lib/sec_id/cusip.rb in sec_id-4.0.0 vs lib/sec_id/cusip.rb in sec_id-4.1.0

@@ -19,29 +19,43 @@
       @issue = cusip_parts[:issue]
       @check_digit = cusip_parts[:check_digit]&.to_i
     end
 
     def calculate_check_digit
-      return mod10(modified_luhn_sum) if valid_format?
+      unless valid_format?
+        raise InvalidFormatError, "CUSIP '#{full_number}' is invalid and check-digit cannot be calculated!"
+      end
 
-      raise InvalidFormatError, "CUSIP '#{full_number}' is invalid and check-digit cannot be calculated!"
+      mod10(modified_luhn_sum)
     end
 
+    def to_isin(country_code)
+      unless ISIN::CGS_COUNTRY_CODES.include?(country_code)
+        raise(InvalidFormatError, "'#{country_code}' is not a CGS country code!")
+      end
+
+      restore!
+      isin = ISIN.new(country_code + full_number)
+      isin.restore!
+      isin
+    end
+
+    # CUSIP International Numbering System
+    def cins?
+      cusip6[0] < '0' || cusip6[0] > '9'
+    end
+
     private
 
     # https://en.wikipedia.org/wiki/Luhn_algorithm
     def modified_luhn_sum
-      sum = 0
-
-      id_digits.reverse.each_slice(2) do |even, odd|
+      reversed_id_digits.each_slice(2).reduce(0) do |sum, (even, odd)|
         double_even = (even || 0) * 2
-        sum += div10mod10(double_even) + div10mod10(odd || 0)
+        sum + div10mod10(double_even) + div10mod10(odd || 0)
       end
-
-      sum
     end
 
-    def id_digits
-      @id_digits ||= identifier.each_char.map(&method(:char_to_digit))
+    def reversed_id_digits
+      identifier.each_char.map(&method(:char_to_digit)).reverse!
     end
   end
 end