fix: manage WebRTC pipeline shutdown

backend/tests/test_voice_webrtc_lifecycle.py

@@ -0,0 +1,65 @@
+from __future__ import annotations
+
+import asyncio
+import unittest
+from unittest.mock import patch
+
+from routes import voice_webrtc
+
+
+class FakeConnection:
+    pc_id = "pc_test"
+
+
+class WebRTCPipelineLifecycleTest(unittest.IsolatedAsyncioTestCase):
+    async def asyncTearDown(self):
+        tasks = list(voice_webrtc._pipeline_tasks)
+        for task in tasks:
+            task.cancel()
+        if tasks:
+            await asyncio.gather(*tasks, return_exceptions=True)
+        voice_webrtc._pipeline_tasks.clear()
+        voice_webrtc._connection_tasks.clear()
+        voice_webrtc._active_connections.clear()
+
+    async def test_pipeline_task_is_retained_until_completion(self):
+        connection = FakeConnection()
+        release = asyncio.Event()
+
+        async def pipeline():
+            await release.wait()
+
+        task = voice_webrtc._start_pipeline_task(connection, pipeline())
+        self.assertIn(task, voice_webrtc._pipeline_tasks)
+        self.assertIs(voice_webrtc._connection_tasks[connection], task)
+
+        release.set()
+        await task
+        await asyncio.sleep(0)
+
+        self.assertNotIn(task, voice_webrtc._pipeline_tasks)
+        self.assertNotIn(connection, voice_webrtc._connection_tasks)
+
+    async def test_stuck_pipeline_is_cancelled_after_close_grace_period(self):
+        connection = FakeConnection()
+        cancelled = asyncio.Event()
+
+        async def pipeline():
+            try:
+                await asyncio.Event().wait()
+            finally:
+                cancelled.set()
+
+        task = voice_webrtc._start_pipeline_task(connection, pipeline())
+        with patch.object(voice_webrtc, "PIPELINE_CLOSE_GRACE_SECONDS", 0.01):
+            await voice_webrtc._wait_for_pipeline_close(
+                task,
+                connection_id=connection.pc_id,
+            )
+
+        self.assertTrue(cancelled.is_set())
+        self.assertTrue(task.cancelled())
+
+
+if __name__ == "__main__":
+    unittest.main()