FIX: Create customer for one off pricing table purchases (#232)

When using the Stripe Pricing Table for one-off purchases
(non-subscription) stripe doesn't automatically create a customer
record. This was causing the pricing table webhook
endpoint to end prematurely and not add users to their appropriate
group after purchase. Now if we detect that there is no customer record
we will make an api call to Stripe to create one.

app/controllers/discourse_subscriptions/hooks_controller.rb

@@ -37,10 +37,14 @@ module DiscourseSubscriptions
         email = checkout_session[:customer_email]
 
         return head 200 if checkout_session[:status] != "complete"
-        return render_json_error "customer not found" if checkout_session[:customer].nil?
         return render_json_error "email not found" if !email
 
-        customer_id = checkout_session[:customer]
+        if checkout_session[:customer].nil?
+          customer = ::Stripe::Customer.create({ email: email })
+          customer_id = customer[:id]
+        else
+          customer_id = checkout_session[:customer]
+        end
 
         if SiteSetting.discourse_subscriptions_enable_verbose_logging
           Rails.logger.warn("Looking up user with email: #{email}")
@@ -48,7 +52,7 @@ module DiscourseSubscriptions
 
         user = ::User.find_by_username_or_email(email)
 
-        return render_json_error "customer not found" if !user
+        return render_json_error "user not found" if !user
 
         discourse_customer = Customer.create(user_id: user.id, customer_id: customer_id)
 

spec/requests/hooks_controller_spec.rb

@@ -88,7 +88,7 @@ RSpec.describe DiscourseSubscriptions::HooksController do
         object: {
           id: "cs_test_a1ENei5A9TGOaEketyV5qweiQR5CyJWHT5j8T3HheQY3uah3RxzKttVUKZ",
           object: "checkout.session",
-          customer: customer.customer_id,
+          customer: nil,
           customer_email: user.email,
           invoice: nil,
           metadata: {
@@ -110,7 +110,7 @@ RSpec.describe DiscourseSubscriptions::HooksController do
           id: "cs_test_a1ENei5A9TGOaEketyV5qweiQR5CyJWHT5j8T3HheQY3uah3RxzKttVUKZ",
           object: "checkout.session",
           customer: nil,
-          customer_email: user.email,
+          customer_email: nil,
           invoice: "in_1P9b7iEYXaQnncSh81AQtuHD",
           metadata: {
           },
@@ -118,7 +118,7 @@ RSpec.describe DiscourseSubscriptions::HooksController do
           payment_status: "paid",
           status: "complete",
           submit_type: nil,
-          subscription: "sub_1P9b7iEYXaQnncSh3H3G9d2Y",
+          subscription: nil,
           success_url: "http://localhost:4200/my/billing/subscriptions",
           url: nil,
         },
@@ -197,6 +197,7 @@ RSpec.describe DiscourseSubscriptions::HooksController do
           .returns(list_line_items_data)
 
         ::Stripe::Webhook.stubs(:construct_event).returns(event)
+        ::Stripe::Customer.stubs(:create).returns(id: "cus_1234")
       end
 
       it "is returns 422" do
@@ -217,6 +218,7 @@ RSpec.describe DiscourseSubscriptions::HooksController do
           .returns(list_line_items_data)
 
         ::Stripe::Webhook.stubs(:construct_event).returns(event)
+        ::Stripe::Customer.stubs(:create).returns(id: "cus_1234")
       end
 
       it "is returns 200" do
@@ -236,6 +238,7 @@ RSpec.describe DiscourseSubscriptions::HooksController do
           .returns(list_line_items_data)
 
         ::Stripe::Webhook.stubs(:construct_event).returns(event)
+        ::Stripe::Customer.stubs(:create).returns(id: "cus_1234")
       end
 
       it "is returns 422" do