Files
modelcontextprotocol--pytho…/tests/client/test_sampling_callback.py
Max Isbey 1b74b06753 Tighten comments and docstrings repo-wide
Cut comment and docstring volume roughly in half across src, tests,
examples, and docs_src: removed comments that restate the adjacent code,
leftover development narration, section banners, and self-evident
Args/Returns blocks, and compressed the remaining docstrings to a
Google-style summary line plus only the detail that earns its place.

Kept (and tightened) the load-bearing content: Raises sections,
deprecation and version-availability notes, spec/RFC/issue references,
why-comments for non-obvious decisions, and all coverage pragmas. The
generated mcp_types.v* wire modules are untouched.
2026-06-29 15:10:27 +00:00

122 lines
4.5 KiB
Python

import pytest
from mcp_types import (
INVALID_REQUEST,
CreateMessageRequestParams,
CreateMessageResult,
CreateMessageResultWithTools,
SamplingMessage,
TextContent,
ToolUseContent,
)
from mcp import Client
from mcp.client import ClientRequestContext
from mcp.server.mcpserver import Context, MCPServer
from mcp.shared.exceptions import MCPError
@pytest.mark.anyio
async def test_sampling_callback():
server = MCPServer("test")
callback_return = CreateMessageResult(
role="assistant",
content=TextContent(type="text", text="This is a response from the sampling callback"),
model="test-model",
stop_reason="endTurn",
)
async def sampling_callback(
context: ClientRequestContext,
params: CreateMessageRequestParams,
) -> CreateMessageResult:
return callback_return
@server.tool("test_sampling")
async def test_sampling_tool(message: str, ctx: Context) -> bool:
value = await ctx.session.create_message( # pyright: ignore[reportDeprecated]
messages=[SamplingMessage(role="user", content=TextContent(type="text", text=message))],
max_tokens=100,
)
assert value == callback_return
return True
async with Client(server, sampling_callback=sampling_callback, mode="legacy") as client:
result = await client.call_tool("test_sampling", {"message": "Test message for sampling"})
assert result.is_error is False
assert isinstance(result.content[0], TextContent)
assert result.content[0].text == "true"
# Without a sampling callback the client responds with an MCPError the tool body
# doesn't catch, so it surfaces as a top-level JSON-RPC error, not an isError result.
async with Client(server, mode="legacy") as client:
with pytest.raises(MCPError) as exc_info:
await client.call_tool("test_sampling", {"message": "Test message for sampling"})
assert exc_info.value.error.code == INVALID_REQUEST
@pytest.mark.anyio
async def test_create_message_backwards_compat_single_content():
server = MCPServer("test")
callback_return = CreateMessageResult(
role="assistant",
content=TextContent(type="text", text="Hello from LLM"),
model="test-model",
stop_reason="endTurn",
)
async def sampling_callback(
context: ClientRequestContext,
params: CreateMessageRequestParams,
) -> CreateMessageResult:
return callback_return
@server.tool("test_backwards_compat")
async def test_tool(message: str, ctx: Context) -> bool:
result = await ctx.session.create_message( # pyright: ignore[reportDeprecated]
messages=[SamplingMessage(role="user", content=TextContent(type="text", text=message))],
max_tokens=100,
)
assert isinstance(result, CreateMessageResult)
assert isinstance(result.content, TextContent)
assert result.content.text == "Hello from LLM"
# content_as_list exists only on CreateMessageResultWithTools
assert not hasattr(result, "content_as_list") or not callable(getattr(result, "content_as_list", None))
return True
async with Client(server, sampling_callback=sampling_callback, mode="legacy") as client:
result = await client.call_tool("test_backwards_compat", {"message": "Test"})
assert result.is_error 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():
# Tests the type directly, not the create_message overload (which 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",
stop_reason="toolUse",
)
content_list = result.content_as_list
assert len(content_list) == 1
assert content_list[0].type == "tool_use"
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",
stop_reason="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"