test: Add chat completion function call functional test

Author: caffeinism

tests/test_functional/fastapi_chat_completion_openai_function_call/server_openai_function_call.py

@@ -0,0 +1,45 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from dotenv import load_dotenv, find_dotenv
+import uvicorn
+
+from langchain_openai_api_bridge.core.create_agent_dto import CreateAgentDto
+from langchain_openai_api_bridge.fastapi.langchain_openai_api_bridge_fastapi import (
+    LangchainOpenaiApiBridgeFastAPI,
+)
+from langchain_openai import ChatOpenAI
+
+_ = load_dotenv(find_dotenv())
+
+
+app = FastAPI(
+    title="Langchain Agent OpenAI API Bridge",
+    version="1.0",
+    description="OpenAI API exposing langchain agent",
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+    expose_headers=["*"],
+)
+
+
+def create_agent(dto: CreateAgentDto):
+    llm = ChatOpenAI(
+        temperature=dto.temperature or 0.7,
+        model=dto.model,
+        max_tokens=dto.max_tokens,
+        api_key=dto.api_key,
+    )
+    return llm.bind_tools(dto.tools)
+
+
+bridge = LangchainOpenaiApiBridgeFastAPI(app=app, agent_factory_provider=create_agent)
+bridge.bind_openai_chat_completion(prefix="/my-custom-path")
+
+if __name__ == "__main__":
+    uvicorn.run(app, host="localhost")

tests/test_functional/fastapi_chat_completion_openai_function_call/test_server_openai_function_call.py

@@ -0,0 +1,147 @@
+import json
+import pytest
+from openai import OpenAI
+from openai.lib.streaming.chat import ChatCompletionStreamState
+from fastapi.testclient import TestClient
+from server_openai_function_call import app
+
+
+test_api = TestClient(app)
+
+
+@pytest.fixture
+def openai_client():
+    return OpenAI(
+        base_url="http://testserver/my-custom-path/openai/v1",
+        http_client=test_api,
+    )
+
+
+def test_chat_completion_function_call_weather(openai_client: OpenAI):
+    tools = [{
+        "type": "function",
+        "function": {
+            "name": "get_weather",
+            "description": "Get current temperature for a given location.",
+            "parameters": {
+                "type": "object",
+                "properties": {
+                    "location": {
+                        "type": "string",
+                        "description": "City and country e.g. Bogotá, Colombia"
+                    }
+                },
+                "required": [
+                    "location"
+                ],
+                "additionalProperties": False
+            },
+            "strict": True
+        }
+    }]
+
+    chat_completion = openai_client.chat.completions.create(
+        model="gpt-4o-mini",
+        messages=[
+            {
+                "role": "user",
+                "content": 'What is the weather like in London today?',
+            }
+        ],
+        tools=tools,
+        tool_choice={"type": "function", "function": {"name": "get_weather"}},
+    )
+
+    assert chat_completion.choices[0].finish_reason == "tool_calls"
+    assert chat_completion.choices[0].message.tool_calls[0].function.name == "get_weather"
+
+    args = json.loads(chat_completion.choices[0].message.tool_calls[0].function.arguments)
+    assert "london" in args["location"].lower()
+
+
+def test_chat_completion_function_call_weather_stream(openai_client: OpenAI):
+    tools = [{
+        "type": "function",
+        "function": {
+            "name": "get_weather",
+            "description": "Get current temperature for a given location.",
+            "parameters": {
+                "type": "object",
+                "properties": {
+                    "location": {
+                        "type": "string",
+                        "description": "City and country e.g. Bogotá, Colombia"
+                    }
+                },
+                "required": [
+                    "location"
+                ],
+                "additionalProperties": False
+            },
+            "strict": True
+        }
+    }]
+
+    chunks = openai_client.chat.completions.create(
+        model="gpt-4o-mini",
+        messages=[
+            {
+                "role": "user",
+                "content": 'What is the weather like in London today?',
+            }
+        ],
+        tools=tools,
+        tool_choice={"type": "function", "function": {"name": "get_weather"}},
+        stream=True,
+    )
+
+    state = ChatCompletionStreamState()
+    for chunk in chunks:
+        state.handle_chunk(chunk)
+
+    chat_completion = state.get_final_completion()
+
+    assert chat_completion.choices[0].finish_reason == "tool_calls"
+    assert chat_completion.choices[0].message.function_call.name == "get_weather"
+    assert chat_completion.choices[0].message.role == "assistant"
+
+    args = json.loads(chat_completion.choices[0].message.function_call.arguments)
+    assert "london" in args["location"].lower()
+
+
+def test_chat_completion_function_call_not_called(openai_client: OpenAI):
+    tools = [{
+        "type": "function",
+        "function": {
+            "name": "get_weather",
+            "description": "Get current temperature for a given location.",
+            "parameters": {
+                "type": "object",
+                "properties": {
+                    "location": {
+                        "type": "string",
+                        "description": "City and country e.g. Bogotá, Colombia"
+                    }
+                },
+                "required": [
+                    "location"
+                ],
+                "additionalProperties": False
+            },
+            "strict": True
+        }
+    }]
+
+    chat_completion = openai_client.chat.completions.create(
+        model="gpt-4o-mini",
+        messages=[
+            {
+                "role": "user",
+                "content": 'Hello!',
+            }
+        ],
+        tools=tools,
+        tool_choice="none",
+    )
+
+    assert chat_completion.choices[0].finish_reason == "stop"