"""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 logging import os import sys 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 class TestFilterMCPChildren: def test_filters_gateway_children_by_argv_marker(self, monkeypatch): """Non-MCP children start with an interpreter/binary, not the marker.""" import sys import tools.mcp_tool as mcp_tool cmdlines = { 101: [ "/usr/bin/python3", "-m", "tui_gateway.slash_worker", "--session-key", "abc", ], 102: [ "/usr/bin/java", "-jar", "/opt/jdtls/plugins/org.eclipse.equinox.launcher_1.7.0.jar", ], 103: ["/usr/bin/node", "server.js"], } class FakeProcess: def __init__(self, pid): self.pid = pid def cmdline(self): return cmdlines[self.pid] fake_psutil = SimpleNamespace( Process=FakeProcess, NoSuchProcess=ProcessLookupError, AccessDenied=PermissionError, ) monkeypatch.setitem(sys.modules, "psutil", fake_psutil) assert mcp_tool._filter_mcp_children({101, 102, 103}) == {103} # --------------------------------------------------------------------------- # Config loading # --------------------------------------------------------------------------- class TestLoadMCPConfig: 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 == {} class TestMCPParallelSafetyProvenance: def test_parallel_safe_servers_keep_exact_raw_names(self, monkeypatch): import tools.mcp_tool as mcp_tool first = SimpleNamespace(session=object(), _registered_tool_names=[]) second = SimpleNamespace(session=object(), _registered_tool_names=[]) with mcp_tool._lock: saved_servers = dict(mcp_tool._servers) saved_parallel = set(mcp_tool._parallel_safe_servers) mcp_tool._servers.clear() mcp_tool._servers.update({"foo-bar": first, "foo_bar": second}) mcp_tool._parallel_safe_servers.clear() try: monkeypatch.setattr(mcp_tool, "_MCP_AVAILABLE", True) monkeypatch.setattr( mcp_tool, "_filter_suspicious_mcp_servers", lambda servers: servers ) mcp_tool.register_mcp_servers( { "foo-bar": {"supports_parallel_tool_calls": True}, "foo_bar": {"supports_parallel_tool_calls": False}, } ) with mcp_tool._lock: assert "foo-bar" in mcp_tool._parallel_safe_servers assert "foo_bar" not in mcp_tool._parallel_safe_servers finally: with mcp_tool._lock: mcp_tool._servers.clear() mcp_tool._servers.update(saved_servers) mcp_tool._parallel_safe_servers.clear() mcp_tool._parallel_safe_servers.update(saved_parallel) def test_tool_provenance_keeps_exact_raw_server_names(self): import tools.mcp_tool as mcp_tool first_tool = "mcp__foo_bar__first" second_tool = "mcp__foo_bar__second" with mcp_tool._lock: saved_map = dict(mcp_tool._mcp_tool_server_names) saved_parallel = set(mcp_tool._parallel_safe_servers) mcp_tool._mcp_tool_server_names.clear() mcp_tool._parallel_safe_servers.clear() mcp_tool._parallel_safe_servers.add("foo-bar") try: mcp_tool._track_mcp_tool_server(first_tool, "foo-bar") mcp_tool._track_mcp_tool_server(second_tool, "foo_bar") assert mcp_tool.is_mcp_tool_parallel_safe(first_tool) is True assert mcp_tool.is_mcp_tool_parallel_safe(second_tool) is False assert mcp_tool.get_registered_mcp_server_names() == { "foo-bar", "foo_bar", } finally: with mcp_tool._lock: mcp_tool._mcp_tool_server_names.clear() mcp_tool._mcp_tool_server_names.update(saved_map) mcp_tool._parallel_safe_servers.clear() mcp_tool._parallel_safe_servers.update(saved_parallel) class TestMCPStatus: def test_status_distinguishes_configured_connecting_failed_and_disabled( self, monkeypatch ): import tools.mcp_tool as mcp_tool monkeypatch.setattr( mcp_tool, "_load_mcp_config", lambda: { "configured": {"command": "docker", "args": ["mcp", "gateway", "run"]}, "connecting": {"command": "slow-mcp"}, "failed": {"command": "bad-mcp"}, "disabled": {"command": "off-mcp", "enabled": False}, }, ) with mcp_tool._lock: saved_servers = dict(mcp_tool._servers) saved_connecting = set(mcp_tool._server_connecting) saved_errors = dict(mcp_tool._server_connect_errors) mcp_tool._servers.clear() mcp_tool._server_connecting.clear() mcp_tool._server_connect_errors.clear() mcp_tool._server_connecting.add("connecting") mcp_tool._server_connect_errors["failed"] = "Connection closed" try: statuses = { entry["name"]: entry for entry in mcp_tool.get_mcp_status() } finally: with mcp_tool._lock: mcp_tool._servers.clear() mcp_tool._servers.update(saved_servers) mcp_tool._server_connecting.clear() mcp_tool._server_connecting.update(saved_connecting) mcp_tool._server_connect_errors.clear() mcp_tool._server_connect_errors.update(saved_errors) assert statuses["configured"]["status"] == "configured" assert statuses["configured"]["connected"] is False assert statuses["configured"]["disabled"] is False assert statuses["connecting"]["status"] == "connecting" assert statuses["failed"]["status"] == "failed" assert statuses["failed"]["error"] == "Connection closed" assert statuses["disabled"]["status"] == "disabled" assert statuses["disabled"]["disabled"] is True class TestLifecycleConfig: def test_get_lifecycle_seconds_accepts_top_level_and_nested_values(self): from tools.mcp_tool import _get_lifecycle_seconds assert ( _get_lifecycle_seconds( {"idle_timeout_seconds": "3.5"}, "idle_timeout_seconds", ) == 3.5 ) assert _get_lifecycle_seconds( {"lifecycle": {"max_lifetime_seconds": 42}}, "max_lifetime_seconds", ) == 42.0 def test_get_lifecycle_seconds_ignores_invalid_values(self, caplog): from tools.mcp_tool import _get_lifecycle_seconds assert ( _get_lifecycle_seconds( {"idle_timeout_seconds": "soon"}, "idle_timeout_seconds", ) is None ) assert ( _get_lifecycle_seconds( {"idle_timeout_seconds": -1}, "idle_timeout_seconds", ) is None ) messages = [record.getMessage() for record in caplog.records] assert any("must be a number of seconds" in msg for msg in messages) assert any("must be positive" in msg for msg in messages) # --------------------------------------------------------------------------- # 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_definitions_as_property_name_is_preserved(self): """A tool parameter literally named ``definitions`` must not be renamed. Regression: the rewrite that promotes the legacy ``definitions`` meta-keyword to ``$defs`` used to fire for *any* key named ``definitions`` anywhere in the tree, including inside ``properties`` dicts. That turned user-facing parameter names into ``$defs``, which Anthropic and OpenAI both reject because ``$`` is not in the ``^[a-zA-Z0-9_.-]{1,64}$`` property-name pattern. Real-world repro: a CI/pipelines MCP tool whose ``definitions`` parameter is an array of pipeline-definition IDs. """ from tools.mcp_tool import _convert_mcp_schema mcp_tool = _make_mcp_tool( name="pipelines_build", description="List pipeline builds", input_schema={ "type": "object", "properties": { "action": {"type": "string"}, "definitions": { "description": "Array of build definition IDs to filter builds.", }, "top": {"type": "integer"}, }, }, ) schema = _convert_mcp_schema("pipelines", mcp_tool) props = schema["parameters"]["properties"] assert "definitions" in props, "user-facing property name was renamed away" assert "$defs" not in props, "user-facing property name was rewritten to $defs" # And the meta-keyword promotion didn't happen at the root either, # because there was no `definitions` meta-keyword to promote. assert "$defs" not in schema["parameters"] assert "definitions" not in schema["parameters"] 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_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_recycled_stdio_server_remains_available_for_lazy_reconnect(self): from tools.mcp_tool import _make_check_fn, _servers server = _make_mock_server("test_server", session=None) server._config = {"command": "npx"} server._recycled_reason = "idle_timeout_seconds" _servers["test_server"] = server try: check = _make_check_fn("test_server") assert check() is True 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_recycled_stdio_server_reconnects_lazily_on_tool_call(self): from tools.mcp_tool import _make_tool_handler, _servers mock_session = MagicMock() mock_session.call_tool = AsyncMock( return_value=_make_call_result("reconnected", is_error=False) ) server = _make_mock_server("test_srv", session=None) server._config = {"command": "npx"} server._recycled_reason = "idle_timeout_seconds" _servers["test_srv"] = server def fake_lazy_reconnect(server_name, srv): assert server_name == "test_srv" assert srv is server srv.session = mock_session srv._recycled_reason = None return True try: handler = _make_tool_handler("test_srv", "greet", 120) with patch("tools.mcp_tool._request_lazy_reconnect", side_effect=fake_lazy_reconnect) as reconnect, \ self._patch_mcp_loop(): result = json.loads(handler({"name": "world"})) assert result["result"] == "reconnected" reconnect.assert_called_once() mock_session.call_tool.assert_called_once_with("greet", arguments={"name": "world"}) finally: _servers.pop("test_srv", None) class TestRunOnMCPLoopInterrupts: @staticmethod def _run_with_future(mcp_mod, future): loop = MagicMock() loop.is_running.return_value = True async def _unused_call(): return "unused" def _schedule(coro, scheduled_loop, **_kwargs): assert scheduled_loop is loop coro.close() return future with patch.object(mcp_mod, "_mcp_loop", loop): with patch("agent.async_utils.safe_schedule_threadsafe", side_effect=_schedule): return mcp_mod._run_on_mcp_loop(_unused_call(), timeout=1) 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(0.02) 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=10) deadline = time.time() + 2 while time.time() < deadline and not cancelled.is_set(): time.sleep(0.01) assert cancelled.is_set() finally: set_interrupt(False, waiter_tid) loop.call_soon_threadsafe(loop.stop) thread.join(timeout=10) 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: # 0.1s is the floor the MCP loop clamps short timeouts to. with pytest.raises(TimeoutError, match=r"MCP call timed out after .*configured timeout: 0.1s"): mcp_mod._run_on_mcp_loop(_slow_call(), timeout=0.1) deadline = time.time() + 2 while time.time() < deadline and not cancelled.is_set(): time.sleep(0.01) assert cancelled.is_set() finally: loop.call_soon_threadsafe(loop.stop) thread.join(timeout=10) 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_same_server_normalization_collision_skips_all_ambiguous_tools(self, caplog): from tools.mcp_tool import _register_server_tools from tools.registry import ToolRegistry registry = ToolRegistry() server = _make_mock_server( "srv", session=MagicMock(), tools=[ _make_mcp_tool("read-file"), _make_mcp_tool("read_file"), _make_mcp_tool("safe_tool"), ], ) config = {"tools": {"resources": False, "prompts": False}} with patch("tools.registry.registry", registry), \ patch("tools.mcp_tool._track_mcp_tool_server"), \ caplog.at_level(logging.ERROR, logger="tools.mcp_tool"): registered = _register_server_tools("srv", server, config) assert registered == ["mcp__srv__safe_tool"] assert registry.get_entry("mcp__srv__read_file") is None assert registry.get_entry("mcp__srv__safe_tool") is not None assert any( "name normalization collision" in record.message and "tool 'read-file'" in record.message and "tool 'read_file'" in record.message for record in caplog.records ) # --------------------------------------------------------------------------- # 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_stdio_recycle_deadline_pauses_while_rpc_active(self): from tools.mcp_tool import MCPServerTask async def _test(): server = MCPServerTask("srv") server._config = {"command": "npx"} server._idle_timeout_seconds = 0.01 server._last_tool_call_at = time.monotonic() - 1.0 async with server._rpc_lock: assert server._stdio_recycle_reason() is None assert server._next_stdio_recycle_deadline() is None 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_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 # The failed server is now serving a post-failure backoff # (#50394: prevents a tight re-spawn storm across the frequent # per-worker-session discovery passes). Expire that cooldown to # simulate the retry window having elapsed. import tools.mcp_tool as _mcp_mod _mcp_mod._server_connect_retry_after.pop("broken", None) # Next call after the cooldown: 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 == [] # --------------------------------------------------------------------------- # Shutdown (public API) # --------------------------------------------------------------------------- class TestShutdown: def test_shutdown_drains_parked_server_after_bounded_wait_expires(self): """The public shutdown path drains a parked server if graceful shutdown stalls. This exercises the production ownership path: a real ``MCPServerTask`` is registered, its parked waiter owns child tasks on the shared loop, and the bounded wait for the scheduled shutdown expires. The loop owner must still cancel and drain that waiter before closing the loop. """ import tools.mcp_tool as mcp_mod from tools.mcp_tool import MCPServerTask, shutdown_mcp_servers shutdown_started = threading.Event() parked_task_done = threading.Event() scheduled_shutdown = {} schedule_count = 0 class StalledShutdownServer(MCPServerTask): async def shutdown(self): shutdown_started.set() await asyncio.Event().wait() server = StalledShutdownServer("parked") with mcp_mod._lock: mcp_mod._servers.clear() mcp_mod._server_connecting.clear() mcp_mod._ensure_mcp_loop() with mcp_mod._lock: loop = mcp_mod._mcp_loop assert loop is not None async def install_parked_waiter(): task = asyncio.create_task(server._wait_for_reconnect_or_shutdown()) server._task = task task.add_done_callback(lambda _task: parked_task_done.set()) await asyncio.sleep(0) return task parked_task = asyncio.run_coroutine_threadsafe( install_parked_waiter(), loop ).result(timeout=2) with mcp_mod._lock: mcp_mod._servers[server.name] = server def schedule_then_report_timeout(coro, target_loop, **_kwargs): nonlocal schedule_count schedule_count += 1 future = asyncio.run_coroutine_threadsafe(coro, target_loop) if schedule_count > 1: return future scheduled_shutdown["future"] = future class TimedOutFuture: def result(self, timeout): assert timeout > 0 assert shutdown_started.wait(timeout=2) raise TimeoutError("simulated bounded MCP shutdown timeout") return TimedOutFuture() try: with patch( "agent.async_utils.safe_schedule_threadsafe", side_effect=schedule_then_report_timeout, ): shutdown_mcp_servers() assert loop.is_closed() assert parked_task_done.is_set(), ( "parked MCPServerTask was not drained before its loop closed" ) assert parked_task.done() assert scheduled_shutdown["future"].done() assert schedule_count == 2 finally: with mcp_mod._lock: mcp_mod._servers.clear() mcp_mod._server_connecting.clear() mcp_mod._stop_mcp_loop() 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_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() # 4 servers each taking 50ms to shut down delay = 0.05 for i in range(4): mock_server = MagicMock() mock_server.name = f"srv_{i}" async def slow_shutdown(): await asyncio.sleep(delay) 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: ~1 delay, not 4. Margin covers scheduling jitter but stays # well under the serial total. assert elapsed < delay * 3, ( f"Shutdown took {elapsed:.3f}s, expected ~{delay}s (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_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 def test_secret_source_injected_vars_are_passed(self, monkeypatch): """Vars tagged by an external secret source (Bitwarden/1Password) are deliberately allowed for MCP stdio servers.""" from hermes_cli import env_loader from tools.mcp_tool import _build_safe_env monkeypatch.setitem(env_loader._SECRET_SOURCES, "ALPACA_API_KEY", "bitwarden") monkeypatch.setitem(env_loader._SECRET_SOURCES, "NOTION_TOKEN", "onepassword") fake_env = { "PATH": "/usr/bin", "ALPACA_API_KEY": "from-bws-key", "NOTION_TOKEN": "from-op", "UNTRACKED_SECRET_KEY": "still-filtered", } with patch.dict("os.environ", fake_env, clear=True): result = _build_safe_env(None) assert result["PATH"] == "/usr/bin" assert result["ALPACA_API_KEY"] == "from-bws-key" assert result["NOTION_TOKEN"] == "from-op" assert "UNTRACKED_SECRET_KEY" not in result def test_windows_location_vars_passed_without_secrets(self): """Windows launcher tools need location vars, but secrets stay filtered.""" from tools.mcp_tool import _build_safe_env fake_env = { "PATH": r"C:\Windows\System32", "ProgramFiles": r"C:\Program Files", "ProgramData": r"C:\ProgramData", "ProgramW6432": r"C:\Program Files", "LOCALAPPDATA": r"C:\Users\alice\AppData\Local", "APPDATA": r"C:\Users\alice\AppData\Roaming", "USERPROFILE": r"C:\Users\alice", "GITHUB_TOKEN": "ghp_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", "OPENAI_API_KEY": "sk-proj-abc123", } with patch.dict("os.environ", fake_env, clear=True): result = _build_safe_env(None) assert result["ProgramFiles"] == r"C:\Program Files" assert result["ProgramData"] == r"C:\ProgramData" assert result["ProgramW6432"] == r"C:\Program Files" assert result["LOCALAPPDATA"].endswith("Local") assert result["APPDATA"].endswith("Roaming") assert result["USERPROFILE"] == r"C:\Users\alice" assert "GITHUB_TOKEN" not in result assert "OPENAI_API_KEY" not in result # --------------------------------------------------------------------------- # _sanitize_error # --------------------------------------------------------------------------- class TestSanitizeError: """Tests for _sanitize_error() credential stripping.""" def test_strips_credentials(self): from tools.mcp_tool import _sanitize_error for text, expected in ( ("Error with ghp_abc123def456", "Error with [REDACTED]"), ("key sk-projABC123xyz", "key [REDACTED]"), ("Authorization: Bearer eyJabc123def", "Authorization: [REDACTED]"), ("url?token=secret123", "url?[REDACTED]"), ): assert _sanitize_error(text) == expected, text # Several credentials in one message are all masked. multi = _sanitize_error("ghp_abc123 and sk-projXyz789 and token=foo") assert "ghp_" not in multi and "sk-" not in multi and "token=" not in multi assert multi.count("[REDACTED]") == 3 def test_no_credentials_unchanged(self): from tools.mcp_tool import _sanitize_error result = _sanitize_error("normal error message") assert result == "normal error message" # --------------------------------------------------------------------------- # 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_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_stdio_unavailable_raises_importerror_not_nameerror(self): """Regression test for #30904. When the mcp SDK isn't installed, ``_run_stdio`` previously leaked a bare ``NameError: name 'StdioServerParameters' is not defined``. The gate now raises a clear ``ImportError`` with install instructions, mirroring ``_run_http``'s behaviour when the HTTP transport is unavailable. """ from tools.mcp_tool import MCPServerTask server = MCPServerTask("local") config = {"command": "python3", "args": ["/tmp/echo.py"]} async def _test(): with patch("tools.mcp_tool._MCP_AVAILABLE", False): with pytest.raises(ImportError, match=r"mcp.*SDK"): await server._run_stdio(config) asyncio.run(_test()) # --------------------------------------------------------------------------- # Reconnection logic # --------------------------------------------------------------------------- class TestReconnection: """Tests for automatic reconnection behavior in MCPServerTask.run().""" def test_reconnect_on_disconnect(self): """After initial success, a connection drop triggers reconnection.""" from tools.mcp_tool import MCPServerTask run_count = 0 target_server = None original_run_stdio = MCPServerTask._run_stdio async def patched_run_stdio(self_srv, config): nonlocal run_count, target_server run_count += 1 if target_server is not self_srv: return await original_run_stdio(self_srv, config) if run_count == 1: # First connection succeeds, then simulate disconnect self_srv.session = MagicMock() self_srv._tools = [] self_srv._ready.set() raise ConnectionError("connection dropped") else: # Reconnection succeeds; signal shutdown so run() exits self_srv.session = MagicMock() self_srv._shutdown_event.set() await self_srv._shutdown_event.wait() async def _test(): nonlocal target_server server = MCPServerTask("test_srv") target_server = server with patch.object(MCPServerTask, "_run_stdio", patched_run_stdio), \ patch("asyncio.sleep", new_callable=AsyncMock): await server.run({"command": "test"}) assert run_count >= 2 # At least one reconnection attempt asyncio.run(_test()) def test_preflight_probe_runs_on_initial_http_connect(self): """The content-type preflight probe fires on the first HTTP connect.""" from tools.mcp_tool import MCPServerTask target_server = None probe = AsyncMock() original_run_http = MCPServerTask._run_http async def patched_run_http(self_srv, config): if target_server is not self_srv: return await original_run_http(self_srv, config) # First connect succeeds; signal shutdown so run() exits cleanly. self_srv.session = MagicMock() self_srv._tools = [] self_srv._ready.set() self_srv._shutdown_event.set() await self_srv._shutdown_event.wait() async def _test(): nonlocal target_server server = MCPServerTask("http_srv") target_server = server with patch.object(MCPServerTask, "_run_http", patched_run_http), \ patch.object(MCPServerTask, "_preflight_content_type", probe), \ patch("asyncio.sleep", new_callable=AsyncMock): await server.run({"url": "https://example.com/mcp"}) # Probe ran exactly once on the initial (pre-_ready) connect. assert probe.await_count == 1 asyncio.run(_test()) # --------------------------------------------------------------------------- # Configurable timeouts # --------------------------------------------------------------------------- class TestConfigurableTimeouts: """Tests for configurable per-server timeouts.""" 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 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_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"] # --------------------------------------------------------------------------- # 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) # -- read_resource -- # -- list_prompts -- # -- 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) # --------------------------------------------------------------------------- # 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) # =========================================================================== # SamplingHandler tests # =========================================================================== 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_coercion_clamping_and_fallbacks(self): # (value, default, caster, kwargs, expected) cases = [ (10, 5, int, {}, 10), ("20", 5, int, {}, 20), ("3.5", 1.0, float, {}, 3.5), (None, 7, int, {}, 7), ("abc", 42, int, {}, 42), (float("inf"), 3.0, float, {}, 3.0), (float("nan"), 4.0, float, {}, 4.0), (-5, 10, int, {"minimum": 1}, 1), (0, 10, int, {"minimum": 0}, 0), ] for value, default, caster, kwargs, expected in cases: assert _safe_numeric(value, default, caster, **kwargs) == expected, value # --------------------------------------------------------------------------- # 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"] # --------------------------------------------------------------------------- # 3. Rate limiting # --------------------------------------------------------------------------- class TestRateLimit: def setup_method(self): self.handler = SamplingHandler("rl", {"max_rpm": 3}) 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_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" # --------------------------------------------------------------------------- # 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_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"} # --------------------------------------------------------------------------- # 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_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": {}}, }, }] # --------------------------------------------------------------------------- # 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"} # --------------------------------------------------------------------------- # 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_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): # Config values clamp to a 1s floor (_safe_numeric minimum), so set the # attribute directly to exercise the timeout branch without a 1s wait. handler = SamplingHandler("to", {}) handler.timeout = 0.05 def slow_call(**kwargs): import threading evt = threading.Event() # Outlives the 0.05s handler timeout, but short enough that the # abandoned worker thread doesn't stall loop shutdown. evt.wait(0.15) 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_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 # --------------------------------------------------------------------------- # 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 # --------------------------------------------------------------------------- # 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 {{{"} # --------------------------------------------------------------------------- # 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 # --------------------------------------------------------------------------- # 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 # --------------------------------------------------------------------------- # 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 # --------------------------------------------------------------------------- # 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_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_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" 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_rejected_when_collision_is_another_mcp(self): """Cross-server MCP collisions preserve the existing owner.""" 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": []}) ) # Cross-server MCP collisions fail closed: the existing owner stays active. assert "mcp__srv__do_thing" not in registered entry = mock_registry.get_entry("mcp__srv__do_thing") assert entry is not None assert entry.toolset == "mcp-old" assert entry.schema["description"] == "From another MCP server" assert mock_registry.get_toolset_for_tool("mcp__srv__do_thing") == "mcp-old" _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_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_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_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_skips_servers_already_connecting(self): """Servers in _server_connecting must not be spawned again (#58862).""" from tools.mcp_tool import ( register_mcp_servers, _servers, _server_connecting, _ensure_mcp_loop, ) fake_config = {"my_srv": {"command": "npx", "args": ["test"]}} # Simulate a prior call that started connecting but hasn't finished _server_connecting.add("my_srv") connect_calls = [] async def fake_register(name, cfg): connect_calls.append(name) server = _make_mock_server(name) server._registered_tool_names = [f"mcp_{name}_tool"] _servers[name] = server return [f"mcp_{name}_tool"] try: 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=[]), \ patch("tools.mcp_tool._connect_cooldown_active", return_value=False): _ensure_mcp_loop() result = register_mcp_servers(fake_config) # Should NOT have attempted to connect my_srv again assert connect_calls == [], ( f"Server already in _server_connecting should be skipped, " f"but connect was called for: {connect_calls}" ) assert result == [] finally: _server_connecting.discard("my_srv") _servers.pop("my_srv", None) def test_clears_stale_connecting_on_timeout(self): """Stale entries in _server_connecting are cleaned up after timeout (#58862).""" from tools.mcp_tool import ( register_mcp_servers, _servers, _server_connecting, _server_connect_errors, _ensure_mcp_loop, ) fake_config = { "srv_a": {"command": "npx", "args": ["a"]}, "srv_b": {"command": "npx", "args": ["b"]}, } # Simulate that srv_a is already connecting from another call _server_connecting.add("srv_a") with patch("tools.mcp_tool._MCP_AVAILABLE", True), \ patch("tools.mcp_tool._run_on_mcp_loop", side_effect=TimeoutError("timed out")), \ patch("tools.mcp_tool._existing_tool_names", return_value=[]), \ patch("tools.mcp_tool._connect_cooldown_active", return_value=False): _ensure_mcp_loop() with pytest.raises(TimeoutError): register_mcp_servers(fake_config) # After timeout, srv_b (which was in new_servers and added to _server_connecting) # should have been cleaned up from _server_connecting. # srv_a should remain since it was added externally and not part of new_servers. assert "srv_b" not in _server_connecting, ( "Stale server added during this call should have been removed from " "_server_connecting after timeout" ) # Cleanup _server_connecting.discard("srv_a") _servers.pop("srv_a", None) _servers.pop("srv_b", None) # --------------------------------------------------------------------------- # Tests for parallel tool call support (port from openai/codex#17667) # --------------------------------------------------------------------------- class TestMcpParallelToolCalls: """Tests for the supports_parallel_tool_calls config option.""" def test_is_mcp_tool_parallel_safe_with_flag(self): """MCP tool from a parallel-safe server returns True.""" from tools.mcp_tool import ( is_mcp_tool_parallel_safe, _mcp_tool_server_names, _parallel_safe_servers, _lock, ) with _lock: _parallel_safe_servers.add("docs") _mcp_tool_server_names["mcp__docs__search"] = "docs" _mcp_tool_server_names["mcp__docs__read_file"] = "docs" _mcp_tool_server_names["mcp__github__list_repos"] = "github" try: assert is_mcp_tool_parallel_safe("mcp__docs__search") is True assert is_mcp_tool_parallel_safe("mcp__docs__read_file") is True # Different server should be False assert is_mcp_tool_parallel_safe("mcp__github__list_repos") is False finally: with _lock: _parallel_safe_servers.discard("docs") _mcp_tool_server_names.pop("mcp__docs__search", None) _mcp_tool_server_names.pop("mcp__docs__read_file", None) _mcp_tool_server_names.pop("mcp__github__list_repos", None) def test_register_mcp_servers_tracks_parallel_flag(self): """register_mcp_servers populates _parallel_safe_servers from config.""" from tools.mcp_tool import ( register_mcp_servers, _parallel_safe_servers, _lock, sanitize_mcp_name_component, ) fake_config = { "parallel_srv": { "command": "echo", "supports_parallel_tool_calls": True, }, "serial_srv": { "command": "echo", "supports_parallel_tool_calls": False, }, "default_srv": { "command": "echo", # no supports_parallel_tool_calls key }, } with patch("tools.mcp_tool._MCP_AVAILABLE", True), \ patch("tools.mcp_tool._ensure_mcp_loop"), \ patch("tools.mcp_tool._run_on_mcp_loop"), \ patch("tools.mcp_tool._existing_tool_names", return_value=[]): register_mcp_servers(fake_config) with _lock: assert sanitize_mcp_name_component("parallel_srv") in _parallel_safe_servers assert sanitize_mcp_name_component("serial_srv") not in _parallel_safe_servers assert sanitize_mcp_name_component("default_srv") not in _parallel_safe_servers # Cleanup _parallel_safe_servers.discard(sanitize_mcp_name_component("parallel_srv")) # --------------------------------------------------------------------------- # Cross-process MCP discovery lock (issue #62771) # --------------------------------------------------------------------------- class TestMCPDiscoveryCrossProcessLock: """Tests for the cross-process MCP discovery guard in discover_mcp_tools().""" @staticmethod def _lock_exclusive(fh): """Lock a file handle exclusively, cross-platform. Mirrors production _try_acquire_mcp_discovery_lock: fcntl on POSIX, portalocker on Windows (portalocker only ships on win32 installs). """ if sys.platform == "win32": import portalocker self._lock_exclusive(fh) else: import fcntl fcntl.flock(fh, fcntl.LOCK_EX | fcntl.LOCK_NB) @pytest.fixture(autouse=True) def _fast_retries(self): """Override retry constants so tests are fast.""" import tools.mcp_tool as mcp_tool orig_max = mcp_tool._MCP_DISCOVERY_LOCK_MAX_RETRIES orig_delay = mcp_tool._MCP_DISCOVERY_LOCK_RETRY_DELAY_S mcp_tool._MCP_DISCOVERY_LOCK_MAX_RETRIES = 3 mcp_tool._MCP_DISCOVERY_LOCK_RETRY_DELAY_S = 0.01 yield mcp_tool._MCP_DISCOVERY_LOCK_MAX_RETRIES = orig_max mcp_tool._MCP_DISCOVERY_LOCK_RETRY_DELAY_S = orig_delay def test_lock_acquired_path(self, tmp_path): """Lock acquired -> discovery runs normally, lock released at end.""" from tools.mcp_tool import ( _LockCookie, discover_mcp_tools, ) lock_file = tmp_path / ".mcp-discovery.lock" fh = open(lock_file, "w", encoding="utf-8") cookie = _LockCookie(fh) def mock_acquire(): return cookie mock_config = {"test_srv": {"command": "echo", "enabled": True}} with patch.object(cookie, "release", wraps=cookie.release) as release_spy: with patch("tools.mcp_tool._try_acquire_mcp_discovery_lock", mock_acquire), \ patch("tools.mcp_tool._MCP_AVAILABLE", True), \ patch("tools.mcp_tool._load_mcp_config", return_value=mock_config), \ patch("tools.mcp_tool.register_mcp_servers", return_value=["mcp__test_srv__ping"]) as reg_spy: result = discover_mcp_tools() assert result == ["mcp__test_srv__ping"] release_spy.assert_called_once() def test_lock_held_retries_exhausted_fallback(self): """All retry attempts see lock held -> runs discovery unguarded.""" from tools.mcp_tool import ( _LOCK_UNAVAILABLE, discover_mcp_tools, _MCP_DISCOVERY_LOCK_MAX_RETRIES, ) mock_config = {"test_srv": {"command": "echo", "enabled": True}} # Every attempt returns None (lock held) with patch("tools.mcp_tool._try_acquire_mcp_discovery_lock", return_value=None), \ patch("tools.mcp_tool._MCP_AVAILABLE", True), \ patch("tools.mcp_tool._load_mcp_config", return_value=mock_config), \ patch("tools.mcp_tool.register_mcp_servers") as reg_spy, \ patch("tools.mcp_tool._existing_tool_names", return_value=[]): result = discover_mcp_tools() # Must still run local discovery reg_spy.assert_called_once_with(mock_config) def test_posix_flock_acquire_and_release(self): """_acquire_lock_on_fh uses fcntl.flock on POSIX.""" import sys import tempfile from unittest.mock import MagicMock mock_fcntl = MagicMock() mock_fcntl.LOCK_EX = 2 mock_fcntl.LOCK_NB = 4 with tempfile.NamedTemporaryFile(prefix="mcp-lock-", suffix=".tmp", delete=False) as tf: lock_path = tf.name try: fh = open(lock_path, "w", encoding="utf-8") with patch.dict("sys.modules", {"fcntl": mock_fcntl}), \ patch("tools.mcp_tool.os.name", "posix"): from tools.mcp_tool import _acquire_lock_on_fh result = _acquire_lock_on_fh(fh) assert result is True mock_fcntl.flock.assert_called_once_with( fh.fileno(), mock_fcntl.LOCK_EX | mock_fcntl.LOCK_NB ) fh.close() finally: try: os.unlink(lock_path) except Exception: pass