Files

137 lines
5.2 KiB
Python

import pytest
from mcp.client.session import ClientSession
from mcp.shared.context import RequestContext
from mcp.shared.memory import (
create_connected_server_and_client_session as create_session,
)
from mcp.types import (
CreateMessageRequestParams,
CreateMessageResult,
CreateMessageResultWithTools,
SamplingMessage,
TextContent,
ToolUseContent,
)
@pytest.mark.anyio
async def test_sampling_callback():
from mcp.server.fastmcp import FastMCP
server = FastMCP("test")
callback_return = CreateMessageResult(
role="assistant",
content=TextContent(type="text", text="This is a response from the sampling callback"),
model="test-model",
stopReason="endTurn",
)
async def sampling_callback(
context: RequestContext[ClientSession, None],
params: CreateMessageRequestParams,
) -> CreateMessageResult:
return callback_return
@server.tool("test_sampling")
async def test_sampling_tool(message: str):
value = await server.get_context().session.create_message(
messages=[SamplingMessage(role="user", content=TextContent(type="text", text=message))],
max_tokens=100,
)
assert value == callback_return
return True
# Test with sampling callback
async with create_session(server._mcp_server, sampling_callback=sampling_callback) as client_session:
# Make a request to trigger sampling callback
result = await client_session.call_tool("test_sampling", {"message": "Test message for sampling"})
assert result.isError is False
assert isinstance(result.content[0], TextContent)
assert result.content[0].text == "true"
# Test without sampling callback
async with create_session(server._mcp_server) as client_session:
# Make a request to trigger sampling callback
result = await client_session.call_tool("test_sampling", {"message": "Test message for sampling"})
assert result.isError is True
assert isinstance(result.content[0], TextContent)
assert result.content[0].text == "Error executing tool test_sampling: Sampling not supported"
@pytest.mark.anyio
async def test_create_message_backwards_compat_single_content():
"""Test backwards compatibility: create_message without tools returns single content."""
from mcp.server.fastmcp import FastMCP
server = FastMCP("test")
# Callback returns single content (text)
callback_return = CreateMessageResult(
role="assistant",
content=TextContent(type="text", text="Hello from LLM"),
model="test-model",
stopReason="endTurn",
)
async def sampling_callback(
context: RequestContext[ClientSession, None],
params: CreateMessageRequestParams,
) -> CreateMessageResult:
return callback_return
@server.tool("test_backwards_compat")
async def test_tool(message: str):
# Call create_message WITHOUT tools
result = await server.get_context().session.create_message(
messages=[SamplingMessage(role="user", content=TextContent(type="text", text=message))],
max_tokens=100,
)
# Backwards compat: result should be CreateMessageResult
assert isinstance(result, CreateMessageResult)
# Content should be single (not a list) - this is the key backwards compat check
assert isinstance(result.content, TextContent)
assert result.content.text == "Hello from LLM"
# CreateMessageResult should NOT have content_as_list (that's on WithTools)
assert not hasattr(result, "content_as_list") or not callable(getattr(result, "content_as_list", None))
return True
async with create_session(server._mcp_server, sampling_callback=sampling_callback) as client_session:
result = await client_session.call_tool("test_backwards_compat", {"message": "Test"})
assert result.isError is False
assert isinstance(result.content[0], TextContent)
assert result.content[0].text == "true"
@pytest.mark.anyio
async def test_create_message_result_with_tools_type():
"""Test that CreateMessageResultWithTools supports content_as_list."""
# Test the type itself, not the overload (overload requires client capability setup)
result = CreateMessageResultWithTools(
role="assistant",
content=ToolUseContent(type="tool_use", id="call_123", name="get_weather", input={"city": "SF"}),
model="test-model",
stopReason="toolUse",
)
# CreateMessageResultWithTools should have content_as_list
content_list = result.content_as_list
assert len(content_list) == 1
assert content_list[0].type == "tool_use"
# It should also work with array content
result_array = CreateMessageResultWithTools(
role="assistant",
content=[
TextContent(type="text", text="Let me check the weather"),
ToolUseContent(type="tool_use", id="call_456", name="get_weather", input={"city": "NYC"}),
],
model="test-model",
stopReason="toolUse",
)
content_list_array = result_array.content_as_list
assert len(content_list_array) == 2
assert content_list_array[0].type == "text"
assert content_list_array[1].type == "tool_use"