An uncaughtException middleware for connect, using domains to allow a clean uncaught errors handling. This module tries to be a better connect-domain module.
Features :
- unit tests, code coverage
- creates a domain for the current request
- detects errors bubbled to this domain
- by default, handles errors with the following "best practices" pattern:
- responds to the corresponding request with the express error handler (remember to set one !)
- starts a security suicide timeout (configurable) in case the shutdown blocks
- if a cluster worker, calls disconnect() (which closes servers and signals the cluster master of our inavailability)
- if not a cluster, closes the server
- a custom error callback may be provided if those default actions are not suitable
- only starts the error callback once, subsequent errors are printed only
- only closes the server or disconnect the worker if not already done (monitoring begins at the middleware creation)
Tested with express 4. Should work with express 3 and connect.
See also node-domain-middleware, express-domain-errors, express-err
Interesting reads :
$ npm install domain-middlewareUsually, domain usage goes hand-in-hand with the cluster module, since the master process can fork a new worker when a worker encounters an error. Please see connect_with_cluster example.
Note : the example code below throws various errors for test, don't do it in production of course:
var http = require('http');
var express = require('express');
var domainMiddleware = require('domain-middleware');
var app = express();
var server = http.createServer(app);
app.use(domainMiddleware({
server: server,
killTimeout: 30000,
}))
.use(function(req, res) {
if (Math.random() > 0.5) {
foo.bar(); // synchronous error
}
setTimeout(function() {
if (Math.random() > 0.5) {
throw new Error('Asynchronous error from timeout');
} else {
res.end('Hello from Connect!');
}
}, 100);
setTimeout(function() {
if (Math.random() > 0.5) {
throw new Error('Mock second error');
}
}, 200);
})
.use(function(err, req, res, next) {
res.end(err.message);
});
server.listen(1984);If the default error handling (shutdown timeout, server close, cluster disconnect) doesn't fit your need, a custom error callback can be provided:
app.use(domainMiddleware({
onError: myErrorHandler <-- params : (req, res, next, err, options)
// all other options no longer have any meaning unless your custom callback use them
}))
Thank you for contributing !
You may want to create an issue first if you are not sure.
- fork
- clone
cd domain-middlewaremake test- (optional : start a branch)
- add tests
- add features
make test-covand check coverage- send pull request https://help.github.com/articles/be-social#pull-requests
(The MIT License)
Copyright (c) 2013 fengmk2 <[email protected]>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.