Skip default check for outputs

lib/service_actor/checkable.rb

@@ -6,6 +6,15 @@ def self.included(base)
   end
 
   module PrependedMethods
+    CHECK_CLASSES = [
+      ServiceActor::Checks::TypeCheck,
+      ServiceActor::Checks::MustCheck,
+      ServiceActor::Checks::InclusionCheck,
+      ServiceActor::Checks::NilCheck,
+      ServiceActor::Checks::DefaultCheck
+    ].freeze
+    private_constant :CHECK_CLASSES
+
     def _call
       self.service_actor_argument_errors = []
 
@@ -20,6 +29,7 @@ def _call
 
     # rubocop:disable Metrics/MethodLength
     def service_actor_checks_for(origin)
+      check_classes = CHECK_CLASSES.select { _1.applicable_to_origin?(origin) }
       self.class.public_send("#{origin}s").each do |input_key, input_options|
         input_options.each do |check_name, check_conditions|
           check_classes.each do |check_class|

lib/service_actor/checks/base.rb

@@ -1,6 +1,10 @@
 # frozen_string_literal: true
 
 class ServiceActor::Checks::Base
+  def self.applicable_to_origin?(_origin)
+    true
+  end
+
   def initialize
     @argument_errors = []
   end

lib/service_actor/checks/default_check.rb

@@ -26,6 +26,10 @@
 #           }
 #   end
 class ServiceActor::Checks::DefaultCheck < ServiceActor::Checks::Base
+  def self.applicable_to_origin?(origin)
+    origin == :input
+  end
+
   def self.check(result:, input_key:, input_options:, actor:, **)
     new(
       result: result,

spec/actor_spec.rb

@@ -721,6 +721,15 @@
       end
     end
 
+    context "with unset output" do
+      specify do
+        actor = WithUnsetOutput.result
+
+        expect(actor).to be_a_success
+        expect(actor.value).to be_nil
+      end
+    end
+
     context "with `failure_class` which is not a class" do
       let(:actor) do
         Class.new(Actor) do

spec/examples/with_unset_output.rb

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+class WithUnsetOutput < Actor
+  output :value, type: String, allow_nil: true
+end