Add finance app with Stripe Checkout subscriptions (#21) (#23)

## Summary - Closes #21 — new Django `finance` app with Stripe as payment provider - Subscription price defaults to **$10 USD / month** via `SUBSCRIPTION_PRICE_AMOUNT_CENTS = 1000` in `settings.py` (env-overridable) - Persists **Invoice** and **Payment** rows; both registered in Django admin (with payment inline on invoices) - Checkout Session API redirects users to Stripe hosted payment; webhook verifies signatures and upserts ledger idempotently ## API - `POST /api/finance/checkout/` — JWT auth → `{ checkout_url, session_id }` - `GET /api/finance/invoices/` / `GET /api/finance/payments/` — own records - `POST /api/finance/webhooks/stripe/` — Stripe signature-verified webhook ## Config Documented in `.env.example` / `.env.prod.example`: `STRIPE_SECRET_KEY`, `STRIPE_PUBLISHABLE_KEY`, `STRIPE_WEBHOOK_SECRET`, optional `STRIPE_PRICE_ID`, `FRONTEND_BASE_URL` ## Test plan - [x] `uv run python manage.py test finance` (17 tests) - [ ] Set Stripe test keys locally; create checkout session; complete payment in Stripe test mode - [ ] Confirm Invoice/Payment appear in `/admin/` - [ ] Point Stripe webhook to `/api/finance/webhooks/stripe/` and verify `checkout.session.completed` / `invoice.paid`Reviewed-on: #23
2026-07-26 17:35:06 -07:00
parent 9984d1c340
commit ad44359804
23 changed files with 1540 additions and 0 deletions
@@ -0,0 +1,66 @@
+"""Tests for finance Invoice / Payment models and admin registration."""
+
+from django.contrib import admin
+from django.test import TestCase
+
+from chat_backend.tests.factories import make_company, make_user
+from finance.models import Invoice, Payment
+
+
+class InvoicePaymentModelTestCase(TestCase):
+    def setUp(self):
+        self.company = make_company()
+        self.user = make_user(company=self.company)
+
+    def test_create_invoice_and_payment(self):
+        invoice = Invoice.objects.create(
+            user=self.user,
+            company=self.company,
+            status=Invoice.Status.OPEN,
+            amount_due=1000,
+            currency="usd",
+            stripe_checkout_session_id="cs_test_1",
+        )
+        payment = Payment.objects.create(
+            user=self.user,
+            company=self.company,
+            invoice=invoice,
+            amount=1000,
+            currency="usd",
+            status=Payment.Status.PENDING,
+            stripe_payment_intent_id="pi_test_1",
+        )
+        self.assertEqual(invoice.provider, Invoice.Provider.STRIPE)
+        self.assertEqual(payment.invoice_id, invoice.pk)
+        self.assertEqual(Invoice.objects.count(), 1)
+        self.assertEqual(Payment.objects.count(), 1)
+
+    def test_mark_payment_succeeded(self):
+        payment = Payment.objects.create(
+            user=self.user,
+            amount=1000,
+            stripe_payment_intent_id="pi_test_2",
+        )
+        payment.mark_succeeded()
+        payment.refresh_from_db()
+        self.assertEqual(payment.status, Payment.Status.SUCCEEDED)
+        self.assertIsNotNone(payment.paid_at)
+
+    def test_unique_stripe_checkout_session_id(self):
+        Invoice.objects.create(
+            user=self.user,
+            stripe_checkout_session_id="cs_unique",
+            amount_due=1000,
+        )
+        with self.assertRaises(Exception):
+            Invoice.objects.create(
+                user=self.user,
+                stripe_checkout_session_id="cs_unique",
+                amount_due=1000,
+            )
+
+
+class FinanceAdminRegistrationTestCase(TestCase):
+    def test_invoice_and_payment_registered(self):
+        self.assertIn(Invoice, admin.site._registry)
+        self.assertIn(Payment, admin.site._registry)