agent-lab/tests/test_debug_runtime.py

import asyncio
import importlib
import json
import logging
from collections.abc import AsyncIterator
from typing import Any

import pytest

from agent_lab.application.contracts import AgentParams, DebugRunRequest, EventAgentParams
from agent_lab.application.event_agent import EventAgentRequest
from agent_lab.application.runtime import DebugRuntime
from agent_lab.application.tools import ToolDefinition, ToolExecutionContext, ToolRegistry
from agent_lab.domain.events import ToolCallEvent
from agent_lab.domain.messages import ChatMessage, StreamItem, TokenUsage


def _runtime_queues_class():
    module = importlib.import_module("agent_lab.application.queues")
    return module.RuntimeQueues


async def _collect_outputs(stream: AsyncIterator[dict[str, Any]]) -> list[dict[str, Any]]:
    return [message async for message in stream]


def _without_audit(outputs: list[dict[str, Any]]) -> list[dict[str, Any]]:
    return [message for message in outputs if message["type"] != "audit"]


def _message_types(outputs: list[dict[str, Any]]) -> list[str]:
    return [message["type"] for message in _without_audit(outputs)]


async def _next_non_audit(
    stream: AsyncIterator[dict[str, Any]],
) -> dict[str, Any]:
    while True:
        message = await anext(stream)
        if message["type"] != "audit":
            return message


async def _next_non_audit_from_queue(queues: Any) -> dict[str, Any]:
    while True:
        message = await queues.output.get()
        if message["type"] != "audit":
            return message


class RecordingQueue(asyncio.Queue):
    def __init__(self, name: str, log: list[tuple[str, str, str]]) -> None:
        super().__init__()
        self.name = name
        self.log = log

    async def put(self, item: Any) -> None:
        self.log.append((self.name, "put", self._describe(item)))
        await super().put(item)

    async def get(self) -> Any:
        item = await super().get()
        self.log.append((self.name, "get", self._describe(item)))
        return item

    def _describe(self, item: Any) -> str:
        if isinstance(item, ChatMessage):
            if item.role == "tool":
                return f"tool:{item.tool_call_id}"
            return item.role
        if isinstance(item, ToolCallEvent):
            return f"event:{item.name}:{item.id}"
        if isinstance(item, EventAgentRequest):
            events = ",".join(f"{event.name}:{event.id}" for event in item.events)
            return f"event_request:{events}"
        if isinstance(item, dict):
            return f"output:{item.get('type')}"
        return type(item).__name__


class FakeChatClient:
    def __init__(self) -> None:
        self.calls = 0

    async def stream_chat(
        self,
        messages: list[ChatMessage],
        tools: list[dict],
        params: AgentParams,
    ) -> AsyncIterator[StreamItem]:
        self.calls += 1
        if self.calls == 1:
            yield StreamItem.event(
                ToolCallEvent(
                    id="call_1",
                    name="handoff_note",
                    arguments={},
                    raw_arguments="{}",
                )
            )
            return

        assert any(message.role == "tool" for message in messages)
        yield StreamItem.message_delta("final answer")


class StrictHistoryChatClient:
    def __init__(self) -> None:
        self.calls = 0
        self.second_call_messages: list[ChatMessage] = []

    async def stream_chat(
        self,
        messages: list[ChatMessage],
        tools: list[dict],
        params: AgentParams,
    ) -> AsyncIterator[StreamItem]:
        self.calls += 1
        if self.calls == 1:
            yield StreamItem.event(
                ToolCallEvent(
                    id="call_1",
                    name="handoff_note",
                    arguments={},
                    raw_arguments="{}",
                )
            )
            return

        self.second_call_messages = list(messages)
        yield StreamItem.message_delta("final answer")


class MultiEventChatClient:
    def __init__(self) -> None:
        self.calls = 0
        self.second_call_messages: list[ChatMessage] = []

    async def stream_chat(
        self,
        messages: list[ChatMessage],
        tools: list[dict],
        params: AgentParams,
    ) -> AsyncIterator[StreamItem]:
        self.calls += 1
        if self.calls == 1:
            yield StreamItem.message_delta("Checking events.")
            yield StreamItem.event(
                ToolCallEvent(
                    id="call_1",
                    name="handoff_note",
                    arguments={"message": "ignored chat argument"},
                    raw_arguments='{"message":"ignored chat argument"}',
                )
            )
            yield StreamItem.event(
                ToolCallEvent(
                    id="call_2",
                    name="audit_note",
                    arguments={"message": "ignored chat argument"},
                    raw_arguments='{"message":"ignored chat argument"}',
                )
            )
            return

        self.second_call_messages = list(messages)
        yield StreamItem.message_delta("Final answer.")


class ToolCapturingChatClient:
    def __init__(self) -> None:
        self.tools: list[dict[str, Any]] = []

    async def stream_chat(
        self,
        messages: list[ChatMessage],
        tools: list[dict],
        params: AgentParams,
    ) -> AsyncIterator[StreamItem]:
        self.tools = list(tools)
        yield StreamItem.message_delta("final answer")


class EventLoopLimitChatClient:
    def __init__(self) -> None:
        self.calls = 0
        self.tools_by_call: list[list[dict[str, Any]]] = []

    async def stream_chat(
        self,
        messages: list[ChatMessage],
        tools: list[dict],
        params: AgentParams,
    ) -> AsyncIterator[StreamItem]:
        self.calls += 1
        self.tools_by_call.append(list(tools))
        if self.calls == 1:
            yield StreamItem.event(
                ToolCallEvent(
                    id="call_1",
                    name="handoff_note",
                    arguments={},
                    raw_arguments="{}",
                )
            )
            return

        yield StreamItem.message_delta("final after event limit")


class RoundStatsChatClient:
    async def stream_chat(
        self,
        messages: list[ChatMessage],
        tools: list[dict],
        params: AgentParams,
    ) -> AsyncIterator[StreamItem]:
        yield StreamItem.message_delta("hello")
        yield StreamItem.usage_item(
            TokenUsage(
                prompt_tokens=10,
                completion_tokens=20,
                total_tokens=30,
                cached_tokens=5,
            )
        )


class EventRoundStatsChatClient:
    def __init__(self) -> None:
        self.calls = 0

    async def stream_chat(
        self,
        messages: list[ChatMessage],
        tools: list[dict],
        params: AgentParams,
    ) -> AsyncIterator[StreamItem]:
        self.calls += 1
        if self.calls == 1:
            yield StreamItem.event(
                ToolCallEvent(
                    id="call_1",
                    name="handoff_note",
                    arguments={},
                    raw_arguments="{}",
                )
            )
            yield StreamItem.usage_item(
                TokenUsage(prompt_tokens=3, completion_tokens=0, total_tokens=3)
            )
            return

        yield StreamItem.message_delta("final answer")
        yield StreamItem.usage_item(
            TokenUsage(prompt_tokens=4, completion_tokens=6, total_tokens=10)
        )


class SlowAfterEventChatClient:
    def __init__(self) -> None:
        self.calls = 0
        self.event_seen = asyncio.Event()
        self.release_stream = asyncio.Event()

    async def stream_chat(
        self,
        messages: list[ChatMessage],
        tools: list[dict],
        params: AgentParams,
    ) -> AsyncIterator[StreamItem]:
        self.calls += 1
        if self.calls == 1:
            yield StreamItem.message_delta("Need event.")
            yield StreamItem.event(
                ToolCallEvent(
                    id="call_1",
                    name="handoff_note",
                    arguments={},
                    raw_arguments="{}",
                )
            )
            self.event_seen.set()
            await self.release_stream.wait()
            return

        yield StreamItem.message_delta("final answer")


def test_runtime_queues_exposes_input_output_and_events_queues():
    RuntimeQueues = _runtime_queues_class()

    queues = RuntimeQueues()

    assert isinstance(queues.input, asyncio.Queue)
    assert isinstance(queues.output, asyncio.Queue)
    assert isinstance(queues.events, asyncio.Queue)
    assert queues.input is not queues.output
    assert queues.input is not queues.events
    assert queues.output is not queues.events


@pytest.mark.asyncio
async def test_runtime_routes_chat_events_through_event_agent_then_continues_chat():
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=["You are a debugger."],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=3),
    )
    client = FakeChatClient()
    runtime = DebugRuntime(client)

    outputs = [message async for message in runtime.run(request)]
    business_outputs = _without_audit(outputs)

    assert client.calls == 2
    assert _message_types(outputs) == [
        "session_started",
        "event",
        "tool_result",
        "round_stats",
        "message_delta",
        "round_stats",
        "done",
    ]
    assert business_outputs[1]["event"]["name"] == "handoff_note"
    assert business_outputs[4]["content"] == "final answer"


@pytest.mark.asyncio
async def test_runtime_emits_audit_events_and_backend_logs(caplog):
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=1),
    )
    runtime = DebugRuntime(FakeChatClient())

    with caplog.at_level(logging.INFO, logger="agent_lab.application.runtime"):
        outputs = [message async for message in runtime.run(request)]

    audit_events = [
        message["event"]
        for message in outputs
        if message["type"] == "audit"
    ]
    assert audit_events == [
        "session_started",
        "chat_round_started",
        "chat_event_detected",
        "event_agent_completed",
        "chat_round_finished",
        "chat_round_started",
        "chat_round_finished",
        "session_finished",
    ]
    assert "chat_event_detected" in caplog.text
    assert "event_agent_completed" in caplog.text


@pytest.mark.asyncio
async def test_runtime_outputs_event_as_soon_as_chat_stream_detects_it():
    RuntimeQueues = _runtime_queues_class()
    queues = RuntimeQueues()
    client = SlowAfterEventChatClient()
    runtime = DebugRuntime(client, queues=queues)
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=1),
    )

    runtime.start(request)

    try:
        assert await _next_non_audit_from_queue(queues) == {"type": "session_started"}
        assert await _next_non_audit_from_queue(queues) == {
            "type": "message_delta",
            "content": "Need event.",
        }
        await asyncio.wait_for(client.event_seen.wait(), timeout=1)
        event_message = await asyncio.wait_for(
            _next_non_audit_from_queue(queues),
            timeout=0.2,
        )

        assert event_message["type"] == "event"
        assert event_message["event"]["name"] == "handoff_note"
    finally:
        client.release_stream.set()
        await runtime.aclose()


@pytest.mark.asyncio
async def test_runtime_batches_round_events_before_continuing_chat_agent():
    def resolve_from_history(
        event: ToolCallEvent,
        context: ToolExecutionContext,
    ) -> dict[str, Any]:
        return {"message": context.history[-1].content, "event": event.name}

    registry = ToolRegistry(
        [
            ToolDefinition(
                name="handoff_note",
                description="Send a handoff note.",
                parameters={
                    "type": "object",
                    "properties": {"message": {"type": "string"}},
                    "required": ["message"],
                },
                handler=lambda event: {
                    "tool": event.name,
                    "message": event.arguments["message"],
                },
                argument_resolver=resolve_from_history,
            ),
            ToolDefinition(
                name="audit_note",
                description="Send an audit note.",
                parameters={
                    "type": "object",
                    "properties": {"message": {"type": "string"}},
                    "required": ["message"],
                },
                handler=lambda event: {
                    "tool": event.name,
                    "message": event.arguments["message"],
                },
                argument_resolver=resolve_from_history,
            ),
        ]
    )
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(
            enabled_tools=["handoff_note", "audit_note"],
            max_event_loops=2,
        ),
    )
    client = MultiEventChatClient()
    runtime = DebugRuntime(client, registry=registry)

    outputs = [message async for message in runtime.run(request)]

    assert _message_types(outputs) == [
        "session_started",
        "message_delta",
        "event",
        "event",
        "tool_result",
        "tool_result",
        "round_stats",
        "message_delta",
        "round_stats",
        "done",
    ]
    assert client.calls == 2
    assert [message.role for message in client.second_call_messages] == [
        "user",
        "assistant",
        "tool",
        "tool",
        "user",
    ]
    assistant_message = client.second_call_messages[1]
    assert assistant_message.content == "Checking events."
    assert assistant_message.tool_calls == [
        {
            "id": "call_1",
            "type": "function",
            "function": {"name": "handoff_note", "arguments": "{}"},
        },
        {
            "id": "call_2",
            "type": "function",
            "function": {"name": "audit_note", "arguments": "{}"},
        },
    ]
    assert [
        json.loads(message.content)
        for message in client.second_call_messages
        if message.role == "tool"
    ] == [
        {"tool": "handoff_note", "message": "Checking events."},
        {"tool": "audit_note", "message": "Checking events."},
    ]
    assert client.second_call_messages[-1].content == (
        "EventAgent results:\n"
        '{"tool": "handoff_note", "message": "Checking events."}\n'
        '{"tool": "audit_note", "message": "Checking events."}'
    )


@pytest.mark.asyncio
async def test_runtime_start_returns_queues_for_downstream_output_consumer():
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=[], max_event_loops=1),
    )
    runtime = DebugRuntime(RoundStatsChatClient())

    queues = runtime.start(request)

    outputs: list[dict[str, Any]] = []
    while True:
        message = await asyncio.wait_for(queues.output.get(), timeout=1)
        outputs.append(message)
        if message["type"] == "done":
            break
    assert _message_types(outputs) == [
        "session_started",
        "message_delta",
        "usage",
        "round_stats",
        "done",
    ]


@pytest.mark.asyncio
async def test_runtime_finalizes_chat_after_reaching_event_loop_limit():
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=1),
    )
    client = EventLoopLimitChatClient()
    runtime = DebugRuntime(client)

    outputs = [message async for message in runtime.run(request)]
    business_outputs = _without_audit(outputs)

    assert client.calls == 2
    assert client.tools_by_call[0][0]["function"]["name"] == "handoff_note"
    assert client.tools_by_call[1] == []
    assert _message_types(outputs) == [
        "session_started",
        "event",
        "tool_result",
        "round_stats",
        "message_delta",
        "round_stats",
        "done",
    ]
    assert business_outputs[4]["content"] == "final after event limit"


@pytest.mark.asyncio
async def test_runtime_buffers_upstream_user_input_until_after_matching_tool_reply():
    RuntimeQueues = _runtime_queues_class()
    queues = RuntimeQueues()
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=2),
    )
    client = StrictHistoryChatClient()
    runtime = DebugRuntime(client, queues=queues)
    stream = runtime.run(request)

    assert await _next_non_audit(stream) == {"type": "session_started"}
    event_message = await _next_non_audit(stream)
    assert event_message["type"] == "event"
    await queues.input.put(ChatMessage(role="user", content="follow-up while tool runs"))
    remaining = [message async for message in stream]

    assert remaining[-1] == {"type": "done"}
    assert [message.role for message in client.second_call_messages] == [
        "user",
        "assistant",
        "tool",
        "user",
        "user",
    ]
    assert client.second_call_messages[2].tool_call_id == "call_1"
    assert client.second_call_messages[3].content.startswith("EventAgent results:\n")
    assert client.second_call_messages[4].content == "follow-up while tool runs"


@pytest.mark.asyncio
async def test_runtime_continues_when_event_agent_tool_handler_raises():
    def fail_tool(event: ToolCallEvent) -> dict[str, Any]:
        raise RuntimeError("boom")

    registry = ToolRegistry(
        [
            ToolDefinition(
                name="handoff_note",
                description="Broken handoff tool.",
                parameters={"type": "object"},
                handler=fail_tool,
            )
        ]
    )
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=2),
    )
    runtime = DebugRuntime(FakeChatClient(), registry=registry)

    outputs = await asyncio.wait_for(
        _collect_outputs(runtime.run(request)),
        timeout=1,
    )
    business_outputs = _without_audit(outputs)

    assert _message_types(outputs) == [
        "session_started",
        "event",
        "tool_result",
        "round_stats",
        "message_delta",
        "round_stats",
        "done",
    ]
    assert json.loads(business_outputs[2]["message"]["content"]) == {
        "tool": "handoff_note",
        "error": "tool handler failed: boom",
    }


@pytest.mark.asyncio
async def test_runtime_uses_event_and_input_queues_for_event_agent_handoff():
    RuntimeQueues = _runtime_queues_class()
    queue_log: list[tuple[str, str, str]] = []
    queues = RuntimeQueues(
        input=RecordingQueue("input", queue_log),
        output=RecordingQueue("output", queue_log),
        events=RecordingQueue("events", queue_log),
    )
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=["You are a debugger."],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=3),
    )
    runtime = DebugRuntime(FakeChatClient(), queues=queues)

    outputs = [message async for message in runtime.run(request)]

    assert _message_types(outputs) == [
        "session_started",
        "event",
        "tool_result",
        "round_stats",
        "message_delta",
        "round_stats",
        "done",
    ]
    assert queue_log.index(("input", "put", "user")) < queue_log.index(
        ("input", "get", "user")
    )
    assert queue_log.index(
        ("events", "put", "event_request:handoff_note:call_1")
    ) < queue_log.index(("events", "get", "event_request:handoff_note:call_1"))
    assert queue_log.index(
        ("events", "get", "event_request:handoff_note:call_1")
    ) < queue_log.index(("input", "put", "tool:call_1"))
    assert queue_log.index(("input", "put", "tool:call_1")) < queue_log.index(
        ("input", "get", "tool:call_1")
    )


@pytest.mark.asyncio
async def test_runtime_run_consumes_output_queue_in_stream_order():
    RuntimeQueues = _runtime_queues_class()
    queue_log: list[tuple[str, str, str]] = []
    queues = RuntimeQueues(
        input=RecordingQueue("input", queue_log),
        output=RecordingQueue("output", queue_log),
        events=RecordingQueue("events", queue_log),
    )
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=["You are a debugger."],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=3),
    )
    runtime = DebugRuntime(FakeChatClient(), queues=queues)

    outputs = [message async for message in runtime.run(request)]

    assert _message_types(outputs) == [
        "session_started",
        "event",
        "tool_result",
        "round_stats",
        "message_delta",
        "round_stats",
        "done",
    ]
    output_puts = [
        entry[2] for entry in queue_log if entry[0] == "output" and entry[1] == "put"
    ]
    output_gets = [
        entry[2] for entry in queue_log if entry[0] == "output" and entry[1] == "get"
    ]
    assert [message for message in output_puts if message != "output:audit"] == [
        "output:session_started",
        "output:event",
        "output:tool_result",
        "output:round_stats",
        "output:message_delta",
        "output:round_stats",
        "output:done",
    ]
    assert output_gets == output_puts


@pytest.mark.asyncio
async def test_runtime_preserves_assistant_tool_calls_before_tool_reply():
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=["You are a debugger."],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=2),
    )
    client = StrictHistoryChatClient()
    runtime = DebugRuntime(client)

    outputs = [message async for message in runtime.run(request)]

    assert client.calls == 2
    assert [message.role for message in client.second_call_messages] == [
        "system",
        "user",
        "assistant",
        "tool",
        "user",
    ]
    assistant_message = client.second_call_messages[2]
    tool_message = client.second_call_messages[3]
    assert assistant_message.content == ""
    assert assistant_message.tool_calls == [
        {
            "id": "call_1",
            "type": "function",
            "function": {
                "name": "handoff_note",
                "arguments": "{}",
            },
        }
    ]
    assert tool_message.tool_call_id == "call_1"
    assert client.second_call_messages[4].content.startswith("EventAgent results:\n")
    assert outputs[-1] == {"type": "done"}


@pytest.mark.asyncio
async def test_runtime_passes_event_names_without_tool_parameters_to_chat_agent():
    registry = ToolRegistry(
        [
            ToolDefinition(
                name="handoff_note",
                description="Registry-owned handoff tool.",
                parameters={
                    "type": "object",
                    "properties": {
                        "message": {"type": "string"},
                        "priority": {"type": "number"},
                    },
                    "required": ["message"],
                },
                handler=lambda event: {"tool": event.name, "message": "handled"},
            )
        ]
    )
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=2),
    )
    client = ToolCapturingChatClient()
    runtime = DebugRuntime(client, registry=registry)

    outputs = [message async for message in runtime.run(request)]

    assert outputs[-1] == {"type": "done"}
    assert client.tools == [
        {
            "type": "function",
            "function": {
                "name": "handoff_note",
                "description": "Registry-owned handoff tool.",
                "parameters": {
                    "type": "object",
                    "properties": {},
                    "additionalProperties": False,
                },
            },
        }
    ]


@pytest.mark.asyncio
async def test_runtime_emits_round_stats_with_clock_and_usage_after_model_turn():
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=[], max_event_loops=1),
    )
    ticks = iter([1.0, 1.123, 1.456])
    runtime = DebugRuntime(RoundStatsChatClient(), clock=lambda: next(ticks))

    outputs = [message async for message in runtime.run(request)]
    business_outputs = _without_audit(outputs)

    assert _message_types(outputs) == [
        "session_started",
        "message_delta",
        "usage",
        "round_stats",
        "done",
    ]
    assert business_outputs[3] == {
        "type": "round_stats",
        "round_index": 1,
        "ttft_ms": 123,
        "elapsed_ms": 456,
        "prompt_tokens": 10,
        "completion_tokens": 20,
        "total_tokens": 30,
        "cached_tokens": 5,
        "had_event": False,
    }


@pytest.mark.asyncio
async def test_runtime_emits_round_stats_for_each_chat_call_in_event_handoff():
    request = DebugRunRequest(
        user_message="debug this",
        system_prompts=[],
        pre_messages=[],
        chat_agent=AgentParams(model="fake-model", temperature=0.1, max_tokens=200),
        event_agent=EventAgentParams(enabled_tools=["handoff_note"], max_event_loops=2),
    )
    ticks = iter([2.0, 2.25, 3.0, 3.05, 3.2])
    client = EventRoundStatsChatClient()
    runtime = DebugRuntime(client, clock=lambda: next(ticks))

    outputs = [message async for message in runtime.run(request)]
    stats = [message for message in outputs if message["type"] == "round_stats"]

    assert client.calls == 2
    assert stats == [
        {
            "type": "round_stats",
            "round_index": 1,
            "ttft_ms": None,
            "elapsed_ms": 250,
            "prompt_tokens": 3,
            "completion_tokens": 0,
            "total_tokens": 3,
            "cached_tokens": 0,
            "had_event": True,
        },
        {
            "type": "round_stats",
            "round_index": 2,
            "ttft_ms": 50,
            "elapsed_ms": 200,
            "prompt_tokens": 4,
            "completion_tokens": 6,
            "total_tokens": 10,
            "cached_tokens": 0,
            "had_event": False,
        },
    ]