Align websocket STT connection failures

tests/test_cartesia_stt.py

@@ -0,0 +1,45 @@
+#
+# Copyright (c) 2024-2026, Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
+from unittest.mock import AsyncMock
+
+import pytest
+from websockets.protocol import State
+
+from pipecat.services.cartesia.stt import CartesiaSTTService
+
+
+class _FakeWebsocket:
+    def __init__(self, *, state=State.OPEN, send_side_effect=None):
+        self.state = state
+        self.send = AsyncMock(side_effect=send_side_effect)
+
+
+@pytest.mark.asyncio
+async def test_cartesia_connect_failure_clears_stale_websocket(monkeypatch):
+    async def fake_websocket_connect(*args, **kwargs):
+        raise RuntimeError("connection failed")
+
+    monkeypatch.setattr("pipecat.services.cartesia.stt.websocket_connect", fake_websocket_connect)
+
+    service = CartesiaSTTService(api_key="test-key", sample_rate=16000)
+    service._websocket = _FakeWebsocket(state=State.CLOSED)
+
+    await service._connect_websocket()
+
+    assert service._websocket is None
+
+
+@pytest.mark.asyncio
+async def test_cartesia_run_stt_logs_send_failure_without_clearing_websocket():
+    service = CartesiaSTTService(api_key="test-key", sample_rate=16000)
+    websocket = _FakeWebsocket(send_side_effect=RuntimeError("websocket closed"))
+    service._websocket = websocket
+
+    async for _ in service.run_stt(b"\x00" * 160):
+        pass
+
+    assert service._websocket is websocket