trycatch

trycatch

An asynchronous domain-based try/catch exception handler with (optional) long stack traces for node.js

With the update to 0.2.0

• error-handling is now domain-based
• long-stack-traces are optional (off by default)
• long-stack-traces are lazy

Also, trycatch conforms to try/catch V8 best practices.

Install

npm install trycatch

Use

var trycatch = require('trycatch')
trycatch(fnTry, fnCatch)

Optional Long-Stack-Traces:

// Because trycatch shims all native I/O calls,
// it must be required & configured with 'long-stack-traces' before any other modules.
var trycatch = require('trycatch')
trycatch.configure({'long-stack-traces': true})
trycatch(fnTry, fnCatch)

Colors:

var trycatch = require('trycatch')
trycatch.configure({
  colors: {
    // 'none' or falsy values will omit
    'node': 'none',
    'node_modules': false,
    'default': 'yellow'
  }
})
trycatch(fnTry, fnCatch)

Advanced Formatting:

var trycatch = require('trycatch')
trycatch.configure({
  format: function(line) {
    // Alter final output (falsy values will omit)
    return line
  }
})
trycatch(fnTry, fnCatch)

Basic Example

var trycatch = require("trycatch"),
  _ = require('underscore')._

  trycatch(function() {
  _.map(['Error 1', 'Error 2'], function foo(v) {
    setTimeout(function() {
      throw new Error(v)
    }, 10)
  })
}, function(err) {
  console.log("Async error caught!\n", err.stack);
});

Output

Advanced Examples

See the /test and examples directories for more use cases.

Returning 500s on Server Request

http.createServer(function(req, res) {
  trycatch(function() {
    setTimeout(function() {
      throw new Error('Baloney!');
    }, 1000);
  }, function(err) {
    res.writeHead(500);
    res.end(err.stack);
  });
}).listen(8000);

Visit http://localhost:8000 and get your 500.

Thanks

Special thanks to Tom Robinson for his long-stack-traces module and Tim Caswell who built out the initial hook.js code.