Conditional Whac-A-Mole: Another solution

toot.rb

class User < Struct.new(:username, :followability)
  def follow
    followability.follow(self)
  end
end

class Follow
  def self.follow(user)
    user.follow
  end
end

class PublicFollowability
  def follow(user)
    Follow.actually_follow(user)
  end
end

class PrivateFollowability
  def follow(user)
    Follow.actually_follow(user) if Follow.confirm_follow(user)
  end
end

toot_spec.rb

require_relative "toot"

describe Follow do
  context "when the user is public" do
    it "follows immediately" do
      user = User.new("garybernhardt", PublicFollowability.new)
      Follow.should_receive(:actually_follow).with(user)
      Follow.follow(user)
    end
  end

  context "when the user is private" do
    let(:user) { User.new("garybernhardt", PrivateFollowability.new) }

    it "does not follow if the user declines the prompt" do
      Follow.stub(:confirm_follow).with(user) { false }
      Follow.should_not_receive(:actually_follow).with(user)
      Follow.follow(user)
    end

    it "does not follow if the user declines the prompt" do
      Follow.stub(:confirm_follow).with(user) { true }
      Follow.should_receive(:actually_follow).with(user)
      Follow.follow(user)
    end
  end
end