增强 execute_command 工具：支持输出截断、并发限制与进程组清理，新增单元测试

tests/test_execute_command_tool.py

@@ -0,0 +1,61 @@
+import asyncio
+import os
+import shlex
+import subprocess
+import sys
+import time
+import unittest
+
+from app.agent.tools.impl.execute_command import (
+    ExecuteCommandTool,
+    MAX_OUTPUT_CHARS,
+)
+
+
+def _python_command(code: str) -> str:
+    """生成当前解释器可执行的 shell 命令，避免依赖系统 python 名称。"""
+    args = [sys.executable, "-c", code]
+    if os.name == "nt":
+        return subprocess.list2cmdline(args)
+    return " ".join(shlex.quote(arg) for arg in args)
+
+
+class TestExecuteCommandTool(unittest.TestCase):
+    def _run_command(self, command: str, timeout: int = 60) -> str:
+        tool = ExecuteCommandTool(session_id="session-1", user_id="10001")
+        return asyncio.run(tool.run(command=command, timeout=timeout))
+
+    def test_large_output_is_truncated_before_returning_to_agent(self):
+        command = _python_command(
+            "import sys; sys.stdout.write('x' * 200000); sys.stdout.flush()"
+        )
+
+        result = self._run_command(command)
+
+        self.assertIn("输出内容过长，已截断", result)
+        self.assertLess(len(result), MAX_OUTPUT_CHARS + 500)
+
+    def test_timeout_returns_partial_output_promptly(self):
+        command = _python_command(
+            "import time; print('started', flush=True); time.sleep(5)"
+        )
+
+        started_at = time.monotonic()
+        result = self._run_command(command, timeout=1)
+        duration = time.monotonic() - started_at
+
+        self.assertLess(duration, 4)
+        self.assertIn("命令执行超时", result)
+        self.assertIn("started", result)
+
+    def test_timeout_is_capped(self):
+        command = _python_command("print('ok')")
+
+        result = self._run_command(command, timeout=9999)
+
+        self.assertIn("timeout 参数超过上限", result)
+        self.assertIn("ok", result)
+
+
+if __name__ == "__main__":
+    unittest.main()