[M4v3R]

I used the prototype mechanism several times when debugging a script that I couldn't easily change source code for. I just typed:

SomeClass.prototype.someMethod

Which outputs the methods source. Then you can add some debug code like console.log(xxx) or even fix a simple bug, copy the whole thing and set it again:

SomeClass.prototype.someMethod = function ...

Voila! Hot code push without an IDE. While that's obviously not ideal, it certainly works in some cases.

[GeneralMayhem]

My favorite trick along those lines:

  var cache = SomeClass.prototype.someMethod;
  SomeClass.prototype.someMethod = function () {
    debugger; // or `throw "stacktrace"`
    cache.apply(this, arguments)
  }

Inserts a stack trace right in the middle of executing someone else's code, which is nice for tracking down why/when that function gets called if documentation is poor, without changing functionality.

[nccong]

Good point. It's a quick way to debug/experiment.