Harrison/file chat history (#3198)

Co-authored-by: Young Lee <joybro201@gmail.com>
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Harrison Chase 2023-04-19 21:05:20 -07:00 committed by GitHub
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from langchain.memory.chat_message_histories.dynamodb import DynamoDBChatMessageHistory
from langchain.memory.chat_message_histories.file import FileChatMessageHistory
from langchain.memory.chat_message_histories.postgres import PostgresChatMessageHistory
from langchain.memory.chat_message_histories.redis import RedisChatMessageHistory
@ -6,4 +7,5 @@ __all__ = [
"DynamoDBChatMessageHistory",
"RedisChatMessageHistory",
"PostgresChatMessageHistory",
"FileChatMessageHistory",
]

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import json
import logging
from pathlib import Path
from typing import List
from langchain.schema import (
AIMessage,
BaseChatMessageHistory,
BaseMessage,
HumanMessage,
messages_from_dict,
messages_to_dict,
)
logger = logging.getLogger(__name__)
class FileChatMessageHistory(BaseChatMessageHistory):
"""
Chat message history that stores history in a local file.
Args:
file_path: path of the local file to store the messages.
"""
def __init__(self, file_path: str):
self.file_path = Path(file_path)
if not self.file_path.exists():
self.file_path.touch()
self.file_path.write_text(json.dumps([]))
@property
def messages(self) -> List[BaseMessage]: # type: ignore
"""Retrieve the messages from the local file"""
items = json.loads(self.file_path.read_text())
messages = messages_from_dict(items)
return messages
def add_user_message(self, message: str) -> None:
self.append(HumanMessage(content=message))
def add_ai_message(self, message: str) -> None:
self.append(AIMessage(content=message))
def append(self, message: BaseMessage) -> None:
"""Append the message to the record in the local file"""
messages = messages_to_dict(self.messages)
messages.append(messages_to_dict([message])[0])
self.file_path.write_text(json.dumps(messages))
def clear(self) -> None:
"""Clear session memory from the local file"""
self.file_path.write_text(json.dumps([]))

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"""Unit tests for memory module"""

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"""Unit tests for chat_message_history modules"""

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import tempfile
from pathlib import Path
from typing import Generator
import pytest
from langchain.memory.chat_message_histories import FileChatMessageHistory
from langchain.schema import AIMessage, HumanMessage
@pytest.fixture
def file_chat_message_history() -> Generator[FileChatMessageHistory, None, None]:
with tempfile.TemporaryDirectory() as temp_dir:
file_path = Path(temp_dir) / "test_chat_history.json"
file_chat_message_history = FileChatMessageHistory(str(file_path))
yield file_chat_message_history
def test_add_messages(file_chat_message_history: FileChatMessageHistory) -> None:
file_chat_message_history.add_user_message("Hello!")
file_chat_message_history.add_ai_message("Hi there!")
messages = file_chat_message_history.messages
assert len(messages) == 2
assert isinstance(messages[0], HumanMessage)
assert isinstance(messages[1], AIMessage)
assert messages[0].content == "Hello!"
assert messages[1].content == "Hi there!"
def test_clear_messages(file_chat_message_history: FileChatMessageHistory) -> None:
file_chat_message_history.add_user_message("Hello!")
file_chat_message_history.add_ai_message("Hi there!")
file_chat_message_history.clear()
messages = file_chat_message_history.messages
assert len(messages) == 0
def test_multiple_sessions(file_chat_message_history: FileChatMessageHistory) -> None:
# First session
file_chat_message_history.add_user_message("Hello, AI!")
file_chat_message_history.add_ai_message("Hello, how can I help you?")
file_chat_message_history.add_user_message("Tell me a joke.")
file_chat_message_history.add_ai_message(
"Why did the chicken cross the road? To get to the other side!"
)
# Ensure the messages are added correctly in the first session
messages = file_chat_message_history.messages
assert len(messages) == 4
assert messages[0].content == "Hello, AI!"
assert messages[1].content == "Hello, how can I help you?"
assert messages[2].content == "Tell me a joke."
expected_content = "Why did the chicken cross the road? To get to the other side!"
assert messages[3].content == expected_content
# Second session (reinitialize FileChatMessageHistory)
file_path = file_chat_message_history.file_path
second_session_chat_message_history = FileChatMessageHistory(
file_path=str(file_path)
)
# Ensure the history is maintained in the second session
messages = second_session_chat_message_history.messages
assert len(messages) == 4
assert messages[0].content == "Hello, AI!"
assert messages[1].content == "Hello, how can I help you?"
assert messages[2].content == "Tell me a joke."
expected_content = "Why did the chicken cross the road? To get to the other side!"
assert messages[3].content == expected_content