Correctly emit memoizers for memoized method mutations

lib/mutant/matcher/method/instance.rb

@@ -59,6 +59,7 @@ module Mutant
 
         # Matcher for memoized instance methods
         class Memoized < self
+          SUBJECT_CLASS = Subject::Method::Instance::Memoized
 
         private
 

lib/mutant/reporter/cli/printer/subject.rb

@@ -7,6 +7,7 @@ module Mutant
         class Subject < self
 
           handle(Mutant::Subject::Method::Instance)
+          handle(Mutant::Subject::Method::Instance::Memoized)
           handle(Mutant::Subject::Method::Singleton)
 
           # Run subject results printer

lib/mutant/strategy/rspec/dm2/lookup/method.rb

@@ -96,6 +96,7 @@ module Mutant
             # Instance method dm2 style method lookup
             class Instance < self
               handle(Subject::Method::Instance)
+              handle(Subject::Method::Instance::Memoized)
 
             private
 

lib/mutant/subject/method/instance.rb

@@ -26,6 +26,7 @@ module Mutant
 
         # Mutator for memoized instance methods
         class Memoized < self
+          include NodeHelpers
 
         private
 
@@ -41,6 +42,16 @@ module Mutant
             end
           end
 
+          # Return neutral mutation
+          #
+          # @return [Mutation::Neutral]
+          #
+          # @api private
+          #
+          def noop_mutation
+            Mutation::Neutral::Noop.new(self, memoizer_node(node))
+          end
+
           # Return memoizer node for mutant
           #
           # @param [Parser::AST::Node] mutant