IRB sessions anywhere!
gem install irb_drop
Anywhere in your code, you can just place
binding.irb_drop
That will drop you into an irb session right there.
Full example:
require 'irb_drop'
x = 1
puts "before drop, x is now: #{x}"
binding.irb_drop # <-- irb shell starts here, assign something to x, exit from irb
# with `exit`
puts "after drop, x is now: #{x}"
Enables you to drop into an IRB session from any code.