gistfile1.txt

# foo_spec.rb
 class Foo
   def self.bar
     raise
   end
 end
 
 describe Foo do
   subject { @foo }
   describe :bad_failure_output do                                                                                               
     before do
       @foo = Foo.bar
     end
     it { should be_nil }
   end
   describe :good_failure_output do
     before do
       @foo = Foo.new
     end
     it { should be_nil }
   end
 end

%rspec foo_spec.rb --format doc