Return last digits that are less than four characters long

git-svn-id: https://activemerchant.googlecode.com/svn/trunk/active_merchant@638 6513ea26-6c20-0410-8a68-89cd7235086d

CHANGELOG

@@ -1,5 +1,6 @@
 = ActiveMerchant CHANGELOG
 
+* Return last_digits that are less than 4 characters long [cody]
 * Fix Bug with Authorize.Net ARB Remote Test [patrick.t.joyce]
 * Add support for forcing test mode on Secure Pay AU gateway [cody]
 * Update Secure Pay Au to meet specs for MessageInfo elements [cody]

lib/active_merchant/billing/credit_card_methods.rb

@@ -84,12 +84,12 @@ def type?(number)
           return nil
         end
 
-        def last_digits(number)          
-          number.to_s.slice(-4..-1) if number.to_s.length >= 4
+        def last_digits(number)     
+          number.to_s.length <= 4 ? number : number.to_s.slice(-4..-1) 
         end
 
         def mask(number)
-          "XXXX-XXXX-XXXX-#{last_digits(number)}" if number.to_s.length >= 4
+          "XXXX-XXXX-XXXX-#{last_digits(number)}"
         end
 
         # Checks to see if the calculated type matches the specified type

test/unit/credit_card_test.rb

@@ -162,9 +162,9 @@ def test_should_display_number
     assert_equal 'XXXX-XXXX-XXXX-1234', CreditCard.new(:number => '111222233331234').display_number
     assert_equal 'XXXX-XXXX-XXXX-1234', CreditCard.new(:number => '1112223331234').display_number
 
-    assert_nil CreditCard.new(:number => nil).display_number
-    assert_nil CreditCard.new(:number => '').display_number
-    assert_nil CreditCard.new(:number => '123').display_number
+    assert_equal 'XXXX-XXXX-XXXX-', CreditCard.new(:number => nil).display_number
+    assert_equal 'XXXX-XXXX-XXXX-', CreditCard.new(:number => '').display_number
+    assert_equal 'XXXX-XXXX-XXXX-123', CreditCard.new(:number => '123').display_number
     assert_equal 'XXXX-XXXX-XXXX-1234', CreditCard.new(:number => '1234').display_number
     assert_equal 'XXXX-XXXX-XXXX-1234', CreditCard.new(:number => '01234').display_number
   end
@@ -222,6 +222,11 @@ def test_should_return_last_four_digits_of_card_number
     assert_equal "8580", ccn.last_digits
   end
 
+  def test_bogus_last_digits
+    ccn = CreditCard.new(:number => "1")
+    assert_equal "1", ccn.last_digits
+  end
+
   def test_should_be_true_when_credit_card_has_a_first_name
     c = CreditCard.new
     assert_false c.first_name?