using node's process to emit events to log stuff from anywhere

process.logger.js

// use like this:
// process.emit( 'app:log', module, arg1, arg2, ..., argN );

var Module = require('module');

function logConsole(method, module) {
  var args = [(new Date()).toJSON(), method];
  var index = 1;

  if (module instanceof Module) {
    args.push(module.id);
    index = 2;
  }

  args.push.apply(args, Array.prototype.slice.call(arguments, index));

  console.log.apply(console, args);
}

['debug', 'error', 'info', 'log', 'warn'].forEach( function(consoleMethod) {
  process.on('app:' + consoleMethod, logConsole.bind(null, consoleMethod.toUpperCase()));
} );

this was jeffwad's original idea

nice

This should be on NPM.

FWIW you should avoid Array.prototype.slice.call(arguments, index) style calls if you care about performance since that will make logConsole unoptimizable by v8. Creating a new array and appending to it in a for-loop will avoid this deoptimization.

The module depd will emit deprecation events on process if there is a listener, automatically suppressing output to STDERR for centralized logging in mind similar to this.

Can you please specify which versions of node are supported? I cant get it working in 6.6.0

WHy

In case it's of interest we've implemented this approach, with some sugar, and browser compatibility, in https://github.com/stencila/logga

Hey @nokome,

My friend @jeffwad — whom I commented above as, having the original idea for this — and I had completely forgotten about it when I got an email notification of your comment from github. 😅

I'm glad posting it gave you some value/inspiration, however small... 😊