From 82634f383cfcce5779e61209154f1553fd5e514b Mon Sep 17 00:00:00 2001
From: Markus Schirp <mbj@schirp-dso.com>
Date: Sun, 11 May 2014 14:38:07 +0000
Subject: [PATCH] Do not present un idempotent interface on abstract class

---
 lib/mutant.rb                     |  2 +-
 lib/mutant/mutation.rb            |  3 ++-
 lib/mutant/mutation/evil.rb       | 12 +-----------
 lib/mutant/mutation/neutral.rb    | 11 -----------
 spec/unit/mutant/mutation_spec.rb | 13 ++++++++-----
 5 files changed, 12 insertions(+), 29 deletions(-)

diff --git a/lib/mutant.rb b/lib/mutant.rb
index 7ddad439..917a795b 100644
--- a/lib/mutant.rb
+++ b/lib/mutant.rb
@@ -61,7 +61,7 @@ module Mutant
 
     begin
       data = Marshal.load(reader.read)
-    rescue ArgumentError => exception
+    rescue ArgumentError
       raise IsolationError, 'Childprocess wrote unmarshallable data'
     end
 
diff --git a/lib/mutant/mutation.rb b/lib/mutant/mutation.rb
index b6b62256..9bcd443b 100644
--- a/lib/mutant/mutation.rb
+++ b/lib/mutant/mutation.rb
@@ -57,8 +57,9 @@ module Mutant
     # @api private
     #
     def identification
-      "#{subject.identification}:#{code}"
+      "#{self.class::SYMBOL}:#{subject.identification}:#{code}"
     end
+    memoize :identification
 
     # Return mutation code
     #
diff --git a/lib/mutant/mutation/evil.rb b/lib/mutant/mutation/evil.rb
index d56711c5..a4d2b6bf 100644
--- a/lib/mutant/mutation/evil.rb
+++ b/lib/mutant/mutation/evil.rb
@@ -6,17 +6,7 @@ module Mutant
     class Evil < self
 
       SHOULD_FAIL = true
-
-      # Return identification
-      #
-      # @return [String]
-      #
-      # @api private
-      #
-      def identification
-        "evil:#{super}"
-      end
-      memoize :identification
+      SYMBOL      = 'evil'.freeze
 
       # Test if killer is successful
       #
diff --git a/lib/mutant/mutation/neutral.rb b/lib/mutant/mutation/neutral.rb
index 0fff82e0..54b0f80c 100644
--- a/lib/mutant/mutation/neutral.rb
+++ b/lib/mutant/mutation/neutral.rb
@@ -15,17 +15,6 @@ module Mutant
 
       end # Noop
 
-      # Return identification
-      #
-      # @return [String]
-      #
-      # @api private
-      #
-      def identification
-        "#{self.class::SYMBOL}:#{super}"
-      end
-      memoize :identification
-
     end # Neutral
   end # Mutation
 end # Mutant
diff --git a/spec/unit/mutant/mutation_spec.rb b/spec/unit/mutant/mutation_spec.rb
index fac8bf2b..8ae7a09a 100644
--- a/spec/unit/mutant/mutation_spec.rb
+++ b/spec/unit/mutant/mutation_spec.rb
@@ -4,10 +4,13 @@ require 'spec_helper'
 
 describe Mutant::Mutation do
 
-  let(:class_under_test) { Class.new(described_class) { memoize :identification }             }
-  let(:object)           { class_under_test.new(mutation_subject, Mutant::NodeHelpers::N_NIL) }
-  let(:mutation_subject) { double('Subject', identification: 'subject', source: 'original')   }
-  let(:node)             { double('Node')                                                     }
+  class TestMutation < Mutant::Mutation
+    SYMBOL = 'test'
+  end
+
+  let(:object)           { TestMutation.new(mutation_subject, Mutant::NodeHelpers::N_NIL)   }
+  let(:mutation_subject) { double('Subject', identification: 'subject', source: 'original') }
+  let(:node)             { double('Node')                                                   }
 
   describe '#code' do
     subject { object.code }
@@ -37,7 +40,7 @@ describe Mutant::Mutation do
 
     subject { object.identification }
 
-    it { should eql('subject:8771a') }
+    it { should eql('test:subject:8771a') }
 
     it_should_behave_like 'an idempotent method'
   end