✨(backend) add connection-test API

Currently users have no way to reliably test their connection before
joining a room. To address this, we plan to build a connection-test
page.

The testing requires a dedicated LiveKit token, issued without going
through the room API, which is tied to registered meetings, lobby
rules, and longer-lived access tokens.

Introduce a new viewset for all diagnostics-related features. The
first route issues a token for diagnostics, even for anonymous
users. Each request creates a new dedicated room so users never
share the same LiveKit room during tests. Tokens are short-lived
(default 10 minutes) to limit reuse, and the endpoint is throttled
to prevent abuse.

A Celery worker also schedules a callback that deletes the room
after a certain delay, in every case.

src/backend/core/tests/services/test_livekit_events.py

@@ -720,6 +720,7 @@ def test_receive_unsupported_event(mock_receive, service):
 
     # Mock returned data with unsupported event type
     mock_data = mock.MagicMock()
+    mock_data.room.name = str(uuid.uuid4())
     mock_data.event = "unsupported_event"
     mock_receive.return_value = mock_data
 
@@ -823,3 +824,33 @@ def test_receive_filter_processes_matching_events(
     service.receive(mock_request)
 
     mock_handle_room_started.assert_called_once()
+
+
+@mock.patch.object(api.WebhookReceiver, "receive")
+@mock.patch.object(LiveKitEventsService, "_handle_room_finished")
+@mock.patch.object(LiveKitEventsService, "_handle_room_started")
+def test_receive_ignores_connection_test_room(
+    mock_handle_room_started,
+    mock_handle_room_finished,
+    mock_receive,
+    mock_livekit_config,
+    settings,
+):
+    """Should ignore all webhook events for connection test rooms in receive()."""
+
+    settings.CONNECTION_TEST_ROOM_PREFIX = "connection-test"
+
+    mock_request = mock.MagicMock()
+    mock_request.headers = {"Authorization": "test_token"}
+    mock_request.body = b"{}"
+
+    mock_data = mock.MagicMock()
+    mock_data.room.name = f"{settings.CONNECTION_TEST_ROOM_PREFIX}-{uuid.uuid4()}"
+    mock_data.event = "room_started"
+    mock_receive.return_value = mock_data
+
+    service = LiveKitEventsService()
+    service.receive(mock_request)
+
+    mock_handle_room_started.assert_not_called()
+    mock_handle_room_finished.assert_not_called()

src/backend/core/tests/services/test_room_management.py

@@ -0,0 +1,60 @@
+"""Tests for the RoomManagement service."""
+
+from unittest import mock
+
+import pytest
+from livekit.api import TwirpError
+
+from core.services.room_management import (
+    RoomManagement,
+    RoomManagementException,
+    RoomNotFoundException,
+)
+
+
+@mock.patch("core.services.room_management.utils.create_livekit_client")
+def test_delete_room_calls_livekit(mock_create_livekit_client):
+    """DeleteRoom is forwarded to the LiveKit API."""
+    mock_api = mock.MagicMock()
+    mock_api.room.delete_room = mock.AsyncMock()
+    mock_api.aclose = mock.AsyncMock()
+    mock_create_livekit_client.return_value = mock_api
+
+    RoomManagement().delete_room("room-abc")
+
+    mock_api.room.delete_room.assert_awaited_once()
+    request = mock_api.room.delete_room.await_args.args[0]
+    assert request.room == "room-abc"
+    mock_api.aclose.assert_awaited_once()
+
+
+@mock.patch("core.services.room_management.utils.create_livekit_client")
+def test_delete_room_raises_not_found(mock_create_livekit_client):
+    """Missing rooms raise RoomNotFoundException."""
+    mock_api = mock.MagicMock()
+    mock_api.room.delete_room = mock.AsyncMock(
+        side_effect=TwirpError("not_found", "room not found", status=404)
+    )
+    mock_api.aclose = mock.AsyncMock()
+    mock_create_livekit_client.return_value = mock_api
+
+    with pytest.raises(RoomNotFoundException):
+        RoomManagement().delete_room("missing-room")
+
+    mock_api.aclose.assert_awaited_once()
+
+
+@mock.patch("core.services.room_management.utils.create_livekit_client")
+def test_delete_room_raises_management_exception(mock_create_livekit_client):
+    """Unexpected Twirp errors raise RoomManagementException."""
+    mock_api = mock.MagicMock()
+    mock_api.room.delete_room = mock.AsyncMock(
+        side_effect=TwirpError("internal", "boom", status=500)
+    )
+    mock_api.aclose = mock.AsyncMock()
+    mock_create_livekit_client.return_value = mock_api
+
+    with pytest.raises(RoomManagementException):
+        RoomManagement().delete_room("room-abc")
+
+    mock_api.aclose.assert_awaited_once()

src/backend/core/tests/tasks/test_connection_test.py

@@ -0,0 +1,51 @@
+"""Tests for connection test Celery tasks."""
+
+from unittest import mock
+
+from django.test.utils import override_settings
+
+from core.services.room_management import (
+    RoomManagementException,
+    RoomNotFoundException,
+)
+from core.tasks.connection_test import delete_connection_test_room
+
+
+@mock.patch("core.tasks.connection_test.RoomManagement.delete_room")
+def test_delete_connection_test_room_calls_room_management(mock_delete_room, settings):
+    """RoomManagement.delete_room is called for connection-test rooms."""
+    settings.CONNECTION_TEST_ROOM_PREFIX = "connection-test"
+    delete_connection_test_room("connection-test-abc")
+
+    mock_delete_room.assert_called_once_with("connection-test-abc")
+
+
+@mock.patch("core.tasks.connection_test.RoomManagement.delete_room")
+def test_delete_connection_test_room_refuses_other_rooms(mock_delete_room, settings):
+    """Refuse to delete rooms outside the connection-test namespace."""
+    settings.CONNECTION_TEST_ROOM_PREFIX = "connection-test"
+    delete_connection_test_room("production-room")
+
+    mock_delete_room.assert_not_called()
+
+
+@mock.patch("core.tasks.connection_test.RoomManagement.delete_room")
+def test_delete_connection_test_room_ignores_missing_room(mock_delete_room, settings):
+    """Missing rooms are treated as already cleaned up."""
+    settings.CONNECTION_TEST_ROOM_PREFIX = "connection-test"
+    mock_delete_room.side_effect = RoomNotFoundException("Room does not exist")
+
+    delete_connection_test_room("connection-test-gone")
+
+    mock_delete_room.assert_called_once_with("connection-test-gone")
+
+
+@mock.patch("core.tasks.connection_test.RoomManagement.delete_room")
+def test_delete_connection_test_room_logs_other_failures(mock_delete_room, settings):
+    """Unexpected LiveKit failures are swallowed after logging."""
+    settings.CONNECTION_TEST_ROOM_PREFIX = "connection-test"
+    mock_delete_room.side_effect = RoomManagementException("Could not delete room")
+
+    delete_connection_test_room("connection-test-fail")
+
+    mock_delete_room.assert_called_once_with("connection-test-fail")

src/backend/core/tests/test_api_diagnostics.py

@@ -0,0 +1,165 @@
+"""Test diagnostics API endpoints."""
+
+import uuid
+from unittest import mock
+
+from django.test.utils import override_settings
+from django.urls import reverse
+
+import jwt
+import pytest
+from rest_framework.test import APIClient
+
+from core.api.throttling import (
+    ConnectionTestAnonRateThrottle,
+    ConnectionTestUserRateThrottle,
+)
+from core.factories import UserFactory
+
+pytestmark = pytest.mark.django_db
+
+
+def test_api_diagnostics_connection_url():
+    """The connection check is exposed under the diagnostics namespace."""
+    assert reverse("diagnostics-connection") == "/api/v1.0/diagnostics/connection/"
+
+
+def test_api_diagnostics_connection_rejects_get():
+    """Only POST is exposed, the endpoint has no side effect to trigger."""
+    client = APIClient()
+    response = client.get("/api/v1.0/diagnostics/connection/")
+
+    assert response.status_code == 405
+
+
+def test_api_diagnostics_connection_returns_ephemeral_livekit_config(settings, client):
+    """Each request gets a dedicated room and a short-lived token."""
+
+    settings.CONNECTION_TEST_TOKEN_TTL_SECONDS = 600
+    settings.CONNECTION_TEST_ROOM_PREFIX = "connection-test"
+
+    response_a = client.post("/api/v1.0/diagnostics/connection/")
+    response_b = client.post("/api/v1.0/diagnostics/connection/")
+
+    assert response_a.status_code == 200
+    assert response_b.status_code == 200
+
+    data_a = response_a.json()
+    data_b = response_b.json()
+
+    room_a = data_a["livekit"]["room"]
+    room_b = data_b["livekit"]["room"]
+
+    assert room_a.startswith("connection-test-")
+    assert room_b.startswith("connection-test-")
+    uuid.UUID(room_a.removeprefix("connection-test-"))
+    uuid.UUID(room_b.removeprefix("connection-test-"))
+    assert room_a != room_b
+    assert data_a["livekit"]["url"]
+    assert data_a["livekit"]["token"]
+    assert data_a["livekit"]["expires_in"] == 600
+    assert data_a["livekit"]["token"] != data_b["livekit"]["token"]
+
+
+def test_api_diagnostics_connection_token_is_short_lived_for_user(settings, client):
+    """Connection test tokens expire quickly for users."""
+
+    settings.CONNECTION_TEST_TOKEN_TTL_SECONDS = 300
+
+    client = APIClient()
+    response = client.post("/api/v1.0/diagnostics/connection/")
+
+    assert response.status_code == 200
+
+    config = response.json()["livekit"]
+    payload = jwt.decode(
+        config["token"],
+        settings.LIVEKIT_CONFIGURATION["api_secret"],
+        algorithms=["HS256"],
+        options={"verify_exp": False},
+    )
+
+    assert config["expires_in"] == 300
+    assert payload["video"]["room"] == config["room"]
+    assert payload["name"] == "Connection Test"
+    assert payload["video"]["roomAdmin"] is False
+    assert payload["exp"] - payload["nbf"] == 300
+
+
+@override_settings()
+def test_api_diagnostics_connection_token_for_authenticated_user(settings, client):
+    """Logged-in users get a token bound to their own identity."""
+
+    settings.CONNECTION_TEST_TOKEN_TTL_SECONDS = 300
+
+    user = UserFactory()
+    client.force_login(user)
+
+    response = client.post("/api/v1.0/diagnostics/connection/")
+
+    assert response.status_code == 200
+
+    payload = jwt.decode(
+        response.json()["livekit"]["token"],
+        settings.LIVEKIT_CONFIGURATION["api_secret"],
+        algorithms=["HS256"],
+        options={"verify_exp": False},
+    )
+
+    assert payload["sub"] == str(user.sub)
+    assert payload["video"]["roomAdmin"] is False
+    assert payload["exp"] - payload["nbf"] == 300
+
+
+@mock.patch("core.api.viewsets.delete_connection_test_room.apply_async")
+def test_api_diagnostics_connection_schedules_room_deletion(
+    mock_apply_async, settings, client
+):
+    """When Celery is enabled, schedule a hard room delete after max age."""
+
+    settings.CELERY_ENABLED = True
+    settings.CONNECTION_TEST_ROOM_MAX_AGE_SECONDS = 300
+    settings.CONNECTION_TEST_ROOM_PREFIX = "connection-test"
+
+    response = client.post("/api/v1.0/diagnostics/connection/")
+
+    assert response.status_code == 200
+    room = response.json()["livekit"]["room"]
+    mock_apply_async.assert_called_once_with(args=[room], countdown=300)
+
+
+@mock.patch("core.api.viewsets.delete_connection_test_room.apply_async")
+def test_api_diagnostics_connection_skips_room_deletion_without_celery(
+    mock_apply_async, settings, client
+):
+    """Without Celery, do not schedule deletion (apply_async would run immediately)."""
+
+    settings.CELERY_ENABLED = False
+    response = client.post("/api/v1.0/diagnostics/connection/")
+
+    assert response.status_code == 200
+    mock_apply_async.assert_not_called()
+
+
+@pytest.mark.parametrize(
+    "throttle_class",
+    [ConnectionTestAnonRateThrottle, ConnectionTestUserRateThrottle],
+)
+def test_api_diagnostics_connection_is_throttled(throttle_class, client):
+    """Both throttles stay wired to the action once routed through the viewset."""
+    with (
+        mock.patch.object(throttle_class, "allow_request", return_value=False),
+        mock.patch.object(throttle_class, "wait", return_value=42),
+    ):
+        response = client.post("/api/v1.0/diagnostics/connection/")
+
+    assert response.status_code == 429
+
+
+def test_api_diagnostics_connection_feature_flag(client, settings):
+    """Should return a not found error when the connection diagnostics feature is disabled."""
+
+    settings.CONNECTION_TEST_ENABLED = False
+
+    response = client.post("/api/v1.0/diagnostics/connection/")
+    assert response.status_code == 404