fi-errors

Fi Errors

An ExpressJS middleware to handle custom errors.

Requirements:

• NodeJS 6.x.x

Installation

npm install --save fi-errors

Configuration

The first step is to create your configuration file. Here you can define your custom errors, redirection urls and excluded requests.

This package comes with a default configuration that you can extend or overwrite.

Sample configuration file

const config = {
  // Custom application errors
  errors: [
    // This error will be added to the component errors list
    { 
      name: 'myCustomError',
      message: 'My custom error default message'
      code: 418
    },
    
    // This error will overwrite the default BadRequestError
    { 
      name: 'BadRequestError',
      message: 'The request could not be understood by the server due to malformed syntax'
      code: 400
    }
  ],

  // Every failed HTTP request to this urls will be terminated 
  exclude: /^\/(assets|api)\//i,

  // Redirection urls
  redirect: {
    error: '/error?err=',
    lost: '/lost?url='
  }
};

Usage

To use the package you must configure it and then bind it to the express application.

Binding the component

const errors = require('fi-errors');
const express = require('express');
const app = express();

// First load the component
errors.configure(config)

// Somehow register your middlewares
registerMiddlewares(app);

// Lastly bind the errors component
errors.bind(app);

Using the component

const errors = require('fi-errors');

const { BadRequestError } = errors.list();
  
  module.exports = (router, db) => {

  const User = db.model('user');

  /**
   * Creates a user.
   */
  router.post('/', (req, res, next) => {

    User.create(req.body)

      .then((user) => {
        if (!user) {
          throw new BadRequestError('The user could not be created');
        }

        res.status(HTTP_CODE_CREATED).json(user._id);
      })

      .catch(next);

  });

});

Every error triggered in a middleware will be catched inside the component, including not found routes and unknown errors.

Documentation

Read the library docs for the methods specification.