Merge pull request #815 from mbj/fix/invalid-block-mutations

Fix invalid block pass mutation

lib/mutant/mutator/node/block.rb

@@ -3,7 +3,6 @@
 module Mutant
   class Mutator
     class Node
-      # Emitter for mutations on 19 blocks
       class Block < self
 
         handle(:block)
@@ -18,7 +17,7 @@ module Mutant
         def dispatch
           emit_singletons
           emit(send) unless n_lambda?(send)
-          emit_send_mutations(&method(:n_send?))
+          emit_send_mutations(&method(:valid_send_mutation?))
           emit_arguments_mutations
 
           mutate_body
@@ -58,6 +57,17 @@ module Mutant
           emit(s(:send, send, body_meta.selector, *body_meta.arguments))
         end
 
+        # Test for valid send mutations
+        #
+        # @return [true, false, nil]
+        def valid_send_mutation?(node)
+          return unless n_send?(node)
+
+          last = AST::Meta::Send.new(node).arguments.last
+
+          !last&.type.equal?(:block_pass)
+        end
+
       end # Block
     end # Node
   end # Mutator

meta/block.rb

@@ -179,3 +179,26 @@ Mutant::Meta::Example.add :block do
   mutation 'foo { }'
   mutation 'foo'
 end
+
+Mutant::Meta::Example.add :block do
+  source 'foo(&:bar).baz {}'
+
+  singleton_mutations
+
+  mutation 'foo(&:bar).baz { raise }'
+  mutation 'foo.baz { }'
+  mutation 'foo(&:bar).baz'
+  mutation 'self.baz {}'
+end
+
+Mutant::Meta::Example.add :block do
+  source 'foo(nil, &:bar).baz {}'
+
+  singleton_mutations
+  mutation 'foo(nil, &:bar).baz { raise }'
+  mutation 'foo(&:bar).baz { }'
+  mutation 'foo(nil).baz { }'
+  mutation 'foo.baz { }'
+  mutation 'self.baz { }'
+  mutation 'foo(nil, &:bar).baz'
+end