Feature: stub implementation

  As an rspec user, I want to stub a complete implementation, not just a
  return value.
  
  Scenario: stub implementation
    Given a file named "stub_implementation.rb" with:
      """
      describe "a stubbed implementation" do
        it "works" do
          object = Object.new
          object.stub(:foo) do |arg|
            if arg == :this
              "got this"
            elsif arg == :that
              "got that"
            end
          end
          
          object.foo(:this).should == "got this"
          object.foo(:that).should == "got that"
        end
      end
      """
    When I run "spec stub_implementation.rb"
    Then the stdout should include "1 example, 0 failures"
