Files
hermes-agent/tests/tools/test_mcp_probe.py
Teknium ce7418e274 feat: interactive MCP tool configuration in hermes tools (#1694)
Add the ability to selectively enable/disable individual MCP server
tools through the interactive 'hermes tools' TUI.

Changes:
- tools/mcp_tool.py: Add probe_mcp_server_tools() — lightweight function
  that temporarily connects to configured MCP servers, discovers their
  tools (names + descriptions), and disconnects. No registry side effects.

- hermes_cli/tools_config.py: Add 'Configure MCP tools' option to the
  interactive menu. When selected:
  1. Probes all enabled MCP servers for their available tools
  2. Shows a per-server curses checklist with tool descriptions
  3. Pre-selects tools based on existing include/exclude config
  4. Writes changes back as tools.exclude entries in config.yaml
  5. Reports which servers failed to connect

The existing CLI commands (hermes tools enable/disable server:tool)
continue to work unchanged. This adds the interactive TUI counterpart
so users can browse and toggle MCP tools visually.

Tests: 22 new tests covering probe function edge cases and interactive
flow (pre-selection, exclude/include modes, description truncation,
multi-server handling, error paths).
2026-03-17 03:48:44 -07:00

211 lines
7.9 KiB
Python

"""Tests for probe_mcp_server_tools() in tools.mcp_tool."""
import asyncio
from types import SimpleNamespace
from unittest.mock import AsyncMock, MagicMock, patch
import pytest
@pytest.fixture(autouse=True)
def _reset_mcp_state():
"""Ensure clean MCP module state before/after each test."""
import tools.mcp_tool as mcp
old_loop = mcp._mcp_loop
old_thread = mcp._mcp_thread
old_servers = dict(mcp._servers)
yield
mcp._servers.clear()
mcp._servers.update(old_servers)
mcp._mcp_loop = old_loop
mcp._mcp_thread = old_thread
class TestProbeMcpServerTools:
"""Tests for the lightweight probe_mcp_server_tools function."""
def test_returns_empty_when_mcp_not_available(self):
with patch("tools.mcp_tool._MCP_AVAILABLE", False):
from tools.mcp_tool import probe_mcp_server_tools
result = probe_mcp_server_tools()
assert result == {}
def test_returns_empty_when_no_config(self):
with patch("tools.mcp_tool._load_mcp_config", return_value={}):
from tools.mcp_tool import probe_mcp_server_tools
result = probe_mcp_server_tools()
assert result == {}
def test_returns_empty_when_all_servers_disabled(self):
config = {
"github": {"command": "npx", "enabled": False},
"slack": {"command": "npx", "enabled": "off"},
}
with patch("tools.mcp_tool._load_mcp_config", return_value=config):
from tools.mcp_tool import probe_mcp_server_tools
result = probe_mcp_server_tools()
assert result == {}
def test_returns_tools_from_successful_server(self):
"""Successfully probed server returns its tools list."""
config = {
"github": {"command": "npx", "connect_timeout": 5},
}
mock_tool_1 = SimpleNamespace(name="create_issue", description="Create a new issue")
mock_tool_2 = SimpleNamespace(name="search_repos", description="Search repositories")
mock_server = MagicMock()
mock_server._tools = [mock_tool_1, mock_tool_2]
mock_server.shutdown = AsyncMock()
async def fake_connect(name, cfg):
return mock_server
with patch("tools.mcp_tool._load_mcp_config", return_value=config), \
patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.mcp_tool._ensure_mcp_loop"), \
patch("tools.mcp_tool._run_on_mcp_loop") as mock_run, \
patch("tools.mcp_tool._stop_mcp_loop"):
# Simulate running the async probe
def run_coro(coro, timeout=120):
loop = asyncio.new_event_loop()
try:
return loop.run_until_complete(coro)
finally:
loop.close()
mock_run.side_effect = run_coro
from tools.mcp_tool import probe_mcp_server_tools
result = probe_mcp_server_tools()
assert "github" in result
assert len(result["github"]) == 2
assert result["github"][0] == ("create_issue", "Create a new issue")
assert result["github"][1] == ("search_repos", "Search repositories")
mock_server.shutdown.assert_awaited_once()
def test_failed_server_omitted_from_results(self):
"""Servers that fail to connect are silently skipped."""
config = {
"github": {"command": "npx", "connect_timeout": 5},
"broken": {"command": "nonexistent", "connect_timeout": 5},
}
mock_tool = SimpleNamespace(name="create_issue", description="Create")
mock_server = MagicMock()
mock_server._tools = [mock_tool]
mock_server.shutdown = AsyncMock()
async def fake_connect(name, cfg):
if name == "broken":
raise ConnectionError("Server not found")
return mock_server
with patch("tools.mcp_tool._load_mcp_config", return_value=config), \
patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.mcp_tool._ensure_mcp_loop"), \
patch("tools.mcp_tool._run_on_mcp_loop") as mock_run, \
patch("tools.mcp_tool._stop_mcp_loop"):
def run_coro(coro, timeout=120):
loop = asyncio.new_event_loop()
try:
return loop.run_until_complete(coro)
finally:
loop.close()
mock_run.side_effect = run_coro
from tools.mcp_tool import probe_mcp_server_tools
result = probe_mcp_server_tools()
assert "github" in result
assert "broken" not in result
def test_handles_tool_without_description(self):
"""Tools without descriptions get empty string."""
config = {"github": {"command": "npx", "connect_timeout": 5}}
mock_tool = SimpleNamespace(name="my_tool") # no description attribute
mock_server = MagicMock()
mock_server._tools = [mock_tool]
mock_server.shutdown = AsyncMock()
async def fake_connect(name, cfg):
return mock_server
with patch("tools.mcp_tool._load_mcp_config", return_value=config), \
patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.mcp_tool._ensure_mcp_loop"), \
patch("tools.mcp_tool._run_on_mcp_loop") as mock_run, \
patch("tools.mcp_tool._stop_mcp_loop"):
def run_coro(coro, timeout=120):
loop = asyncio.new_event_loop()
try:
return loop.run_until_complete(coro)
finally:
loop.close()
mock_run.side_effect = run_coro
from tools.mcp_tool import probe_mcp_server_tools
result = probe_mcp_server_tools()
assert result["github"][0] == ("my_tool", "")
def test_cleanup_called_even_on_failure(self):
"""_stop_mcp_loop is called even when probe fails."""
config = {"github": {"command": "npx", "connect_timeout": 5}}
with patch("tools.mcp_tool._load_mcp_config", return_value=config), \
patch("tools.mcp_tool._ensure_mcp_loop"), \
patch("tools.mcp_tool._run_on_mcp_loop", side_effect=RuntimeError("boom")), \
patch("tools.mcp_tool._stop_mcp_loop") as mock_stop:
from tools.mcp_tool import probe_mcp_server_tools
result = probe_mcp_server_tools()
assert result == {}
mock_stop.assert_called_once()
def test_skips_disabled_servers(self):
"""Disabled servers are not probed."""
config = {
"github": {"command": "npx", "connect_timeout": 5},
"disabled_one": {"command": "npx", "enabled": False},
}
mock_tool = SimpleNamespace(name="create_issue", description="Create")
mock_server = MagicMock()
mock_server._tools = [mock_tool]
mock_server.shutdown = AsyncMock()
connect_calls = []
async def fake_connect(name, cfg):
connect_calls.append(name)
return mock_server
with patch("tools.mcp_tool._load_mcp_config", return_value=config), \
patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.mcp_tool._ensure_mcp_loop"), \
patch("tools.mcp_tool._run_on_mcp_loop") as mock_run, \
patch("tools.mcp_tool._stop_mcp_loop"):
def run_coro(coro, timeout=120):
loop = asyncio.new_event_loop()
try:
return loop.run_until_complete(coro)
finally:
loop.close()
mock_run.side_effect = run_coro
from tools.mcp_tool import probe_mcp_server_tools
result = probe_mcp_server_tools()
assert "github" in result
assert "disabled_one" not in result
assert "disabled_one" not in connect_calls