It's very powerful though which is a bit terrifying. You can literally monkey patch Object at runtime and add methods to every single instantiated object! (I believe this is how rspec works..)
Awesome, but with great power come great responsibility ;)
RSpec moved from that quite some time ago. Monkey patching nowadays is usually frowned upon, even refinements, which could simulate monkey patching in a limited scope, are rarely used.
Oh I'm extremely out of date, I was into ruby back when Why's guide was a thing. Maybe I'll revisit it someday if I ever get bored of go paying the rent.
Awesome, but with great power come great responsibility ;)