Files
hermes-agent/tests/tools/test_mcp_dynamic_discovery.py
2026-04-14 17:19:20 -07:00

161 lines
6.3 KiB
Python

"""Tests for MCP dynamic tool discovery (notifications/tools/list_changed)."""
import asyncio
from types import SimpleNamespace
from unittest.mock import AsyncMock, MagicMock, patch
import pytest
from tools.mcp_tool import MCPServerTask, _register_server_tools
from tools.registry import ToolRegistry
def _make_mcp_tool(name: str, desc: str = ""):
return SimpleNamespace(name=name, description=desc, inputSchema=None)
class TestRegisterServerTools:
"""Tests for the extracted _register_server_tools helper."""
@pytest.fixture
def mock_registry(self):
return ToolRegistry()
def test_exposes_live_server_aliases(self, mock_registry):
"""Registered MCP tools are reachable via live raw-server aliases."""
server = MCPServerTask("my_srv")
server._tools = [_make_mcp_tool("my_tool", "desc")]
server.session = MagicMock()
from toolsets import resolve_toolset, validate_toolset
with patch("tools.registry.registry", mock_registry):
registered = _register_server_tools("my_srv", server, {})
assert "mcp_my_srv_my_tool" in registered
assert "mcp_my_srv_my_tool" in mock_registry.get_all_tool_names()
assert validate_toolset("my_srv") is True
assert "mcp_my_srv_my_tool" in resolve_toolset("my_srv")
class TestRefreshTools:
"""Tests for MCPServerTask._refresh_tools nuke-and-repave cycle."""
@pytest.fixture
def mock_registry(self):
return ToolRegistry()
@pytest.mark.asyncio
async def test_nuke_and_repave(self, mock_registry):
"""Old tools are removed and new tools registered on refresh."""
server = MCPServerTask("live_srv")
server._refresh_lock = asyncio.Lock()
server._config = {}
from toolsets import resolve_toolset
# Seed initial state: one old tool registered
mock_registry.register(
name="mcp_live_srv_old_tool", toolset="mcp-live_srv", schema={},
handler=lambda x: x, check_fn=lambda: True, is_async=False,
description="", emoji="",
)
server._registered_tool_names = ["mcp_live_srv_old_tool"]
# New tool list from server
new_tool = _make_mcp_tool("new_tool", "new behavior")
server.session = SimpleNamespace(
list_tools=AsyncMock(
return_value=SimpleNamespace(tools=[new_tool])
)
)
with patch("tools.registry.registry", mock_registry):
await server._refresh_tools()
assert "mcp_live_srv_old_tool" not in mock_registry.get_all_tool_names()
assert "mcp_live_srv_old_tool" not in resolve_toolset("live_srv")
assert "mcp_live_srv_new_tool" in mock_registry.get_all_tool_names()
assert "mcp_live_srv_new_tool" in resolve_toolset("live_srv")
assert server._registered_tool_names == ["mcp_live_srv_new_tool"]
class TestMessageHandler:
"""Tests for MCPServerTask._make_message_handler dispatch."""
@pytest.mark.asyncio
async def test_dispatches_tool_list_changed(self):
from tools.mcp_tool import _MCP_NOTIFICATION_TYPES
if not _MCP_NOTIFICATION_TYPES:
pytest.skip("MCP SDK ToolListChangedNotification not available")
from mcp.types import ServerNotification, ToolListChangedNotification
server = MCPServerTask("notif_srv")
with patch.object(MCPServerTask, "_refresh_tools", new_callable=AsyncMock) as mock_refresh:
handler = server._make_message_handler()
notification = ServerNotification(
root=ToolListChangedNotification(method="notifications/tools/list_changed")
)
await handler(notification)
mock_refresh.assert_awaited_once()
@pytest.mark.asyncio
async def test_ignores_exceptions_and_other_messages(self):
server = MCPServerTask("notif_srv")
with patch.object(MCPServerTask, "_refresh_tools", new_callable=AsyncMock) as mock_refresh:
handler = server._make_message_handler()
# Exceptions should not trigger refresh
await handler(RuntimeError("connection dead"))
# Unknown message types should not trigger refresh
await handler({"jsonrpc": "2.0", "result": "ok"})
mock_refresh.assert_not_awaited()
class TestDeregister:
"""Tests for ToolRegistry.deregister."""
def test_removes_tool(self):
reg = ToolRegistry()
reg.register(name="foo", toolset="ts1", schema={}, handler=lambda x: x)
assert "foo" in reg.get_all_tool_names()
reg.deregister("foo")
assert "foo" not in reg.get_all_tool_names()
def test_cleans_up_toolset_check(self):
reg = ToolRegistry()
check = lambda: True # noqa: E731
reg.register(name="foo", toolset="ts1", schema={}, handler=lambda x: x, check_fn=check)
assert reg.is_toolset_available("ts1")
reg.deregister("foo")
# Toolset check should be gone since no tools remain
assert "ts1" not in reg._toolset_checks
def test_preserves_toolset_check_if_other_tools_remain(self):
reg = ToolRegistry()
check = lambda: True # noqa: E731
reg.register(name="foo", toolset="ts1", schema={}, handler=lambda x: x, check_fn=check)
reg.register(name="bar", toolset="ts1", schema={}, handler=lambda x: x)
reg.deregister("foo")
# bar still in ts1, so check should remain
assert "ts1" in reg._toolset_checks
def test_removes_toolset_alias_when_last_tool_is_removed(self):
reg = ToolRegistry()
reg.register(name="foo", toolset="mcp-srv", schema={}, handler=lambda x: x)
reg.register_toolset_alias("srv", "mcp-srv")
reg.deregister("foo")
assert reg.get_toolset_alias_target("srv") is None
def test_preserves_toolset_alias_while_toolset_still_exists(self):
reg = ToolRegistry()
reg.register(name="foo", toolset="mcp-srv", schema={}, handler=lambda x: x)
reg.register(name="bar", toolset="mcp-srv", schema={}, handler=lambda x: x)
reg.register_toolset_alias("srv", "mcp-srv")
reg.deregister("foo")
assert reg.get_toolset_alias_target("srv") == "mcp-srv"
def test_noop_for_unknown_tool(self):
reg = ToolRegistry()
reg.deregister("nonexistent") # Should not raise