Rename method and return directly list[LLMMessage]

Author: stellasia

src/neo4j_graphrag/llm/base.py

@@ -30,7 +30,7 @@
 from neo4j_graphrag.tool import Tool
 
 from .rate_limit import RateLimitHandler
-from .utils import legacy_inputs_to_message_history
+from .utils import legacy_inputs_to_messages
 
 
 class LLMInterface(ABC):
@@ -65,10 +65,8 @@ def invoke(
         message_history: Optional[Union[List[LLMMessage], MessageHistory]] = None,
         system_instruction: Optional[str] = None,
     ) -> LLMResponse:
-        message_history = legacy_inputs_to_message_history(
-            input, message_history, system_instruction
-        )
-        return self._invoke(message_history.messages)
+        messages = legacy_inputs_to_messages(input, message_history, system_instruction)
+        return self._invoke(messages)
 
     @abstractmethod
     def _invoke(
@@ -94,10 +92,8 @@ async def ainvoke(
         message_history: Optional[Union[List[LLMMessage], MessageHistory]] = None,
         system_instruction: Optional[str] = None,
     ) -> LLMResponse:
-        message_history = legacy_inputs_to_message_history(
-            input, message_history, system_instruction
-        )
-        return await self._ainvoke(message_history.messages)
+        messages = legacy_inputs_to_messages(input, message_history, system_instruction)
+        return await self._ainvoke(messages)
 
     @abstractmethod
     async def _ainvoke(
@@ -142,10 +138,8 @@ def invoke_with_tools(
             LLMGenerationError: If anything goes wrong.
             NotImplementedError: If the LLM provider does not support tool calling.
         """
-        history = legacy_inputs_to_message_history(
-            input, message_history, system_instruction
-        )
-        return self._invoke_with_tools(history.messages, tools)
+        messages = legacy_inputs_to_messages(input, message_history, system_instruction)
+        return self._invoke_with_tools(messages, tools)
 
     def _invoke_with_tools(
         self, inputs: list[LLMMessage], tools: Sequence[Tool]
@@ -177,10 +171,8 @@ async def ainvoke_with_tools(
             LLMGenerationError: If anything goes wrong.
             NotImplementedError: If the LLM provider does not support tool calling.
         """
-        history = legacy_inputs_to_message_history(
-            input, message_history, system_instruction
-        )
-        return await self._ainvoke_with_tools(history.messages, tools)
+        messages = legacy_inputs_to_messages(input, message_history, system_instruction)
+        return await self._ainvoke_with_tools(messages, tools)
 
     async def _ainvoke_with_tools(
         self, inputs: list[LLMMessage], tools: Sequence[Tool]

src/neo4j_graphrag/llm/utils.py

@@ -1,49 +1,57 @@
 import warnings
 from typing import Union, Optional
 
-from neo4j_graphrag.message_history import MessageHistory, InMemoryMessageHistory
+from neo4j_graphrag.message_history import MessageHistory
 from neo4j_graphrag.types import LLMMessage
 
 
-def legacy_inputs_to_message_history(
+def system_instruction_from_messages(messages: list[LLMMessage]) -> str | None:
+    for message in messages:
+        if message["role"] == "system":
+            return message["content"]
+    return None
+
+
+def legacy_inputs_to_messages(
     input: Union[str, list[LLMMessage], MessageHistory],
     message_history: Optional[Union[list[LLMMessage], MessageHistory]] = None,
     system_instruction: Optional[str] = None,
-) -> MessageHistory:
+) -> list[LLMMessage]:
     if message_history:
         warnings.warn(
             "Using message_history parameter is deprecated and will be removed in 2.0. Use a list of inputs or a MessageHistory instead.",
             DeprecationWarning,
         )
         if isinstance(message_history, MessageHistory):
-            history = message_history
+            messages = message_history.messages
         else:  # list[LLMMessage]
-            history = InMemoryMessageHistory(message_history)
+            messages = []
     else:
-        history = InMemoryMessageHistory()
+        messages = []
     if system_instruction is not None:
         warnings.warn(
             "Using system_instruction parameter is deprecated and will be removed in 2.0. Use a list of inputs or a MessageHistory instead.",
             DeprecationWarning,
         )
-        if history.is_empty():
-            history.add_message(
+        if system_instruction_from_messages(messages) is not None:
+            warnings.warn(
+                "system_instruction provided but ignored as the message history already contains a system message",
+                RuntimeWarning,
+            )
+        else:
+            messages.append(
                 LLMMessage(
                     role="system",
                     content=system_instruction,
                 ),
             )
-        else:
-            warnings.warn(
-                "system_instruction provided but ignored as the message history is not empty",
-                RuntimeWarning,
-            )
+
     if isinstance(input, str):
-        history.add_message(LLMMessage(role="user", content=input))
-        return history
+        messages.append(LLMMessage(role="user", content=input))
+        return messages
     if isinstance(input, list):
-        history.add_messages(input)
-        return history
+        messages.extend(input)
+        return messages
     # input is a MessageHistory instance
-    history.add_messages(input.messages)
-    return history
+    messages.extend(input.messages)
+    return messages