express-errors-handler

express-errors-handler

Some middleware for Express and Node that sets up Raven (or not as appropriate) depending on sensible environment variables.

Installation

npm install --save express-errors-handler

Usage

var express = require('express');
var app = express();
var eeh = require('express-errors-handler')
var errorMiddleware = eeh.middleware;

var promiseEnabledApi = require('./my-promise-enabled-api');

// A typical route using Promises
app.get('/a-typical-route', function(req, res, next) {
	promiseEnabledApi.getSomeThings()
		.then(function(someThings) {
			res.render(someThings);
		})

		// Make sure to end all Promise chains with a `catch`
		// that passes the error to the next middleware
		.catch(next);
});

// A typical route with an upstream dependency
app.get('/a-typical-route', function(req, res, next) {
	fetch('http://a.url.i-like')
		.then(function(someThings) {
			res.render(someThings);
		})
		// chosse what status to send when an upstream service errors
		.catch(eeh.upstreamErrorHandler(404))

		// Make sure to end all Promise chains with a `catch`
		// that passes the error to the next middleware
		.catch(next);
});


// Make sure the middleware is added after your routes otherwise you'll lose the errors
app.use(errorMiddleware);

Supported environment variables

• NODE_ENV - mode to operate in, can be either PRODUCTION (sends bugs to aggregator) or any another value (shows bugs to user)
• RAVEN_URL - URL to report bugs captured in production
• SPLUNK_URL - URL to send non critical or upstream bugs too

License

This software is published by the Financial Times under the MIT license.