From 640ce5360eb0cd51bd12943b4a21abf24834c111 Mon Sep 17 00:00:00 2001
From: Markus Schirp <mbj@seonic.net>
Date: Wed, 1 Aug 2012 14:54:49 +0200
Subject: [PATCH] Correct mutations of send to self

* Invert the behaviour as this direction of mutation does make sense.
---
 lib/mutant/mutator/call.rb                    | 36 ++++++++++++---
 .../each_spec.rb => mutation_spec.rb}         |  8 ++--
 .../unit/mutant/mutator/call/mutation_spec.rb | 44 +++++++++++--------
 3 files changed, 60 insertions(+), 28 deletions(-)
 rename spec/unit/mutant/mutator/block/{class_methods/each_spec.rb => mutation_spec.rb} (63%)

diff --git a/lib/mutant/mutator/call.rb b/lib/mutant/mutator/call.rb
index 02eeed1a..ba14ebb1 100644
--- a/lib/mutant/mutator/call.rb
+++ b/lib/mutant/mutator/call.rb
@@ -41,11 +41,37 @@ module Mutant
         receiver.kind_of?(Rubinius::AST::Self)
       end
 
-      def emit_explicit_self_receiver
+      # Emit mutation that replaces explicit send to self with implicit send to self.
+      # 
+      # @example:
+      #
+      #   # This class does use Foo#a with explicitly specifing the receiver self.
+      #   # But an implicit (privately) call should be used as there is no need for 
+      #   # specifing en explicit receiver.
+      #
+      #   class Foo         # Mutation
+      #     def print_a     # def print_a
+      #       puts self.a   #   puts a
+      #     end             # end
+      #
+      #     def a
+      #       :bar
+      #     end
+      #   end
+      #
+      #   There will not be any exception so the mutant is not killed and such calls where
+      #   implicit receiver should be used will be spotted.
+      #
+      # @reutrn [undefined]
+      #
+      # @api private
+      #
+      def emit_implicit_self_receiver
+        return unless self?
         mutant = dup_node
-        mutant.privately = false
+        mutant.privately = true
         # TODO: Fix rubinius to allow this as an attr_accessor
-        mutant.instance_variable_set(:@vcall_style,false)
+        mutant.instance_variable_set(:@vcall_style,true)
         emit_safe(mutant)
       end
 
@@ -56,7 +82,7 @@ module Mutant
       # @api private
       #
       def dispatch
-        emit_explicit_self_receiver
+        emit_implicit_self_receiver
       end
 
       class SendWithArguments < Call
@@ -72,7 +98,7 @@ module Mutant
         # @api private
         #
         def dispatch
-          emit_explicit_self_receiver
+          super
         end
       end
     end
diff --git a/spec/unit/mutant/mutator/block/class_methods/each_spec.rb b/spec/unit/mutant/mutator/block/mutation_spec.rb
similarity index 63%
rename from spec/unit/mutant/mutator/block/class_methods/each_spec.rb
rename to spec/unit/mutant/mutator/block/mutation_spec.rb
index 00c4fb7f..37fd24d5 100644
--- a/spec/unit/mutant/mutator/block/class_methods/each_spec.rb
+++ b/spec/unit/mutant/mutator/block/mutation_spec.rb
@@ -1,8 +1,8 @@
 require 'spec_helper'
 
-describe Mutant::Mutator::Block, '.each' do
+describe Mutant::Mutator, 'block' do
   # Two send operations
-  let(:source) { "foo\nbar" }
+  let(:source) { "self.foo\nself.bar" }
 
   let(:mutations) do
     mutations = []
@@ -12,8 +12,8 @@ describe Mutant::Mutator::Block, '.each' do
     mutations << "self.foo\nbar"
 
    ## Remove statement in block
-    mutations << [:block, 'foo'.to_sexp]
-    mutations << [:block, 'bar'.to_sexp]
+    mutations << [:block, 'self.foo'.to_sexp]
+    mutations << [:block, 'self.bar'.to_sexp]
   end
 
   it_should_behave_like 'a mutation enumerator method'
diff --git a/spec/unit/mutant/mutator/call/mutation_spec.rb b/spec/unit/mutant/mutator/call/mutation_spec.rb
index 4f2f5e37..67f73e59 100644
--- a/spec/unit/mutant/mutator/call/mutation_spec.rb
+++ b/spec/unit/mutant/mutator/call/mutation_spec.rb
@@ -2,46 +2,52 @@ require 'spec_helper'
 
 describe Mutant::Mutator, 'call' do
   context 'send without arguments' do
-    context 'to self' do
+    context 'with self as receiver' do
 
-      context 'implict' do
+      context 'implicit' do
         let(:source) { 'foo' }
 
-        let(:mutations) do
-          mutations = []
-          # with explicit receiver (not send privately)
-          mutations << 'self.foo' 
-        end
-
-        it_should_behave_like 'a mutation enumerator method'
+        it_should_behave_like 'a noop mutation enumerator method'
       end
 
       context 'explict' do
         let(:source) { 'self.foo' }
 
-        it_should_behave_like 'a noop mutation enumerator method'
+        let(:mutations) do
+          mutations = []
+          # with implicit receiver (send privately)
+          mutations << 'foo' 
+        end
+
+        it_should_behave_like 'a mutation enumerator method'
       end
     end
+
+    context 'to some object' do
+      let(:source) { '1.foo' }
+
+      it_should_behave_like 'a noop mutation enumerator method'
+    end
   end
 
   context 'send with arguments' do
-    context 'to self' do
+    context 'with self as receiver' do
       context 'implicit' do
         let(:source) { 'foo(1)' }
 
-        let(:mutations) do
-          mutations = []
-          # with explicit receiver (not send privately)
-          mutations << 'self.foo(1)'
-        end
-
-        it_should_behave_like 'a mutation enumerator method'
+        it_should_behave_like 'a noop mutation enumerator method'
       end
 
       context 'explicit' do
         let(:source) { 'self.foo(1)' }
 
-        it_should_behave_like 'a noop mutation enumerator method'
+        let(:mutations) do
+          mutations = []
+          # with implicit receiver (send privately)
+          mutations << 'foo(1)'
+        end
+
+        it_should_behave_like 'a mutation enumerator method'
       end
     end
   end