explicit requires, fast specs, and crazy dependencies

gistfile1.rb

#foo.rb

class Foo < Bar
end

#bar.rb
class Bar < ActiveRecord::Base
   #all sorts of crazy code that depends on a bunch of wacky stuff my tests don't care about
end


#In my test code, I want to do this

it "does something" do
  fake_foo = stub
  Foo.stub(:find).and_return(fake_foo) #note that referencing Foo requires the class Foo to be defined
end

#but, I can't require foo.rb because I would need to require bar.rb, which requires me to pull in a bunch of wacky stuff
#my current solution is something like this:

before {
  class Foo; end
}

it "does something" do
  Foo.stub(:and).and_return(fake_foo)
end

after {
  Object.send(:remove_const, "Foo")
}

#But that seems ugly. I'm looking for better ideas.  Thoughts?