mirror of
https://github.com/PrefectHQ/fastmcp.git
synced 2026-08-09 23:29:10 +02:00
5fa2883670TasksExtension serves io.modelcontextprotocol/tasks on the extension API: a decide-and-task tools/call interceptor (era-gated to modern connections), tasks/get with inlined results and inputRequests, tasks/update delivering poll-based in-task elicitation, tasks/cancel, durable creation, and auth-scoped task isolation. Wire models validate against the vendored ext-tasks schema. Worker-side Context hooks are refcounted so sibling servers cannot strand each other's workers. Co-Authored-By: Claude <noreply@anthropic.com>
99 lines
3 KiB
Python
99 lines
3 KiB
Python
"""
|
|
Tests that synchronous functions cannot be used as background tasks.
|
|
|
|
SEP-2663 tasks are tools-only. Docket requires async functions for background
|
|
execution, so FastMCP raises ValueError when task=True is used with a sync tool
|
|
function. These are registration-time checks and need no running server.
|
|
"""
|
|
|
|
import pytest
|
|
|
|
from fastmcp import FastMCP
|
|
from fastmcp.tools.function_tool import FunctionTool
|
|
|
|
|
|
async def test_sync_tool_with_explicit_task_true_raises():
|
|
"""Sync tool with task=True raises ValueError."""
|
|
mcp = FastMCP("test")
|
|
|
|
with pytest.raises(
|
|
ValueError, match="uses a sync function but has task execution enabled"
|
|
):
|
|
|
|
@mcp.tool(task=True)
|
|
def sync_tool(x: int) -> int:
|
|
"""A synchronous tool."""
|
|
return x * 2
|
|
|
|
|
|
async def test_sync_tool_with_inherited_task_true_raises():
|
|
"""Sync tool inheriting task=True from server raises ValueError."""
|
|
mcp = FastMCP("test", tasks=True)
|
|
|
|
with pytest.raises(
|
|
ValueError, match="uses a sync function but has task execution enabled"
|
|
):
|
|
|
|
@mcp.tool() # Inherits task=True from server
|
|
def sync_tool(x: int) -> int:
|
|
"""A synchronous tool."""
|
|
return x * 2
|
|
|
|
|
|
async def test_async_tool_with_task_true_remains_enabled():
|
|
"""Async tools with task=True keep task support enabled."""
|
|
mcp = FastMCP("test")
|
|
|
|
@mcp.tool(task=True)
|
|
async def async_tool(x: int) -> int:
|
|
"""An async tool."""
|
|
return x * 2
|
|
|
|
tool = await mcp.get_tool("async_tool")
|
|
assert isinstance(tool, FunctionTool)
|
|
assert tool.task_config.mode == "optional"
|
|
|
|
|
|
async def test_sync_tool_with_task_false_works():
|
|
"""Sync tool with explicit task=False works (no error)."""
|
|
mcp = FastMCP("test", tasks=True)
|
|
|
|
@mcp.tool(task=False) # Explicitly disable
|
|
def sync_tool(x: int) -> int:
|
|
"""A synchronous tool."""
|
|
return x * 2
|
|
|
|
tool = await mcp.get_tool("sync_tool")
|
|
assert isinstance(tool, FunctionTool)
|
|
assert tool.task_config.mode == "forbidden"
|
|
|
|
|
|
# =============================================================================
|
|
# Callable classes with async __call__
|
|
# =============================================================================
|
|
|
|
|
|
async def test_async_callable_class_tool_with_task_true_works():
|
|
"""Callable class with async __call__ and task=True should work."""
|
|
from fastmcp.tools import Tool
|
|
|
|
class AsyncCallableTool:
|
|
async def __call__(self, x: int) -> int:
|
|
return x * 2
|
|
|
|
tool = Tool.from_function(AsyncCallableTool(), task=True)
|
|
assert tool.task_config.mode == "optional"
|
|
|
|
|
|
async def test_sync_callable_class_tool_with_task_true_raises():
|
|
"""Callable class with sync __call__ and task=True should raise."""
|
|
from fastmcp.tools import Tool
|
|
|
|
class SyncCallableTool:
|
|
def __call__(self, x: int) -> int:
|
|
return x * 2
|
|
|
|
with pytest.raises(
|
|
ValueError, match="uses a sync function but has task execution enabled"
|
|
):
|
|
Tool.from_function(SyncCallableTool(), task=True)
|