[johnfn]

When people say "magic", what they often mean is "code over here can effect the execution of code over there in an implicit way". Like in Ruby, I could conditionally monkey-patch a function into an object someone way over there was using, causing code to break.

Other languages, like those with stronger type systems, will not allow this to happen.

[brightball]

Yea, monkey patching is helpful when dealing with a 3rd party library that needs to be tweaked 10 layers up the inheritance chain without having to change the object type all over the whole system.

If it gets overused it causes problems but there are times when it is close to a miracle. That said, there is a reason ruby devs are so test conscious.

[johnfn]

Yeah - of course monkey patching has good uses :) The problem is that when you're trying to debug an issue, it's another thing that you'll have to remember - "is anyone monkey patching something in here?"

[brightball]

Yea, I can't work on Ruby codebases without something like Rubymine where I can jump straight to the declaration for that exact reason.