Add test for home page template issues

tests/test_routes/test_frontend.py

@@ -1,13 +1,17 @@
 import random
+from pathlib import Path
 from unittest.mock import AsyncMock
 from uuid import UUID
 
 import jwt
 import pytest
 from databases import Database
 from fastapi import HTTPException
+from fastapi.templating import Jinja2Templates
+from jinja2 import StrictUndefined
 from pytest_mock import MockerFixture
 
+import rctab
 from rctab.crud.accounting_models import subscription, subscription_details
 from rctab.crud.schema import RoleAssignment, SubscriptionState, UserRBAC
 from rctab.routers.frontend import home
@@ -97,6 +101,16 @@ async def test_no_username_no_subscriptions(
 async def test_render_home_page(mocker: MockerFixture, test_db: Database) -> None:
     """Check that we can pick up on undefined variable template issues."""
 
+    # Use StrictUndefined while testing
+    mocker.patch(
+        "rctab.routers.frontend.templates",
+        Jinja2Templates(
+            (
+                Path(rctab.routers.frontend.__file__).parent.parent / "templates"
+            ).absolute(),
+            undefined=StrictUndefined,
+        ),
+    )
     subscription_id = UUID(int=random.randint(0, (2**32) - 1))
 
     await test_db.execute(