Add explicit resbody mutator

Closes: #117

lib/mutant.rb

@@ -92,6 +92,7 @@ require 'mutant/mutator/node/block'
 require 'mutant/mutator/node/if'
 require 'mutant/mutator/node/case'
 require 'mutant/mutator/node/splat'
+require 'mutant/mutator/node/resbody'
 require 'mutant/config'
 require 'mutant/loader'
 require 'mutant/context'

lib/mutant/mutator/node/generic.rb

@@ -12,7 +12,7 @@ module Mutant
         handle(
           :ensure,
           :rescue, :redo, :defined?,
-          :regopt, :resbody, :retry, :arg_expr,
+          :regopt, :retry, :arg_expr,
           :kwrestarg, :kwoptarg, :kwarg, :undef, :module, :empty,
           :alias, :for, :xstr, :back_ref, :class,
           :sclass, :match_with_lvasgn, :match_current_line

lib/mutant/mutator/node/resbody.rb

@@ -0,0 +1,45 @@
+module Mutant
+  class Mutator
+    class Node
+      # Mutator for resbody nodes
+      class Resbody < self
+
+        handle(:resbody)
+
+        children :captures, :assignment, :block
+
+      private
+
+        # Emit mutations
+        #
+        # @return [undefined]
+        #
+        # @api private
+        #
+        def dispatch
+          emit_assignment(nil)
+          emit_block_mutations if block
+          mutate_captures
+        end
+
+        # Mutate captures
+        #
+        # @return [undefined]
+        #
+        # @api private
+        #
+        def mutate_captures
+          return unless captures
+          emit_captures(nil)
+          Util::Array.each(captures.children, self) do |matchers|
+            next if matchers.empty?
+            emit_captures(s(:array, *matchers))
+            # p capture
+            # emit_captures(s(:array, *capture))
+          end
+        end
+
+      end # Resbody
+    end # Node
+  end # Mutator
+end # Mutant

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

@@ -3,22 +3,71 @@
 require 'spec_helper'
 
 describe Mutant::Mutator::Node::Generic, 'rescue' do
-  let(:source) { 'begin; rescue Exception => e; true end' }
-
-  let(:mutations) do
-    mutations = []
-    mutations << 'begin; rescue Exception => srandom; true; end'
-    mutations << 'begin; rescue Exception => e; false; end'
-    mutations << 'begin; rescue Exception => e; nil; end'
-    mutations << 'begin; rescue nil => e; true; end'
-#    mutations << 'begin; rescue => e; true; end'  # FIXME
-  end
 
   before do
     Mutant::Random.stub(hex_string: 'random')
   end
 
-  pending do
+  context 'multiple exception selectors and assignment' do
+    let(:source) { 'begin; rescue ExceptionA, ExceptionB => error; true; end' }
+
+    let(:mutations) do
+      mutations = []
+      mutations << 'nil'
+      # mutations << 'begin; rescue ExceptionA, ExceptionB => error; true; end'
+      mutations << 'begin; rescue ExceptionA, ExceptionB; true; end'
+      mutations << 'begin; rescue ExceptionA, ExceptionB => error; false; end'
+      mutations << 'begin; rescue ExceptionA, ExceptionB => error; nil; end'
+      mutations << 'begin; rescue ExceptionA, nil => error; true; end'
+      mutations << 'begin; rescue ExceptionA => error; true; end'
+      mutations << 'begin; rescue ExceptionB => error; true; end'
+      mutations << 'begin; rescue nil, ExceptionB => error; true; end'
+      mutations << 'begin; rescue => error; true; end'
+    end
+
+    it_should_behave_like 'a mutator'
+  end
+
+  context 'single exception selector and assignment' do
+    let(:source) { 'begin; rescue Exception => error; true; end' }
+
+    let(:mutations) do
+      mutations = []
+      mutations << 'nil'
+      mutations << 'begin; rescue Exception; true; end'
+      mutations << 'begin; rescue Exception => error; false; end'
+      mutations << 'begin; rescue Exception => error; nil; end'
+      mutations << 'begin; rescue nil => error; true; end'
+      mutations << 'begin; rescue => error; true; end'
+    end
+
+    it_should_behave_like 'a mutator'
+  end
+
+  context 'no exection selector and assignment' do
+    let(:source) { 'begin; rescue => error; true end' }
+
+    let(:mutations) do
+      mutations = []
+      mutations << 'nil'
+      mutations << 'begin; rescue => error; false; end'
+      mutations << 'begin; rescue => error; nil; end'
+      mutations << 'begin; rescue; true; end'
+    end
+
+    it_should_behave_like 'a mutator'
+  end
+
+  context 'no exection selector and no assignment' do
+    let(:source) { 'begin; rescue; true end' }
+
+    let(:mutations) do
+      mutations = []
+      mutations << 'nil'
+      mutations << 'begin; rescue; false; end'
+      mutations << 'begin; rescue; nil; end'
+    end
+
     it_should_behave_like 'a mutator'
   end
 end