fix(payments): make checkout attempts idempotent and reconcilable

apps/payments/tests/integration/test_payment_admin.py

@@ -42,9 +42,14 @@ def test_discount_code_admin_crud_and_restore(client, user_factory, auth_headers
     assert DiscountCode.objects.filter(pk=code.pk).exists()
 
 
-@pytest.mark.parametrize("gateway_result,expected", [({"errors": {"code": -9}}, 502), (None, 502)])
-def test_payment_create_gateway_failures_leave_no_active_payment(client, user_factory, auth_headers, event_factory,
-                                                                 mocker, settings, gateway_result, expected):
+@pytest.mark.parametrize(
+    "gateway_result,expected_status,expected_payment_status",
+    [({"errors": {"code": -9}}, "failed", Payment.OrderStatusChoices.FAILED), (None, "pending", Payment.OrderStatusChoices.PENDING)],
+)
+def test_payment_create_gateway_failure_is_persisted_conservatively(
+    client, user_factory, auth_headers, event_factory, mocker, settings,
+    gateway_result, expected_status, expected_payment_status,
+):
     settings.ZARINPAL_MERCHANT_ID = "test"
     settings.ZARINPAL_REQUEST_URL = "https://gateway.example/request"
     user = user_factory()
@@ -56,8 +61,9 @@ def test_payment_create_gateway_failures_leave_no_active_payment(client, user_fa
         gateway.return_value.json.return_value = gateway_result
     response = _send(client, "post", "/api/payments/create", auth_headers(user),
                      {"event_id": event.pk, "description": "Ticket"})
-    assert response.status_code == expected
-    assert not Payment.objects.filter(user=user, event=event).exists()
+    assert response.status_code == 200
+    assert response.json()["status"] == expected_status
+    assert Payment.objects.filter(user=user, event=event, status=expected_payment_status).count() == 1
     assert Registration.objects.filter(user=user, event=event).exists()
 
 
@@ -74,14 +80,16 @@ def test_payment_callback_verification_failures_notify_once(client, user_factory
                                      base_amount=25000, authority="AUTH-FAIL", status=Payment.OrderStatusChoices.PENDING)
     gateway = mocker.patch("apps.payments.api.views.requests.post")
     notify = mocker.patch("apps.payments.api.views.notify_user")
+    retry = mocker.patch("apps.payments.api.views.reconcile_payment.apply_async")
     if gateway_result is None:
         gateway.side_effect = RuntimeError("offline")
     else:
         gateway.return_value.json.return_value = gateway_result
     response = client.get("/api/payments/callback", {"Authority": "AUTH-FAIL", "Status": "OK"})
-    assert response.status_code == 302 and "status=failed" in response.url
+    assert response.status_code == 302 and "status=pending" in response.url
     payment.refresh_from_db()
     registration.refresh_from_db()
-    assert payment.status == Payment.OrderStatusChoices.FAILED
+    assert payment.status == Payment.OrderStatusChoices.PENDING
     assert registration.status == Registration.StatusChoices.PENDING
-    notify.assert_called_once()
+    notify.assert_not_called()
+    retry.assert_called_once_with(args=(payment.id,), countdown=60)