Take care to not mutate self.class into class

lib/mutant/mutator/node/send.rb

@@ -29,7 +29,7 @@ module Mutant
         # @api private
         #
         def emit_receiver
-          unless self?
+          unless to_self?
             emit(receiver)
           end
         end
@@ -53,7 +53,7 @@ module Mutant
         # @api private
         #
         def emit_receiver_mutations
-          unless self?
+          unless to_self? or self_class?
             emit_attribute_mutations(:receiver) 
           end
         end
@@ -93,17 +93,33 @@ module Mutant
         # Check if receiver is self
         #
         # @return [true]
-        #   returns true when receiver is a Rubinius::AST::Self node
+        #   if receiver is a Rubinius::AST::Self node
         #
         # @return [false]
         #   return false otherwise
         #
         # @api private
         #
-        def self?
+        def to_self?
           receiver.kind_of?(Rubinius::AST::Self)
         end
 
+        # Check if receiver is self.class
+        #
+        # @return [true]
+        #   if receiver is a "self.class" construct
+        #
+        # @return [false]
+        #   otherwise
+        #
+        # @api private
+        #   
+        def self_class?
+          receiver.kind_of?(Rubinius::AST::Send) && 
+          receiver.name == :class                && 
+          receiver.receiver.kind_of?(Rubinius::AST::Self)
+        end
+
         # Emit mutation that replaces explicit send to self with implicit send to self
         # 
         # @example:
@@ -130,7 +146,7 @@ module Mutant
         # @api private
         #
         def emit_implicit_self_receiver
-          return unless self?
+          return unless to_self?
           mutant = dup_node
           mutant.privately = true
           # TODO: Fix rubinius to allow this as an attr_accessor

spec/unit/mutant/mutator/node/send/mutation_spec.rb

@@ -32,6 +32,17 @@ describe Mutant::Mutator, 'send' do
 
       it_should_behave_like 'a mutator'
     end
+
+    context 'to self.class.foo' do
+      let(:source) { 'self.class.foo' }
+
+      let(:mutations) do
+        mutations = []
+        mutations << 'self.class'
+      end
+
+      it_should_behave_like 'a mutator'
+    end
   end
 
   context 'send with arguments' do