chore: import upstream snapshot with attribution

tests/interaction/lowlevel/test_list_changed.py

@@ -0,0 +1,136 @@
+"""List-changed notifications from the low-level Server, driven through the public Client API.
+
+``send_*_list_changed`` does not take a ``related_request_id``, so over streamable HTTP the
+notification routes to the standalone GET stream and is not guaranteed to arrive before the tool
+result on its POST stream. Tests therefore wait on an event the collector sets, the same pattern
+as ``transports/test_streamable_http.py::test_unrelated_server_messages_arrive_on_the_standalone_stream``.
+The collector still records every message it receives, so the snapshot also proves nothing else
+was delivered.
+
+The servers register the parent capability (resources/prompts) so that part of the spec's
+precondition holds, but the ``listChanged`` sub-capability stays ``False``: ``NotificationOptions``
+is not threaded through any of the suite's connection paths. The tests therefore rely on the
+recorded ``lifecycle:capability:server-not-advertised`` divergence and will need updating
+alongside the fix that introduces capability gating.
+"""
+
+import anyio
+import mcp_types as types
+import pytest
+from inline_snapshot import snapshot
+from mcp_types import (
+    CallToolResult,
+    PromptListChangedNotification,
+    ResourceListChangedNotification,
+    TextContent,
+    ToolListChangedNotification,
+)
+
+from mcp.server import Server, ServerRequestContext
+from tests.interaction._connect import Connect
+from tests.interaction._helpers import IncomingMessage
+from tests.interaction._requirements import requirement
+
+pytestmark = pytest.mark.anyio
+
+
+@requirement("tools:list-changed")
+async def test_tool_list_changed_notification(connect: Connect) -> None:
+    """A tools/list_changed notification sent during a tool call reaches the client's message handler."""
+    received: list[IncomingMessage] = []
+    seen = anyio.Event()
+
+    async def collect(message: IncomingMessage) -> None:
+        received.append(message)
+        seen.set()
+
+    async def list_tools(
+        ctx: ServerRequestContext, params: types.PaginatedRequestParams | None
+    ) -> types.ListToolsResult:
+        return types.ListToolsResult(tools=[types.Tool(name="install", input_schema={"type": "object"})])
+
+    async def call_tool(ctx: ServerRequestContext, params: types.CallToolRequestParams) -> CallToolResult:
+        assert params.name == "install"
+        await ctx.session.send_tool_list_changed()
+        return CallToolResult(content=[TextContent(text="installed")])
+
+    server = Server("registry", on_list_tools=list_tools, on_call_tool=call_tool)
+
+    async with connect(server, message_handler=collect) as client:
+        await client.call_tool("install", {})
+        with anyio.fail_after(5):
+            await seen.wait()
+
+    assert received == snapshot([ToolListChangedNotification()])
+
+
+@requirement("resources:list-changed")
+async def test_resource_list_changed_notification(connect: Connect) -> None:
+    """A resources/list_changed notification sent during a tool call reaches the client's message handler."""
+    received: list[IncomingMessage] = []
+    seen = anyio.Event()
+
+    async def collect(message: IncomingMessage) -> None:
+        received.append(message)
+        seen.set()
+
+    async def list_tools(
+        ctx: ServerRequestContext, params: types.PaginatedRequestParams | None
+    ) -> types.ListToolsResult:
+        return types.ListToolsResult(tools=[types.Tool(name="mount", input_schema={"type": "object"})])
+
+    async def call_tool(ctx: ServerRequestContext, params: types.CallToolRequestParams) -> CallToolResult:
+        assert params.name == "mount"
+        await ctx.session.send_resource_list_changed()
+        return CallToolResult(content=[TextContent(text="mounted")])
+
+    async def list_resources(
+        ctx: ServerRequestContext, params: types.PaginatedRequestParams | None
+    ) -> types.ListResourcesResult:
+        """Registered so the resources capability is advertised; the client never lists resources."""
+        raise NotImplementedError
+
+    server = Server("registry", on_list_tools=list_tools, on_call_tool=call_tool, on_list_resources=list_resources)
+
+    async with connect(server, message_handler=collect) as client:
+        await client.call_tool("mount", {})
+        with anyio.fail_after(5):
+            await seen.wait()
+
+    assert received == snapshot([ResourceListChangedNotification()])
+
+
+@requirement("prompts:list-changed")
+async def test_prompt_list_changed_notification(connect: Connect) -> None:
+    """A prompts/list_changed notification sent during a tool call reaches the client's message handler."""
+    received: list[IncomingMessage] = []
+    seen = anyio.Event()
+
+    async def collect(message: IncomingMessage) -> None:
+        received.append(message)
+        seen.set()
+
+    async def list_tools(
+        ctx: ServerRequestContext, params: types.PaginatedRequestParams | None
+    ) -> types.ListToolsResult:
+        return types.ListToolsResult(tools=[types.Tool(name="learn", input_schema={"type": "object"})])
+
+    async def call_tool(ctx: ServerRequestContext, params: types.CallToolRequestParams) -> CallToolResult:
+        assert params.name == "learn"
+        await ctx.session.send_prompt_list_changed()
+        return CallToolResult(content=[TextContent(text="learned")])
+
+    async def list_prompts(
+        ctx: ServerRequestContext, params: types.PaginatedRequestParams | None
+    ) -> types.ListPromptsResult:
+        """Registered so the prompts capability is advertised; the client never lists prompts."""
+        raise NotImplementedError
+
+    server = Server("registry", on_list_tools=list_tools, on_call_tool=call_tool, on_list_prompts=list_prompts)
+
+    async with connect(server, message_handler=collect) as client:
+        await client.call_tool("learn", {})
+        with anyio.fail_after(5):
+            await seen.wait()
+
+    assert received == snapshot([PromptListChangedNotification()])