Refactor format batch of Ruby and Rake

lib/retest/command/rake.rb

@@ -10,7 +10,7 @@ def to_s
       end
 
       def format_batch(*files)
-        files.size > 1 ? "\"{#{files.join(',')}}\"" : files.first
+        files.size > 1 ? %Q{"{#{files.join(',')}}"} : files.first
       end
 
       private

lib/retest/command/ruby.rb

@@ -10,7 +10,7 @@ def to_s
       end
 
       def format_batch(*files)
-        %Q{-e "#{files.map { |file| "require './#{file}';" }.join}"}
+        files.size > 1 ? %Q{-e "#{files.map { |file| "require './#{file}';" }.join}"} : files.first
       end
     end
   end

test/retest/command/ruby_test.rb

@@ -37,7 +37,7 @@ def test_to_s
       end
 
       def test_format_with_one_file
-        assert_equal %Q{-e "require './a/file/path.rb';"}, @subject.format_batch('a/file/path.rb')
+        assert_equal 'a/file/path.rb', @subject.format_batch('a/file/path.rb')
       end
 
       def test_format_with_multiple_files