test: add test case for testing .stop() branches

Signed-off-by: Casper Nielsen <casper@diagrid.io>

Author: CasperGN

tests/durabletask/test_worker_stop.py

@@ -0,0 +1,57 @@
+from unittest.mock import MagicMock, patch
+
+import grpc
+
+from durabletask.worker import TaskHubGrpcWorker
+
+
+# Helper to create a running worker with a mocked runLoop
+def _make_running_worker():
+    worker = TaskHubGrpcWorker()
+    worker._is_running = True
+    worker._runLoop = MagicMock()
+    worker._runLoop.is_alive.return_value = False
+    return worker
+
+
+def test_stop_with_grpc_future():
+    worker = _make_running_worker()
+    mock_future = MagicMock(spec=grpc.Future)
+    worker._response_stream = mock_future
+    worker.stop()
+    mock_future.cancel.assert_called_once()
+
+
+def test_stop_with_generator_call():
+    worker = _make_running_worker()
+    mock_call = MagicMock()
+    mock_stream = MagicMock()
+    mock_stream.call = mock_call
+    worker._response_stream = mock_stream
+    worker.stop()
+    mock_call.cancel.assert_called_once()
+
+
+def test_stop_with_unknown_stream_type(caplog):
+    worker = _make_running_worker()
+    # Not a grpc.Future, no 'call' attribute
+    worker._response_stream = object()
+    with caplog.at_level("WARNING"):
+        worker.stop()
+    assert any("Unknown response stream type" in m for m in caplog.text.splitlines())
+
+
+def test_stop_with_none_stream():
+    worker = _make_running_worker()
+    worker._response_stream = None
+    # Should not raise
+    worker.stop()
+
+
+def test_stop_when_not_running():
+    worker = TaskHubGrpcWorker()
+    worker._is_running = False
+    # Should return immediately, not set _shutdown
+    with patch.object(worker._shutdown, "set") as shutdown_set:
+        worker.stop()
+        shutdown_set.assert_not_called()