gistfile1.txt

# from the context of within an rspec test:

  mock_it { render :text => "hello" }

  def mock_it(&block)
    ApplicationController.class_eval do
      define_method mocked_method do
        return block.call if block_given?
      end 
    end 
  end 

==>  undefined method `render' for #<RSpec::Core::ExampleGroup::Nested_1::Nested_2:0x00000103ad1318>