add sync_subscriptions to FakeProcessor::Customer (#1156)

Author: jlthai

app/models/pay/fake_processor/customer.rb

@@ -55,6 +55,10 @@ def subscribe(name: Pay.default_product_name, plan: Pay.default_plan_name, **opt
         subscriptions.create!(attributes)
       end
 
+      def sync_subscriptions(**options)
+        []
+      end
+
       def add_payment_method(payment_method_id, default: false)
         # Make to generate a processor_id
         api_record

test/pay/fake_processor/customer_test.rb

@@ -60,6 +60,12 @@ class Pay::FakeProcessor::CustomerTest < ActiveSupport::TestCase
     assert_equal "Fake", payment_method.brand
   end
 
+  test "fake processor sync_subscriptions" do
+    assert_nothing_raised do
+      @pay_customer.sync_subscriptions
+    end
+  end
+
   test "generates fake processor_id" do
     user = users(:none)
     pay_customer = user.set_payment_processor :fake_processor, allow_fake: true