bad-request-error

BadRequestError is a custom error constructor for HTTP errors (bad parameters, forbidden, unauthorized…). It takes an error message as first parameter and optionally a HTTP error code as second parameter (defaults to 400).

Installation

It requires at least Node V6 as it uses JavaScript classes.

npm install --save bad-request-error

Usage

In addition to the native Error constructor properties, BadRequestError adds httpStatus and has its name property set to BadRequestError.

const BadRequestError = require('bad-request-error');

async function addComment(req, res) {
    await const isCorrectPasswd = checkPasswd(req);
    if (!isCorrectPasswd) return throw new BadRequestError('Your password looks wrong', 401);

    // whatever you have to do if password is correct
}

It's very convenient to use it with an error handler function like the following:

// /lib/handleError.js

/**
 * Send client err if it's validation error or log if it's a native or low level error
 * @param { Object } err error object
 * @param { Object } res
 */
function handleError(err, res) {
    // send errmsg to user if it's a BadRequestError
    if (res && err.name && err.name === 'BadRequestError') {
        res.status(err.httpStatus).json({ error: err.message });
        return;
    }

    // send http err if res object is provided
    if (res) res.status(500).send('Server Error');

    // if it's more low level, or if errorField isn't an error's propt
    console.error(err); // or custom logger like winston
}

module.exports = handleError;

If using promises, the error is easily handled in a catch block.

const BadRequestError = require('bad-request-error');
const handleError = require('/lib/handleError');

// this function return a promise with the same BadRequestError as above if password doesn't match
// BadRequestError('Your password looks wrong', 401);
function checkPasswd(passwd) {}

function addComment(req, res) {
    checkPasswd(req.body.passwd)
    .then(() => {
        // whatever you have to do if password is correct
    })
    .catch(err => handleError(err, res));
}

Contributing

There's sure room for improvement, so feel free to hack around and submit PRs! Please just follow the style of the existing code, which is Airbnb's style with minor modifications.

To maintain things clear and visual, please follow the git commit template.