Test external calendar api

com/api.py

@@ -12,7 +12,7 @@ from core.views.files import send_raw_file
 class CalendarController(ControllerBase):
     CACHE_FOLDER: Path = settings.MEDIA_ROOT / "com" / "calendars"
 
-    @route.get("/external.ics")
+    @route.get("/external.ics", url_name="calendar_external")
     def calendar_external(self):
         """Return the ICS file of the AE Google Calendar
 
@@ -27,6 +27,6 @@ class CalendarController(ControllerBase):
             return send_raw_file(calendar)
         raise Http404
 
-    @route.get("/internal.ics")
+    @route.get("/internal.ics", url_name="calendar_internal")
     def calendar_internal(self):
         return send_raw_file(IcsCalendar.get_internal())

com/tests/test_api.py

@@ -0,0 +1,54 @@
+from dataclasses import dataclass
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+import pytest
+from django.conf import settings
+from django.test.client import Client
+from django.urls import reverse
+
+from com.calendar import IcsCalendar
+
+
+@dataclass
+class MockResponse:
+    status: int
+    value: str
+
+    @property
+    def data(self):
+        return self.value.encode("utf8")
+
+
+@pytest.mark.django_db
+class TestExternalCalendar:
+    @pytest.fixture
+    def mock_request(self):
+        request = MagicMock()
+        with patch("urllib3.request", request):
+            yield request
+
+    @pytest.fixture(autouse=True)
+    def clear_cache(self):
+        IcsCalendar._EXTERNAL_CALENDAR.unlink(missing_ok=True)
+
+    @pytest.mark.parametrize("error_code", [403, 404, 500])
+    def test_fetch_error(
+        self, client: Client, mock_request: MagicMock, error_code: int
+    ):
+        mock_request.return_value = MockResponse(error_code, "not allowed")
+        assert client.get(reverse("api:calendar_external")).status_code == 404
+
+    def test_fetch_success(self, client: Client, mock_request: MagicMock):
+        external_response = MockResponse(200, "Definitely an ICS")
+        mock_request.return_value = external_response
+        response = client.get(reverse("api:calendar_external"))
+        assert response.status_code == 200
+        redirect = Path(response.headers.get("X-Accel-Redirect", ""))
+        assert redirect.is_relative_to(Path("/") / settings.MEDIA_ROOT.stem)
+        out_file = settings.MEDIA_ROOT / redirect.relative_to(
+            Path("/") / settings.MEDIA_ROOT.stem
+        )
+        assert out_file.exists()
+        with open(out_file, "r") as f:
+            assert f.read() == external_response.value