community(sparkllm): Add function call support in Sparkllm chat model. (#20607)

- **Description:** Add function call support in Sparkllm chat model.
Related documents
https://www.xfyun.cn/doc/spark/Web.html#_2-function-call%E8%AF%B4%E6%98%8E
- @baskaryan

---------

Co-authored-by: ccurme <chester.curme@gmail.com>

libs/community/langchain_community/chat_models/sparkllm.py

@@ -8,7 +8,7 @@ import threading
 from datetime import datetime
 from queue import Queue
 from time import mktime
-from typing import Any, Dict, Generator, Iterator, List, Mapping, Optional, Type
+from typing import Any, Dict, Generator, Iterator, List, Mapping, Optional, Type, cast
 from urllib.parse import urlencode, urlparse, urlunparse
 from wsgiref.handlers import format_date_time
 
@@ -26,9 +26,15 @@ from langchain_core.messages import (
     BaseMessageChunk,
     ChatMessage,
     ChatMessageChunk,
+    FunctionMessageChunk,
     HumanMessage,
     HumanMessageChunk,
     SystemMessage,
+    ToolMessageChunk,
+)
+from langchain_core.output_parsers.openai_tools import (
+    make_invalid_tool_call,
+    parse_tool_call,
 )
 from langchain_core.outputs import (
     ChatGeneration,
@@ -48,13 +54,24 @@ SPARK_API_URL = "wss://spark-api.xf-yun.com/v3.5/chat"
 SPARK_LLM_DOMAIN = "generalv3.5"
 
 
-def _convert_message_to_dict(message: BaseMessage) -> dict:
+def convert_message_to_dict(message: BaseMessage) -> dict:
+    message_dict: Dict[str, Any]
     if isinstance(message, ChatMessage):
         message_dict = {"role": "user", "content": message.content}
     elif isinstance(message, HumanMessage):
         message_dict = {"role": "user", "content": message.content}
     elif isinstance(message, AIMessage):
         message_dict = {"role": "assistant", "content": message.content}
+        if "function_call" in message.additional_kwargs:
+            message_dict["function_call"] = message.additional_kwargs["function_call"]
+            # If function call only, content is None not empty string
+            if message_dict["content"] == "":
+                message_dict["content"] = None
+        if "tool_calls" in message.additional_kwargs:
+            message_dict["tool_calls"] = message.additional_kwargs["tool_calls"]
+            # If tool calls only, content is None not empty string
+            if message_dict["content"] == "":
+                message_dict["content"] = None
     elif isinstance(message, SystemMessage):
         message_dict = {"role": "system", "content": message.content}
     else:
@@ -63,14 +80,35 @@ def _convert_message_to_dict(message: BaseMessage) -> dict:
     return message_dict
 
 
-def _convert_dict_to_message(_dict: Mapping[str, Any]) -> BaseMessage:
+def convert_dict_to_message(_dict: Mapping[str, Any]) -> BaseMessage:
     msg_role = _dict["role"]
     msg_content = _dict["content"]
     if msg_role == "user":
         return HumanMessage(content=msg_content)
     elif msg_role == "assistant":
+        invalid_tool_calls = []
+        additional_kwargs: Dict = {}
+        if function_call := _dict.get("function_call"):
+            additional_kwargs["function_call"] = dict(function_call)
+        tool_calls = []
+        if raw_tool_calls := _dict.get("tool_calls"):
+            additional_kwargs["tool_calls"] = raw_tool_calls
+            for raw_tool_call in _dict["tool_calls"]:
+                try:
+                    tool_calls.append(parse_tool_call(raw_tool_call, return_id=True))
+                except Exception as e:
+                    invalid_tool_calls.append(
+                        make_invalid_tool_call(raw_tool_call, str(e))
+                    )
+        else:
+            additional_kwargs = {}
         content = msg_content or ""
-        return AIMessage(content=content)
+        return AIMessage(
+            content=content,
+            additional_kwargs=additional_kwargs,
+            tool_calls=tool_calls,
+            invalid_tool_calls=invalid_tool_calls,
+        )
     elif msg_role == "system":
         return SystemMessage(content=msg_content)
     else:
@@ -80,12 +118,24 @@ def _convert_dict_to_message(_dict: Mapping[str, Any]) -> BaseMessage:
 def _convert_delta_to_message_chunk(
     _dict: Mapping[str, Any], default_class: Type[BaseMessageChunk]
 ) -> BaseMessageChunk:
-    msg_role = _dict["role"]
-    msg_content = _dict.get("content", "")
+    msg_role = cast(str, _dict.get("role"))
+    msg_content = cast(str, _dict.get("content") or "")
+    additional_kwargs: Dict = {}
+    if _dict.get("function_call"):
+        function_call = dict(_dict["function_call"])
+        if "name" in function_call and function_call["name"] is None:
+            function_call["name"] = ""
+        additional_kwargs["function_call"] = function_call
+    if _dict.get("tool_calls"):
+        additional_kwargs["tool_calls"] = _dict["tool_calls"]
     if msg_role == "user" or default_class == HumanMessageChunk:
         return HumanMessageChunk(content=msg_content)
     elif msg_role == "assistant" or default_class == AIMessageChunk:
-        return AIMessageChunk(content=msg_content)
+        return AIMessageChunk(content=msg_content, additional_kwargs=additional_kwargs)
+    elif msg_role == "function" or default_class == FunctionMessageChunk:
+        return FunctionMessageChunk(content=msg_content, name=_dict["name"])
+    elif msg_role == "tool" or default_class == ToolMessageChunk:
+        return ToolMessageChunk(content=msg_content, tool_call_id=_dict["tool_call_id"])
     elif msg_role or default_class == ChatMessageChunk:
         return ChatMessageChunk(content=msg_content, role=msg_role)
     else:
@@ -335,7 +385,7 @@ class ChatSparkLLM(BaseChatModel):
         default_chunk_class = AIMessageChunk
 
         self.client.arun(
-            [_convert_message_to_dict(m) for m in messages],
+            [convert_message_to_dict(m) for m in messages],
             self.spark_user_id,
             self.model_kwargs,
             streaming=True,
@@ -365,7 +415,7 @@ class ChatSparkLLM(BaseChatModel):
             return generate_from_stream(stream_iter)
 
         self.client.arun(
-            [_convert_message_to_dict(m) for m in messages],
+            [convert_message_to_dict(m) for m in messages],
             self.spark_user_id,
             self.model_kwargs,
             False,
@@ -378,7 +428,7 @@ class ChatSparkLLM(BaseChatModel):
             if "data" not in content:
                 continue
             completion = content["data"]
-        message = _convert_dict_to_message(completion)
+        message = convert_dict_to_message(completion)
         generations = [ChatGeneration(message=message)]
         return ChatResult(generations=generations, llm_output=llm_output)
 

libs/community/tests/integration_tests/chat_models/test_sparkllm.py

@@ -1,7 +1,48 @@
+from typing import Any
+
 from langchain_core.messages import AIMessage, AIMessageChunk, HumanMessage
+from langchain_core.prompts import ChatPromptTemplate, HumanMessagePromptTemplate
 
 from langchain_community.chat_models.sparkllm import ChatSparkLLM
 
+_FUNCTIONS: Any = [
+    {
+        "type": "function",
+        "function": {
+            "name": "get_current_weather",
+            "description": "Get the current weather in a given location",
+            "parameters": {
+                "type": "object",
+                "properties": {
+                    "location": {
+                        "type": "string",
+                        "description": "The city and state, e.g. San Francisco, CA",
+                    },
+                    "unit": {"type": "string", "enum": ["celsius", "fahrenheit"]},
+                },
+                "required": ["location"],
+            },
+        },
+    }
+]
+
+
+def test_functions_call_thoughts() -> None:
+    chat = ChatSparkLLM(timeout=30)
+
+    prompt_tmpl = "Use the given functions to answer following question: {input}"
+    prompt_msgs = [
+        HumanMessagePromptTemplate.from_template(prompt_tmpl),
+    ]
+    prompt = ChatPromptTemplate(messages=prompt_msgs)
+
+    chain = prompt | chat.bind(functions=_FUNCTIONS)
+
+    message = HumanMessage(content="What's the weather like in Shanghai today?")
+    response = chain.batch([{"input": message}])
+    assert isinstance(response[0], AIMessage)
+    assert "tool_calls" in response[0].additional_kwargs
+
 
 def test_initialization() -> None:
     """Test chat model initialization."""

libs/community/tests/unit_tests/chat_models/test_sparkllm.py

@@ -0,0 +1,85 @@
+from langchain_core.messages import (
+    AIMessage,
+    HumanMessage,
+    SystemMessage,
+)
+from langchain_core.output_parsers.openai_tools import (
+    parse_tool_call,
+)
+
+from langchain_community.chat_models.sparkllm import (
+    convert_dict_to_message,
+    convert_message_to_dict,
+)
+
+
+def test__convert_dict_to_message_human() -> None:
+    message_dict = {"role": "user", "content": "foo"}
+    result = convert_dict_to_message(message_dict)
+    expected_output = HumanMessage(content="foo")
+    assert result == expected_output
+
+
+def test__convert_dict_to_message_ai() -> None:
+    message_dict = {"role": "assistant", "content": "foo"}
+    result = convert_dict_to_message(message_dict)
+    expected_output = AIMessage(content="foo")
+    assert result == expected_output
+
+
+def test__convert_dict_to_message_other_role() -> None:
+    message_dict = {"role": "system", "content": "foo"}
+    result = convert_dict_to_message(message_dict)
+    expected_output = SystemMessage(content="foo")
+    assert result == expected_output
+
+
+def test__convert_dict_to_message_function_call() -> None:
+    raw_function_calls = [
+        {
+            "function": {
+                "name": "get_current_weather",
+                "arguments": '{"location": "Boston", "unit": "fahrenheit"}',
+            },
+            "type": "function",
+        }
+    ]
+    message_dict = {
+        "role": "assistant",
+        "content": "foo",
+        "tool_calls": raw_function_calls,
+    }
+    result = convert_dict_to_message(message_dict)
+
+    tool_calls = [
+        parse_tool_call(raw_tool_call, return_id=True)
+        for raw_tool_call in raw_function_calls
+    ]
+    expected_output = AIMessage(
+        content="foo",
+        additional_kwargs={"tool_calls": raw_function_calls},
+        tool_calls=tool_calls,
+        invalid_tool_calls=[],
+    )
+    assert result == expected_output
+
+
+def test__convert_message_to_dict_human() -> None:
+    message = HumanMessage(content="foo")
+    result = convert_message_to_dict(message)
+    expected_output = {"role": "user", "content": "foo"}
+    assert result == expected_output
+
+
+def test__convert_message_to_dict_ai() -> None:
+    message = AIMessage(content="foo")
+    result = convert_message_to_dict(message)
+    expected_output = {"role": "assistant", "content": "foo"}
+    assert result == expected_output
+
+
+def test__convert_message_to_dict_system() -> None:
+    message = SystemMessage(content="foo")
+    result = convert_message_to_dict(message)
+    expected_output = {"role": "system", "content": "foo"}
+    assert result == expected_output