Add Stripe Customer Portal session API for account billing (#35)

## Summary - Companion to [chat_web_app#33](ai_ml_operations/chat_web_app#33) (Account billing + Customer Portal) - Follow-on from finance MVP [#21](#21): add authenticated `POST /api/finance/portal/` that creates a Stripe Billing Portal session and returns `portal_url` - Resolve Stripe customer from the user's latest `Invoice.stripe_customer_id`; return `400` when missing (user must complete Checkout first) - Document `STRIPE_PORTAL_RETURN_URL` (default `{FRONTEND_BASE_URL}/account/`) in settings + env examples ## Test plan - [ ] `manage.py test finance.tests.test_portal finance.tests.test_checkout` - [ ] Authenticated portal create with invoice that has `stripe_customer_id` → `201` + `portal_url` - [ ] No customer / unpaid user → `400` with clear detail - [ ] Missing `STRIPE_SECRET_KEY` → `503` - [ ] Unauthenticated → `401` - [ ] Custom `return_url` in body overrides default portal return URLReviewed-on: #35
2026-07-31 03:54:28 -07:00
parent ee3d47c8c3
commit 67f16565e9
9 changed files with 193 additions and 2 deletions
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+"""Tests for Stripe Customer Portal session API (mocked Stripe SDK)."""
+
+from unittest.mock import MagicMock, patch
+
+from django.test import override_settings
+from django.urls import reverse
+from rest_framework import status
+from rest_framework.test import APITestCase
+
+from chat_backend.tests.factories import make_company, make_user
+from finance.models import Invoice
+
+
+class CreateBillingPortalSessionViewTestCase(APITestCase):
+    def setUp(self):
+        self.company = make_company()
+        self.user = make_user(company=self.company)
+        self.client.force_authenticate(user=self.user)
+        self.url = reverse("finance_portal")
+
+    def _create_invoice_with_customer(self, customer_id="cus_test_abc"):
+        return Invoice.objects.create(
+            user=self.user,
+            company=self.company,
+            amount_due=1000,
+            amount_paid=1000,
+            status=Invoice.Status.PAID,
+            stripe_checkout_session_id="cs_portal_test",
+            stripe_customer_id=customer_id,
+            stripe_subscription_id="sub_test_abc",
+            description="Chat Subscription",
+        )
+
+    @override_settings(
+        STRIPE_SECRET_KEY="sk_test_fake",
+        STRIPE_PORTAL_RETURN_URL="http://localhost:3000/account/",
+    )
+    @patch("finance.services.stripe_service.stripe.billing_portal.Session.create")
+    def test_creates_portal_session(self, mock_create):
+        self._create_invoice_with_customer()
+        mock_session = MagicMock()
+        mock_session.url = "https://billing.stripe.com/p/session/test_portal"
+        mock_create.return_value = mock_session
+
+        response = self.client.post(self.url, {}, format="json")
+
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        self.assertEqual(
+            response.data["portal_url"],
+            "https://billing.stripe.com/p/session/test_portal",
+        )
+        mock_create.assert_called_once_with(
+            customer="cus_test_abc",
+            return_url="http://localhost:3000/account/",
+        )
+
+    @override_settings(
+        STRIPE_SECRET_KEY="sk_test_fake",
+        STRIPE_PORTAL_RETURN_URL="http://localhost:3000/account/",
+    )
+    @patch("finance.services.stripe_service.stripe.billing_portal.Session.create")
+    def test_accepts_custom_return_url(self, mock_create):
+        self._create_invoice_with_customer()
+        mock_session = MagicMock()
+        mock_session.url = "https://billing.stripe.com/p/session/custom"
+        mock_create.return_value = mock_session
+
+        response = self.client.post(
+            self.url,
+            {"return_url": "http://localhost:3000/account/#billing"},
+            format="json",
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        self.assertEqual(
+            mock_create.call_args.kwargs["return_url"],
+            "http://localhost:3000/account/#billing",
+        )
+
+    @override_settings(STRIPE_SECRET_KEY="sk_test_fake")
+    def test_no_stripe_customer_returns_400(self):
+        Invoice.objects.create(
+            user=self.user,
+            company=self.company,
+            amount_due=1000,
+            stripe_checkout_session_id="cs_no_customer",
+            stripe_customer_id="",
+        )
+        response = self.client.post(self.url, {}, format="json")
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+        self.assertIn("No Stripe customer", response.data["detail"])
+
+    @override_settings(STRIPE_SECRET_KEY="")
+    def test_missing_stripe_key_returns_503(self):
+        self._create_invoice_with_customer()
+        response = self.client.post(self.url, {}, format="json")
+        self.assertEqual(response.status_code, status.HTTP_503_SERVICE_UNAVAILABLE)
+
+    def test_unauthenticated_rejected(self):
+        self.client.force_authenticate(user=None)
+        response = self.client.post(self.url, {}, format="json")
+        self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)