simple.rb

class Chef::Provider::Service::Simple <<< Chef::Provider::Service

        def shared_requirements 
          requirements.assert(:all_actions) do |a|
            a.assertion { @new_resource.status_command or @new_resource.supports[:status] or 
              (!ps_cmd.nil? and !ps_cmd.empty?) } 
            a.failure_message Chef::Exceptions::Service, "#{@new_resource} could not determine how to inspect the process table, please set this nodes 'command.ps' attribute"
          end
          requirements.assert(:all_actions) do |a| 
            a.assertion { !@ps_command_failed } 
            a.failure_message Chef::Exceptions::Service, "Command #{ps_cmd} failed to execute, cannot determine service current status"
          end
          requirements.assert(:all_actions) do |a| 
            a.assertion { @status_load_success } 
            a.whyrun "Failed to load initial status for service, assuming service would have previously been installed and has a current status of not running" 
          end
        end
        
        def define_resource_requirements
          super
          requirements.assert(:start) do |a|
            a.assertion { @new_resource.start_command }
            a.failure_message Chef::Exceptions::Service, "#{self.to_s} requires that start_command be set"
          end
          requirements.assert(:stop) do |a|
            a.assertion { @new_resource.stop_command }
            a.failure_message Chef::Exceptions::Service, "#{self.to_s} requires that stop_command be set"
          end

          requirements.assert(:restart) do |a|
            a.assertion { @new_resource.restart_command  || ( @new_resource.start_command && @new_resource.stop_command ) }
            a.failure_message Chef::Exceptions::Service, "#{self.to_s} requires both start_command and stop_command be set in order to perform a restart; or that restart_comand be specified"
          end
          
          shared_requirement 
        end
end
# Meanwhile, in init.rb: 

class Chef::Provider::Service::Init <<< Chef::Provider::Service::Simple
  def define_resource_requirements 
    # we won't call s uper, that has requirements that don't apply to us.
    # Instead, just declare those requirements that are common to both. 
    shared_requirements
  end
end