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hermes-agent/tests/tools/test_mcp_tool.py
Teknium 4e89c53082
fix(async): close unscheduled coroutines in all threadsafe bridges (#26584) 
Wraps every sync->async coroutine-scheduling site in the codebase with a
new agent.async_utils.safe_schedule_threadsafe() helper that closes the
coroutine on scheduling failure (closed loop, shutdown race, etc.)
instead of leaking it as 'coroutine was never awaited' RuntimeWarnings
plus reference leaks.

22 production call sites migrated across the codebase:
- acp_adapter/events.py, acp_adapter/permissions.py
- agent/lsp/manager.py
- cron/scheduler.py (media + text delivery paths)
- gateway/platforms/feishu.py (5 sites, via existing _submit_on_loop helper
  which now delegates to safe_schedule_threadsafe)
- gateway/run.py (10 sites: telegram rename, agent:step hook, status
  callback, interim+bg-review, clarify send, exec-approval button+text,
  temp-bubble cleanup, channel-directory refresh)
- plugins/memory/hindsight, plugins/platforms/google_chat
- tools/browser_supervisor.py (3), browser_cdp_tool.py,
  computer_use/cua_backend.py, slash_confirm.py
- tools/environments/modal.py (_AsyncWorker)
- tools/mcp_tool.py (2 + 8 _run_on_mcp_loop callers converted to
  factory-style so the coroutine is never constructed on a dead loop)
- tui_gateway/ws.py

Tests: new tests/agent/test_async_utils.py covers helper behavior under
live loop, dead loop, None loop, and scheduling exceptions. Regression
tests added at three PR-original sites (acp events, acp permissions,
mcp loop runner) mirroring contributor's intent.

Live-tested end-to-end:
- Helper stress test: 1500 schedules across live/dead/race scenarios,
  zero leaked coroutines
- Race exercised: 5000 schedules with loop killed mid-flight, 100 ok /
  4900 None returns, zero leaks
- hermes chat -q with terminal tool call (exercises step_callback bridge)
- MCP probe against failing subprocess servers + factory path
- Real gateway daemon boot + SIGINT shutdown across multiple platform
  adapter inits
- WSTransport 100 live + 50 dead-loop writes
- Cron delivery path live + dead loop

Salvages PR #2657 — adopts contributor's intent over a much wider site
list and a single centralized helper instead of inline try/except at
each site. 3 of the original PR's 6 sites no longer exist on main
(environments/patches.py deleted, DingTalk refactored to native async);
the equivalent fix lives in tools/environments/modal.py instead.

Co-authored-by: JithendraNara <jithendranaidunara@gmail.com>
2026-05-15 14:00:01 -07:00

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"""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
import threading
import time
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_definitions_refs_are_rewritten_to_defs(self):
from tools.mcp_tool import _convert_mcp_schema
mcp_tool = _make_mcp_tool(
name="submit",
description="Submit a payload",
input_schema={
"type": "object",
"properties": {
"input": {"$ref": "#/definitions/Payload"},
},
"required": ["input"],
"definitions": {
"Payload": {
"type": "object",
"properties": {
"query": {"type": "string"},
},
"required": ["query"],
}
},
},
)
schema = _convert_mcp_schema("forms", mcp_tool)
assert schema["parameters"]["properties"]["input"]["$ref"] == "#/$defs/Payload"
assert "$defs" in schema["parameters"]
assert "definitions" not in schema["parameters"]
def test_nested_definition_refs_are_rewritten_recursively(self):
from tools.mcp_tool import _convert_mcp_schema
mcp_tool = _make_mcp_tool(
name="nested",
description="Nested schema",
input_schema={
"type": "object",
"properties": {
"items": {
"type": "array",
"items": {"$ref": "#/definitions/Entry"},
},
},
"definitions": {
"Entry": {
"type": "object",
"properties": {
"child": {"$ref": "#/definitions/Child"},
},
},
"Child": {
"type": "object",
"properties": {
"value": {"type": "string"},
},
},
},
},
)
schema = _convert_mcp_schema("forms", mcp_tool)
assert schema["parameters"]["properties"]["items"]["items"]["$ref"] == "#/$defs/Entry"
assert schema["parameters"]["$defs"]["Entry"]["properties"]["child"]["$ref"] == "#/$defs/Child"
def test_missing_type_on_object_is_coerced(self):
"""Schemas that describe an object but omit ``type`` get type='object'."""
from tools.mcp_tool import _normalize_mcp_input_schema
schema = _normalize_mcp_input_schema({
"properties": {"q": {"type": "string"}},
"required": ["q"],
})
assert schema["type"] == "object"
assert schema["properties"]["q"]["type"] == "string"
assert schema["required"] == ["q"]
def test_null_type_on_object_is_coerced(self):
"""type: None should be treated like missing type (common MCP server bug)."""
from tools.mcp_tool import _normalize_mcp_input_schema
schema = _normalize_mcp_input_schema({
"type": None,
"properties": {"x": {"type": "integer"}},
})
assert schema["type"] == "object"
def test_required_pruned_when_property_missing(self):
"""Gemini 400s on required names that don't exist in properties."""
from tools.mcp_tool import _normalize_mcp_input_schema
schema = _normalize_mcp_input_schema({
"type": "object",
"properties": {"a": {"type": "string"}},
"required": ["a", "ghost", "phantom"],
})
assert schema["required"] == ["a"]
def test_required_removed_when_all_names_dangle(self):
from tools.mcp_tool import _normalize_mcp_input_schema
schema = _normalize_mcp_input_schema({
"type": "object",
"properties": {},
"required": ["ghost"],
})
assert "required" not in schema
def test_required_pruning_applies_recursively_inside_nested_objects(self):
"""Nested object schemas also get required pruning."""
from tools.mcp_tool import _normalize_mcp_input_schema
schema = _normalize_mcp_input_schema({
"type": "object",
"properties": {
"filter": {
"type": "object",
"properties": {"field": {"type": "string"}},
"required": ["field", "missing"],
},
},
})
assert schema["properties"]["filter"]["required"] == ["field"]
def test_object_in_array_items_gets_properties_filled(self):
"""Array-item object schemas without properties get an empty dict."""
from tools.mcp_tool import _normalize_mcp_input_schema
schema = _normalize_mcp_input_schema({
"type": "object",
"properties": {
"items": {
"type": "array",
"items": {"type": "object"},
},
},
})
assert schema["properties"]["items"]["items"]["properties"] == {}
def test_optional_nullable_field_is_collapsed_to_non_null_schema(self):
"""Anthropic rejects MCP/Pydantic anyOf-null optional parameter schemas."""
from tools.mcp_tool import _normalize_mcp_input_schema
schema = _normalize_mcp_input_schema({
"type": "object",
"properties": {
"command": {"type": "string"},
"workdir": {
"anyOf": [{"type": "string"}, {"type": "null"}],
"default": None,
"description": "Optional working directory",
},
},
"required": ["command"],
})
assert schema["properties"]["workdir"] == {
"type": "string",
"nullable": True,
"default": None,
"description": "Optional working directory",
}
assert schema["required"] == ["command"]
def test_nested_nullable_array_items_are_collapsed(self):
from tools.mcp_tool import _normalize_mcp_input_schema
schema = _normalize_mcp_input_schema({
"type": "object",
"properties": {
"filters": {
"type": "array",
"items": {
"oneOf": [
{
"type": "object",
"properties": {"field": {"type": "string"}},
},
{"type": "null"},
]
},
}
},
})
assert schema["properties"]["filters"]["items"] == {
"type": "object",
"properties": {"field": {"type": "string"}},
"nullable": True,
}
def test_convert_mcp_schema_survives_missing_inputschema_attribute(self):
"""A Tool object without .inputSchema must not crash registration."""
import types
from tools.mcp_tool import _convert_mcp_schema
bare_tool = types.SimpleNamespace(name="probe", description="Probe")
schema = _convert_mcp_schema("srv", bare_tool)
assert schema["name"] == "mcp_srv_probe"
assert schema["parameters"] == {"type": "object", "properties": {}}
def test_convert_mcp_schema_with_none_inputschema(self):
"""Tool with inputSchema=None produces a valid empty object schema."""
import types
from tools.mcp_tool import _convert_mcp_schema
# Note: _make_mcp_tool(input_schema=None) falls back to a default —
# build the namespace directly so .inputSchema really is None.
mcp_tool = types.SimpleNamespace(name="probe", description="Probe", inputSchema=None)
schema = _convert_mcp_schema("srv", 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)
# ---------------------------------------------------------------------------
# MCP loop runner
# ---------------------------------------------------------------------------
class TestRunOnMcpLoop:
def test_scheduler_failure_closes_factory_coroutine(self):
"""If run_coroutine_threadsafe raises, the factory's coroutine is closed."""
import gc
import warnings
import tools.mcp_tool as mcp
created = {"coro": None}
async def _sample():
return "ok"
def factory():
created["coro"] = _sample()
return created["coro"]
fake_loop = MagicMock()
fake_loop.is_running.return_value = True
with patch.object(mcp, "_mcp_loop", fake_loop):
with warnings.catch_warnings(record=True) as caught:
warnings.simplefilter("always")
with patch(
"agent.async_utils.asyncio.run_coroutine_threadsafe",
side_effect=RuntimeError("scheduler down"),
):
with pytest.raises(RuntimeError):
mcp._run_on_mcp_loop(factory)
gc.collect()
assert created["coro"] is not None
assert created["coro"].cr_frame is None
runtime_warnings = [
w for w in caught
if issubclass(w.category, RuntimeWarning)
and "was never awaited" in str(w.message)
and "_sample" in str(w.message)
]
assert runtime_warnings == []
def test_dead_loop_closes_passed_coroutine(self):
"""If loop is None, a passed coroutine (not factory) is closed."""
import gc
import warnings
import tools.mcp_tool as mcp
async def _sample():
return "ok"
coro = _sample()
with patch.object(mcp, "_mcp_loop", None):
with warnings.catch_warnings(record=True) as caught:
warnings.simplefilter("always")
with pytest.raises(RuntimeError, match="not running"):
mcp._run_on_mcp_loop(coro)
gc.collect()
assert coro.cr_frame is None
runtime_warnings = [
w for w in caught
if issubclass(w.category, RuntimeWarning)
and "was never awaited" in str(w.message)
and "_sample" in str(w.message)
]
assert runtime_warnings == []
# ---------------------------------------------------------------------------
# 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_or_factory, timeout=30):
coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
return asyncio.run(coro)
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)
def test_interrupted_call_returns_interrupted_error(self):
from tools.mcp_tool import _make_tool_handler, _servers
mock_session = MagicMock()
server = _make_mock_server("test_srv", session=mock_session)
_servers["test_srv"] = server
try:
handler = _make_tool_handler("test_srv", "greet", 120)
def _interrupting_run(coro_or_factory, timeout=30):
coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
coro.close()
raise InterruptedError("User sent a new message")
with patch(
"tools.mcp_tool._run_on_mcp_loop",
side_effect=_interrupting_run,
):
result = json.loads(handler({}))
assert result == {"error": "MCP call interrupted: user sent a new message"}
finally:
_servers.pop("test_srv", None)
class TestRunOnMCPLoopInterrupts:
def test_interrupt_cancels_waiting_mcp_call(self):
import tools.mcp_tool as mcp_mod
from tools.interrupt import set_interrupt
loop = asyncio.new_event_loop()
thread = threading.Thread(target=loop.run_forever, daemon=True)
thread.start()
cancelled = threading.Event()
async def _slow_call():
try:
await asyncio.sleep(5)
return "done"
except asyncio.CancelledError:
cancelled.set()
raise
old_loop = mcp_mod._mcp_loop
old_thread = mcp_mod._mcp_thread
mcp_mod._mcp_loop = loop
mcp_mod._mcp_thread = thread
waiter_tid = threading.current_thread().ident
def _interrupt_soon():
time.sleep(0.2)
set_interrupt(True, waiter_tid)
interrupter = threading.Thread(target=_interrupt_soon, daemon=True)
interrupter.start()
try:
with pytest.raises(InterruptedError, match="User sent a new message"):
mcp_mod._run_on_mcp_loop(_slow_call(), timeout=2)
deadline = time.time() + 2
while time.time() < deadline and not cancelled.is_set():
time.sleep(0.05)
assert cancelled.is_set()
finally:
set_interrupt(False, waiter_tid)
loop.call_soon_threadsafe(loop.stop)
thread.join(timeout=2)
loop.close()
mcp_mod._mcp_loop = old_loop
mcp_mod._mcp_thread = old_thread
def test_timeout_reports_elapsed_and_configured_timeout(self):
import tools.mcp_tool as mcp_mod
loop = asyncio.new_event_loop()
thread = threading.Thread(target=loop.run_forever, daemon=True)
thread.start()
cancelled = threading.Event()
async def _slow_call():
try:
await asyncio.sleep(5)
return "done"
except asyncio.CancelledError:
cancelled.set()
raise
old_loop = mcp_mod._mcp_loop
old_thread = mcp_mod._mcp_thread
mcp_mod._mcp_loop = loop
mcp_mod._mcp_thread = thread
try:
with pytest.raises(TimeoutError, match=r"MCP call timed out after .*configured timeout: 0.2s"):
mcp_mod._run_on_mcp_loop(_slow_call(), timeout=0.2)
deadline = time.time() + 2
while time.time() < deadline and not cancelled.is_set():
time.sleep(0.05)
assert cancelled.is_set()
finally:
loop.call_soon_threadsafe(loop.stop)
thread.join(timeout=2)
loop.close()
mcp_mod._mcp_loop = old_loop
mcp_mod._mcp_thread = old_thread
# ---------------------------------------------------------------------------
# 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_resolves_live_from_registry(self):
"""MCP toolsets resolve through the live registry without TOOLSETS mutation."""
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
from toolsets import resolve_toolset, validate_toolset
mock_registry = ToolRegistry()
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
with patch("tools.mcp_tool._connect_server", side_effect=fake_connect), \
patch("tools.registry.registry", mock_registry):
asyncio.run(
_discover_and_register_server("myserver", {"command": "test"})
)
assert validate_toolset("myserver") is True
assert validate_toolset("mcp-myserver") is True
assert "mcp_myserver_ping" in resolve_toolset("myserver")
assert "mcp_myserver_ping" in resolve_toolset("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_refresh_tools_deregisters_removed_tools(self):
"""Dynamic refresh removes stale registry entries for deleted tools."""
from tools.registry import ToolRegistry
from tools.mcp_tool import MCPServerTask
mock_registry = ToolRegistry()
server = MCPServerTask("srv")
server._config = {"command": "test"}
server._tools = [_make_mcp_tool("old"), _make_mcp_tool("keep")]
server._registered_tool_names = ["mcp_srv_old", "mcp_srv_keep"]
server.session = MagicMock()
server.session.list_tools = AsyncMock(
return_value=SimpleNamespace(tools=[_make_mcp_tool("keep"), _make_mcp_tool("new")])
)
with patch("tools.registry.registry", mock_registry):
mock_registry.register(
name="mcp_srv_old",
toolset="mcp-srv",
schema={"name": "mcp_srv_old", "description": "Old"},
handler=lambda *_args, **_kwargs: "{}",
)
mock_registry.register(
name="mcp_srv_keep",
toolset="mcp-srv",
schema={"name": "mcp_srv_keep", "description": "Keep"},
handler=lambda *_args, **_kwargs: "{}",
)
asyncio.run(server._refresh_tools())
names = mock_registry.get_all_tool_names()
assert "mcp_srv_old" not in names
assert "mcp_srv_keep" in names
assert "mcp_srv_new" in names
assert set(server._registered_tool_names) == {
"mcp_srv_keep",
"mcp_srv_new",
"mcp_srv_list_resources",
"mcp_srv_read_resource",
"mcp_srv_list_prompts",
"mcp_srv_get_prompt",
}
def test_schedule_tools_refresh_keeps_task_until_done(self):
"""Background refresh tasks are strongly referenced and then discarded."""
from tools.mcp_tool import MCPServerTask
async def _test():
started = asyncio.Event()
finish = asyncio.Event()
server = MCPServerTask("srv")
async def fake_refresh(_server):
started.set()
await finish.wait()
with patch.object(MCPServerTask, "_refresh_tools", new=fake_refresh):
server._schedule_tools_refresh()
await started.wait()
assert len(server._pending_refresh_tasks) == 1
task = next(iter(server._pending_refresh_tasks))
assert not task.done()
finish.set()
await task
await asyncio.sleep(0)
assert server._pending_refresh_tasks == set()
asyncio.run(_test())
def test_shutdown_cancels_pending_refresh_tasks(self):
"""shutdown() cancels in-flight background refresh tasks."""
from tools.mcp_tool import MCPServerTask
async def _test():
started = asyncio.Event()
cancelled = asyncio.Event()
server = MCPServerTask("srv")
async def fake_refresh(_server):
started.set()
try:
await asyncio.sleep(3600)
except asyncio.CancelledError:
cancelled.set()
raise
with patch.object(MCPServerTask, "_refresh_tools", new=fake_refresh):
server._schedule_tools_refresh()
await started.wait()
await server.shutdown()
assert cancelled.is_set()
assert server._pending_refresh_tasks == set()
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_resolve_through_server_aliases(self):
"""Discovered MCP tools resolve through raw server-name aliases."""
from tools.mcp_tool import MCPServerTask
from tools.registry import ToolRegistry
from toolsets import resolve_toolset, validate_toolset
mock_tools = [_make_mcp_tool("list_files", "List files")]
mock_session = MagicMock()
mock_registry = ToolRegistry()
fresh_servers = {}
async def fake_connect(name, config):
server = MCPServerTask(name)
server.session = mock_session
server._tools = mock_tools
return server
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("tools.registry.registry", mock_registry):
from tools.mcp_tool import discover_mcp_tools
result = discover_mcp_tools()
assert "mcp_fs_list_files" in result
assert validate_toolset("fs") is True
assert validate_toolset("mcp-fs") is True
assert "mcp_fs_list_files" in resolve_toolset("fs")
assert "mcp_fs_list_files" in resolve_toolset("mcp-fs")
def test_server_toolset_skips_builtin_collision(self):
"""MCP raw aliases never overwrite a built-in toolset name."""
from tools.mcp_tool import MCPServerTask
from tools.registry import ToolRegistry
from toolsets import resolve_toolset, validate_toolset
mock_tools = [_make_mcp_tool("run", "Run command")]
mock_session = MagicMock()
fresh_servers = {}
mock_registry = ToolRegistry()
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("tools.registry.registry", mock_registry), \
patch("toolsets.TOOLSETS", fake_toolsets):
from tools.mcp_tool import discover_mcp_tools
discover_mcp_tools()
assert fake_toolsets["terminal"]["description"] == "Terminal tools"
assert "mcp_terminal_run" not in resolve_toolset("terminal")
assert validate_toolset("mcp-terminal") is True
assert "mcp_terminal_run" in resolve_toolset("mcp-terminal")
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_deregisters_registered_tools(self):
"""shutdown_mcp_servers removes MCP tools and their raw alias."""
import tools.mcp_tool as mcp_mod
from tools.mcp_tool import MCPServerTask, shutdown_mcp_servers, _servers
from tools.registry import registry
from toolsets import resolve_toolset, validate_toolset
_servers.clear()
registry.register(
name="mcp_test_ping",
toolset="mcp-test",
schema={
"name": "mcp_test_ping",
"description": "Ping",
"parameters": {"type": "object", "properties": {}},
},
handler=lambda *_args, **_kwargs: "{}",
)
registry.register_toolset_alias("test", "mcp-test")
server = MCPServerTask("test")
server._registered_tool_names = ["mcp_test_ping"]
_servers["test"] = server
mcp_mod._ensure_mcp_loop()
try:
assert validate_toolset("test") is True
assert "mcp_test_ping" in resolve_toolset("test")
shutdown_mcp_servers()
finally:
mcp_mod._mcp_loop = None
mcp_mod._mcp_thread = None
assert "mcp_test_ping" not in registry.get_all_tool_names()
assert validate_toolset("test") is False
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())
def test_http_seeds_initial_protocol_header(self):
from tools.mcp_tool import LATEST_PROTOCOL_VERSION, MCPServerTask
server = MCPServerTask("remote")
captured = {}
class DummyAsyncClient:
def __init__(self, **kwargs):
captured.update(kwargs)
async def __aenter__(self):
return self
async def __aexit__(self, exc_type, exc, tb):
return False
class DummyTransportCtx:
async def __aenter__(self):
return MagicMock(), MagicMock(), (lambda: None)
async def __aexit__(self, exc_type, exc, tb):
return False
class DummySession:
def __init__(self, *args, **kwargs):
pass
async def __aenter__(self):
return self
async def __aexit__(self, exc_type, exc, tb):
return False
async def initialize(self):
return None
class DummyLegacyTransportCtx:
def __init__(self, **kwargs):
captured["legacy_headers"] = kwargs.get("headers")
async def __aenter__(self):
return MagicMock(), MagicMock(), (lambda: None)
async def __aexit__(self, exc_type, exc, tb):
return False
async def _discover_tools(self):
self._shutdown_event.set()
async def _run(config, *, new_http):
captured.clear()
with patch("tools.mcp_tool._MCP_HTTP_AVAILABLE", True), \
patch("tools.mcp_tool._MCP_NEW_HTTP", new_http), \
patch("httpx.AsyncClient", DummyAsyncClient), \
patch("tools.mcp_tool.streamable_http_client", return_value=DummyTransportCtx()), \
patch("tools.mcp_tool.streamablehttp_client", side_effect=lambda url, **kwargs: DummyLegacyTransportCtx(**kwargs)), \
patch("tools.mcp_tool.ClientSession", DummySession), \
patch.object(MCPServerTask, "_discover_tools", _discover_tools):
await server._run_http(config)
asyncio.run(_run({"url": "https://example.com/mcp"}, new_http=True))
assert captured["headers"]["mcp-protocol-version"] == LATEST_PROTOCOL_VERSION
asyncio.run(_run({
"url": "https://example.com/mcp",
"headers": {"mcp-protocol-version": "custom-version"},
}, new_http=True))
assert captured["headers"]["mcp-protocol-version"] == "custom-version"
asyncio.run(_run({
"url": "https://example.com/mcp",
"headers": {"MCP-Protocol-Version": "custom-version"},
}, new_http=True))
assert captured["headers"]["MCP-Protocol-Version"] == "custom-version"
assert "mcp-protocol-version" not in captured["headers"]
asyncio.run(_run({"url": "https://example.com/mcp"}, new_http=False))
assert captured["legacy_headers"]["mcp-protocol-version"] == LATEST_PROTOCOL_VERSION
asyncio.run(_run({
"url": "https://example.com/mcp",
"headers": {"MCP-Protocol-Version": "custom-version"},
}, new_http=False))
assert captured["legacy_headers"]["MCP-Protocol-Version"] == "custom-version"
assert "mcp-protocol-version" not in captured["legacy_headers"]
# ---------------------------------------------------------------------------
# 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 retries up to _MAX_INITIAL_CONNECT_RETRIES times.
Before the MCP resilience fix, initial failures gave up immediately.
Now they retry with backoff to handle transient DNS/network blips.
"""
from tools.mcp_tool import MCPServerTask, _MAX_INITIAL_CONNECT_RETRIES
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"})
# Now retries up to _MAX_INITIAL_CONNECT_RETRIES before giving up
assert run_count == _MAX_INITIAL_CONNECT_RETRIES + 1
assert server._error is not None
assert "cannot connect" in str(server._error)
asyncio.run(_test())
def test_initial_oauth_failure_does_not_retry(self):
"""Initial OAuth failures stop immediately to avoid repeated browser prompts."""
from tools.mcp_tool import MCPServerTask
run_count = 0
target_server = None
oauth_error = RuntimeError("Token exchange failed (400): Unknown client_id")
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 oauth_error
async def _test():
nonlocal target_server
server = MCPServerTask("oauth_srv")
target_server = server
with patch.object(MCPServerTask, "_run_stdio", patched_run_stdio), \
patch("tools.mcp_tool._is_auth_error", return_value=True), \
patch("asyncio.sleep", new_callable=AsyncMock) as mock_sleep:
await server.run({"command": "test"})
assert run_count == 1
assert server._error is oauth_error
assert server._ready.is_set()
assert mock_sleep.await_count == 0
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:
def fake_run(coro, timeout=30):
coro.close()
return json.dumps({"result": "ok"})
mock_run.side_effect = fake_run
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_or_factory, timeout=30):
coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
return asyncio.run(coro)
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
class _CompatType:
def __init__(self, **kwargs):
self.__dict__.update(kwargs)
try:
from mcp.types import (
CreateMessageResult,
ErrorData,
SamplingCapability,
TextContent,
)
except ImportError:
CreateMessageResult = _CompatType
ErrorData = _CompatType
SamplingCapability = _CompatType
TextContent = _CompatType
try:
from mcp.types import CreateMessageResultWithTools
except ImportError:
CreateMessageResultWithTools = _CompatType
try:
from mcp.types import SamplingToolsCapability
except ImportError:
SamplingToolsCapability = _CompatType
try:
from mcp.types import ToolUseContent
except ImportError:
ToolUseContent = _CompatType
from tools.mcp_tool import (
CreateMessageResultWithTools,
SamplingHandler,
SamplingToolsCapability,
ToolUseContent,
_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 == []
# ---------------------------------------------------------------------------
# Tool name collision protection
# ---------------------------------------------------------------------------
class TestRegistryCollisionWarning:
"""registry.register() warns when a tool name is overwritten by a different toolset."""
def test_overwrite_different_toolset_logs_warning(self, caplog):
"""Overwriting a tool from a different toolset is REJECTED with an error."""
from tools.registry import ToolRegistry
import logging
reg = ToolRegistry()
schema = {"name": "my_tool", "description": "test", "parameters": {"type": "object", "properties": {}}}
handler = lambda args, **kw: "{}"
reg.register(name="my_tool", toolset="builtin", schema=schema, handler=handler)
with caplog.at_level(logging.ERROR, logger="tools.registry"):
reg.register(name="my_tool", toolset="mcp-ext", schema=schema, handler=handler)
assert any("rejected" in r.message.lower() for r in caplog.records)
assert any("builtin" in r.message and "mcp-ext" in r.message for r in caplog.records)
# The original tool should still be from 'builtin', not overwritten
assert reg.get_toolset_for_tool("my_tool") == "builtin"
def test_overwrite_same_toolset_no_warning(self, caplog):
"""Re-registering within the same toolset is silent (e.g. reconnect)."""
from tools.registry import ToolRegistry
import logging
reg = ToolRegistry()
schema = {"name": "my_tool", "description": "test", "parameters": {"type": "object", "properties": {}}}
handler = lambda args, **kw: "{}"
reg.register(name="my_tool", toolset="mcp-server", schema=schema, handler=handler)
with caplog.at_level(logging.WARNING, logger="tools.registry"):
reg.register(name="my_tool", toolset="mcp-server", schema=schema, handler=handler)
assert not any("collision" in r.message.lower() for r in caplog.records)
class TestMCPBuiltinCollisionGuard:
"""MCP tools that collide with built-in tool names are skipped."""
def test_mcp_tool_skipped_when_builtin_exists(self):
"""An MCP tool whose prefixed name collides with a built-in is skipped."""
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
mock_registry = ToolRegistry()
# Pre-register a "built-in" tool with the name that the MCP tool would produce.
# Server "abc", tool "search" → mcp_abc_search
builtin_schema = {
"name": "mcp_abc_search",
"description": "A hypothetical built-in",
"parameters": {"type": "object", "properties": {}},
}
mock_registry.register(
name="mcp_abc_search", toolset="web",
schema=builtin_schema, handler=lambda a, **k: "{}",
)
mock_tools = [_make_mcp_tool("search", "Search the web")]
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("abc", {"command": "test", "args": []})
)
# The MCP tool should have been skipped — built-in preserved.
assert "mcp_abc_search" not in registered
assert mock_registry.get_toolset_for_tool("mcp_abc_search") == "web"
_servers.pop("abc", None)
def test_mcp_tool_registered_when_no_builtin_collision(self):
"""MCP tools register normally when there's no collision."""
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
mock_registry = ToolRegistry()
mock_tools = [_make_mcp_tool("web_search", "Search the web")]
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("minimax", {"command": "test", "args": []})
)
assert "mcp_minimax_web_search" in registered
assert mock_registry.get_toolset_for_tool("mcp_minimax_web_search") == "mcp-minimax"
_servers.pop("minimax", None)
def test_mcp_tool_allowed_when_collision_is_another_mcp(self):
"""Collision between two MCP toolsets is allowed (last wins)."""
from tools.registry import ToolRegistry
from tools.mcp_tool import _discover_and_register_server, _servers, MCPServerTask
mock_registry = ToolRegistry()
# Pre-register an MCP tool from a different server.
mcp_schema = {
"name": "mcp_srv_do_thing",
"description": "From another MCP server",
"parameters": {"type": "object", "properties": {}},
}
mock_registry.register(
name="mcp_srv_do_thing", toolset="mcp-old",
schema=mcp_schema, handler=lambda a, **k: "{}",
)
mock_tools = [_make_mcp_tool("do_thing", "Do a thing")]
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("srv", {"command": "test", "args": []})
)
# MCP-to-MCP collision is allowed — the new server wins.
assert "mcp_srv_do_thing" in registered
assert mock_registry.get_toolset_for_tool("mcp_srv_do_thing") == "mcp-srv"
_servers.pop("srv", None)
# ---------------------------------------------------------------------------
# sanitize_mcp_name_component
# ---------------------------------------------------------------------------
class TestSanitizeMcpNameComponent:
"""Verify sanitize_mcp_name_component handles all edge cases."""
def test_hyphens_replaced(self):
from tools.mcp_tool import sanitize_mcp_name_component
assert sanitize_mcp_name_component("my-server") == "my_server"
def test_dots_replaced(self):
from tools.mcp_tool import sanitize_mcp_name_component
assert sanitize_mcp_name_component("ai.exa") == "ai_exa"
def test_slashes_replaced(self):
from tools.mcp_tool import sanitize_mcp_name_component
assert sanitize_mcp_name_component("ai.exa/exa") == "ai_exa_exa"
def test_mixed_special_characters(self):
from tools.mcp_tool import sanitize_mcp_name_component
assert sanitize_mcp_name_component("@scope/my-pkg.v2") == "_scope_my_pkg_v2"
def test_alphanumeric_and_underscores_preserved(self):
from tools.mcp_tool import sanitize_mcp_name_component
assert sanitize_mcp_name_component("my_server_123") == "my_server_123"
def test_empty_string(self):
from tools.mcp_tool import sanitize_mcp_name_component
assert sanitize_mcp_name_component("") == ""
def test_none_returns_empty(self):
from tools.mcp_tool import sanitize_mcp_name_component
assert sanitize_mcp_name_component(None) == ""
def test_slash_in_convert_mcp_schema(self):
"""Server names with slashes produce valid tool names via _convert_mcp_schema."""
from tools.mcp_tool import _convert_mcp_schema
mcp_tool = _make_mcp_tool(name="search")
schema = _convert_mcp_schema("ai.exa/exa", mcp_tool)
assert schema["name"] == "mcp_ai_exa_exa_search"
# Must match Anthropic's pattern: ^[a-zA-Z0-9_-]{1,128}$
import re
assert re.match(r"^[a-zA-Z0-9_-]{1,128}$", schema["name"])
def test_slash_in_build_utility_schemas(self):
"""Server names with slashes produce valid utility tool names."""
from tools.mcp_tool import _build_utility_schemas
schemas = _build_utility_schemas("ai.exa/exa")
for s in schemas:
name = s["schema"]["name"]
assert "/" not in name
assert "." not in name
def test_slash_in_server_alias_resolution(self):
"""Server names with slashes resolve through their live MCP alias."""
from tools.registry import ToolRegistry
from toolsets import resolve_toolset, validate_toolset
reg = ToolRegistry()
reg.register(
name="mcp_ai_exa_exa_search",
toolset="mcp-ai.exa/exa",
schema={"name": "mcp_ai_exa_exa_search", "description": "Search", "parameters": {"type": "object", "properties": {}}},
handler=lambda *_args, **_kwargs: "{}",
)
reg.register_toolset_alias("ai.exa/exa", "mcp-ai.exa/exa")
with patch("tools.registry.registry", reg):
assert validate_toolset("ai.exa/exa") is True
assert "mcp_ai_exa_exa_search" in resolve_toolset("ai.exa/exa")
# ---------------------------------------------------------------------------
# register_mcp_servers public API
# ---------------------------------------------------------------------------
class TestRegisterMcpServers:
"""Verify the new register_mcp_servers() public API."""
def test_empty_servers_returns_empty(self):
from tools.mcp_tool import register_mcp_servers
with patch("tools.mcp_tool._MCP_AVAILABLE", True):
result = register_mcp_servers({})
assert result == []
def test_mcp_not_available_returns_empty(self):
from tools.mcp_tool import register_mcp_servers
with patch("tools.mcp_tool._MCP_AVAILABLE", False):
result = register_mcp_servers({"srv": {"command": "test"}})
assert result == []
def test_skips_already_connected_servers(self):
from tools.mcp_tool import register_mcp_servers, _servers
mock_server = _make_mock_server("existing")
_servers["existing"] = mock_server
try:
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._existing_tool_names", return_value=["mcp_existing_tool"]):
result = register_mcp_servers({"existing": {"command": "test"}})
assert result == ["mcp_existing_tool"]
finally:
_servers.pop("existing", None)
def test_skips_disabled_servers(self):
from tools.mcp_tool import register_mcp_servers, _servers
try:
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._existing_tool_names", return_value=[]):
result = register_mcp_servers({"srv": {"command": "test", "enabled": False}})
assert result == []
finally:
_servers.pop("srv", None)
def test_connects_new_servers(self):
from tools.mcp_tool import register_mcp_servers, _servers, _ensure_mcp_loop
fake_config = {"my_server": {"command": "npx", "args": ["test"]}}
async def fake_register(name, cfg):
server = _make_mock_server(name)
server._registered_tool_names = ["mcp_my_server_tool1"]
_servers[name] = server
return ["mcp_my_server_tool1"]
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._discover_and_register_server", side_effect=fake_register), \
patch("tools.mcp_tool._existing_tool_names", return_value=["mcp_my_server_tool1"]):
_ensure_mcp_loop()
result = register_mcp_servers(fake_config)
assert "mcp_my_server_tool1" in result
_servers.pop("my_server", None)
def test_logs_summary_on_success(self):
from tools.mcp_tool import register_mcp_servers, _servers, _ensure_mcp_loop
fake_config = {"srv": {"command": "npx", "args": ["test"]}}
async def fake_register(name, cfg):
server = _make_mock_server(name)
server._registered_tool_names = ["mcp_srv_t1", "mcp_srv_t2"]
_servers[name] = server
return ["mcp_srv_t1", "mcp_srv_t2"]
with patch("tools.mcp_tool._MCP_AVAILABLE", True), \
patch("tools.mcp_tool._discover_and_register_server", side_effect=fake_register), \
patch("tools.mcp_tool._existing_tool_names", return_value=["mcp_srv_t1", "mcp_srv_t2"]):
_ensure_mcp_loop()
with patch("tools.mcp_tool.logger") as mock_logger:
register_mcp_servers(fake_config)
info_calls = [str(c) for c in mock_logger.info.call_args_list]
assert any("2 tool(s)" in c and "1 server(s)" in c for c in info_calls), (
f"Summary should report 2 tools from 1 server, got: {info_calls}"
)
_servers.pop("srv", None)
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