fastmcp/tests/server/plugins/test_code_mode_plugin.py
2026-05-10 09:13:02 -04:00

106 lines
3.8 KiB
Python

"""Tests for the CodeMode plugin wrapper.
Transform behavior (what `CodeModeTransform` does to the catalog, how
discovery tools render, sandbox execution, etc.) is covered by
`test_code_mode.py` and `test_code_mode_discovery.py`. This file only
covers the plugin layer itself — config validation, meta derivation,
dict-config coercion, and the deprecation shim at the old import path.
"""
from __future__ import annotations
import warnings
from typing import Any
import pytest
from pydantic import ValidationError
from fastmcp import FastMCP
from fastmcp.server.plugins.code_mode import CodeMode, CodeModeConfig
class _NoopSandbox:
async def run(
self,
code: str,
*,
inputs: dict[str, Any] | None = None,
external_functions: dict[str, Any] | None = None,
) -> Any:
return None
class TestCodeModeConfig:
def test_config_generic_binding(self):
"""`Plugin[CodeModeConfig]` binds CodeModeConfig as the validated config type."""
assert CodeMode._config_cls is CodeModeConfig
assert CodeMode.Config is CodeModeConfig
def test_dict_config_accepted(self):
"""Dict config works for loading from JSON/YAML."""
plugin = CodeMode({"execute_tool_name": "go"})
assert plugin.config.execute_tool_name == "go"
def test_unknown_sandbox_rejected(self):
with pytest.raises((ValidationError, Exception), match="sandbox"):
CodeMode.Config(sandbox="docker") # ty: ignore[invalid-argument-type]
def test_unknown_config_key_rejected(self):
with pytest.raises((ValidationError, Exception), match="forbid|extra"):
CodeMode.Config(not_a_real_option=True) # ty: ignore[unknown-argument]
def test_default_meta(self):
"""CodeMode uses Plugin's auto-derived meta: kebab-cased class
name, no independent version (bundled first-party plugin)."""
assert CodeMode.meta.name == "code-mode"
assert CodeMode.meta.version is None
class TestDeprecationShim:
"""The old `fastmcp.experimental.transforms.code_mode` path still works but warns."""
def test_old_package_import_emits_deprecation_warning(self):
import importlib
import sys
from fastmcp.exceptions import FastMCPDeprecationWarning
sys.modules.pop("fastmcp.experimental.transforms.code_mode", None)
with warnings.catch_warnings(record=True) as caught:
warnings.simplefilter("always")
importlib.import_module("fastmcp.experimental.transforms.code_mode")
fastmcp_deprecations = [
w for w in caught if issubclass(w.category, FastMCPDeprecationWarning)
]
assert any(
"plugins.code_mode" in str(w.message) for w in fastmcp_deprecations
), (
f"expected FastMCPDeprecationWarning pointing at plugins.code_mode, "
f"got {[(w.category.__name__, str(w.message)) for w in caught]}"
)
async def test_legacy_add_transform_pattern_still_works(self):
"""End-to-end: old `add_transform(CodeMode(...))` code keeps
working. The point of the shim is that this doesn't break — the
identity-check test alone wouldn't catch a regression where
`CodeMode` at the old path drifted to the plugin class."""
from fastmcp.exceptions import FastMCPDeprecationWarning
with warnings.catch_warnings():
warnings.simplefilter("ignore", FastMCPDeprecationWarning)
from fastmcp.experimental.transforms.code_mode import (
CodeMode as OldCodeMode,
)
mcp = FastMCP("legacy")
@mcp.tool
def ping() -> str:
return "pong"
mcp.add_transform(OldCodeMode(sandbox_provider=_NoopSandbox()))
tools = await mcp.list_tools(run_middleware=False)
assert {t.name for t in tools} == {"search", "get_schema", "execute"}