.status.... Not sure why my code above didn't work (if anyone knows I'd still like to hear why) but here is my new function:

exports.checkAccountPayload = (req, res, next) => {
  if (req.body.name === undefined || req.body.budget === undefined) {
    res.status(400).json({ message: "name and budget are required" });
  } else if (req.body.name.trim().length < 3 || req.body.name.trim().length > 100) {
    res.status(400).json({ message: "name of account must be between 3 and 100" });
  } else if (typeof req.body.budget !== 'number' || isNaN(req.body.budget)) {
    res.status(400).json({ message: "budget of account must be a number" });
  } else if (req.body.budget < 0 || req.body.budget > 1000000) {
    res.status(400).json({ message: "budget of account is too large or too small" });
  }
  next()
}