Pact.service_consumer "My Service Consumer" do
  has_pact_with "My Service Provider" do
    mock_service :my_service_provider do
      port <port-num>
      standalone true #Tell the pact gem not to automatically start the mock service
    end
  end
end

Pact.provider_states_for "Some Consumer" do
  set_up do
    # Set up code here 
  end
  tear_down do
    # tear down code here
  end
end

Pact.service_consumer "My Consumer" do
  app <your rack app here>
  port 4321
end

my_service_provider.
  .given("it is RFC 2616 compliant")
  .upon_receiving("a request with a header with commas separated values")
  .with( method: :get, path: '/', headers: {'X-Request-Multival' => "A, B"} )
  .will_respond_with(
    status: 200, headers: {'X-Response-Multival' => "C, D"}
  )