how can I log every method call in node.js without adding debug lines everywhere?

Question

I would like to log the user_id of the person making a request and the method name of every method called for a javascript class. For example:

35 - log_in
35 -          


        

Answer 1

This is one alternative, not entirely sure how reliable it is though, it feels a bit wrong:

(function () {
  var oldCall = Function.prototype.call;
  var newCall = function(self) {
    Function.prototype.call = oldCall;
    console.log('Function called:', this.name);
    var args = Array.prototype.slice.call(arguments, 1);
    Function.prototype.call = newCall;
    this.apply(self, args);
  }
  Function.prototype.call = newCall;
})();

As you can see, it overwrites the call function - this creates a slight problem when you try to call console.log() so you need to swap the function back. But it seems to work!

EDIT

Since this is tagged CoffeeScript:

do ->
  oldCall = Function::call
  newCall = (self) ->
    Function::call = oldCall
    console.log "Function called: #{this.name}"
    args = Array.prototype.slice.call arguments, 1
    Function::call = newCall
    this.apply self, args
  Function::call = newCall