Add full checkout flow test with proper client_reference_id

- Test simulates complete Stripe checkout flow end-to-end -
Step 1: checkout.session.completed with client_reference_id -
Step 2: customer.subscription.created with subscription details -
Verifies customer linking and plan upgrade to pro tier - Tests ensure
webhook flow works without calling real Stripe API - Validates that
client_reference_id properly links session to user

1 files changed, 37 insertions, 23 deletions

diff --git a/Biz/PodcastItLater/Billing.py b/Biz/PodcastItLater/Billing.py
index 46e67ff..404064d 100644
--- a/Biz/PodcastItLater/Billing.py
+++ b/Biz/PodcastItLater/Billing.py
@@ -462,30 +462,10 @@ class TestWebhookHandling(Test.TestCase):
         """Clean up test database."""
         Core.Database.teardown()
 
-    def test_subscription_created(self) -> None:
-        """Test handling subscription.created webhook with mock data."""
+    def test_full_checkout_flow(self) -> None:
+        """Test complete checkout flow from session to subscription."""
         # Create test user
         user_id, _token = Core.Database.create_user("test@example.com")
-        Core.Database.set_user_stripe_customer(user_id, "cus_test123")
-
-        # Mock subscription event
-        subscription = {
-            "id": "sub_test123",
-            "customer": "cus_test123",
-            "status": "active",
-            "current_period_start": 1700000000,
-            "current_period_end": 1702592000,
-            "cancel_at_period_end": False,
-            "items": {
-                "data": [
-                    {
-                        "price": {
-                            "id": "price_test_pro",
-                        },
-                    },
-                ],
-            },
-        }
 
         # Temporarily set price mapping for test
         global PRICE_TO_TIER
@@ -493,15 +473,49 @@ class TestWebhookHandling(Test.TestCase):
         PRICE_TO_TIER["price_test_pro"] = "pro"
 
         try:
+            # Step 1: Handle checkout.session.completed
+            checkout_session = {
+                "id": "cs_test123",
+                "client_reference_id": str(user_id),
+                "customer": "cus_test123",
+                "metadata": {"user_id": str(user_id), "tier": "pro"},
+            }
+            _handle_checkout_completed(checkout_session)
+
+            # Verify customer was linked
+            user = Core.Database.get_user_by_id(user_id)
+            self.assertIsNotNone(user)
+            assert user is not None
+            self.assertEqual(user["stripe_customer_id"], "cus_test123")
+
+            # Step 2: Handle customer.subscription.created
+            subscription = {
+                "id": "sub_test123",
+                "customer": "cus_test123",
+                "status": "active",
+                "current_period_start": 1700000000,
+                "current_period_end": 1702592000,
+                "cancel_at_period_end": False,
+                "items": {
+                    "data": [
+                        {
+                            "price": {
+                                "id": "price_test_pro",
+                            },
+                        },
+                    ],
+                },
+            }
             _update_subscription_state(subscription)
 
-            # Verify user was updated
+            # Verify subscription was created and user upgraded
             user = Core.Database.get_user_by_id(user_id)
             self.assertIsNotNone(user)
             assert user is not None
             self.assertEqual(user["plan_tier"], "pro")
             self.assertEqual(user["subscription_status"], "active")
             self.assertEqual(user["stripe_subscription_id"], "sub_test123")
+            self.assertEqual(user["stripe_customer_id"], "cus_test123")
         finally:
             PRICE_TO_TIER = old_mapping