Braintree Blue: actually, really, truly fix nil address fields

Previously, on Battlestar Galactica, we only filtered out the address
if the fields were nil. But some of our library consumers like to pass
in empty strings, which we treated as actual data, whereas Braintree
Blue weirdly insists "" is not a valid address. Treat empty strings
the same as nil values.

Unit: 57 tests, 150 assertions, 0 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications
100% passed

Remote: 66 tests, 378 assertions, 0 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications
100% passed

lib/active_merchant/billing/gateways/braintree_blue.rb

@@ -39,6 +39,7 @@ module Billing #:nodoc:
     #
     class BraintreeBlueGateway < Gateway
       include BraintreeCommon
+      include Empty
 
       self.display_name = 'Braintree (Blue Platform)'
 
@@ -261,7 +262,7 @@ def add_credit_card_to_customer(credit_card, options)
           }
           if options[:billing_address]
             address = map_address(options[:billing_address])
-            parameters[:credit_card][:billing_address] = address unless address.all? { |_k, v| v.nil? }
+            parameters[:credit_card][:billing_address] = address unless address.all? { |_k, v| empty?(v) }
           end
 
           result = @braintree_gateway.credit_card.create(parameters)
@@ -309,7 +310,7 @@ def merge_credit_card_options(parameters, options)
         parameters[:credit_card][:options] = valid_options
         if options[:billing_address]
           address = map_address(options[:billing_address])
-          parameters[:credit_card][:billing_address] = address unless address.all? { |_k, v| v.nil? }
+          parameters[:credit_card][:billing_address] = address unless address.all? { |_k, v| empty?(v) }
         end
         parameters
       end

test/remote/gateways/remote_braintree_blue_test.rb

@@ -46,7 +46,7 @@ def test_successful_authorize_with_nil_billing_address_options
         :phone => '123-456-7890',
         :company => nil,
         :address1 => nil,
-        :address2 => nil,
+        :address2 => '',
         :city => nil,
         :state => nil,
         :zip => nil,

test/unit/gateways/braintree_blue_test.rb

@@ -386,7 +386,7 @@ def test_store_with_nil_billing_address_options
       :phone => '123-456-7890',
       :company => nil,
       :address1 => nil,
-      :address2 => nil,
+      :address2 => '',
       :city => nil,
       :state => nil,
       :zip => nil,