Files
hermes-agent/tests/tools/test_mcp_oauth.py
Teknium cc54818d26 fix(mcp): stability fix pack — reload timeout, shutdown cleanup, event loop handler, OAuth non-blocking (#4757)
Four fixes for MCP server stability issues reported by community member
(terminal lockup, zombie processes, escape sequence pollution, startup hang):

1. MCP reload timeout guard (cli.py): _check_config_mcp_changes now runs
   _reload_mcp in a separate daemon thread with a 30s hard timeout. Previously,
   a hung MCP server could block the process_loop thread indefinitely, freezing
   the entire TUI (user can type but nothing happens, only Ctrl+D/Ctrl+\ work).

2. MCP stdio subprocess PID tracking (mcp_tool.py): Tracks child PIDs spawned
   by stdio_client via before/after snapshots of /proc children. On shutdown,
   _stop_mcp_loop force-kills any tracked PIDs that survived the SDK's graceful
   SIGTERM→SIGKILL cleanup. Prevents zombie MCP server processes from
   accumulating across sessions.

3. MCP event loop exception handler (mcp_tool.py): Installs
   _mcp_loop_exception_handler on the MCP background event loop — same pattern
   as the existing _suppress_closed_loop_errors on prompt_toolkit's loop.
   Suppresses benign 'Event loop is closed' RuntimeError from httpx transport
   __del__ during MCP shutdown. Salvaged from PR #2538 (acsezen).

4. MCP OAuth non-blocking (mcp_oauth.py): Replaces blocking input() call in
   _wait_for_callback with OAuthNonInteractiveError raise. Adds _is_interactive()
   TTY detection. In non-interactive environments, build_oauth_auth() still
   returns a provider (cached tokens + refresh work), but the callback handler
   raises immediately instead of blocking the MCP event loop for 120s. Re-raises
   OAuth setup failures in _run_http so failed servers are reported cleanly
   without blocking others. Salvaged from PRs #4521 (voidborne-d) and #4465
   (heathley).

Closes #2537, closes #4462
Related: #4128, #3436
2026-04-03 02:29:20 -07:00

338 lines
12 KiB
Python

"""Tests for tools/mcp_oauth.py — thin OAuth adapter over MCP SDK."""
import json
import os
from pathlib import Path
from unittest.mock import patch, MagicMock, AsyncMock
import pytest
from tools.mcp_oauth import (
HermesTokenStorage,
OAuthNonInteractiveError,
build_oauth_auth,
remove_oauth_tokens,
_find_free_port,
_can_open_browser,
_is_interactive,
_wait_for_callback,
)
# ---------------------------------------------------------------------------
# HermesTokenStorage
# ---------------------------------------------------------------------------
class TestHermesTokenStorage:
def test_roundtrip_tokens(self, tmp_path, monkeypatch):
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
storage = HermesTokenStorage("test-server")
import asyncio
# Initially empty
assert asyncio.run(storage.get_tokens()) is None
# Save and retrieve
mock_token = MagicMock()
mock_token.model_dump.return_value = {
"access_token": "abc123",
"token_type": "Bearer",
"refresh_token": "ref456",
}
asyncio.run(storage.set_tokens(mock_token))
# File exists with correct permissions
token_path = tmp_path / "mcp-tokens" / "test-server.json"
assert token_path.exists()
data = json.loads(token_path.read_text())
assert data["access_token"] == "abc123"
def test_roundtrip_client_info(self, tmp_path, monkeypatch):
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
storage = HermesTokenStorage("test-server")
import asyncio
assert asyncio.run(storage.get_client_info()) is None
mock_client = MagicMock()
mock_client.model_dump.return_value = {
"client_id": "hermes-123",
"client_secret": "secret",
}
asyncio.run(storage.set_client_info(mock_client))
client_path = tmp_path / "mcp-tokens" / "test-server.client.json"
assert client_path.exists()
def test_remove_cleans_up(self, tmp_path, monkeypatch):
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
storage = HermesTokenStorage("test-server")
# Create files
d = tmp_path / "mcp-tokens"
d.mkdir(parents=True)
(d / "test-server.json").write_text("{}")
(d / "test-server.client.json").write_text("{}")
storage.remove()
assert not (d / "test-server.json").exists()
assert not (d / "test-server.client.json").exists()
# ---------------------------------------------------------------------------
# build_oauth_auth
# ---------------------------------------------------------------------------
class TestBuildOAuthAuth:
def test_returns_oauth_provider(self):
try:
from mcp.client.auth import OAuthClientProvider
except ImportError:
pytest.skip("MCP SDK auth not available")
auth = build_oauth_auth("test", "https://example.com/mcp")
assert isinstance(auth, OAuthClientProvider)
def test_returns_none_without_sdk(self, monkeypatch):
import tools.mcp_oauth as mod
orig_import = __builtins__.__import__ if hasattr(__builtins__, '__import__') else __import__
def _block_import(name, *args, **kwargs):
if "mcp.client.auth" in name:
raise ImportError("blocked")
return orig_import(name, *args, **kwargs)
with patch("builtins.__import__", side_effect=_block_import):
result = build_oauth_auth("test", "https://example.com")
# May or may not be None depending on import caching, but shouldn't crash
assert result is None or result is not None
# ---------------------------------------------------------------------------
# Utility functions
# ---------------------------------------------------------------------------
class TestUtilities:
def test_find_free_port_returns_int(self):
port = _find_free_port()
assert isinstance(port, int)
assert 1024 <= port <= 65535
def test_can_open_browser_false_in_ssh(self, monkeypatch):
monkeypatch.setenv("SSH_CLIENT", "1.2.3.4 1234 22")
assert _can_open_browser() is False
def test_can_open_browser_false_without_display(self, monkeypatch):
monkeypatch.delenv("SSH_CLIENT", raising=False)
monkeypatch.delenv("SSH_TTY", raising=False)
monkeypatch.delenv("DISPLAY", raising=False)
# Mock os.name and uname for non-macOS, non-Windows
monkeypatch.setattr(os, "name", "posix")
monkeypatch.setattr(os, "uname", lambda: type("", (), {"sysname": "Linux"})())
assert _can_open_browser() is False
# ---------------------------------------------------------------------------
# remove_oauth_tokens
# ---------------------------------------------------------------------------
class TestPathTraversal:
"""Verify server_name is sanitized to prevent path traversal."""
def test_path_traversal_blocked(self, tmp_path, monkeypatch):
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
storage = HermesTokenStorage("../../.ssh/config")
path = storage._tokens_path()
# Should stay within mcp-tokens directory
assert "mcp-tokens" in str(path)
assert ".ssh" not in str(path.resolve())
def test_dots_and_slashes_sanitized(self, tmp_path, monkeypatch):
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
storage = HermesTokenStorage("../../../etc/passwd")
path = storage._tokens_path()
resolved = path.resolve()
assert resolved.is_relative_to((tmp_path / "mcp-tokens").resolve())
def test_normal_name_unchanged(self, tmp_path, monkeypatch):
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
storage = HermesTokenStorage("my-mcp-server")
assert "my-mcp-server.json" in str(storage._tokens_path())
def test_special_chars_sanitized(self, tmp_path, monkeypatch):
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
storage = HermesTokenStorage("server@host:8080/path")
path = storage._tokens_path()
assert "@" not in path.name
assert ":" not in path.name
assert "/" not in path.stem
class TestCallbackHandlerIsolation:
"""Verify concurrent OAuth flows don't share state."""
def test_independent_result_dicts(self):
from tools.mcp_oauth import _make_callback_handler
_, result_a = _make_callback_handler()
_, result_b = _make_callback_handler()
result_a["auth_code"] = "code_A"
result_b["auth_code"] = "code_B"
assert result_a["auth_code"] == "code_A"
assert result_b["auth_code"] == "code_B"
def test_handler_writes_to_own_result(self):
from tools.mcp_oauth import _make_callback_handler
from io import BytesIO
from unittest.mock import MagicMock
HandlerClass, result = _make_callback_handler()
assert result["auth_code"] is None
# Simulate a GET request
handler = HandlerClass.__new__(HandlerClass)
handler.path = "/callback?code=test123&state=mystate"
handler.wfile = BytesIO()
handler.send_response = MagicMock()
handler.send_header = MagicMock()
handler.end_headers = MagicMock()
handler.do_GET()
assert result["auth_code"] == "test123"
assert result["state"] == "mystate"
class TestOAuthPortSharing:
"""Verify build_oauth_auth and _wait_for_callback use the same port."""
def test_port_stored_globally(self):
import tools.mcp_oauth as mod
# Reset
mod._oauth_port = None
try:
from mcp.client.auth import OAuthClientProvider
except ImportError:
pytest.skip("MCP SDK auth not available")
build_oauth_auth("test-port", "https://example.com/mcp")
assert mod._oauth_port is not None
assert isinstance(mod._oauth_port, int)
assert 1024 <= mod._oauth_port <= 65535
class TestRemoveOAuthTokens:
def test_removes_files(self, tmp_path, monkeypatch):
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
d = tmp_path / "mcp-tokens"
d.mkdir()
(d / "myserver.json").write_text("{}")
(d / "myserver.client.json").write_text("{}")
remove_oauth_tokens("myserver")
assert not (d / "myserver.json").exists()
assert not (d / "myserver.client.json").exists()
def test_no_error_when_files_missing(self, tmp_path, monkeypatch):
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
remove_oauth_tokens("nonexistent") # should not raise
# ---------------------------------------------------------------------------
# Non-interactive / startup-safety tests (issue #4462)
# ---------------------------------------------------------------------------
class TestIsInteractive:
"""_is_interactive() detects headless/daemon/container environments."""
def test_false_when_stdin_not_tty(self, monkeypatch):
mock_stdin = MagicMock()
mock_stdin.isatty.return_value = False
monkeypatch.setattr("tools.mcp_oauth.sys.stdin", mock_stdin)
assert _is_interactive() is False
def test_true_when_stdin_is_tty(self, monkeypatch):
mock_stdin = MagicMock()
mock_stdin.isatty.return_value = True
monkeypatch.setattr("tools.mcp_oauth.sys.stdin", mock_stdin)
assert _is_interactive() is True
def test_false_when_stdin_has_no_isatty(self, monkeypatch):
"""Some environments replace stdin with an object without isatty()."""
mock_stdin = object() # no isatty attribute
monkeypatch.setattr("tools.mcp_oauth.sys.stdin", mock_stdin)
assert _is_interactive() is False
class TestWaitForCallbackNoBlocking:
"""_wait_for_callback() must never call input() — it raises instead."""
def test_raises_on_timeout_instead_of_input(self):
"""When no auth code arrives, raises OAuthNonInteractiveError."""
import tools.mcp_oauth as mod
import asyncio
mod._oauth_port = _find_free_port()
async def instant_sleep(_seconds):
pass
with patch.object(mod.asyncio, "sleep", instant_sleep):
with patch("builtins.input", side_effect=AssertionError("input() must not be called")):
with pytest.raises(OAuthNonInteractiveError, match="callback timed out"):
asyncio.run(_wait_for_callback())
class TestBuildOAuthAuthNonInteractive:
"""build_oauth_auth() in non-interactive mode."""
def test_noninteractive_without_cached_tokens_warns(self, tmp_path, monkeypatch, caplog):
"""Without cached tokens, non-interactive mode logs a clear warning."""
try:
from mcp.client.auth import OAuthClientProvider
except ImportError:
pytest.skip("MCP SDK auth not available")
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
mock_stdin = MagicMock()
mock_stdin.isatty.return_value = False
monkeypatch.setattr("tools.mcp_oauth.sys.stdin", mock_stdin)
import logging
with caplog.at_level(logging.WARNING, logger="tools.mcp_oauth"):
auth = build_oauth_auth("atlassian", "https://mcp.atlassian.com/v1/mcp")
assert auth is not None
assert "no cached tokens found" in caplog.text.lower()
assert "non-interactive" in caplog.text.lower()
def test_noninteractive_with_cached_tokens_no_warning(self, tmp_path, monkeypatch, caplog):
"""With cached tokens, non-interactive mode logs no 'no cached tokens' warning."""
try:
from mcp.client.auth import OAuthClientProvider
except ImportError:
pytest.skip("MCP SDK auth not available")
monkeypatch.setenv("HERMES_HOME", str(tmp_path))
mock_stdin = MagicMock()
mock_stdin.isatty.return_value = False
monkeypatch.setattr("tools.mcp_oauth.sys.stdin", mock_stdin)
# Pre-populate cached tokens
d = tmp_path / "mcp-tokens"
d.mkdir(parents=True)
(d / "atlassian.json").write_text(json.dumps({
"access_token": "cached",
"token_type": "Bearer",
}))
import logging
with caplog.at_level(logging.WARNING, logger="tools.mcp_oauth"):
auth = build_oauth_auth("atlassian", "https://mcp.atlassian.com/v1/mcp")
assert auth is not None
assert "no cached tokens found" not in caplog.text.lower()