lib/vindetta/calculator.rb in vindetta-0.17.1 vs lib/vindetta/calculator.rb in vindetta-0.19.0

@@ -1,15 +1,19 @@
 module Vindetta
   class Calculator
-    MAP = %w(0 1 2 3 4 5 6 7 8 9 X)
+    CHECK_DIGITS = "0123456789X".chars
     WEIGHTS = [8, 7, 6, 5, 4, 3, 2, 10, 0, 9, 8, 7, 6, 5, 4, 3, 2]
 
     def self.check_digit(vin)
-      sum = Transliterator
+      CHECK_DIGITS[sum(vin) % CHECK_DIGITS.length]
+    end
+
+    private
+
+    def self.sum(vin)
+      Transliterator
         .vin(vin)
         .zip(WEIGHTS)
-        .reduce(0) {|sum, (a, b)| sum + (a * b) }
-
-      MAP[sum % 11]
+        .reduce(0) { |sum, (a, b)| sum + (a * b) }
     end
   end
 end