Move additionalProperties to 3.0 Schema node

This will be modelled differently for OpenAPI 3.1 where a JSON schema
can itself have a boolean value and thus we won't be using Boolean or
Schema anymore as a 3.1 Schema will suffice.

lib/openapi3_parser/node/schema.rb

@@ -157,19 +157,6 @@ def properties
         self["properties"]
       end
 
-      # @return [Boolean]
-      def additional_properties?
-        self["additionalProperties"] != false
-      end
-
-      # @return [Schema, nil]
-      def additional_properties_schema
-        properties = self["additionalProperties"]
-        return if [true, false].include?(properties)
-
-        properties
-      end
-
       # @return [String, nil]
       def description
         self["description"]

lib/openapi3_parser/node/schema/v3_0.rb

@@ -21,6 +21,19 @@ def exclusive_maximum?
         def exclusive_minimum?
           self["exclusiveMinimum"]
         end
+
+        # @return [Boolean]
+        def additional_properties?
+          self["additionalProperties"] != false
+        end
+
+        # @return [Schema, nil]
+        def additional_properties_schema
+          properties = self["additionalProperties"]
+          return if [true, false].include?(properties)
+
+          properties
+        end
       end
     end
   end

lib/openapi3_parser/node_factory/schema/common.rb

@@ -33,10 +33,6 @@ def self.included(base)
           base.field "not", factory: :referenceable_schema
           base.field "items", factory: :referenceable_schema
           base.field "properties", factory: :schema_map_factory
-          base.field "additionalProperties",
-                     validate: :additional_properties_input_type,
-                     factory: :additional_properties_factory,
-                     default: false
           base.field "description", input_type: String
           base.field "format", input_type: String
           base.field "default"
@@ -106,19 +102,6 @@ def referenceable_schema_array(context)
             value_factory: NodeFactory::Schema.factory(context)
           )
         end
-
-        def additional_properties_input_type(validatable)
-          input = validatable.input
-          return if [true, false].include?(input) || input.is_a?(Hash)
-
-          validatable.add_error("Expected a Boolean or an Object")
-        end
-
-        def additional_properties_factory(context)
-          return context.input if [true, false].include?(context.input)
-
-          referenceable_schema(context)
-        end
       end
     end
   end

lib/openapi3_parser/node_factory/schema/v3_0.rb

@@ -13,10 +13,16 @@ class V3_0 < NodeFactory::Object # rubocop:disable Naming/ClassAndModuleCamelCas
         field "type", input_type: String
 
         # JSON Schema 2016 has these exclusive fields as booleans whereas
-        # in JSON Schema 2021 (OpenAPI 3.1) these are numbers
+        # in JSON Schema 2020 (OpenAPI 3.1) these are numbers
         field "exclusiveMaximum", input_type: :boolean, default: false
         field "exclusiveMinimum", input_type: :boolean, default: false
 
+        # JSON Schema 2020 accepts a schema (albeit a more complex one) than
+        # this schema or boolean approach
+        field "additionalProperties", validate: :additional_properties_input_type,
+                                      factory: :additional_properties_factory,
+                                      default: false
+
         validate :items_for_array
 
         def build_node(data, node_context)
@@ -36,6 +42,19 @@ def items_for_array(validatable)
 
           validatable.add_error("items must be defined for a type of array")
         end
+
+        def additional_properties_input_type(validatable)
+          input = validatable.input
+          return if [true, false].include?(input) || input.is_a?(Hash)
+
+          validatable.add_error("Expected a Boolean or an Object")
+        end
+
+        def additional_properties_factory(context)
+          return context.input if [true, false].include?(context.input)
+
+          referenceable_schema(context)
+        end
       end
     end
   end

spec/lib/openapi3_parser/node_factory/schema/v3_0_spec.rb

@@ -72,4 +72,35 @@
         .with_message("items must be defined for a type of array")
     end
   end
+
+  describe "validating additionalProperties" do
+    it "is valid for a boolean" do
+      true_instance = described_class.new(
+        create_node_factory_context({ "additionalProperties" => true })
+      )
+      expect(true_instance).to be_valid
+
+      false_instance = described_class.new(
+        create_node_factory_context({ "additionalProperties" => false })
+      )
+      expect(false_instance).to be_valid
+    end
+
+    it "is valid for a schema" do
+      instance = described_class.new(
+        create_node_factory_context({ "additionalProperties" => { "type" => "object" } })
+      )
+      expect(instance).to be_valid
+    end
+
+    it "is invalid for something different" do
+      instance = described_class.new(
+        create_node_factory_context({ "additionalProperties" => %w[item1 item2] })
+      )
+      expect(instance).not_to be_valid
+      expect(instance)
+        .to have_validation_error("#/additionalProperties")
+        .with_message("Expected a Boolean or an Object")
+    end
+  end
 end

spec/support/schema_common.rb

@@ -88,37 +88,6 @@
       expect(read_only).to be_valid
     end
   end
-
-  describe "validating additionalProperties" do
-    it "is valid for a boolean" do
-      true_instance = described_class.new(
-        create_node_factory_context({ "additionalProperties" => true })
-      )
-      expect(true_instance).to be_valid
-
-      false_instance = described_class.new(
-        create_node_factory_context({ "additionalProperties" => false })
-      )
-      expect(false_instance).to be_valid
-    end
-
-    it "is valid for a schema" do
-      instance = described_class.new(
-        create_node_factory_context({ "additionalProperties" => { "type" => "object" } })
-      )
-      expect(instance).to be_valid
-    end
-
-    it "is invalid for something different" do
-      instance = described_class.new(
-        create_node_factory_context({ "additionalProperties" => %w[item1 item2] })
-      )
-      expect(instance).not_to be_valid
-      expect(instance)
-        .to have_validation_error("#/additionalProperties")
-        .with_message("Expected a Boolean or an Object")
-    end
-  end
 end
 
 RSpec.shared_examples "schema node" do |openapi_version:|