Is there a pattern to not include provider states if all provider states are

no_op

?

Pact.provider_states_for 'My Service' do
  provider_state 'some state that needs no setup' do
    no_op
  end

  provider_state 'some other state that needs no setup' do
    no_op
  end
end

No, but that would be a good idea.

The warning that provider states are missing is still needed to inform the provider to add them if they are needed. But if there's some way within

pact_helper

to explicitly indicate that no setup/teardown is necessary for any provider states for the specific consumer, that could reduce complexity a little...

You can raise it in the pact-ruby repository, or in pact.canny.io @Jason Wang