Can you 'require' ruby file in irb session, automatically, on every command?

Damien Roche picture Damien Roche · Jun 13, 2012 · Viewed 11.8k times · Source

I am currently editing a file, and I'm using irb to test the api:

> require './file.rb'
> o = Object.new
> o.method

I then want to be able to edit the file.rb, and be able to see changes immediately. Example: assume new_method did not exist when I first required file.rb:

> o.new_method

Which will return an error. Is there a sandbox/developer mode or a method whereby I can achieve the above without having to reload the file every time? Require will not work after the first require, regardless. I assume worst case I'd have to use load instead.

Answer

bta picture bta · Jun 13, 2012

I usually create a simple function like this:

def reload
    load 'myscript.rb'
    # Load any other necessary files here ...
end

With that, a simple reload will re-import all of the scripts that I'm working on. It's not automatic, but it's the closest thing that I've been able to come up with.

You may be able to override method_missing to call this function automatically when your object is invoked with a method that doesn't exist. I've never tried it myself, though, so I can't give any specific advice. It also wouldn't help if you're calling a method that already exists but has simply been modified.

In my own laziness, I've gone as far as mapping one of the programmable buttons on my mouse to the key sequence "reload<enter>". When I'm using irb, all it takes is the twitch of a pinky finger to reload everything. Consequently when I'm not using irb, I end up with the string "reload" inserted in documents unintentionally (but that's a different problem entirely).