Add mutators to force true and false conditions in if and unless nodes

lib/mutant/mutator/node/if.rb

@@ -21,6 +21,8 @@ module Mutant
           emit_inverted_condition 
           emit_deleted_if_branch
           emit_deleted_else_branch
+          emit_true_if_branch
+          emit_false_if_branch
         end
 
         # Test if attribute is non nil literal
@@ -73,6 +75,26 @@ module Mutant
           emit_self(condition, body, nil)
         end
 
+        # Emit true if branch
+        #
+        # @return [undefined]
+        #
+        # @api private
+        #
+        def emit_true_if_branch
+          emit_self(new(Rubinius::AST::TrueLiteral), if_branch, else_branch)
+        end
+
+        # Emit false if branch
+        #
+        # @return [undefined]
+        #
+        # @api private
+        #
+        def emit_false_if_branch
+          emit_self(new(Rubinius::AST::FalseLiteral), if_branch, else_branch)
+        end
+
         # Return if_branch of node
         #
         # @return [Rubinius::AST::Node]

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

@@ -26,6 +26,12 @@ describe Mutant::Mutator, 'if statement' do
       # mutations of else body
       mutants << 'if self.condition; true;  else true;  end' 
       mutants << 'if self.condition; true;  else nil;   end' 
+
+      # mutation of condition to always be true
+      mutants << 'if true; true; else false; end'
+
+      # mutation of condition to always be false
+      mutants << 'if false; true; else false; end'
     end
 
     it_should_behave_like 'a mutator'
@@ -40,6 +46,8 @@ describe Mutant::Mutator, 'if statement' do
       mutants << 'if condition; true; end'
       mutants << 'unless condition; false; end'
       mutants << 'unless condition; nil; end'
+      mutants << 'unless true; true; end'
+      mutants << 'unless false; true; end'
     end
 
     it_should_behave_like 'a mutator'
@@ -53,6 +61,8 @@ describe Mutant::Mutator, 'if statement' do
       mutants << 'if !condition; true; end'
       mutants << 'if condition; false; end'
       mutants << 'if condition; nil; end'
+      mutants << 'if true; true; end'
+      mutants << 'if false; true; end'
     end
 
     it_should_behave_like 'a mutator'