String methods

lib/differ/string.rb

@@ -4,6 +4,18 @@ def diff(old)
       Differ.diff(self, old, $; || "\n")
     end
     alias :- :diff
+
+    def diff_by_char(old)
+      Differ.diff(self, old, '')
+    end
+
+    def diff_by_word(old)
+      Differ.diff(self, old, /\b/)
+    end
+
+    def diff_by_line(old)
+      Differ.diff(self, old, "\n")
+    end
   end
 end
 

spec/differ/string_spec.rb

@@ -35,4 +35,25 @@
       'TO' - 'FROM'
     end
   end
+
+  describe '#diff_by_char' do
+    it 'should call Differ#diff' do
+      Differ.should_receive(:diff).with('Othellos', 'hello', '').once
+      'Othellos'.diff_by_char('hello')
+    end
+  end
+
+  describe '#diff_by_word' do
+    it 'should call Differ#diff' do
+      Differ.should_receive(:diff).with('Othellos', 'hello', /\b/).once
+      'Othellos'.diff_by_word('hello')
+    end
+  end
+
+  describe '#diff_by_line' do
+    it 'should call Differ#diff' do
+      Differ.should_receive(:diff).with('Othellos', 'hello', "\n").once
+      'Othellos'.diff_by_line('hello')
+    end
+  end
 end

spec/spec_helper.rb

@@ -4,7 +4,7 @@
 $LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
 require 'differ'
 
-Spec::Runner.configure do |config|
+RSpec.configure do |config|
 
 end