Merge pull request mbj#739 from michaelherold/fix-to-i-to-implicit-self

Stop mutation of `#to_i` to implicit `self`

config/flay.yml

@@ -1,3 +1,3 @@
 ---
 threshold: 16
-total_score: 1321
+total_score: 1316

lib/mutant/mutator/node/send.rb

@@ -182,7 +182,7 @@ def emit_drop_mutation
         #
         # @return [undefined]
         def emit_integer_mutation
-          return unless selector.equal?(:to_i)
+          return unless receiver && selector.equal?(:to_i)
 
           emit(s(:send, nil, :Integer, receiver))
         end

meta/send.rb

@@ -135,6 +135,13 @@
   mutation 'map'
 end
 
+Mutant::Meta::Example.add :send do
+  source 'to_i'
+
+  singleton_mutations
+  mutation 'to_int'
+end
+
 Mutant::Meta::Example.add :send do
   source 'foo.to_s'