Allow procedures without validation blocks

Updated the `procedure` method to support registration without a validation block, defaulting to an empty contract. Simplified example usages in configuration files to reflect this change.

Author: wilsonsilva

examples/procedures.rb

@@ -52,9 +52,5 @@
   end
 
   # Used only to test internal server errors
-  procedure(:explode) do
-    params do
-      # No params
-    end
-  end
+  procedure(:explode)
 end

examples/rails-single-file-routing/config.ru

@@ -22,11 +22,7 @@ JSONRPC.configure do |config|
     end
   end
 
-  procedure(:ping) do
-    params do
-      # no params
-    end
-  end
+  procedure(:ping)
 end
 
 # Define the application

examples/rails/config/initializers/jsonrpc.rb

@@ -54,9 +54,5 @@
 #   end
 #
 #   # Used only to test internal server errors
-#   procedure(:explode) do
-#     params do
-#       # No params
-#     end
-#   end
+#   procedure(:explode)
 # end

lib/jsonrpc/configuration.rb

@@ -162,15 +162,24 @@ def self.instance
     #     end
     #   end
     #
+    # @example Register a procedure without validation
+    #   config.procedure('ping')
+    #
     # @param method_name [String, Symbol] the name of the procedure
     # @param allow_positional_arguments [Boolean] whether the procedure accepts positional arguments
     #
-    # @yield A block that defines the validation contract using Dry::Validation DSL
+    # @yield [optional] A block that defines the validation contract using Dry::Validation DSL
     #
     # @return [Procedure] the registered procedure
     #
-    def procedure(method_name, allow_positional_arguments: false, &)
-      contract_class = Class.new(Dry::Validation::Contract, &)
+    def procedure(method_name, allow_positional_arguments: false, &block)
+      contract_class = if block
+                         Class.new(Dry::Validation::Contract, &block)
+                       else
+                         Class.new(Dry::Validation::Contract) do
+                           params {} # rubocop:disable Lint/EmptyBlock
+                         end
+                       end
       contract_class.class_eval { import_predicates_as_macros }
       contract = contract_class.new