Custom Error Classes
- All classes inherit from the abstract class (lib/abstract-error.js) inspired by dustin senos's post.
- The abstract error class inherits from the in built error object.
- All error classes exported in lib/main.js -> index.js
- Easy logging integration with express.js using the log errors module
App Error Classes (module.exports.general)
1. ValidationError
2. DatabaseError
Express Error Classes (module.exports.request)
1. BadRequest = Bad Request Error (400)
2. Unauthorized = Unauthorized Error (401)
3. Forbidden = Forbidden Error (403)
4. NotAcceptable Request Not Acceptable Error (406)
Sample Usage
1. General Error Classes
var main = require('./../lib/main');var ValidationError = main.general.ValidationError; var msg = "terrible input", ValError = new ValidationError(msg); console.log('ValError', ValError);STDOUT output:
ValError { name: 'Validation', logLevel: 'warning', doNotKill: undefined, resCode: undefined, message: 'not a valid date'}2. Request Error Classes
var BadRequestError = main.request.BadRequest;var msg = "just an awful request", ReqError = new BadRequestError(msg); console.log('ReqError', ReqError);STDOUT output:
ReqError { name: 'BadRequest', logLevel: 'warning', resCode: 400, message: 'just an awful request'}Using with Express.js
Easy integration with the log errors module
var BadRequestError = require('customErrors').request.BadRequest;var logErrors = require('log-errors'); // define some routesapp.get('/some/route', function(req, res, next) { if ('error thrown') { next(new BadRequestError('reason for the bad request being thrown')); }}); //... catchall error middleware (put at very end beneath all routes)app.configure('development', function() { // wrap the logger if you need to do something // with the error before passing it to the logger app.use(function(err, req, res, next) { err.resCode || (err.resCode = 400); logErrors.development(err, req, res, next); });}); app.configure('production', function() { // defaults to sending 500 response if err.resCode is not set app.use(logErrors.production);});Reference
Header status codes
log levels
Visionmedia Logging Module
0 EMERGENCY system is unusable
1 ALERT action must be taken immediately
2 CRITICAL the system is in critical condition
3 ERROR error condition
4 WARNING warning condition
5 NOTICE a normal but significant condition
6 INFO a purely informational message
7 DEBUG messages to debug an application