turns: add TranscriptionUserTurnStartStrategy

tests/test_user_turn_start_strategy.py

@@ -7,12 +7,16 @@
 import unittest
 
 from pipecat.frames.frames import (
+    BotStartedSpeakingFrame,
     InterimTranscriptionFrame,
     TranscriptionFrame,
     VADUserStartedSpeakingFrame,
     VADUserStoppedSpeakingFrame,
 )
 from pipecat.turns.user.min_words_user_turn_start_strategy import MinWordsUserTurnStartStrategy
+from pipecat.turns.user.transcription_user_turn_start_strategy import (
+    TranscriptionUserTurnStartStrategy,
+)
 from pipecat.turns.user.vad_user_turn_start_strategy import VADUserTurnStartStrategy
 
 
@@ -104,3 +108,24 @@ class TestVADUserTurnStartStrategy(unittest.IsolatedAsyncioTestCase):
 
         await strategy.process_frame(VADUserStartedSpeakingFrame())
         self.assertTrue(should_start)
+
+
+class TestTranscriptionUserTurnStartStrategy(unittest.IsolatedAsyncioTestCase):
+    async def test_transcription_strategy(self):
+        strategy = TranscriptionUserTurnStartStrategy()
+
+        should_start = None
+
+        @strategy.event_handler("on_user_turn_started")
+        async def on_user_turn_started(strategy):
+            nonlocal should_start
+            should_start = True
+
+        await strategy.process_frame(TranscriptionFrame(text="Hello!", user_id="", timestamp="now"))
+        self.assertFalse(should_start)
+
+        await strategy.process_frame(BotStartedSpeakingFrame())
+        self.assertFalse(should_start)
+
+        await strategy.process_frame(TranscriptionFrame(text="Hello!", user_id="", timestamp="now"))
+        self.assertTrue(should_start)