DateOfBirth#to_s should always return a string

Author: chrismytton

lib/date_of_birth.rb

@@ -6,8 +6,8 @@ def initialize(date_string)
   end
 
   def to_s
-    return if match.nil?
-    "%d-%02d-%02d" % [ match[:year], month(match[:month]), match[:day] ]
+    return '' if match.nil?
+    '%d-%02d-%02d' % [match[:year], month(match[:month]), match[:day]]
   end
 
   private