Add AssistantContextSyncProcessor to manage LLM context synchronization during assistant interruptions. Update ProductTextStreamProcessor to track last streamed text and modify pipeline to integrate new context sync functionality. Enhance tests to verify context sync behavior for interrupted assistant turns.

engine/context_sync.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+from typing import Any
+
+from pipecat.frames.frames import Frame, InterruptionFrame, LLMMessagesAppendFrame
+from pipecat.processors.frame_processor import FrameDirection, FrameProcessor
+
+from .text_stream import ProductTextStreamProcessor, maybe_sync_assistant_context
+
+
+class AssistantContextSyncProcessor(FrameProcessor):
+    """Sync LLM context to urgent-streamed assistant text before text-input turns.
+
+    ``input.text`` with ``interrupt: true`` queues ``InterruptionFrame`` before
+    ``LLMMessagesAppendFrame``. This processor runs context repair after the
+    interrupt has propagated (including TTS-phase interrupts) and before the new
+    user message is appended.
+    """
+
+    def __init__(
+        self,
+        *,
+        text_stream: ProductTextStreamProcessor,
+        assistant_aggregator: Any,
+    ) -> None:
+        super().__init__()
+        self._text_stream = text_stream
+        self._assistant_aggregator = assistant_aggregator
+        self._sync_on_next_append = False
+
+    async def process_frame(self, frame: Frame, direction: FrameDirection) -> None:
+        await super().process_frame(frame, direction)
+
+        if isinstance(frame, InterruptionFrame):
+            self._sync_on_next_append = True
+        elif isinstance(frame, LLMMessagesAppendFrame) and self._sync_on_next_append:
+            self._sync_on_next_append = False
+            maybe_sync_assistant_context(self._assistant_aggregator, self._text_stream)
+
+        await self.push_frame(frame, direction)