Couple of minor improvements

Gemfile

@@ -7,6 +7,7 @@ if branch == "master" || branch >= "v2.0"
   gem "rails-controller-testing", group: :test
 else
   gem "rails", "~> 4.2"
+  gem "rails_test_params_backport", group: :test
 end
 
 # Provides basic authentication functionality for testing parts of your engine

app/models/solidus_paypal_braintree/source.rb

@@ -2,6 +2,7 @@ module SolidusPaypalBraintree
   class Source < ApplicationRecord
     PAYPAL = "PayPalAccount"
     APPLE_PAY = "ApplePayCard"
+    CREDIT_CARD = "CreditCard"
 
     belongs_to :user, class_name: "Spree::User"
     belongs_to :payment_method, class_name: 'Spree::PaymentMethod'
@@ -10,8 +11,9 @@ class Source < ApplicationRecord
     belongs_to :customer, class_name: "SolidusPaypalBraintree::Customer"
 
     scope :with_payment_profile, -> { joins(:customer) }
+    scope :credit_card, -> { where(payment_type: CREDIT_CARD) }
 
-    delegate :last_4, :card_type, to: :braintree_payment_method
+    delegate :last_4, :card_type, to: :braintree_payment_method, allow_nil: true
 
     # we are not currenctly supporting an "imported" flag
     def imported
@@ -46,6 +48,10 @@ def paypal?
       payment_type == PAYPAL
     end
 
+    def credit_card?
+      payment_type == CREDIT_CARD
+    end
+
     private
 
     def braintree_payment_method

spec/controllers/solidus_paypal_braintree/checkouts_controller_spec.rb

@@ -7,7 +7,7 @@
   include_context 'order ready for payment'
 
   describe 'PATCH update', vcr: { cassette_name: 'checkout/update' } do
-    subject(:patch_update) { patch :update, params }
+    subject(:patch_update) { patch :update, params: params }
 
     let(:params) do
       {

spec/controllers/solidus_paypal_braintree/client_tokens_controller_spec.rb

@@ -13,7 +13,7 @@
 
     context 'with a payment method id' do
       subject(:response) do
-        post :create, token: user.spree_api_key
+        post :create, params: { token: user.spree_api_key }
       end
 
       it "returns a client token", aggregate_failures: true do
@@ -30,7 +30,7 @@
         end
 
         subject(:response) do
-          post :create, token: user.spree_api_key, payment_method_id: 3
+          post :create, params: { token: user.spree_api_key, payment_method_id: 3 }
         end
 
         it 'uses the selected gateway' do

spec/controllers/solidus_paypal_braintree/configurations_controller_spec.rb

@@ -36,7 +36,7 @@
       }
     end
 
-    subject { post :update, configurations_params }
+    subject { post :update, params: configurations_params }
 
     context "with valid parameters" do
       it "updates the configuration" do

spec/controllers/solidus_paypal_braintree/transactions_controller_spec.rb

@@ -14,7 +14,7 @@
 
   cassette_options = { cassette_name: "transactions_controller/create" }
   describe "POST create", vcr: cassette_options do
-    subject(:post_create) { post :create, params }
+    subject(:post_create) { post :create, params: params }
     let!(:country) { create :country, iso: 'US' }
     let!(:state) { create :state, abbr: 'WA', country: country }