Files
hermes-agent/tests/tools/test_mcp_tool.py

2753 lines
104 KiB
Python

"""Tests for the MCP (Model Context Protocol) client support.
All tests use mocks -- no real MCP servers or subprocesses are started.
"""
import asyncio
import json
import os
from types import SimpleNamespace
from unittest.mock import AsyncMock, MagicMock, patch
import pytest
# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
def _make_mcp_tool(name="read_file", description="Read a file", input_schema=None):
"""Create a fake MCP Tool object matching the SDK interface."""
tool = SimpleNamespace()
tool.name = name
tool.description = description
tool.inputSchema = input_schema or {
"type": "object",
"properties": {
"path": {"type": "string", "description": "File path"},
},
"required": ["path"],
}
return tool
def _make_call_result(text="file contents here", is_error=False):
"""Create a fake MCP CallToolResult."""
block = SimpleNamespace(text=text)
return SimpleNamespace(content=[block], isError=is_error)
def _make_mock_server(name, session=None, tools=None):
"""Create an MCPServerTask with mock attributes for testing."""
from tools.mcp_tool import MCPServerTask
server = MCPServerTask(name)
server.session = session
server._tools = tools or []
return server
# ---------------------------------------------------------------------------
# Config loading
# ---------------------------------------------------------------------------
class TestLoadMCPConfig:
def test_no_config_returns_empty(self):
"""No mcp_servers key in config -> empty dict."""
with patch("hermes_cli.config.load_config", return_value={"model": "test"}):
from tools.mcp_tool import _load_mcp_config
result = _load_mcp_config()
assert result == {}
def test_valid_config_parsed(self):
"""Valid mcp_servers config is returned as-is."""
servers = {
"filesystem": {
"command": "npx",
"args": ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"],
"env": {},
}
}
with patch("hermes_cli.config.load_config", return_value={"mcp_servers": servers}):
from tools.mcp_tool import _load_mcp_config
result = _load_mcp_config()
assert "filesystem" in result
assert result["filesystem"]["command"] == "npx"
def test_mcp_servers_not_dict_returns_empty(self):
"""mcp_servers set to non-dict value -> empty dict."""
with patch("hermes_cli.config.load_config", return_value={"mcp_servers": "invalid"}):
from tools.mcp_tool import _load_mcp_config
result = _load_mcp_config()
assert result == {}
# ---------------------------------------------------------------------------
# Schema conversion
# ---------------------------------------------------------------------------
class TestSchemaConversion:
def test_converts_mcp_tool_to_hermes_schema(self):
from tools.mcp_tool import _convert_mcp_schema
mcp_tool = _make_mcp_tool(name="read_file", description="Read a file")
schema = _convert_mcp_schema("filesystem", mcp_tool)
assert schema["name"] == "mcp_filesystem_read_file"
assert schema["description"] == "Read a file"
assert "properties" in schema["parameters"]
def test_empty_input_schema_gets_default(self):
from tools.mcp_tool import _convert_mcp_schema
mcp_tool = _make_mcp_tool(name="ping", description="Ping", input_schema=None)
mcp_tool.inputSchema = None
schema = _convert_mcp_schema("test", mcp_tool)
assert schema["parameters"]["type"] == "object"
assert schema["parameters"]["properties"] == {}
def test_object_schema_without_properties_gets_normalized(self):
from tools.mcp_tool import _convert_mcp_schema
mcp_tool = _make_mcp_tool(
name="ask",
description="Ask Crawl4AI",
input_schema={"type": "object"},
)
schema = _convert_mcp_schema("crawl4ai", mcp_tool)
assert schema["parameters"] == {"type": "object", "properties": {}}
def test_tool_name_prefix_format(self):
from tools.mcp_tool import _convert_mcp_schema
mcp_tool = _make_mcp_tool(name="list_dir")
schema = _convert_mcp_schema("my_server", mcp_tool)
assert schema["name"] == "mcp_my_server_list_dir"
def test_hyphens_sanitized_to_underscores(self):
"""Hyphens in tool/server names are replaced with underscores for LLM compat."""
from tools.mcp_tool import _convert_mcp_schema
mcp_tool = _make_mcp_tool(name="get-sum")
schema = _convert_mcp_schema("my-server", mcp_tool)
assert schema["name"] == "mcp_my_server_get_sum"
assert "-" not in schema["name"]
# ---------------------------------------------------------------------------
# Check function
# ---------------------------------------------------------------------------
class TestCheckFunction:
def test_disconnected_returns_false(self):
from tools.mcp_tool import _make_check_fn, _servers
_servers.pop("test_server", None)
check = _make_check_fn("test_server")
assert check() is False
def test_connected_returns_true(self):
from tools.mcp_tool import _make_check_fn, _servers
server = _make_mock_server("test_server", session=MagicMock())
_servers["test_server"] = server
try:
check = _make_check_fn("test_server")
assert check() is True
finally:
_servers.pop("test_server", None)
def test_session_none_returns_false(self):
from tools.mcp_tool import _make_check_fn, _servers
server = _make_mock_server("test_server", session=None)
_servers["test_server"] = server
try:
check = _make_check_fn("test_server")
assert check() is False
finally:
_servers.pop("test_server", None)
# ---------------------------------------------------------------------------
# Tool handler
# ---------------------------------------------------------------------------
class TestToolHandler:
"""Tool handlers are sync functions that schedule work on the MCP loop."""
def _patch_mcp_loop(self, coro_side_effect=None):
"""Return a patch for _run_on_mcp_loop that runs the coroutine directly."""
def fake_run(coro, timeout=30):
loop = asyncio.new_event_loop()
try:
return loop.run_until_complete(coro)
finally:
loop.close()
if coro_side_effect:
return patch("tools.mcp_tool._run_on_mcp_loop", side_effect=coro_side_effect)
return patch("tools.mcp_tool._run_on_mcp_loop", side_effect=fake_run)
def test_successful_call(self):
from tools.mcp_tool import _make_tool_handler, _servers
mock_session = MagicMock()
mock_session.call_tool = AsyncMock(
return_value=_make_call_result("hello world", is_error=False)
)
server = _make_mock_server("test_srv", session=mock_session)
_servers["test_srv"] = server
try:
handler = _make_tool_handler("test_srv", "greet", 120)
with self._patch_mcp_loop():
result = json.loads(handler({"name": "world"}))
assert result["result"] == "hello world"
mock_session.call_tool.assert_called_once_with("greet", arguments={"name": "world"})
finally:
_servers.pop("test_srv", None)
def test_mcp_error_result(self):
from tools.mcp_tool import _make_tool_handler, _servers
mock_session = MagicMock()
mock_session.call_tool = AsyncMock(
return_value=_make_call_result("something went wrong", is_error=True)
)
server = _make_mock_server("test_srv", session=mock_session)
_servers["test_srv"] = server
try:
handler = _make_tool_handler("test_srv", "fail_tool", 120)
with self._patch_mcp_loop():
result = json.loads(handler({}))
assert "error" in result
assert "something went wrong" in result["error"]
finally:
_servers.pop("test_srv", None)
def test_disconnected_server(self):
from tools.mcp_tool import _make_tool_handler, _servers
_servers.pop("ghost", None)
handler = _make_tool_handler("ghost", "any_tool", 120)
result = json.loads(handler({}))
assert "error" in result
assert "not connected" in result["error"]
def test_exception_during_call(self):
from tools.mcp_tool import _make_tool_handler, _servers
mock_session = MagicMock()
mock_session.call_tool = AsyncMock(side_effect=RuntimeError("connection lost"))
server = _make_mock_server("test_srv", session=mock_session)
_servers["test_srv"] = server
try:
handler = _make_tool_handler("test_srv", "broken_tool", 120)
with self._patch_mcp_loop():
result = json.loads(handler({}))
assert "error" in result
assert "connection lost" in result["error"]
finally:
_servers.pop("test_srv", None)
# ---------------------------------------------------------------------------
# Tool registration (discovery + register)
# ---------------------------------------------------------------------------
class TestDiscoverAndRegister:
def test_tools_registered_in_registry(self):
"""_discover_and_register_server registers tools with correct names."""
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
mock_registry = ToolRegistry()
mock_tools = [
_make_mcp_tool("read_file", "Read a file"),
_make_mcp_tool("write_file", "Write a file"),
]
mock_session = MagicMock()
async def fake_connect(name, config):
server = MCPServerTask(name)
server.session = mock_session
server._tools = mock_tools
return server
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.registry.registry", mock_registry):
registered = asyncio.run(
_discover_and_register_server("fs", {"command": "npx", "args": []})
)
assert "mcp_fs_read_file" in registered
assert "mcp_fs_write_file" in registered
assert "mcp_fs_read_file" in mock_registry.get_all_tool_names()
assert "mcp_fs_write_file" in mock_registry.get_all_tool_names()
_servers.pop("fs", None)
def test_toolset_created(self):
"""A custom toolset is created for the MCP server."""
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
mock_tools = [_make_mcp_tool("ping", "Ping")]
mock_session = MagicMock()
async def fake_connect(name, config):
server = MCPServerTask(name)
server.session = mock_session
server._tools = mock_tools
return server
mock_create = MagicMock()
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("toolsets.create_custom_toolset", mock_create):
asyncio.run(
_discover_and_register_server("myserver", {"command": "test"})
)
mock_create.assert_called_once()
call_kwargs = mock_create.call_args
assert call_kwargs[1]["name"] == "mcp-myserver" or call_kwargs[0][0] == "mcp-myserver"
_servers.pop("myserver", None)
def test_schema_format_correct(self):
"""Registered schemas have the correct format."""
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
mock_registry = ToolRegistry()
mock_tools = [_make_mcp_tool("do_thing", "Do something")]
mock_session = MagicMock()
async def fake_connect(name, config):
server = MCPServerTask(name)
server.session = mock_session
server._tools = mock_tools
return server
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.registry.registry", mock_registry):
asyncio.run(
_discover_and_register_server("srv", {"command": "test"})
)
entry = mock_registry._tools.get("mcp_srv_do_thing")
assert entry is not None
assert entry.schema["name"] == "mcp_srv_do_thing"
assert "parameters" in entry.schema
assert entry.is_async is False
assert entry.toolset == "mcp-srv"
_servers.pop("srv", None)
# ---------------------------------------------------------------------------
# MCPServerTask (run / start / shutdown)
# ---------------------------------------------------------------------------
class TestMCPServerTask:
"""Test the MCPServerTask lifecycle with mocked MCP SDK."""
def _mock_stdio_and_session(self, session):
"""Return patches for stdio_client and ClientSession as async CMs."""
mock_read, mock_write = MagicMock(), MagicMock()
mock_stdio_cm = MagicMock()
mock_stdio_cm.__aenter__ = AsyncMock(return_value=(mock_read, mock_write))
mock_stdio_cm.__aexit__ = AsyncMock(return_value=False)
mock_cs_cm = MagicMock()
mock_cs_cm.__aenter__ = AsyncMock(return_value=session)
mock_cs_cm.__aexit__ = AsyncMock(return_value=False)
return (
patch("tools.mcp_tool.stdio_client", return_value=mock_stdio_cm),
patch("tools.mcp_tool.ClientSession", return_value=mock_cs_cm),
mock_read, mock_write,
)
def test_start_connects_and_discovers_tools(self):
"""start() creates a Task that connects, discovers tools, and waits."""
from tools.mcp_tool import MCPServerTask
mock_tools = [_make_mcp_tool("echo")]
mock_session = MagicMock()
mock_session.initialize = AsyncMock()
mock_session.list_tools = AsyncMock(
return_value=SimpleNamespace(tools=mock_tools)
)
p_stdio, p_cs, _, _ = self._mock_stdio_and_session(mock_session)
async def _test():
with patch("tools.mcp_tool.StdioServerParameters"), p_stdio, p_cs:
server = MCPServerTask("test_srv")
await server.start({"command": "npx", "args": ["-y", "test"]})
assert server.session is mock_session
assert len(server._tools) == 1
assert server._tools[0].name == "echo"
mock_session.initialize.assert_called_once()
await server.shutdown()
assert server.session is None
asyncio.run(_test())
def test_no_command_raises(self):
"""Missing 'command' in config raises ValueError."""
from tools.mcp_tool import MCPServerTask
async def _test():
server = MCPServerTask("bad")
with pytest.raises(ValueError, match="no 'command'"):
await server.start({"args": []})
asyncio.run(_test())
def test_empty_env_gets_safe_defaults(self):
"""Empty env dict gets safe default env vars (PATH, HOME, etc.)."""
from tools.mcp_tool import MCPServerTask
mock_session = MagicMock()
mock_session.initialize = AsyncMock()
mock_session.list_tools = AsyncMock(
return_value=SimpleNamespace(tools=[])
)
p_stdio, p_cs, _, _ = self._mock_stdio_and_session(mock_session)
async def _test():
with patch("tools.mcp_tool.StdioServerParameters") as mock_params, \
p_stdio, p_cs, \
patch.dict("os.environ", {"PATH": "/usr/bin", "HOME": "/home/test"}, clear=False):
server = MCPServerTask("srv")
await server.start({"command": "node", "env": {}})
# Empty dict -> safe env vars (not None)
call_kwargs = mock_params.call_args
env_arg = call_kwargs.kwargs.get("env")
assert env_arg is not None
assert isinstance(env_arg, dict)
assert "PATH" in env_arg
assert "HOME" in env_arg
await server.shutdown()
asyncio.run(_test())
def test_shutdown_signals_task_exit(self):
"""shutdown() signals the event and waits for task completion."""
from tools.mcp_tool import MCPServerTask
mock_session = MagicMock()
mock_session.initialize = AsyncMock()
mock_session.list_tools = AsyncMock(
return_value=SimpleNamespace(tools=[])
)
p_stdio, p_cs, _, _ = self._mock_stdio_and_session(mock_session)
async def _test():
with patch("tools.mcp_tool.StdioServerParameters"), p_stdio, p_cs:
server = MCPServerTask("srv")
await server.start({"command": "npx"})
assert server.session is not None
assert not server._task.done()
await server.shutdown()
assert server.session is None
assert server._task.done()
asyncio.run(_test())
# ---------------------------------------------------------------------------
# discover_mcp_tools toolset injection
# ---------------------------------------------------------------------------
class TestToolsetInjection:
def test_mcp_tools_added_to_all_hermes_toolsets(self):
"""Discovered MCP tools are dynamically injected into all hermes-* toolsets."""
from tools.mcp_tool import MCPServerTask
mock_tools = [_make_mcp_tool("list_files", "List files")]
mock_session = MagicMock()
fresh_servers = {}
async def fake_connect(name, config):
server = MCPServerTask(name)
server.session = mock_session
server._tools = mock_tools
return server
fake_toolsets = {
"hermes-cli": {"tools": ["terminal"], "description": "CLI", "includes": []},
"hermes-telegram": {"tools": ["terminal"], "description": "TG", "includes": []},
"hermes-gateway": {"tools": [], "description": "GW", "includes": []},
"non-hermes": {"tools": [], "description": "other", "includes": []},
}
fake_config = {"fs": {"command": "npx", "args": []}}
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._servers", fresh_servers), \
patch("tools.mcp_tool._load_mcp_config", return_value=fake_config), \
patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("toolsets.TOOLSETS", fake_toolsets):
from tools.mcp_tool import discover_mcp_tools
result = discover_mcp_tools()
assert "mcp_fs_list_files" in result
# All hermes-* toolsets get injection
assert "mcp_fs_list_files" in fake_toolsets["hermes-cli"]["tools"]
assert "mcp_fs_list_files" in fake_toolsets["hermes-telegram"]["tools"]
assert "mcp_fs_list_files" in fake_toolsets["hermes-gateway"]["tools"]
# Non-hermes toolset should NOT get injection
assert "mcp_fs_list_files" not in fake_toolsets["non-hermes"]["tools"]
# Original tools preserved
assert "terminal" in fake_toolsets["hermes-cli"]["tools"]
# Server name becomes a standalone toolset
assert "fs" in fake_toolsets
assert "mcp_fs_list_files" in fake_toolsets["fs"]["tools"]
assert fake_toolsets["fs"]["description"].startswith("MCP server '")
def test_server_toolset_skips_builtin_collision(self):
"""MCP server named after a built-in toolset shouldn't overwrite it."""
from tools.mcp_tool import MCPServerTask
mock_tools = [_make_mcp_tool("run", "Run command")]
mock_session = MagicMock()
fresh_servers = {}
async def fake_connect(name, config):
server = MCPServerTask(name)
server.session = mock_session
server._tools = mock_tools
return server
fake_toolsets = {
"hermes-cli": {"tools": ["terminal"], "description": "CLI", "includes": []},
# Built-in toolset named "terminal" — must not be overwritten
"terminal": {"tools": ["terminal"], "description": "Terminal tools", "includes": []},
}
fake_config = {"terminal": {"command": "npx", "args": []}}
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._servers", fresh_servers), \
patch("tools.mcp_tool._load_mcp_config", return_value=fake_config), \
patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("toolsets.TOOLSETS", fake_toolsets):
from tools.mcp_tool import discover_mcp_tools
discover_mcp_tools()
# Built-in toolset preserved — description unchanged
assert fake_toolsets["terminal"]["description"] == "Terminal tools"
def test_server_connection_failure_skipped(self):
"""If one server fails to connect, others still proceed."""
from tools.mcp_tool import MCPServerTask
mock_tools = [_make_mcp_tool("ping", "Ping")]
mock_session = MagicMock()
fresh_servers = {}
call_count = 0
async def flaky_connect(name, config):
nonlocal call_count
call_count += 1
if name == "broken":
raise ConnectionError("cannot reach server")
server = MCPServerTask(name)
server.session = mock_session
server._tools = mock_tools
return server
fake_config = {
"broken": {"command": "bad"},
"good": {"command": "npx", "args": []},
}
fake_toolsets = {
"hermes-cli": {"tools": [], "description": "CLI", "includes": []},
}
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._servers", fresh_servers), \
patch("tools.mcp_tool._load_mcp_config", return_value=fake_config), \
patch("tools.mcp_tool._connect_server", side_effect=flaky_connect), \
patch("toolsets.TOOLSETS", fake_toolsets):
from tools.mcp_tool import discover_mcp_tools
result = discover_mcp_tools()
assert "mcp_good_ping" in result
assert "mcp_broken_ping" not in result
assert call_count == 2
def test_partial_failure_retry_on_second_call(self):
"""Failed servers are retried on subsequent discover_mcp_tools() calls."""
from tools.mcp_tool import MCPServerTask
mock_tools = [_make_mcp_tool("ping", "Ping")]
mock_session = MagicMock()
# Use a real dict so idempotency logic works correctly
fresh_servers = {}
call_count = 0
broken_fixed = False
async def flaky_connect(name, config):
nonlocal call_count
call_count += 1
if name == "broken" and not broken_fixed:
raise ConnectionError("cannot reach server")
server = MCPServerTask(name)
server.session = mock_session
server._tools = mock_tools
return server
fake_config = {
"broken": {"command": "bad"},
"good": {"command": "npx", "args": []},
}
fake_toolsets = {
"hermes-cli": {"tools": [], "description": "CLI", "includes": []},
}
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._servers", fresh_servers), \
patch("tools.mcp_tool._load_mcp_config", return_value=fake_config), \
patch("tools.mcp_tool._connect_server", side_effect=flaky_connect), \
patch("toolsets.TOOLSETS", fake_toolsets):
from tools.mcp_tool import discover_mcp_tools
# First call: good connects, broken fails
result1 = discover_mcp_tools()
assert "mcp_good_ping" in result1
assert "mcp_broken_ping" not in result1
first_attempts = call_count
# "Fix" the broken server
broken_fixed = True
call_count = 0
# Second call: should retry broken, skip good
result2 = discover_mcp_tools()
assert "mcp_good_ping" in result2
assert "mcp_broken_ping" in result2
assert call_count == 1 # Only broken retried
# ---------------------------------------------------------------------------
# Graceful fallback
# ---------------------------------------------------------------------------
class TestGracefulFallback:
def test_mcp_unavailable_returns_empty(self):
"""When _MCP_AVAILABLE is False, discover_mcp_tools is a no-op."""
with patch("tools.mcp_tool._MCP_AVAILABLE", False):
from tools.mcp_tool import discover_mcp_tools
result = discover_mcp_tools()
assert result == []
def test_no_servers_returns_empty(self):
"""No MCP servers configured -> empty list."""
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._servers", {}), \
patch("tools.mcp_tool._load_mcp_config", return_value={}):
from tools.mcp_tool import discover_mcp_tools
result = discover_mcp_tools()
assert result == []
# ---------------------------------------------------------------------------
# Shutdown (public API)
# ---------------------------------------------------------------------------
class TestShutdown:
def test_no_servers_safe(self):
"""shutdown_mcp_servers with no servers does nothing."""
from tools.mcp_tool import shutdown_mcp_servers, _servers
_servers.clear()
shutdown_mcp_servers() # Should not raise
def test_shutdown_clears_servers(self):
"""shutdown_mcp_servers calls shutdown() on each server and clears dict."""
import tools.mcp_tool as mcp_mod
from tools.mcp_tool import shutdown_mcp_servers, _servers
_servers.clear()
mock_server = MagicMock()
mock_server.name = "test"
mock_server.shutdown = AsyncMock()
_servers["test"] = mock_server
mcp_mod._ensure_mcp_loop()
try:
shutdown_mcp_servers()
finally:
mcp_mod._mcp_loop = None
mcp_mod._mcp_thread = None
assert len(_servers) == 0
mock_server.shutdown.assert_called_once()
def test_shutdown_handles_errors(self):
"""shutdown_mcp_servers handles errors during close gracefully."""
import tools.mcp_tool as mcp_mod
from tools.mcp_tool import shutdown_mcp_servers, _servers
_servers.clear()
mock_server = MagicMock()
mock_server.name = "broken"
mock_server.shutdown = AsyncMock(side_effect=RuntimeError("close failed"))
_servers["broken"] = mock_server
mcp_mod._ensure_mcp_loop()
try:
shutdown_mcp_servers() # Should not raise
finally:
mcp_mod._mcp_loop = None
mcp_mod._mcp_thread = None
assert len(_servers) == 0
def test_shutdown_is_parallel(self):
"""Multiple servers are shut down in parallel via asyncio.gather."""
import tools.mcp_tool as mcp_mod
from tools.mcp_tool import shutdown_mcp_servers, _servers
import time
_servers.clear()
# 3 servers each taking 1s to shut down
for i in range(3):
mock_server = MagicMock()
mock_server.name = f"srv_{i}"
async def slow_shutdown():
await asyncio.sleep(1)
mock_server.shutdown = slow_shutdown
_servers[f"srv_{i}"] = mock_server
mcp_mod._ensure_mcp_loop()
try:
start = time.monotonic()
shutdown_mcp_servers()
elapsed = time.monotonic() - start
finally:
mcp_mod._mcp_loop = None
mcp_mod._mcp_thread = None
assert len(_servers) == 0
# Parallel: ~1s, not ~3s. Allow some margin.
assert elapsed < 2.5, f"Shutdown took {elapsed:.1f}s, expected ~1s (parallel)"
# ---------------------------------------------------------------------------
# _build_safe_env
# ---------------------------------------------------------------------------
class TestBuildSafeEnv:
"""Tests for _build_safe_env() environment filtering."""
def test_only_safe_vars_passed(self):
"""Only safe baseline vars and XDG_* from os.environ are included."""
from tools.mcp_tool import _build_safe_env
fake_env = {
"PATH": "/usr/bin",
"HOME": "/home/test",
"USER": "test",
"LANG": "en_US.UTF-8",
"LC_ALL": "C",
"TERM": "xterm",
"SHELL": "/bin/bash",
"TMPDIR": "/tmp",
"XDG_DATA_HOME": "/home/test/.local/share",
"SECRET_KEY": "should_not_appear",
"AWS_ACCESS_KEY_ID": "AKIAIOSFODNN7EXAMPLE",
}
with patch.dict("os.environ", fake_env, clear=True):
result = _build_safe_env(None)
# Safe vars present
assert result["PATH"] == "/usr/bin"
assert result["HOME"] == "/home/test"
assert result["USER"] == "test"
assert result["LANG"] == "en_US.UTF-8"
assert result["XDG_DATA_HOME"] == "/home/test/.local/share"
# Unsafe vars excluded
assert "SECRET_KEY" not in result
assert "AWS_ACCESS_KEY_ID" not in result
def test_user_env_merged(self):
"""User-specified env vars are merged into the safe env."""
from tools.mcp_tool import _build_safe_env
with patch.dict("os.environ", {"PATH": "/usr/bin"}, clear=True):
result = _build_safe_env({"MY_CUSTOM_VAR": "hello"})
assert result["PATH"] == "/usr/bin"
assert result["MY_CUSTOM_VAR"] == "hello"
def test_user_env_overrides_safe(self):
"""User env can override safe defaults."""
from tools.mcp_tool import _build_safe_env
with patch.dict("os.environ", {"PATH": "/usr/bin"}, clear=True):
result = _build_safe_env({"PATH": "/custom/bin"})
assert result["PATH"] == "/custom/bin"
def test_none_user_env(self):
"""None user_env still returns safe vars from os.environ."""
from tools.mcp_tool import _build_safe_env
with patch.dict("os.environ", {"PATH": "/usr/bin", "HOME": "/root"}, clear=True):
result = _build_safe_env(None)
assert isinstance(result, dict)
assert result["PATH"] == "/usr/bin"
assert result["HOME"] == "/root"
def test_secret_vars_excluded(self):
"""Sensitive env vars from os.environ are NOT passed through."""
from tools.mcp_tool import _build_safe_env
fake_env = {
"PATH": "/usr/bin",
"AWS_SECRET_ACCESS_KEY": "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY",
"GITHUB_TOKEN": "ghp_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
"OPENAI_API_KEY": "sk-proj-abc123",
"DATABASE_URL": "postgres://user:pass@localhost/db",
"API_SECRET": "supersecret",
}
with patch.dict("os.environ", fake_env, clear=True):
result = _build_safe_env(None)
assert "PATH" in result
assert "AWS_SECRET_ACCESS_KEY" not in result
assert "GITHUB_TOKEN" not in result
assert "OPENAI_API_KEY" not in result
assert "DATABASE_URL" not in result
assert "API_SECRET" not in result
# ---------------------------------------------------------------------------
# _sanitize_error
# ---------------------------------------------------------------------------
class TestSanitizeError:
"""Tests for _sanitize_error() credential stripping."""
def test_strips_github_pat(self):
from tools.mcp_tool import _sanitize_error
result = _sanitize_error("Error with ghp_abc123def456")
assert result == "Error with [REDACTED]"
def test_strips_openai_key(self):
from tools.mcp_tool import _sanitize_error
result = _sanitize_error("key sk-projABC123xyz")
assert result == "key [REDACTED]"
def test_strips_bearer_token(self):
from tools.mcp_tool import _sanitize_error
result = _sanitize_error("Authorization: Bearer eyJabc123def")
assert result == "Authorization: [REDACTED]"
def test_strips_token_param(self):
from tools.mcp_tool import _sanitize_error
result = _sanitize_error("url?token=secret123")
assert result == "url?[REDACTED]"
def test_no_credentials_unchanged(self):
from tools.mcp_tool import _sanitize_error
result = _sanitize_error("normal error message")
assert result == "normal error message"
def test_multiple_credentials(self):
from tools.mcp_tool import _sanitize_error
result = _sanitize_error("ghp_abc123 and sk-projXyz789 and token=foo")
assert "ghp_" not in result
assert "sk-" not in result
assert "token=" not in result
assert result.count("[REDACTED]") == 3
# ---------------------------------------------------------------------------
# HTTP config
# ---------------------------------------------------------------------------
class TestHTTPConfig:
"""Tests for HTTP transport detection and handling."""
def test_is_http_with_url(self):
from tools.mcp_tool import MCPServerTask
server = MCPServerTask("remote")
server._config = {"url": "https://example.com/mcp"}
assert server._is_http() is True
def test_is_stdio_with_command(self):
from tools.mcp_tool import MCPServerTask
server = MCPServerTask("local")
server._config = {"command": "npx", "args": []}
assert server._is_http() is False
def test_conflicting_url_and_command_warns(self):
"""Config with both url and command logs a warning and uses HTTP."""
from tools.mcp_tool import MCPServerTask
server = MCPServerTask("conflict")
config = {"url": "https://example.com/mcp", "command": "npx", "args": []}
# url takes precedence
server._config = config
assert server._is_http() is True
def test_http_unavailable_raises(self):
from tools.mcp_tool import MCPServerTask
server = MCPServerTask("remote")
config = {"url": "https://example.com/mcp"}
async def _test():
with patch("tools.mcp_tool._MCP_HTTP_AVAILABLE", False):
with pytest.raises(ImportError, match="HTTP transport"):
await server._run_http(config)
asyncio.run(_test())
# ---------------------------------------------------------------------------
# Reconnection logic
# ---------------------------------------------------------------------------
class TestReconnection:
"""Tests for automatic reconnection behavior in MCPServerTask.run()."""
def test_reconnect_on_disconnect(self):
"""After initial success, a connection drop triggers reconnection."""
from tools.mcp_tool import MCPServerTask
run_count = 0
target_server = None
original_run_stdio = MCPServerTask._run_stdio
async def patched_run_stdio(self_srv, config):
nonlocal run_count, target_server
run_count += 1
if target_server is not self_srv:
return await original_run_stdio(self_srv, config)
if run_count == 1:
# First connection succeeds, then simulate disconnect
self_srv.session = MagicMock()
self_srv._tools = []
self_srv._ready.set()
raise ConnectionError("connection dropped")
else:
# Reconnection succeeds; signal shutdown so run() exits
self_srv.session = MagicMock()
self_srv._shutdown_event.set()
await self_srv._shutdown_event.wait()
async def _test():
nonlocal target_server
server = MCPServerTask("test_srv")
target_server = server
with patch.object(MCPServerTask, "_run_stdio", patched_run_stdio), \
patch("asyncio.sleep", new_callable=AsyncMock):
await server.run({"command": "test"})
assert run_count >= 2 # At least one reconnection attempt
asyncio.run(_test())
def test_no_reconnect_on_shutdown(self):
"""If shutdown is requested, don't attempt reconnection."""
from tools.mcp_tool import MCPServerTask
run_count = 0
target_server = None
original_run_stdio = MCPServerTask._run_stdio
async def patched_run_stdio(self_srv, config):
nonlocal run_count, target_server
run_count += 1
if target_server is not self_srv:
return await original_run_stdio(self_srv, config)
self_srv.session = MagicMock()
self_srv._tools = []
self_srv._ready.set()
raise ConnectionError("connection dropped")
async def _test():
nonlocal target_server
server = MCPServerTask("test_srv")
target_server = server
server._shutdown_event.set() # Shutdown already requested
with patch.object(MCPServerTask, "_run_stdio", patched_run_stdio), \
patch("asyncio.sleep", new_callable=AsyncMock):
await server.run({"command": "test"})
# Should not retry because shutdown was set
assert run_count == 1
asyncio.run(_test())
def test_no_reconnect_on_initial_failure(self):
"""First connection failure reports error immediately, no retry."""
from tools.mcp_tool import MCPServerTask
run_count = 0
target_server = None
original_run_stdio = MCPServerTask._run_stdio
async def patched_run_stdio(self_srv, config):
nonlocal run_count, target_server
run_count += 1
if target_server is not self_srv:
return await original_run_stdio(self_srv, config)
raise ConnectionError("cannot connect")
async def _test():
nonlocal target_server
server = MCPServerTask("test_srv")
target_server = server
with patch.object(MCPServerTask, "_run_stdio", patched_run_stdio), \
patch("asyncio.sleep", new_callable=AsyncMock):
await server.run({"command": "test"})
# Only one attempt, no retry on initial failure
assert run_count == 1
assert server._error is not None
assert "cannot connect" in str(server._error)
asyncio.run(_test())
# ---------------------------------------------------------------------------
# Configurable timeouts
# ---------------------------------------------------------------------------
class TestConfigurableTimeouts:
"""Tests for configurable per-server timeouts."""
def test_default_timeout(self):
"""Server with no timeout config gets _DEFAULT_TOOL_TIMEOUT."""
from tools.mcp_tool import MCPServerTask, _DEFAULT_TOOL_TIMEOUT
server = MCPServerTask("test_srv")
assert server.tool_timeout == _DEFAULT_TOOL_TIMEOUT
assert server.tool_timeout == 120
def test_custom_timeout(self):
"""Server with timeout=180 in config gets 180."""
from tools.mcp_tool import MCPServerTask
target_server = None
original_run_stdio = MCPServerTask._run_stdio
async def patched_run_stdio(self_srv, config):
if target_server is not self_srv:
return await original_run_stdio(self_srv, config)
self_srv.session = MagicMock()
self_srv._tools = []
self_srv._ready.set()
await self_srv._shutdown_event.wait()
async def _test():
nonlocal target_server
server = MCPServerTask("test_srv")
target_server = server
with patch.object(MCPServerTask, "_run_stdio", patched_run_stdio):
task = asyncio.ensure_future(
server.run({"command": "test", "timeout": 180})
)
await server._ready.wait()
assert server.tool_timeout == 180
server._shutdown_event.set()
await task
asyncio.run(_test())
def test_timeout_passed_to_handler(self):
"""The tool handler uses the server's configured timeout."""
from tools.mcp_tool import _make_tool_handler, _servers, MCPServerTask
mock_session = MagicMock()
mock_session.call_tool = AsyncMock(
return_value=_make_call_result("ok", is_error=False)
)
server = _make_mock_server("test_srv", session=mock_session)
server.tool_timeout = 180
_servers["test_srv"] = server
try:
handler = _make_tool_handler("test_srv", "my_tool", 180)
with patch("tools.mcp_tool._run_on_mcp_loop") as mock_run:
mock_run.return_value = json.dumps({"result": "ok"})
handler({})
# Verify timeout=180 was passed
call_kwargs = mock_run.call_args
assert call_kwargs.kwargs.get("timeout") == 180 or \
(len(call_kwargs.args) > 1 and call_kwargs.args[1] == 180) or \
call_kwargs[1].get("timeout") == 180
finally:
_servers.pop("test_srv", None)
# ---------------------------------------------------------------------------
# Utility tool schemas (Resources & Prompts)
# ---------------------------------------------------------------------------
class TestUtilitySchemas:
"""Tests for _build_utility_schemas() and the schema format of utility tools."""
def test_builds_four_utility_schemas(self):
from tools.mcp_tool import _build_utility_schemas
schemas = _build_utility_schemas("myserver")
assert len(schemas) == 4
names = [s["schema"]["name"] for s in schemas]
assert "mcp_myserver_list_resources" in names
assert "mcp_myserver_read_resource" in names
assert "mcp_myserver_list_prompts" in names
assert "mcp_myserver_get_prompt" in names
def test_hyphens_sanitized_in_utility_names(self):
from tools.mcp_tool import _build_utility_schemas
schemas = _build_utility_schemas("my-server")
names = [s["schema"]["name"] for s in schemas]
for name in names:
assert "-" not in name
assert "mcp_my_server_list_resources" in names
def test_list_resources_schema_no_required_params(self):
from tools.mcp_tool import _build_utility_schemas
schemas = _build_utility_schemas("srv")
lr = next(s for s in schemas if s["handler_key"] == "list_resources")
params = lr["schema"]["parameters"]
assert params["type"] == "object"
assert params["properties"] == {}
assert "required" not in params
def test_read_resource_schema_requires_uri(self):
from tools.mcp_tool import _build_utility_schemas
schemas = _build_utility_schemas("srv")
rr = next(s for s in schemas if s["handler_key"] == "read_resource")
params = rr["schema"]["parameters"]
assert "uri" in params["properties"]
assert params["properties"]["uri"]["type"] == "string"
assert params["required"] == ["uri"]
def test_list_prompts_schema_no_required_params(self):
from tools.mcp_tool import _build_utility_schemas
schemas = _build_utility_schemas("srv")
lp = next(s for s in schemas if s["handler_key"] == "list_prompts")
params = lp["schema"]["parameters"]
assert params["type"] == "object"
assert params["properties"] == {}
assert "required" not in params
def test_get_prompt_schema_requires_name(self):
from tools.mcp_tool import _build_utility_schemas
schemas = _build_utility_schemas("srv")
gp = next(s for s in schemas if s["handler_key"] == "get_prompt")
params = gp["schema"]["parameters"]
assert "name" in params["properties"]
assert params["properties"]["name"]["type"] == "string"
assert "arguments" in params["properties"]
assert params["properties"]["arguments"]["type"] == "object"
assert params["required"] == ["name"]
def test_schemas_have_descriptions(self):
from tools.mcp_tool import _build_utility_schemas
schemas = _build_utility_schemas("test_srv")
for entry in schemas:
desc = entry["schema"]["description"]
assert desc and len(desc) > 0
assert "test_srv" in desc
# ---------------------------------------------------------------------------
# Utility tool handlers (Resources & Prompts)
# ---------------------------------------------------------------------------
class TestUtilityHandlers:
"""Tests for the MCP Resources & Prompts handler functions."""
def _patch_mcp_loop(self):
"""Return a patch for _run_on_mcp_loop that runs the coroutine directly."""
def fake_run(coro, timeout=30):
loop = asyncio.new_event_loop()
try:
return loop.run_until_complete(coro)
finally:
loop.close()
return patch("tools.mcp_tool._run_on_mcp_loop", side_effect=fake_run)
# -- list_resources --
def test_list_resources_success(self):
from tools.mcp_tool import _make_list_resources_handler, _servers
mock_resource = SimpleNamespace(
uri="file:///tmp/test.txt", name="test.txt",
description="A test file", mimeType="text/plain",
)
mock_session = MagicMock()
mock_session.list_resources = AsyncMock(
return_value=SimpleNamespace(resources=[mock_resource])
)
server = _make_mock_server("srv", session=mock_session)
_servers["srv"] = server
try:
handler = _make_list_resources_handler("srv", 120)
with self._patch_mcp_loop():
result = json.loads(handler({}))
assert "resources" in result
assert len(result["resources"]) == 1
assert result["resources"][0]["uri"] == "file:///tmp/test.txt"
assert result["resources"][0]["name"] == "test.txt"
finally:
_servers.pop("srv", None)
def test_list_resources_empty(self):
from tools.mcp_tool import _make_list_resources_handler, _servers
mock_session = MagicMock()
mock_session.list_resources = AsyncMock(
return_value=SimpleNamespace(resources=[])
)
server = _make_mock_server("srv", session=mock_session)
_servers["srv"] = server
try:
handler = _make_list_resources_handler("srv", 120)
with self._patch_mcp_loop():
result = json.loads(handler({}))
assert result["resources"] == []
finally:
_servers.pop("srv", None)
def test_list_resources_disconnected(self):
from tools.mcp_tool import _make_list_resources_handler, _servers
_servers.pop("ghost", None)
handler = _make_list_resources_handler("ghost", 120)
result = json.loads(handler({}))
assert "error" in result
assert "not connected" in result["error"]
# -- read_resource --
def test_read_resource_success(self):
from tools.mcp_tool import _make_read_resource_handler, _servers
content_block = SimpleNamespace(text="Hello from resource")
mock_session = MagicMock()
mock_session.read_resource = AsyncMock(
return_value=SimpleNamespace(contents=[content_block])
)
server = _make_mock_server("srv", session=mock_session)
_servers["srv"] = server
try:
handler = _make_read_resource_handler("srv", 120)
with self._patch_mcp_loop():
result = json.loads(handler({"uri": "file:///tmp/test.txt"}))
assert result["result"] == "Hello from resource"
mock_session.read_resource.assert_called_once_with("file:///tmp/test.txt")
finally:
_servers.pop("srv", None)
def test_read_resource_missing_uri(self):
from tools.mcp_tool import _make_read_resource_handler, _servers
server = _make_mock_server("srv", session=MagicMock())
_servers["srv"] = server
try:
handler = _make_read_resource_handler("srv", 120)
result = json.loads(handler({}))
assert "error" in result
assert "uri" in result["error"].lower()
finally:
_servers.pop("srv", None)
def test_read_resource_disconnected(self):
from tools.mcp_tool import _make_read_resource_handler, _servers
_servers.pop("ghost", None)
handler = _make_read_resource_handler("ghost", 120)
result = json.loads(handler({"uri": "test://x"}))
assert "error" in result
assert "not connected" in result["error"]
# -- list_prompts --
def test_list_prompts_success(self):
from tools.mcp_tool import _make_list_prompts_handler, _servers
mock_prompt = SimpleNamespace(
name="summarize", description="Summarize text",
arguments=[
SimpleNamespace(name="text", description="Text to summarize", required=True),
],
)
mock_session = MagicMock()
mock_session.list_prompts = AsyncMock(
return_value=SimpleNamespace(prompts=[mock_prompt])
)
server = _make_mock_server("srv", session=mock_session)
_servers["srv"] = server
try:
handler = _make_list_prompts_handler("srv", 120)
with self._patch_mcp_loop():
result = json.loads(handler({}))
assert "prompts" in result
assert len(result["prompts"]) == 1
assert result["prompts"][0]["name"] == "summarize"
assert result["prompts"][0]["arguments"][0]["name"] == "text"
finally:
_servers.pop("srv", None)
def test_list_prompts_empty(self):
from tools.mcp_tool import _make_list_prompts_handler, _servers
mock_session = MagicMock()
mock_session.list_prompts = AsyncMock(
return_value=SimpleNamespace(prompts=[])
)
server = _make_mock_server("srv", session=mock_session)
_servers["srv"] = server
try:
handler = _make_list_prompts_handler("srv", 120)
with self._patch_mcp_loop():
result = json.loads(handler({}))
assert result["prompts"] == []
finally:
_servers.pop("srv", None)
def test_list_prompts_disconnected(self):
from tools.mcp_tool import _make_list_prompts_handler, _servers
_servers.pop("ghost", None)
handler = _make_list_prompts_handler("ghost", 120)
result = json.loads(handler({}))
assert "error" in result
assert "not connected" in result["error"]
# -- get_prompt --
def test_get_prompt_success(self):
from tools.mcp_tool import _make_get_prompt_handler, _servers
mock_msg = SimpleNamespace(
role="assistant",
content=SimpleNamespace(text="Here is a summary of your text."),
)
mock_session = MagicMock()
mock_session.get_prompt = AsyncMock(
return_value=SimpleNamespace(messages=[mock_msg], description=None)
)
server = _make_mock_server("srv", session=mock_session)
_servers["srv"] = server
try:
handler = _make_get_prompt_handler("srv", 120)
with self._patch_mcp_loop():
result = json.loads(handler({"name": "summarize", "arguments": {"text": "hello"}}))
assert "messages" in result
assert len(result["messages"]) == 1
assert result["messages"][0]["role"] == "assistant"
assert "summary" in result["messages"][0]["content"].lower()
mock_session.get_prompt.assert_called_once_with(
"summarize", arguments={"text": "hello"}
)
finally:
_servers.pop("srv", None)
def test_get_prompt_missing_name(self):
from tools.mcp_tool import _make_get_prompt_handler, _servers
server = _make_mock_server("srv", session=MagicMock())
_servers["srv"] = server
try:
handler = _make_get_prompt_handler("srv", 120)
result = json.loads(handler({}))
assert "error" in result
assert "name" in result["error"].lower()
finally:
_servers.pop("srv", None)
def test_get_prompt_disconnected(self):
from tools.mcp_tool import _make_get_prompt_handler, _servers
_servers.pop("ghost", None)
handler = _make_get_prompt_handler("ghost", 120)
result = json.loads(handler({"name": "test"}))
assert "error" in result
assert "not connected" in result["error"]
def test_get_prompt_default_arguments(self):
from tools.mcp_tool import _make_get_prompt_handler, _servers
mock_session = MagicMock()
mock_session.get_prompt = AsyncMock(
return_value=SimpleNamespace(messages=[], description=None)
)
server = _make_mock_server("srv", session=mock_session)
_servers["srv"] = server
try:
handler = _make_get_prompt_handler("srv", 120)
with self._patch_mcp_loop():
handler({"name": "test_prompt"})
# arguments defaults to {} when not provided
mock_session.get_prompt.assert_called_once_with(
"test_prompt", arguments={}
)
finally:
_servers.pop("srv", None)
# ---------------------------------------------------------------------------
# Utility tools registration in _discover_and_register_server
# ---------------------------------------------------------------------------
class TestUtilityToolRegistration:
"""Verify utility tools are registered alongside regular MCP tools."""
def test_utility_tools_registered(self):
"""_discover_and_register_server registers all 4 utility tools."""
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
mock_registry = ToolRegistry()
mock_tools = [_make_mcp_tool("read_file", "Read a file")]
mock_session = MagicMock()
async def fake_connect(name, config):
server = MCPServerTask(name)
server.session = mock_session
server._tools = mock_tools
return server
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.registry.registry", mock_registry):
registered = asyncio.run(
_discover_and_register_server("fs", {"command": "npx", "args": []})
)
# Regular tool + 4 utility tools
assert "mcp_fs_read_file" in registered
assert "mcp_fs_list_resources" in registered
assert "mcp_fs_read_resource" in registered
assert "mcp_fs_list_prompts" in registered
assert "mcp_fs_get_prompt" in registered
assert len(registered) == 5
# All in the registry
all_names = mock_registry.get_all_tool_names()
for name in registered:
assert name in all_names
_servers.pop("fs", None)
def test_utility_tools_in_same_toolset(self):
"""Utility tools belong to the same mcp-{server} toolset."""
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
mock_registry = ToolRegistry()
mock_session = MagicMock()
async def fake_connect(name, config):
server = MCPServerTask(name)
server.session = mock_session
server._tools = []
return server
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.registry.registry", mock_registry):
asyncio.run(
_discover_and_register_server("myserv", {"command": "test"})
)
# Check that utility tools are in the right toolset
for tool_name in ["mcp_myserv_list_resources", "mcp_myserv_read_resource",
"mcp_myserv_list_prompts", "mcp_myserv_get_prompt"]:
entry = mock_registry._tools.get(tool_name)
assert entry is not None, f"{tool_name} not found in registry"
assert entry.toolset == "mcp-myserv"
_servers.pop("myserv", None)
def test_utility_tools_have_check_fn(self):
"""Utility tools have a working check_fn."""
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
mock_registry = ToolRegistry()
mock_session = MagicMock()
async def fake_connect(name, config):
server = MCPServerTask(name)
server.session = mock_session
server._tools = []
return server
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.registry.registry", mock_registry):
asyncio.run(
_discover_and_register_server("chk", {"command": "test"})
)
entry = mock_registry._tools.get("mcp_chk_list_resources")
assert entry is not None
# Server is connected, check_fn should return True
assert entry.check_fn() is True
# Disconnect the server
_servers["chk"].session = None
assert entry.check_fn() is False
_servers.pop("chk", None)
# ===========================================================================
# SamplingHandler tests
# ===========================================================================
import math
import time
from mcp.types import (
CreateMessageResult,
CreateMessageResultWithTools,
ErrorData,
SamplingCapability,
SamplingToolsCapability,
TextContent,
ToolUseContent,
)
from tools.mcp_tool import SamplingHandler, _safe_numeric
# ---------------------------------------------------------------------------
# Helpers for sampling tests
# ---------------------------------------------------------------------------
def _make_sampling_params(
messages=None,
max_tokens=100,
system_prompt=None,
model_preferences=None,
temperature=None,
stop_sequences=None,
tools=None,
tool_choice=None,
):
"""Create a fake CreateMessageRequestParams using SimpleNamespace.
Each message must have a ``content_as_list`` attribute that mirrors
the SDK helper so that ``_convert_messages`` works correctly.
"""
if messages is None:
content = SimpleNamespace(text="Hello")
msg = SimpleNamespace(role="user", content=content, content_as_list=[content])
messages = [msg]
params = SimpleNamespace(
messages=messages,
maxTokens=max_tokens,
modelPreferences=model_preferences,
temperature=temperature,
stopSequences=stop_sequences,
tools=tools,
toolChoice=tool_choice,
)
if system_prompt is not None:
params.systemPrompt = system_prompt
return params
def _make_llm_response(
content="LLM response",
model="test-model",
finish_reason="stop",
tool_calls=None,
):
"""Create a fake OpenAI chat completion response (text)."""
message = SimpleNamespace(content=content, tool_calls=tool_calls)
choice = SimpleNamespace(
finish_reason=finish_reason,
message=message,
)
usage = SimpleNamespace(total_tokens=42)
return SimpleNamespace(choices=[choice], model=model, usage=usage)
def _make_llm_tool_response(tool_calls_data=None, model="test-model"):
"""Create a fake response with tool_calls.
``tool_calls_data``: list of (id, name, arguments_json) tuples.
"""
if tool_calls_data is None:
tool_calls_data = [("call_1", "get_weather", '{"city": "London"}')]
tc_list = [
SimpleNamespace(
id=tc_id,
function=SimpleNamespace(name=name, arguments=args),
)
for tc_id, name, args in tool_calls_data
]
return _make_llm_response(
content=None,
model=model,
finish_reason="tool_calls",
tool_calls=tc_list,
)
# ---------------------------------------------------------------------------
# 1. _safe_numeric helper
# ---------------------------------------------------------------------------
class TestSafeNumeric:
def test_int_passthrough(self):
assert _safe_numeric(10, 5, int) == 10
def test_string_coercion(self):
assert _safe_numeric("20", 5, int) == 20
def test_none_returns_default(self):
assert _safe_numeric(None, 7, int) == 7
def test_inf_returns_default(self):
assert _safe_numeric(float("inf"), 3.0, float) == 3.0
def test_nan_returns_default(self):
assert _safe_numeric(float("nan"), 4.0, float) == 4.0
def test_below_minimum_clamps(self):
assert _safe_numeric(-5, 10, int, minimum=1) == 1
def test_minimum_zero_allowed(self):
assert _safe_numeric(0, 10, int, minimum=0) == 0
def test_non_numeric_string_returns_default(self):
assert _safe_numeric("abc", 42, int) == 42
def test_float_coercion(self):
assert _safe_numeric("3.5", 1.0, float) == 3.5
# ---------------------------------------------------------------------------
# 2. SamplingHandler initialization and config parsing
# ---------------------------------------------------------------------------
class TestSamplingHandlerInit:
def test_defaults(self):
h = SamplingHandler("srv", {})
assert h.server_name == "srv"
assert h.max_rpm == 10
assert h.timeout == 30
assert h.max_tokens_cap == 4096
assert h.max_tool_rounds == 5
assert h.model_override is None
assert h.allowed_models == []
assert h.metrics == {"requests": 0, "errors": 0, "tokens_used": 0, "tool_use_count": 0}
def test_custom_config(self):
cfg = {
"max_rpm": 20,
"timeout": 60,
"max_tokens_cap": 2048,
"max_tool_rounds": 3,
"model": "gpt-4o",
"allowed_models": ["gpt-4o", "gpt-3.5-turbo"],
"log_level": "debug",
}
h = SamplingHandler("custom", cfg)
assert h.max_rpm == 20
assert h.timeout == 60.0
assert h.max_tokens_cap == 2048
assert h.max_tool_rounds == 3
assert h.model_override == "gpt-4o"
assert h.allowed_models == ["gpt-4o", "gpt-3.5-turbo"]
def test_string_numeric_config_values(self):
"""YAML sometimes delivers numeric values as strings."""
cfg = {"max_rpm": "15", "timeout": "45.5", "max_tokens_cap": "1024"}
h = SamplingHandler("s", cfg)
assert h.max_rpm == 15
assert h.timeout == 45.5
assert h.max_tokens_cap == 1024
# ---------------------------------------------------------------------------
# 3. Rate limiting
# ---------------------------------------------------------------------------
class TestRateLimit:
def setup_method(self):
self.handler = SamplingHandler("rl", {"max_rpm": 3})
def test_allows_under_limit(self):
assert self.handler._check_rate_limit() is True
assert self.handler._check_rate_limit() is True
assert self.handler._check_rate_limit() is True
def test_rejects_over_limit(self):
for _ in range(3):
self.handler._check_rate_limit()
assert self.handler._check_rate_limit() is False
def test_window_expiry(self):
"""Old timestamps should be purged from the sliding window."""
for _ in range(3):
self.handler._check_rate_limit()
# Simulate timestamps from 61 seconds ago
self.handler._rate_timestamps[:] = [time.time() - 61] * 3
assert self.handler._check_rate_limit() is True
# ---------------------------------------------------------------------------
# 4. Model resolution
# ---------------------------------------------------------------------------
class TestResolveModel:
def setup_method(self):
self.handler = SamplingHandler("mr", {})
def test_no_preference_no_override(self):
assert self.handler._resolve_model(None) is None
def test_config_override_wins(self):
self.handler.model_override = "override-model"
prefs = SimpleNamespace(hints=[SimpleNamespace(name="hint-model")])
assert self.handler._resolve_model(prefs) == "override-model"
def test_hint_used_when_no_override(self):
prefs = SimpleNamespace(hints=[SimpleNamespace(name="hint-model")])
assert self.handler._resolve_model(prefs) == "hint-model"
def test_empty_hints(self):
prefs = SimpleNamespace(hints=[])
assert self.handler._resolve_model(prefs) is None
def test_hint_without_name(self):
prefs = SimpleNamespace(hints=[SimpleNamespace(name=None)])
assert self.handler._resolve_model(prefs) is None
# ---------------------------------------------------------------------------
# 5. Message conversion
# ---------------------------------------------------------------------------
class TestConvertMessages:
def setup_method(self):
self.handler = SamplingHandler("mc", {})
def test_single_text_message(self):
content = SimpleNamespace(text="Hello world")
msg = SimpleNamespace(role="user", content=content, content_as_list=[content])
params = _make_sampling_params(messages=[msg])
result = self.handler._convert_messages(params)
assert len(result) == 1
assert result[0] == {"role": "user", "content": "Hello world"}
def test_image_message(self):
text_block = SimpleNamespace(text="Look at this")
img_block = SimpleNamespace(data="abc123", mimeType="image/png")
msg = SimpleNamespace(
role="user",
content=[text_block, img_block],
content_as_list=[text_block, img_block],
)
params = _make_sampling_params(messages=[msg])
result = self.handler._convert_messages(params)
assert len(result) == 1
parts = result[0]["content"]
assert len(parts) == 2
assert parts[0] == {"type": "text", "text": "Look at this"}
assert parts[1]["type"] == "image_url"
assert "data:image/png;base64,abc123" in parts[1]["image_url"]["url"]
def test_tool_result_message(self):
inner = SimpleNamespace(text="42 degrees")
tr_block = SimpleNamespace(toolUseId="call_1", content=[inner])
msg = SimpleNamespace(
role="user",
content=[tr_block],
content_as_list=[tr_block],
)
params = _make_sampling_params(messages=[msg])
result = self.handler._convert_messages(params)
assert len(result) == 1
assert result[0]["role"] == "tool"
assert result[0]["tool_call_id"] == "call_1"
assert result[0]["content"] == "42 degrees"
def test_tool_use_message(self):
tu_block = SimpleNamespace(
id="call_2", name="get_weather", input={"city": "London"}
)
msg = SimpleNamespace(
role="assistant",
content=[tu_block],
content_as_list=[tu_block],
)
params = _make_sampling_params(messages=[msg])
result = self.handler._convert_messages(params)
assert len(result) == 1
assert result[0]["role"] == "assistant"
assert len(result[0]["tool_calls"]) == 1
assert result[0]["tool_calls"][0]["function"]["name"] == "get_weather"
assert json.loads(result[0]["tool_calls"][0]["function"]["arguments"]) == {"city": "London"}
def test_mixed_text_and_tool_use(self):
"""Assistant message with both text and tool_calls."""
text_block = SimpleNamespace(text="Let me check the weather")
tu_block = SimpleNamespace(
id="call_3", name="get_weather", input={"city": "Paris"}
)
msg = SimpleNamespace(
role="assistant",
content=[text_block, tu_block],
content_as_list=[text_block, tu_block],
)
params = _make_sampling_params(messages=[msg])
result = self.handler._convert_messages(params)
assert len(result) == 1
assert result[0]["content"] == "Let me check the weather"
assert len(result[0]["tool_calls"]) == 1
def test_fallback_without_content_as_list(self):
"""When content_as_list is absent, falls back to content."""
content = SimpleNamespace(text="Fallback text")
msg = SimpleNamespace(role="user", content=content)
params = _make_sampling_params(messages=[msg])
result = self.handler._convert_messages(params)
assert len(result) == 1
assert result[0]["content"] == "Fallback text"
# ---------------------------------------------------------------------------
# 6. Text-only sampling callback (full flow)
# ---------------------------------------------------------------------------
class TestSamplingCallbackText:
def setup_method(self):
self.handler = SamplingHandler("txt", {})
def test_text_response(self):
"""Full flow: text response returns CreateMessageResult."""
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_response(
content="Hello from LLM"
)
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
params = _make_sampling_params()
result = asyncio.run(self.handler(None, params))
assert isinstance(result, CreateMessageResult)
assert isinstance(result.content, TextContent)
assert result.content.text == "Hello from LLM"
assert result.model == "test-model"
assert result.role == "assistant"
assert result.stopReason == "endTurn"
def test_system_prompt_prepended(self):
"""System prompt is inserted as the first message."""
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_response()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
) as mock_call:
params = _make_sampling_params(system_prompt="Be helpful")
asyncio.run(self.handler(None, params))
call_args = mock_call.call_args
messages = call_args.kwargs["messages"]
assert messages[0] == {"role": "system", "content": "Be helpful"}
def test_server_tools_with_object_schema_are_normalized(self):
"""Server-provided tools should gain empty properties for object schemas."""
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_response()
server_tool = SimpleNamespace(
name="ask",
description="Ask Crawl4AI",
inputSchema={"type": "object"},
)
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
) as mock_call:
params = _make_sampling_params(tools=[server_tool])
asyncio.run(self.handler(None, params))
tools = mock_call.call_args.kwargs["tools"]
assert tools == [{
"type": "function",
"function": {
"name": "ask",
"description": "Ask Crawl4AI",
"parameters": {"type": "object", "properties": {}},
},
}]
def test_length_stop_reason(self):
"""finish_reason='length' maps to stopReason='maxTokens'."""
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_response(
finish_reason="length"
)
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
params = _make_sampling_params()
result = asyncio.run(self.handler(None, params))
assert isinstance(result, CreateMessageResult)
assert result.stopReason == "maxTokens"
# ---------------------------------------------------------------------------
# 7. Tool use sampling callback
# ---------------------------------------------------------------------------
class TestSamplingCallbackToolUse:
def setup_method(self):
self.handler = SamplingHandler("tu", {})
def test_tool_use_response(self):
"""LLM tool_calls response returns CreateMessageResultWithTools."""
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_tool_response()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
params = _make_sampling_params()
result = asyncio.run(self.handler(None, params))
assert isinstance(result, CreateMessageResultWithTools)
assert result.stopReason == "toolUse"
assert result.model == "test-model"
assert len(result.content) == 1
tc = result.content[0]
assert isinstance(tc, ToolUseContent)
assert tc.name == "get_weather"
assert tc.id == "call_1"
assert tc.input == {"city": "London"}
def test_multiple_tool_calls(self):
"""Multiple tool_calls in a single response."""
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_tool_response(
tool_calls_data=[
("call_a", "func_a", '{"x": 1}'),
("call_b", "func_b", '{"y": 2}'),
]
)
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(self.handler(None, _make_sampling_params()))
assert isinstance(result, CreateMessageResultWithTools)
assert len(result.content) == 2
assert result.content[0].name == "func_a"
assert result.content[1].name == "func_b"
# ---------------------------------------------------------------------------
# 8. Tool loop governance
# ---------------------------------------------------------------------------
class TestToolLoopGovernance:
def test_max_tool_rounds_enforcement(self):
"""After max_tool_rounds consecutive tool responses, an error is returned."""
handler = SamplingHandler("tl", {"max_tool_rounds": 2})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_tool_response()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
params = _make_sampling_params()
# Round 1, 2: allowed
r1 = asyncio.run(handler(None, params))
assert isinstance(r1, CreateMessageResultWithTools)
r2 = asyncio.run(handler(None, params))
assert isinstance(r2, CreateMessageResultWithTools)
# Round 3: exceeds limit
r3 = asyncio.run(handler(None, params))
assert isinstance(r3, ErrorData)
assert "Tool loop limit exceeded" in r3.message
def test_text_response_resets_counter(self):
"""A text response resets the tool loop counter."""
handler = SamplingHandler("tl2", {"max_tool_rounds": 1})
# Use a list to hold the current response, so the side_effect can
# pick up changes between calls.
responses = [_make_llm_tool_response()]
with patch(
"agent.auxiliary_client.call_llm",
side_effect=lambda **kw: responses[0],
):
# Tool response (round 1 of 1 allowed)
r1 = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(r1, CreateMessageResultWithTools)
# Text response resets counter
responses[0] = _make_llm_response()
r2 = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(r2, CreateMessageResult)
# Tool response again (should succeed since counter was reset)
responses[0] = _make_llm_tool_response()
r3 = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(r3, CreateMessageResultWithTools)
def test_max_tool_rounds_zero_disables(self):
"""max_tool_rounds=0 means tool loops are disabled entirely."""
handler = SamplingHandler("tl3", {"max_tool_rounds": 0})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_tool_response()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, ErrorData)
assert "Tool loops disabled" in result.message
# ---------------------------------------------------------------------------
# 9. Error paths: rate limit, timeout, no provider
# ---------------------------------------------------------------------------
class TestSamplingErrors:
def test_rate_limit_error(self):
handler = SamplingHandler("rle", {"max_rpm": 1})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_response()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
# First call succeeds
r1 = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(r1, CreateMessageResult)
# Second call is rate limited
r2 = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(r2, ErrorData)
assert "rate limit" in r2.message.lower()
assert handler.metrics["errors"] == 1
def test_timeout_error(self):
handler = SamplingHandler("to", {"timeout": 0.05})
def slow_call(**kwargs):
import threading
evt = threading.Event()
evt.wait(5) # blocks for up to 5 seconds (cancelled by timeout)
return _make_llm_response()
with patch(
"agent.auxiliary_client.call_llm",
side_effect=slow_call,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, ErrorData)
assert "timed out" in result.message.lower()
assert handler.metrics["errors"] == 1
def test_no_provider_error(self):
handler = SamplingHandler("np", {})
with patch(
"agent.auxiliary_client.call_llm",
side_effect=RuntimeError("No LLM provider configured"),
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, ErrorData)
assert handler.metrics["errors"] == 1
def test_empty_choices_returns_error(self):
"""LLM returning choices=[] is handled gracefully, not IndexError."""
handler = SamplingHandler("ec", {})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = SimpleNamespace(
choices=[],
model="test-model",
usage=SimpleNamespace(total_tokens=0),
)
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, ErrorData)
assert "empty response" in result.message.lower()
assert handler.metrics["errors"] == 1
def test_none_choices_returns_error(self):
"""LLM returning choices=None is handled gracefully, not TypeError."""
handler = SamplingHandler("nc", {})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = SimpleNamespace(
choices=None,
model="test-model",
usage=SimpleNamespace(total_tokens=0),
)
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, ErrorData)
assert "empty response" in result.message.lower()
assert handler.metrics["errors"] == 1
def test_missing_choices_attr_returns_error(self):
"""LLM response without choices attribute is handled gracefully."""
handler = SamplingHandler("mc", {})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = SimpleNamespace(
model="test-model",
usage=SimpleNamespace(total_tokens=0),
)
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, ErrorData)
assert "empty response" in result.message.lower()
assert handler.metrics["errors"] == 1
# ---------------------------------------------------------------------------
# 10. Model whitelist
# ---------------------------------------------------------------------------
class TestModelWhitelist:
def test_allowed_model_passes(self):
handler = SamplingHandler("wl", {"allowed_models": ["gpt-4o", "test-model"]})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_response()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, CreateMessageResult)
def test_disallowed_model_rejected(self):
handler = SamplingHandler("wl2", {"allowed_models": ["gpt-4o"], "model": "test-model"})
fake_client = MagicMock()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, ErrorData)
assert "not allowed" in result.message
assert handler.metrics["errors"] == 1
def test_empty_whitelist_allows_all(self):
handler = SamplingHandler("wl3", {"allowed_models": []})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_response()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, CreateMessageResult)
# ---------------------------------------------------------------------------
# 11. Malformed tool_call arguments
# ---------------------------------------------------------------------------
class TestMalformedToolCallArgs:
def test_invalid_json_wrapped_as_raw(self):
"""Malformed JSON arguments get wrapped in {"_raw": ...}."""
handler = SamplingHandler("mf", {})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_tool_response(
tool_calls_data=[("call_x", "some_tool", "not valid json {{{")]
)
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, CreateMessageResultWithTools)
tc = result.content[0]
assert isinstance(tc, ToolUseContent)
assert tc.input == {"_raw": "not valid json {{{"}
def test_dict_args_pass_through(self):
"""When arguments are already a dict, they pass through directly."""
handler = SamplingHandler("mf2", {})
# Build a tool call where arguments is already a dict
tc_obj = SimpleNamespace(
id="call_d",
function=SimpleNamespace(name="do_stuff", arguments={"key": "val"}),
)
message = SimpleNamespace(content=None, tool_calls=[tc_obj])
choice = SimpleNamespace(finish_reason="tool_calls", message=message)
usage = SimpleNamespace(total_tokens=10)
response = SimpleNamespace(choices=[choice], model="m", usage=usage)
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = response
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
result = asyncio.run(handler(None, _make_sampling_params()))
assert isinstance(result, CreateMessageResultWithTools)
assert result.content[0].input == {"key": "val"}
# ---------------------------------------------------------------------------
# 12. Metrics tracking
# ---------------------------------------------------------------------------
class TestMetricsTracking:
def test_request_and_token_metrics(self):
handler = SamplingHandler("met", {})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_response()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
asyncio.run(handler(None, _make_sampling_params()))
assert handler.metrics["requests"] == 1
assert handler.metrics["tokens_used"] == 42
assert handler.metrics["errors"] == 0
def test_tool_use_count_metric(self):
handler = SamplingHandler("met2", {})
fake_client = MagicMock()
fake_client.chat.completions.create.return_value = _make_llm_tool_response()
with patch(
"agent.auxiliary_client.call_llm",
return_value=fake_client.chat.completions.create.return_value,
):
asyncio.run(handler(None, _make_sampling_params()))
assert handler.metrics["tool_use_count"] == 1
assert handler.metrics["requests"] == 1
def test_error_metric_incremented(self):
handler = SamplingHandler("met3", {})
with patch(
"agent.auxiliary_client.call_llm",
side_effect=RuntimeError("No LLM provider configured"),
):
asyncio.run(handler(None, _make_sampling_params()))
assert handler.metrics["errors"] == 1
assert handler.metrics["requests"] == 0
# ---------------------------------------------------------------------------
# 13. session_kwargs()
# ---------------------------------------------------------------------------
class TestSessionKwargs:
def test_returns_correct_keys(self):
handler = SamplingHandler("sk", {})
kwargs = handler.session_kwargs()
assert "sampling_callback" in kwargs
assert "sampling_capabilities" in kwargs
assert kwargs["sampling_callback"] is handler
def test_sampling_capabilities_type(self):
handler = SamplingHandler("sk2", {})
kwargs = handler.session_kwargs()
cap = kwargs["sampling_capabilities"]
assert isinstance(cap, SamplingCapability)
assert isinstance(cap.tools, SamplingToolsCapability)
# ---------------------------------------------------------------------------
# 14. MCPServerTask integration
# ---------------------------------------------------------------------------
class TestMCPServerTaskSamplingIntegration:
def test_sampling_handler_created_when_enabled(self):
"""MCPServerTask.run() creates a SamplingHandler when sampling is enabled."""
from tools.mcp_tool import MCPServerTask, _MCP_SAMPLING_TYPES
server = MCPServerTask("int_test")
config = {
"command": "fake",
"sampling": {"enabled": True, "max_rpm": 5},
}
# We only need to test the setup logic, not the actual connection.
# Calling run() would attempt a real connection, so we test the
# sampling setup portion directly.
server._config = config
sampling_config = config.get("sampling", {})
if sampling_config.get("enabled", True) and _MCP_SAMPLING_TYPES:
server._sampling = SamplingHandler(server.name, sampling_config)
else:
server._sampling = None
assert server._sampling is not None
assert isinstance(server._sampling, SamplingHandler)
assert server._sampling.server_name == "int_test"
assert server._sampling.max_rpm == 5
def test_sampling_handler_none_when_disabled(self):
"""MCPServerTask._sampling is None when sampling is disabled."""
from tools.mcp_tool import MCPServerTask, _MCP_SAMPLING_TYPES
server = MCPServerTask("int_test2")
config = {
"command": "fake",
"sampling": {"enabled": False},
}
server._config = config
sampling_config = config.get("sampling", {})
if sampling_config.get("enabled", True) and _MCP_SAMPLING_TYPES:
server._sampling = SamplingHandler(server.name, sampling_config)
else:
server._sampling = None
assert server._sampling is None
def test_session_kwargs_used_in_stdio(self):
"""When sampling is set, session_kwargs() are passed to ClientSession."""
from tools.mcp_tool import MCPServerTask
server = MCPServerTask("sk_test")
server._sampling = SamplingHandler("sk_test", {"max_rpm": 7})
kwargs = server._sampling.session_kwargs()
assert "sampling_callback" in kwargs
assert "sampling_capabilities" in kwargs
# ---------------------------------------------------------------------------
# Discovery failed_count tracking
# ---------------------------------------------------------------------------
class TestDiscoveryFailedCount:
"""Verify discover_mcp_tools() correctly tracks failed server connections."""
def test_failed_server_increments_failed_count(self):
"""When _discover_and_register_server raises, failed_count increments."""
from tools.mcp_tool import discover_mcp_tools, _servers, _ensure_mcp_loop
fake_config = {
"good_server": {"command": "npx", "args": ["good"]},
"bad_server": {"command": "npx", "args": ["bad"]},
}
async def fake_register(name, cfg):
if name == "bad_server":
raise ConnectionError("Connection refused")
# Simulate successful registration
from tools.mcp_tool import MCPServerTask
server = MCPServerTask(name)
server.session = MagicMock()
server._tools = [_make_mcp_tool("tool_a")]
_servers[name] = server
return [f"mcp_{name}_tool_a"]
with patch("tools.mcp_tool._load_mcp_config", return_value=fake_config), \
patch("tools.mcp_tool._discover_and_register_server", side_effect=fake_register), \
patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._existing_tool_names", return_value=["mcp_good_server_tool_a"]):
_ensure_mcp_loop()
# Capture the logger to verify failed_count in summary
with patch("tools.mcp_tool.logger") as mock_logger:
discover_mcp_tools()
# Find the summary info call
info_calls = [
str(call)
for call in mock_logger.info.call_args_list
if "failed" in str(call).lower() or "MCP:" in str(call)
]
# The summary should mention the failure
assert any("1 failed" in str(c) for c in info_calls), (
f"Summary should report 1 failed server, got: {info_calls}"
)
_servers.pop("good_server", None)
_servers.pop("bad_server", None)
def test_all_servers_fail_still_prints_summary(self):
"""When all servers fail, a summary with failure count is still printed."""
from tools.mcp_tool import discover_mcp_tools, _servers, _ensure_mcp_loop
fake_config = {
"srv1": {"command": "npx", "args": ["a"]},
"srv2": {"command": "npx", "args": ["b"]},
}
async def always_fail(name, cfg):
raise ConnectionError(f"Server {name} refused")
with patch("tools.mcp_tool._load_mcp_config", return_value=fake_config), \
patch("tools.mcp_tool._discover_and_register_server", side_effect=always_fail), \
patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._existing_tool_names", return_value=[]):
_ensure_mcp_loop()
with patch("tools.mcp_tool.logger") as mock_logger:
discover_mcp_tools()
# Summary must be printed even when all servers fail
info_calls = [str(call) for call in mock_logger.info.call_args_list]
assert any("2 failed" in str(c) for c in info_calls), (
f"Summary should report 2 failed servers, got: {info_calls}"
)
_servers.pop("srv1", None)
_servers.pop("srv2", None)
def test_ok_servers_excludes_failures(self):
"""ok_servers count correctly excludes failed servers."""
from tools.mcp_tool import discover_mcp_tools, _servers, _ensure_mcp_loop
fake_config = {
"ok1": {"command": "npx", "args": ["ok1"]},
"ok2": {"command": "npx", "args": ["ok2"]},
"fail1": {"command": "npx", "args": ["fail"]},
}
async def selective_register(name, cfg):
if name == "fail1":
raise ConnectionError("Refused")
from tools.mcp_tool import MCPServerTask
server = MCPServerTask(name)
server.session = MagicMock()
server._tools = [_make_mcp_tool("t")]
_servers[name] = server
return [f"mcp_{name}_t"]
with patch("tools.mcp_tool._load_mcp_config", return_value=fake_config), \
patch("tools.mcp_tool._discover_and_register_server", side_effect=selective_register), \
patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._existing_tool_names", return_value=["mcp_ok1_t", "mcp_ok2_t"]):
_ensure_mcp_loop()
with patch("tools.mcp_tool.logger") as mock_logger:
discover_mcp_tools()
info_calls = [str(call) for call in mock_logger.info.call_args_list]
# Should say "2 server(s)" not "3 server(s)"
assert any("2 server" in str(c) for c in info_calls), (
f"Summary should report 2 ok servers, got: {info_calls}"
)
assert any("1 failed" in str(c) for c in info_calls), (
f"Summary should report 1 failed, got: {info_calls}"
)
_servers.pop("ok1", None)
_servers.pop("ok2", None)
_servers.pop("fail1", None)
class TestMCPSelectiveToolLoading:
"""Tests for per-server MCP filtering and utility tool policies."""
def _make_server(self, name, tool_names, session=None):
server = _make_mock_server(
name,
session=session or SimpleNamespace(),
tools=[_make_mcp_tool(n, n) for n in tool_names],
)
return server
def _run_discover(self, name, tool_names, config, session=None):
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers
mock_registry = ToolRegistry()
server = self._make_server(name, tool_names, session=session)
async def fake_connect(_name, _config):
return server
async def run():
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.registry.registry", mock_registry), \
patch("toolsets.create_custom_toolset"):
return await _discover_and_register_server(name, config)
try:
registered = asyncio.run(run())
finally:
_servers.pop(name, None)
return registered, mock_registry
def test_include_takes_precedence_over_exclude(self):
config = {
"url": "https://mcp.example.com",
"tools": {
"include": ["create_service"],
"exclude": ["create_service", "delete_service"],
},
}
registered, _ = self._run_discover(
"ink",
["create_service", "delete_service", "list_services"],
config,
session=SimpleNamespace(),
)
assert registered == ["mcp_ink_create_service"]
def test_exclude_filter_registers_all_except_listed_tools(self):
config = {
"url": "https://mcp.example.com",
"tools": {"exclude": ["delete_service"]},
}
registered, _ = self._run_discover(
"ink_exclude",
["create_service", "delete_service", "list_services"],
config,
session=SimpleNamespace(),
)
assert registered == [
"mcp_ink_exclude_create_service",
"mcp_ink_exclude_list_services",
]
def test_include_filter_skips_utility_tools_without_capabilities(self):
config = {
"url": "https://mcp.example.com",
"tools": {"include": ["create_service"]},
}
registered, mock_registry = self._run_discover(
"ink_no_caps",
["create_service", "delete_service"],
config,
session=SimpleNamespace(),
)
assert registered == ["mcp_ink_no_caps_create_service"]
assert set(mock_registry.get_all_tool_names()) == {"mcp_ink_no_caps_create_service"}
def test_no_filter_registers_all_server_tools_when_no_utilities_supported(self):
registered, _ = self._run_discover(
"ink_no_filter",
["create_service", "delete_service", "list_services"],
{"url": "https://mcp.example.com"},
session=SimpleNamespace(),
)
assert registered == [
"mcp_ink_no_filter_create_service",
"mcp_ink_no_filter_delete_service",
"mcp_ink_no_filter_list_services",
]
def test_resources_and_prompts_can_be_disabled_explicitly(self):
session = SimpleNamespace(
list_resources=AsyncMock(),
read_resource=AsyncMock(),
list_prompts=AsyncMock(),
get_prompt=AsyncMock(),
)
config = {
"url": "https://mcp.example.com",
"tools": {
"resources": False,
"prompts": False,
},
}
registered, _ = self._run_discover(
"ink_disabled_utils",
["create_service"],
config,
session=session,
)
assert registered == ["mcp_ink_disabled_utils_create_service"]
def test_registers_only_utility_tools_supported_by_server_capabilities(self):
session = SimpleNamespace(
list_resources=AsyncMock(return_value=SimpleNamespace(resources=[])),
read_resource=AsyncMock(return_value=SimpleNamespace(contents=[])),
)
registered, _ = self._run_discover(
"ink_resources_only",
["create_service"],
{"url": "https://mcp.example.com"},
session=session,
)
assert "mcp_ink_resources_only_create_service" in registered
assert "mcp_ink_resources_only_list_resources" in registered
assert "mcp_ink_resources_only_read_resource" in registered
assert "mcp_ink_resources_only_list_prompts" not in registered
assert "mcp_ink_resources_only_get_prompt" not in registered
def test_existing_tool_names_reflect_registered_subset(self):
from tools.mcp_tool import _existing_tool_names, _servers, _discover_and_register_server
from tools.registry import ToolRegistry
mock_registry = ToolRegistry()
server = self._make_server(
"ink_existing",
["create_service", "delete_service"],
session=SimpleNamespace(),
)
async def fake_connect(_name, _config):
return server
async def run():
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch.dict("tools.mcp_tool._servers", {}, clear=True), \
patch("tools.registry.registry", mock_registry), \
patch("toolsets.create_custom_toolset"):
registered = await _discover_and_register_server(
"ink_existing",
{"url": "https://mcp.example.com", "tools": {"include": ["create_service"]}},
)
return registered, _existing_tool_names()
try:
registered, existing = asyncio.run(run())
assert registered == ["mcp_ink_existing_create_service"]
assert existing == ["mcp_ink_existing_create_service"]
finally:
_servers.pop("ink_existing", None)
def test_no_toolset_created_when_everything_is_filtered_out(self):
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers
mock_registry = ToolRegistry()
server = self._make_server("ink_none", ["create_service"], session=SimpleNamespace())
mock_create = MagicMock()
async def fake_connect(_name, _config):
return server
async def run():
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.registry.registry", mock_registry), \
patch("toolsets.create_custom_toolset", mock_create):
return await _discover_and_register_server(
"ink_none",
{
"url": "https://mcp.example.com",
"tools": {
"include": ["missing_tool"],
"resources": False,
"prompts": False,
},
},
)
try:
registered = asyncio.run(run())
assert registered == []
mock_create.assert_not_called()
assert mock_registry.get_all_tool_names() == []
finally:
_servers.pop("ink_none", None)
def test_enabled_false_skips_connection_attempt(self):
from tools.mcp_tool import discover_mcp_tools
connect_called = []
async def fake_connect(name, config):
connect_called.append(name)
return self._make_server(name, ["create_service"])
fake_config = {
"ink": {
"url": "https://mcp.example.com",
"enabled": False,
}
}
fake_toolsets = {
"hermes-cli": {"tools": [], "description": "CLI", "includes": []},
}
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._servers", {}), \
patch("tools.mcp_tool._load_mcp_config", return_value=fake_config), \
patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("toolsets.TOOLSETS", fake_toolsets):
result = discover_mcp_tools()
assert connect_called == []
assert result == []