- src/backends/langgraph.py: LangGraphBackend implements ChatBackend; complete() runs one graph turn per session (thread_id=sessionId) and returns state-prefixed content; stream() emits the full state prefix before body fragments (full-answer slicing, not yet real incremental output - assignment 8) - src/core/config.py: AGENT_BACKEND=fastgpt|langgraph, langgraph mode no longer requires FastGPT credentials at startup - src/core/fastgpt_client.py: lifespan builds the backend by switch - test/backends/test_langgraph_backend.py: adapter acceptance tests Verified: - pytest: 48 passed - AGENT_BACKEND=langgraph uvicorn: POST /chat -> 1002; browser_addon -> browser_addon.1002; SSE = stage_code, text_delta, single done Known limit: stream slices a complete answer; no formUpdate deltas yet (assignment 6).
63 lines
2.0 KiB
Python
63 lines
2.0 KiB
Python
"""作业 2 验收测试:LangGraph 后端适配器。
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通过标准(对应迁移计划作业 2):
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- ``complete()`` 返回带 ``<state>1002</state>`` 前缀的 ``ChatResult``,
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API 层据此解析阶段码;
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- ``stream()`` 先产出含完整 state 前缀的 ``TextDelta``,再产出正文,
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保证 ``stage_code`` 事件先于正文;
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- 会话通过 ``thread_id = session_id`` 绑定(图 checkpoint 语义)。
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注意:``src/backends/langgraph.py`` 中的 TODO 完成前,
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本文件的测试会失败,属于预期状态。
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"""
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import pytest
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from src.backends.chat import ChatInput, TextDelta
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from src.backends.langgraph import LangGraphBackend
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def make_input() -> ChatInput:
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return ChatInput(
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session_id="session-001",
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text="发生了交通事故",
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client_mode="direct",
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)
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@pytest.mark.asyncio
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async def test_complete_returns_state_prefixed_result() -> None:
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backend = LangGraphBackend()
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result = await backend.complete(make_input())
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assert result.content.startswith("<state>1002</state>")
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assert "发生了交通事故" in result.content
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@pytest.mark.asyncio
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async def test_stream_emits_prefix_before_body() -> None:
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backend = LangGraphBackend()
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events = [event async for event in backend.stream(make_input())]
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assert events, "stream 至少应产生一个 TextDelta"
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assert all(isinstance(event, TextDelta) for event in events)
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joined = "".join(event.text for event in events)
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assert joined.startswith("<state>1002</state>")
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assert "发生了交通事故" in joined
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@pytest.mark.asyncio
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async def test_sessions_are_isolated_by_thread_id() -> None:
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backend = LangGraphBackend()
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first = await backend.complete(make_input())
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second = await backend.complete(make_input())
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other = await backend.complete(
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ChatInput(session_id="session-002", text="你好", client_mode="direct")
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)
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assert first.content != "" and second.content != ""
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assert "你好" in other.content
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