Manually dup Keys instead of marshalling/unmarshalling

Marshalling/unmarshalling does not work when definitions cannot be marshalled (Lambda, for example).

lib/definition/model.rb

@@ -40,8 +40,7 @@ def _definition
         @_definition ||= if superclass == ::Definition::Model
                            ::Definition.Keys {}
                          else
-                           # Create a deep copy of parent's definition
-                           Marshal.load(Marshal.dump(superclass._definition))
+                           superclass._definition.dup
                          end
       end
     end

lib/definition/types/keys.rb

@@ -63,6 +63,13 @@ def initialize(name, req: {}, opt: {}, defaults: {}, options: {})
         self.ignore_extra_keys = options.fetch(:ignore_extra_keys, false)
       end
 
+      def initialize_dup(_other)
+        super
+        self.required_definitions = required_definitions.dup
+        self.optional_definitions = optional_definitions.dup
+        self.defaults = defaults.dup
+      end
+
       def conform(input_value) # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/MethodLength, Metrics/PerceivedComplexity
         # input_value is duplicated because we don't want to modify the user object that is passed into this function.
         # The following logic will iterate over each definition and delete the key associated with the definition from

spec/lib/definition/model_spec.rb

@@ -5,7 +5,7 @@
 describe Definition::Model do
   let(:test_model_class) do
     Class.new(described_class) do
-      required :name, Definition.Type(String)
+      required :name, Definition.NonEmptyString
       optional :email, Definition.Type(String)
     end
   end
@@ -177,7 +177,7 @@
         end.to raise_error(Definition::InvalidModelError, /age/)
       end
 
-      it "doesn't change parent's defintion" do
+      it "doesn't change parent's definition" do
         expect do
           Class.new(test_model_class) do
             required :required_child_attribute, Definition.Type(Integer)

spec/lib/definition/types/keys_spec.rb

@@ -189,4 +189,36 @@
       end
     end
   end
+
+  describe ".dup" do
+    it "dups definitions and defaults" do
+      original = described_class.new("person",
+                                     req:      {
+                                       name: Definition.Type(String)
+                                     },
+                                     opt:      {
+                                       age:        Definition.Type(Integer),
+                                       authorized: Definition.Boolean
+                                     },
+                                     defaults: {
+                                       authorized: false
+                                     })
+      copy = original.dup
+
+      original.required_definitions.clear
+      original.optional_definitions.clear
+      original.defaults.clear
+
+      value = {
+        name: "John",
+        age:  18
+      }
+      expected = {
+        name:       "John",
+        age:        18,
+        authorized: false
+      }
+      expect(copy.conform(value)).to conform_with(expected)
+    end
+  end
 end