lib/dryspec/helpers.rb
def subject_should_not_raise(*args)
      error, message = args
      it_string = "subject should not raise #{error}"
      it_string += " (#{message.inspect})" if message

      it it_string do
        expect { subject }.not_to raise_error error, message
      end
    end
def subject_should_not_raise(*args)
      error, message = args
      it_string = "subject should not raise #{error}"
      it_string += " (#{message.inspect})" if message

      it it_string do
        expect { subject }.not_to raise_error error, message
      end
    end
Allows you to simply specify that the subject should not raise an exception.
 Takes no arguments or arguments of an exception class, a string, or both.

 As with RSpec's basic `not_to raise_error` matcher, if you give a specific error, other
 unexpected errors may be swallowed silently

 @example Subject does not raise an error
   # Before
   subject { 1 }
   it 'should not raise an exception' do
     expect { subject }.not_to raise_error
   end

   # After
   subject { 1 }
   subject_should_not_raise