user upgrades: add bank payment methods for European countries.

Add the following bank redirect payment methods:

* https://stripe.com/docs/payments/bancontact
* https://stripe.com/docs/payments/eps
* https://stripe.com/docs/payments/giropay
* https://stripe.com/docs/payments/ideal
* https://stripe.com/docs/payments/p24

These methods are used in Austria, Belgium, Germany, the Netherlands,
and Poland.

These methods require payments to be denominated in EUR, which means we
have to set prices in both USD and EUR, and we have to automatically
detect which currency to use based on the user's country. We also have
to automatically detect which payment methods to offer based on the
user's country. We do this by using Cloudflare's CF-IPCountry header to
geolocate the user's country.

This also switches to using prices and products defined in Stripe
instead of generated on-the-fly when creating the checkout.

test/functional/webhooks_controller_test.rb

@@ -1,7 +1,13 @@
 require 'test_helper'
 
 class WebhooksControllerTest < ActionDispatch::IntegrationTest
-  mock_stripe!
+  setup do
+    StripeMock.start
+  end
+
+  teardown do
+    StripeMock.stop
+  end
 
   def post_webhook(*args, payment_status: "paid", **metadata)
     event = StripeMock.mock_webhook_event(*args, payment_status: payment_status, metadata: metadata)

test/test_helpers/stripe_test_helper.rb

@@ -3,11 +3,11 @@ StripeMock.webhook_fixture_path = "test/fixtures/stripe-webhooks"
 module StripeTestHelper
   def mock_stripe!
     setup do
-      StripeMock.start
+      StripeMock.start unless UserUpgrade.enabled?
     end
 
     teardown do
-      StripeMock.stop
+      StripeMock.stop unless UserUpgrade.enabled?
     end
   end
 end

test/unit/user_upgrade_test.rb

@@ -58,6 +58,116 @@ class UserUpgradeTest < ActiveSupport::TestCase
           end
         end
       end
+
+      context "for each upgrade type" do
+        setup do
+          skip unless UserUpgrade.enabled?
+        end
+
+        should "choose the right price in USD for a gold upgrade" do
+          @user_upgrade = create(:self_gold_upgrade)
+          @checkout = @user_upgrade.create_checkout!(country: "US")
+
+          assert_equal(UserUpgrade.gold_price, @user_upgrade.payment_intent.amount)
+          assert_equal("usd", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right price in USD for a platinum upgrade" do
+          @user_upgrade = create(:self_platinum_upgrade)
+          @checkout = @user_upgrade.create_checkout!(country: "US")
+
+          assert_equal(UserUpgrade.platinum_price, @user_upgrade.payment_intent.amount)
+          assert_equal("usd", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right price in USD for a gold to platinum upgrade" do
+          @user_upgrade = create(:self_gold_to_platinum_upgrade)
+          @checkout = @user_upgrade.create_checkout!(country: "US")
+
+          assert_equal(UserUpgrade.gold_to_platinum_price, @user_upgrade.payment_intent.amount)
+          assert_equal("usd", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right price in EUR for a gold upgrade" do
+          @user_upgrade = create(:self_gold_upgrade)
+          @checkout = @user_upgrade.create_checkout!(country: "DE")
+
+          assert_equal(0.8 * UserUpgrade.gold_price, @user_upgrade.payment_intent.amount)
+          assert_equal("eur", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right price in EUR for a platinum upgrade" do
+          @user_upgrade = create(:self_platinum_upgrade)
+          @checkout = @user_upgrade.create_checkout!(country: "DE")
+
+          assert_equal(0.8 * UserUpgrade.platinum_price, @user_upgrade.payment_intent.amount)
+          assert_equal("eur", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right price in EUR for a gold to platinum upgrade" do
+          @user_upgrade = create(:self_gold_to_platinum_upgrade)
+          @checkout = @user_upgrade.create_checkout!(country: "DE")
+
+          assert_equal(0.8 * UserUpgrade.gold_to_platinum_price, @user_upgrade.payment_intent.amount)
+          assert_equal("eur", @user_upgrade.payment_intent.currency)
+        end
+      end
+
+      context "for each country" do
+        setup do
+          @user_upgrade = create(:self_gold_upgrade)
+          skip unless UserUpgrade.enabled?
+        end
+
+        should "choose the right payment methods for US" do
+          @checkout = @user_upgrade.create_checkout!(country: "US")
+
+          assert_equal(["card"], @checkout.payment_method_types)
+          assert_equal("usd", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right payment methods for AT" do
+          @checkout = @user_upgrade.create_checkout!(country: "AT")
+
+          assert_equal(["card", "eps"], @checkout.payment_method_types)
+          assert_equal("eur", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right payment methods for BE" do
+          @checkout = @user_upgrade.create_checkout!(country: "BE")
+
+          assert_equal(["card", "bancontact"], @checkout.payment_method_types)
+          assert_equal("eur", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right payment methods for DE" do
+          @checkout = @user_upgrade.create_checkout!(country: "DE")
+
+          assert_equal(["card", "giropay"], @checkout.payment_method_types)
+          assert_equal("eur", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right payment methods for NL" do
+          @checkout = @user_upgrade.create_checkout!(country: "NL")
+
+          assert_equal(["card", "ideal"], @checkout.payment_method_types)
+          assert_equal("eur", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right payment methods for PL" do
+          @checkout = @user_upgrade.create_checkout!(country: "PL")
+
+          assert_equal(["card", "p24"], @checkout.payment_method_types)
+          assert_equal("eur", @user_upgrade.payment_intent.currency)
+        end
+
+        should "choose the right payment methods for an unsupported country" do
+          @checkout = @user_upgrade.create_checkout!(country: "MX")
+
+          assert_equal(["card"], @checkout.payment_method_types)
+          assert_equal("usd", @user_upgrade.payment_intent.currency)
+        end
+      end
     end
 
     context "the #receipt_url method" do
@@ -65,6 +175,8 @@ class UserUpgradeTest < ActiveSupport::TestCase
 
       context "a pending upgrade" do
         should "not have a receipt" do
+          skip unless UserUpgrade.enabled?
+
           @user_upgrade = create(:self_gold_upgrade, status: "pending")
           @user_upgrade.create_checkout!