Add support for Customer Balance Transaction resource and APIs

lib/stripe/customer_balance_transaction.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module Stripe
+  class CustomerBalanceTransaction < APIResource
+    OBJECT_NAME = "customer_balance_transaction".freeze
+
+    def resource_url
+      if !respond_to?(:customer) || customer.nil?
+        raise NotImplementedError,
+              "Customer Balance Transactions cannot be accessed without a customer ID."
+      end
+      "#{Customer.resource_url}/#{CGI.escape(customer)}/balance_transactions/#{CGI.escape(id)}"
+    end
+
+    def self.retrieve(_id, _opts = {})
+      raise NotImplementedError,
+            "Customer Balance Transactions cannot be retrieved without a customer ID. " \
+            "Retrieve a Customer Balance Transaction using Customer.retrieve_customer_balance_transaction('cus_123', 'cbtxn_123')"
+    end
+
+    def self.update(_id, _params = nil, _opts = nil)
+      raise NotImplementedError,
+            "Customer Balance Transactions cannot be retrieved without a customer ID. " \
+            "Update a Customer Balance Transaction using Customer.update_balance_transaction('cus_123', 'cbtxn_123', params)"
+    end
+  end
+end

lib/stripe/object_types.rb

@@ -29,6 +29,7 @@ def self.object_names_to_classes # rubocop:disable Metrics/MethodLength
         Coupon::OBJECT_NAME => Coupon,
         CreditNote::OBJECT_NAME => CreditNote,
         Customer::OBJECT_NAME => Customer,
+        CustomerBalanceTransaction::OBJECT_NAME   => CustomerBalanceTransaction,
         Discount::OBJECT_NAME => Discount,
         Dispute::OBJECT_NAME => Dispute,
         EphemeralKey::OBJECT_NAME => EphemeralKey,

lib/stripe/resources.rb

@@ -19,6 +19,7 @@
 require "stripe/resources/coupon"
 require "stripe/resources/credit_note"
 require "stripe/resources/customer"
+require "stripe/customer_balance_transaction"
 require "stripe/resources/discount"
 require "stripe/resources/dispute"
 require "stripe/resources/ephemeral_key"

lib/stripe/resources/customer.rb

@@ -19,6 +19,9 @@ class Customer < APIResource
     nested_resource_class_methods :source,
                                   operations: %i[create retrieve update delete list]
 
+    nested_resource_class_methods :balance_transaction,
+                                  operations: %i[create retrieve update list]
+
     # The API request for deleting a card or bank account and for detaching a
     # source object are the same.
     class << self

test/stripe/customer_balance_transaction_test.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require ::File.expand_path("../../test_helper", __FILE__)
+
+module Stripe
+  class CustomerBalanceTransactionTest < Test::Unit::TestCase
+    context "#resource_url" do
+      should "return a resource URL" do
+        transaction = Stripe::CustomerBalanceTransaction.construct_from(
+          id: "cbtxn_123",
+          customer: "cus_123"
+        )
+        assert_equal "/v1/customers/cus_123/balance_transactions/cbtxn_123",
+                     transaction.resource_url
+      end
+
+      should "raise without a customer" do
+        transaction = Stripe::CustomerBalanceTransaction.construct_from(id: "cbtxn_123")
+        assert_raises NotImplementedError do
+          transaction.resource_url
+        end
+      end
+    end
+
+    should "raise on #retrieve" do
+      assert_raises NotImplementedError do
+        Stripe::CustomerBalanceTransaction.retrieve("cbtxn_123")
+      end
+    end
+
+    should "raise on #update" do
+      assert_raises NotImplementedError do
+        Stripe::CustomerBalanceTransaction.update("cbtxn_123")
+      end
+    end
+  end
+end

test/stripe/customer_test.rb

@@ -222,5 +222,48 @@ class CustomerTest < Test::Unit::TestCase
         assert sources.data.is_a?(Array)
       end
     end
+
+    context "#create_balance_transaction" do
+      should "create a customer balance transaction" do
+        Stripe::Customer.create_balance_transaction(
+          "cus_123",
+          amount: 1234,
+          currency: "usd"
+        )
+        assert_requested :post, "#{Stripe.api_base}/v1/customers/cus_123/balance_transactions"
+      end
+    end
+
+    context "#retrieve_balance_transaction" do
+      should "retrieve a customer balance transaction" do
+        Stripe::Customer.retrieve_balance_transaction(
+          "cus_123",
+          "cbtxn_123"
+        )
+        assert_requested :get, "#{Stripe.api_base}/v1/customers/cus_123/balance_transactions/cbtxn_123"
+      end
+    end
+
+    context "#update_balance_transaction" do
+      should "update a customer balance transaction" do
+        Stripe::Customer.update_balance_transaction(
+          "cus_123",
+          "cbtxn_123",
+          description: "new"
+        )
+        assert_requested :post, "#{Stripe.api_base}/v1/customers/cus_123/balance_transactions/cbtxn_123"
+      end
+    end
+
+    context "#list_balance_transactions" do
+      should "list the customer balance transactions" do
+        sources = Stripe::Customer.list_balance_transactions(
+          "cus_123"
+        )
+        assert_requested :get, "#{Stripe.api_base}/v1/customers/cus_123/balance_transactions"
+        assert sources.is_a?(Stripe::ListObject)
+        assert sources.data.is_a?(Array)
+      end
+    end
   end
 end