♻️ 大幅重构，拆分模块，增加一些MCP相关限制

tests/test_tool_loop.py

@@ -0,0 +1,101 @@
+from types import SimpleNamespace
+from typing import Any, cast
+import unittest
+
+# ruff: noqa: I001
+import tests.bootstrap  # noqa: F401
+from nonebot_plugin_llmchat.config import PresetConfig, ScopedConfig
+from nonebot_plugin_llmchat.conversation import ConversationService
+from nonebot_plugin_llmchat.state import StateStore
+
+
+class FakeToolCall:
+    def __init__(self):
+        self.id = "call-1"
+        self.function = SimpleNamespace(name="mcp__demo__search", arguments='{"query":"same"}')
+
+    def model_dump(self):
+        return {
+            "id": self.id,
+            "type": "function",
+            "function": {"name": self.function.name, "arguments": self.function.arguments},
+        }
+
+
+class FakeMessage:
+    def __init__(self, content=None, tool_calls=None):
+        self.content = content
+        self.tool_calls = tool_calls
+        self.reasoning_content = None
+
+
+class FakeCompletions:
+    def __init__(self):
+        self.calls = []
+
+    async def create(self, **kwargs):
+        self.calls.append(kwargs)
+        if "tools" not in kwargs:
+            message = FakeMessage("final answer")
+        else:
+            message = FakeMessage(tool_calls=[FakeToolCall()])
+        return SimpleNamespace(choices=[SimpleNamespace(message=message)], usage=None)
+
+
+class FakeClient:
+    def __init__(self):
+        self.chat = SimpleNamespace(completions=FakeCompletions())
+
+
+class FakeMCPClient:
+    def __init__(self):
+        self.call_count = 0
+
+    def get_friendly_name(self, _name):
+        return "测试工具"
+
+    async def call_tool(self, *_args, **_kwargs):
+        self.call_count += 1
+        return "result"
+
+
+class ToolLoopTests(unittest.IsolatedAsyncioTestCase):
+    async def test_repeated_tool_calls_are_bounded_and_forced_to_finish(self):
+        preset = PresetConfig(
+            name="test",
+            api_base="https://example.invalid/v1",
+            api_key="test",
+            model_name="test",
+            support_mcp=True,
+        )
+        config = ScopedConfig(
+            api_presets=[preset],
+            default_preset="test",
+            max_tool_rounds=3,
+            max_repeated_tool_calls=2,
+        )
+        sent = []
+
+        async def sender(message):
+            sent.append(message)
+
+        service = ConversationService(config, StateStore(config), {"bot"}, sender)
+        client = FakeClient()
+        mcp_client = FakeMCPClient()
+        transcript = [{"role": "user", "content": "hello"}]
+        message = await service._run_tool_loop(
+            client=cast(Any, client),
+            preset=preset,
+            mcp_client=cast(Any, mcp_client),
+            request_config={"model": "test", "tools": [{}]},
+            messages=[{"role": "system", "content": "system"}],
+            transcript=transcript,
+            event=cast(Any, SimpleNamespace(self_id=1)),
+            is_group=False,
+        )
+
+        assert message.content == "final answer"
+        assert mcp_client.call_count == 2
+        assert len(client.chat.completions.calls) == 5
+        assert "tools" not in client.chat.completions.calls[-1]
+        assert "达到上限" in transcript[-1]["content"]