Mock Pay under test, not part of the system

test/integration/cold_messages_test.rb

@@ -1,6 +1,8 @@
 require "test_helper"
 
 class ColdMessagesTest < ActionDispatch::IntegrationTest
+  include PayHelper
+
   setup do
     @developer = developers(:available)
     @business = businesses(:with_conversation)
@@ -22,14 +24,8 @@ class ColdMessagesTest < ActionDispatch::IntegrationTest
   end
 
   test "must have an active business subscription" do
-    # TODO: Mock Stripe or Pay, not part of the system.
-    mock = Minitest::Mock.new
-    def mock.url
-      "checkout.stripe.com"
-    end
-
     sign_in businesses(:one).user
-    BusinessSubscriptionCheckout.stub :new, mock do
+    stub_pay(businesses(:one).user, expected_success_url: new_developer_message_url(@developer)) do
       get new_developer_message_path(@developer)
       assert_redirected_to "checkout.stripe.com"
     end

test/integration/messages_test.rb

@@ -1,6 +1,8 @@
 require "test_helper"
 
 class MessagesTest < ActionDispatch::IntegrationTest
+  include PayHelper
+
   setup do
     @developer = developers(:with_conversation)
     @business = businesses(:with_conversation)
@@ -55,13 +57,7 @@ class MessagesTest < ActionDispatch::IntegrationTest
     pay_subscriptions(:business).update!(status: :incomplete)
     sign_in @business.user
 
-    # TODO: Mock Stripe or Pay, not part of the system.
-    mock = Minitest::Mock.new
-    def mock.url
-      "checkout.stripe.com"
-    end
-
-    BusinessSubscriptionCheckout.stub :new, mock do
+    stub_pay(@business.user, expected_success_url: new_developer_message_url(@developer)) do
       assert_no_difference "Message.count" do
         post conversation_messages_path(@conversation), params: message_params
       end

test/models/business_subscription_checkout_test.rb

@@ -1,11 +1,48 @@
 require "test_helper"
 
 class BusinessSubscriptionCheckoutTest < ActiveSupport::TestCase
-  # TODO: Implement these tests.
-  # test "sets Stripe as the payment processor"
-  # test "builds a subscription Stripe Checkout"
-  # test "redirects to sending a developer message if a developer is given"
-  # test "redirects to conversations if the user has a business profile"
-  # test "redirects to adding a business profile if the user doesn't have one"
-  # test "returns a Stripe Checkout URL"
+  include PayHelper
+  include Rails.application.routes.url_helpers
+
+  test "creates a Pay::Customer for Stripe for the user" do
+    user = users(:with_business)
+    stub_pay(user) do
+      assert_changes "Pay::Customer.count", 1 do
+        BusinessSubscriptionCheckout.new(user).url
+      end
+    end
+    assert_equal Pay::Customer.last.owner, user
+    assert Pay::Customer.last.stripe?
+  end
+
+  test "redirects to sending a developer message if a developer is given" do
+    user = users(:with_business)
+    developer = developers(:available)
+
+    stub_pay(user, expected_success_url: new_developer_message_url(developer)) do
+      BusinessSubscriptionCheckout.new(user, developer: developer).url
+    end
+  end
+
+  test "redirects to conversations if the user has a business profile" do
+    user = users(:with_business)
+    stub_pay(user, expected_success_url: conversations_url) do
+      BusinessSubscriptionCheckout.new(user).url
+    end
+  end
+
+  test "redirects to adding a business profile if the user doesn't have one" do
+    user = users(:empty)
+    stub_pay(user, expected_success_url: new_business_url) do
+      BusinessSubscriptionCheckout.new(user).url
+    end
+  end
+
+  test "returns a Stripe Checkout URL" do
+    user = users(:with_business)
+    stub_pay(user) do
+      url = BusinessSubscriptionCheckout.new(user).url
+      assert_equal url, "checkout.stripe.com"
+    end
+  end
 end

test/support/helpers/pay_helper.rb

@@ -0,0 +1,24 @@
+module PayHelper
+  extend ActiveSupport::Concern
+
+  included do
+    def stub_pay(user, expected_success_url: conversations_url)
+      checkout = Minitest::Mock.new
+      checkout.expect(:url, "checkout.stripe.com")
+
+      payment_processor = Minitest::Mock.new
+      payment_processor.expect(:checkout, checkout, [{
+        mode: "subscription",
+        line_items: "price_FAKE_PRICE_ID_FOR_TESTS",
+        success_url: expected_success_url
+      }])
+
+      user.stub(:payment_processor, payment_processor) do
+        yield
+      end
+
+      checkout.verify
+      payment_processor.verify
+    end
+  end
+end