lib/petrarca.rb in petrarca-0.4.14 vs lib/petrarca.rb in petrarca-0.5.0

@@ -13,32 +13,32 @@
   REGISTRANT_RANGES = Helpers.load_ranges("#{data_dir}/registrant_ranges.txt")
 
   extend self
 
   def valid?(isbn)
-    case isbn.delete("-").size
+    case isbn.to_s.delete("-").size
     when 13
       ISBN13.valid?(isbn)
     when 10
       ISBN10.valid?(isbn)
     else
       false
     end
   end
 
   def correct_format?(isbn)
-    case isbn.delete("-").size
+    case isbn.to_s.delete("-").size
     when 13
       ISBN13.correct_format?(isbn)
     when 10
       ISBN10.correct_format?(isbn)
     else
       false
     end
   end
 
   def calc_check_digit(isbn)
-    isbn = isbn.delete("-")
+    isbn = isbn.to_s.delete("-")
     case isbn.size
     when 12, 13
       ISBN13.calc_check_digit(isbn)
     when 9, 10
       ISBN10.calc_check_digit(isbn)