test(loop): cover /stop checkpoint recovery

tests/agent/test_loop_save_turn.py

@@ -1,3 +1,4 @@
+import asyncio
 from pathlib import Path
 from unittest.mock import AsyncMock, MagicMock
 
@@ -308,3 +309,111 @@ async def test_next_turn_after_crash_closes_pending_user_turn_before_new_input(t
         {"role": "assistant", "content": "new answer"},
     ]
     assert AgentLoop._PENDING_USER_TURN_KEY not in session.metadata
+
+
+@pytest.mark.asyncio
+async def test_stop_preserves_runtime_checkpoint_for_next_turn(tmp_path: Path) -> None:
+    from nanobot.command.builtin import cmd_stop
+    from nanobot.command.router import CommandContext
+
+    loop = _make_full_loop(tmp_path)
+    loop.consolidator.maybe_consolidate_by_tokens = AsyncMock(return_value=False)  # type: ignore[method-assign]
+
+    checkpoint_saved = asyncio.Event()
+
+    async def interrupted_run_agent_loop(_initial_messages, *, session=None, **_kwargs):
+        assert session is not None
+        loop._set_runtime_checkpoint(
+            session,
+            {
+                "assistant_message": {
+                    "role": "assistant",
+                    "content": "working",
+                    "tool_calls": [
+                        {
+                            "id": "call_done",
+                            "type": "function",
+                            "function": {"name": "read_file", "arguments": "{}"},
+                        },
+                        {
+                            "id": "call_pending",
+                            "type": "function",
+                            "function": {"name": "exec", "arguments": "{}"},
+                        },
+                    ],
+                },
+                "completed_tool_results": [
+                    {
+                        "role": "tool",
+                        "tool_call_id": "call_done",
+                        "name": "read_file",
+                        "content": "ok",
+                    }
+                ],
+                "pending_tool_calls": [
+                    {
+                        "id": "call_pending",
+                        "type": "function",
+                        "function": {"name": "exec", "arguments": "{}"},
+                    }
+                ],
+            },
+        )
+        checkpoint_saved.set()
+        await asyncio.Event().wait()
+
+    loop._run_agent_loop = interrupted_run_agent_loop  # type: ignore[method-assign]
+
+    first_msg = InboundMessage(channel="feishu", sender_id="u1", chat_id="c4", content="keep progress")
+    task = asyncio.create_task(loop._process_message(first_msg))
+    loop._active_tasks[first_msg.session_key] = [task]
+    await asyncio.wait_for(checkpoint_saved.wait(), timeout=1.0)
+
+    stop_msg = InboundMessage(channel="feishu", sender_id="u1", chat_id="c4", content="/stop")
+    stop_ctx = CommandContext(msg=stop_msg, session=None, key=stop_msg.session_key, raw="/stop", loop=loop)
+    stop_result = await cmd_stop(stop_ctx)
+
+    assert "Stopped 1 task" in stop_result.content
+    assert task.done()
+
+    loop.sessions.invalidate("feishu:c4")
+    interrupted = loop.sessions.get_or_create("feishu:c4")
+    assert interrupted.metadata.get(AgentLoop._PENDING_USER_TURN_KEY) is True
+    assert interrupted.metadata.get(AgentLoop._RUNTIME_CHECKPOINT_KEY) is not None
+
+    async def resumed_run_agent_loop(initial_messages, **_kwargs):
+        return (
+            "next answer",
+            None,
+            [*initial_messages, {"role": "assistant", "content": "next answer"}],
+            "stop",
+            False,
+        )
+
+    loop._run_agent_loop = resumed_run_agent_loop  # type: ignore[method-assign]
+    result = await loop._process_message(
+        InboundMessage(channel="feishu", sender_id="u1", chat_id="c4", content="continue here")
+    )
+
+    assert result is not None
+    assert result.content == "next answer"
+
+    session = loop.sessions.get_or_create("feishu:c4")
+    assert [
+        {k: v for k, v in m.items() if k in {"role", "content", "tool_call_id", "name"}}
+        for m in session.messages
+    ] == [
+        {"role": "user", "content": "keep progress"},
+        {"role": "assistant", "content": "working"},
+        {"role": "tool", "tool_call_id": "call_done", "name": "read_file", "content": "ok"},
+        {
+            "role": "tool",
+            "tool_call_id": "call_pending",
+            "name": "exec",
+            "content": "Error: Task interrupted before this tool finished.",
+        },
+        {"role": "user", "content": "continue here"},
+        {"role": "assistant", "content": "next answer"},
+    ]
+    assert AgentLoop._PENDING_USER_TURN_KEY not in session.metadata
+    assert AgentLoop._RUNTIME_CHECKPOINT_KEY not in session.metadata