"""MCP 服务改了、删了、新加了，运行时拿到的工具要跟着变。 mcp_manager 按服务名缓存工具（每次都拉起一个 stdio 子进程太贵），而以前缓存只在 「一个都没加载过」时才建：改了启动命令，运行照样用旧命令建出来的工具；删掉的服务 照样能被节点调到；缓存建好之后新加的服务，工具列表里永远没有它，除非有人去点刷新。 这里用一个假的 MCP 客户端：它建出来的工具在 description 里写着自己是按哪个命令 （或地址）连的，于是一眼看得出拿到的是新配置还是旧配置。 """ from __future__ import annotations from typing import Any import pytest from httpx import ASGITransport, AsyncClient from langchain_core.tools import StructuredTool from app.main import app class _FakeClient: """一次连接 = 一次 get_tools。connects 记下每次连的是哪个服务、按什么配置。""" connects: list[tuple[str, str]] = [] def __init__(self, servers: dict[str, dict[str, Any]]) -> None: self.servers = servers async def get_tools(self) -> list[StructuredTool]: (name, cfg), = self.servers.items() via = cfg.get("command") or cfg.get("url") or "" _FakeClient.connects.append((name, via)) async def _echo(text: str = "") -> str: return f"{via}:{text}" return [StructuredTool.from_function(coroutine=_echo, name="echo", description=f"via {via}")] @pytest.fixture def manager(monkeypatch): """每个测试一个干净的 McpManager，接口层和运行时拿到的是同一个。""" import langchain_mcp_adapters.client as mcp_client import app.api.tools as tools_api import app.tools.mcp_manager as mcp_module _FakeClient.connects = [] monkeypatch.setattr(mcp_client, "MultiServerMCPClient", _FakeClient) fresh = mcp_module.McpManager() monkeypatch.setattr(mcp_module, "mcp_manager", fresh) monkeypatch.setattr(tools_api, "mcp_manager", fresh) return fresh @pytest.fixture async def client(): transport = ASGITransport(app=app) async with AsyncClient(transport=transport, base_url="http://test") as c: yield c @pytest.fixture async def server(client, manager): """一个叫 files 的 stdio 服务，测完删掉（测试里已经删了的就不用再删）。""" r = await client.post("/api/mcp/servers", json={ "name": "files", "transport": "stdio", "command": "fs-v1"}) assert r.status_code == 201, r.text row = r.json() yield row await client.delete(f"/api/mcp/servers/{row['id']}") def _body(row: dict[str, Any], **changes: Any) -> dict[str, Any]: keys = ("name", "transport", "command", "args", "env", "url", "enabled") return {**{k: row[k] for k in keys}, **changes} async def _via(manager, ref: str) -> list[str]: """运行时按引用取到的工具，各自是按什么配置连的。""" return [t.description for t in await manager.get_tools([ref])] async def test_changing_the_command_drops_the_tools_built_from_the_old_one(client, manager, server): assert await _via(manager, "mcp:files/echo") == ["via fs-v1"] r = await client.patch(f"/api/mcp/servers/{server['id']}", json=_body(server, command="fs-v2")) assert r.status_code == 200, r.text assert "files" not in manager._tools, "保存之后旧工具就该丢掉，而不是等下次有人用" assert await _via(manager, "mcp:files/echo") == ["via fs-v2"], "改了启动命令，运行还在用旧命令建的工具" listed = [t for t in await manager.list_tools() if t["server"] == "files"] assert [t["description"] for t in listed] == ["via fs-v2"] async def test_changing_the_address_of_an_http_server_reconnects(client, manager): r = await client.post("/api/mcp/servers", json={ "name": "remote", "transport": "http", "url": "https://mcp-a.example/mcp"}) row = r.json() try: assert await _via(manager, "mcp:remote/*") == ["via https://mcp-a.example/mcp"] await client.patch(f"/api/mcp/servers/{row['id']}", json=_body(row, url="https://mcp-b.example/mcp")) assert await _via(manager, "mcp:remote/*") == ["via https://mcp-b.example/mcp"] finally: await client.delete(f"/api/mcp/servers/{row['id']}") async def test_a_deleted_server_is_gone_from_runs_and_from_the_list(client, manager, server): assert await _via(manager, "mcp:files/*") == ["via fs-v1"] r = await client.delete(f"/api/mcp/servers/{server['id']}") assert r.status_code == 204 assert "files" not in manager._tools assert await manager.get_tools(["mcp:files/*"]) == [], "删掉的服务还能被节点调到" assert not [t for t in await manager.list_tools() if t["server"] == "files"] tools = (await client.get("/api/tools")).json() assert not [t for t in tools if t["id"].startswith("mcp:files/")] async def test_a_disabled_server_is_not_handed_out(client, manager, server): assert await _via(manager, "mcp:files/*") == ["via fs-v1"] await client.patch(f"/api/mcp/servers/{server['id']}", json=_body(server, enabled=False)) assert await manager.get_tools(["mcp:files/*"]) == [] # 再打开：下次用时照常连上 await client.patch(f"/api/mcp/servers/{server['id']}", json=_body(server, enabled=True)) assert await _via(manager, "mcp:files/*") == ["via fs-v1"] async def test_renaming_moves_the_tools_to_the_new_name(client, manager, server): assert await _via(manager, "mcp:files/*") == ["via fs-v1"] await client.patch(f"/api/mcp/servers/{server['id']}", json=_body(server, name="documents")) assert await manager.get_tools(["mcp:files/*"]) == [] assert await _via(manager, "mcp:documents/echo") == ["via fs-v1"] async def test_a_server_added_after_the_cache_is_warm_shows_up(client, manager, server): assert await _via(manager, "mcp:files/*") == ["via fs-v1"] r = await client.post("/api/mcp/servers", json={ "name": "later", "transport": "stdio", "command": "later-v1"}) row = r.json() try: servers = {t["server"] for t in await manager.list_tools()} assert {"files", "later"} <= servers, "缓存建好之后新加的服务，工具列表里没有它" assert await _via(manager, "mcp:later/echo") == ["via later-v1"] finally: await client.delete(f"/api/mcp/servers/{row['id']}") async def test_unchanged_servers_are_not_reconnected_on_every_use(client, manager, server): for _ in range(3): await manager.get_tools(["mcp:files/*"]) await manager.list_tools() assert _FakeClient.connects.count(("files", "fs-v1")) == 1 # 只改名字以外无关连接的保存（原样再存一次）也不该重连 await client.patch(f"/api/mcp/servers/{server['id']}", json=_body(server)) await manager.get_tools(["mcp:files/*"]) assert _FakeClient.connects.count(("files", "fs-v1")) == 1 async def test_a_change_made_behind_the_api_is_still_noticed(client, manager, server): """缓存认的是连接配置，不只是接口层的通知：库里的配置变了，下次用时就重连。""" from app.db.base import SessionLocal from app.db.models import McpServer assert await _via(manager, "mcp:files/*") == ["via fs-v1"] async with SessionLocal() as session: row = await session.get(McpServer, server["id"]) row.command = "fs-v3" await session.commit() assert await _via(manager, "mcp:files/*") == ["via fs-v3"] async def test_a_load_that_raced_with_an_edit_is_not_cached(client, manager, server, monkeypatch): """连接要花时间（stdio 子进程、最长 30 秒）。连到一半服务被改了，这次连的是旧配置， 结果不能进缓存，也不能把旧配置的「连得上」写回库里。""" import asyncio gate = asyncio.Event() started = asyncio.Event() original = _FakeClient.get_tools async def _slow(self): started.set() await gate.wait() return await original(self) monkeypatch.setattr(_FakeClient, "get_tools", _slow) loading = asyncio.create_task(manager.get_tools(["mcp:files/*"])) await started.wait() await client.patch(f"/api/mcp/servers/{server['id']}", json=_body(server, command="fs-v2")) gate.set() await loading # 这一次拿到什么都行：它开始时配置还是旧的 async def _row() -> dict[str, Any]: return next(s for s in (await client.get("/api/mcp/servers")).json() if s["id"] == server["id"]) stale = await _row() assert stale["status"] == "unknown" and stale["last_check_ok"] is None, \ f"旧配置那次连接的结论写回了库里：{stale}" monkeypatch.setattr(_FakeClient, "get_tools", original) assert await _via(manager, "mcp:files/*") == ["via fs-v2"] fresh = await _row() assert fresh["status"] == "ok" and fresh["last_check_ok"] is True async def test_a_missing_command_is_named_in_the_error(client, manager, monkeypatch): """stdio 客户端抛的 FileNotFoundError 常常不带文件名，报错里得补上配置的那条命令， 不能只剩一句「找不到命令 」。""" async def _missing(self): raise FileNotFoundError() monkeypatch.setattr(_FakeClient, "get_tools", _missing) r = await client.post("/api/mcp/servers", json={ "name": "ghost", "transport": "stdio", "command": "ghost-mcp-server", "args": ["--stdio"]}) row = r.json() try: assert await manager.get_tools(["mcp:ghost/*"]) == [] listed = next(s for s in (await client.get("/api/mcp/servers")).json() if s["id"] == row["id"]) assert listed["status"] == "error" assert "ghost-mcp-server" in listed["last_error"], listed["last_error"] probe = (await client.post(f"/api/mcp/servers/{row['id']}/probe")).json() assert probe["ok"] is False and "ghost-mcp-server" in probe["error"], probe finally: await client.delete(f"/api/mcp/servers/{row['id']}")