fix(system): improve error reporting for subprocess failures and add tests for output handling

tests/test_system_utils.py

@@ -0,0 +1,44 @@
+import subprocess
+from unittest import TestCase
+from unittest.mock import patch
+
+from app.utils.system import SystemUtils
+
+
+class SystemUtilsTest(TestCase):
+
+    def test_execute_with_subprocess_keeps_stdout_when_command_fails(self):
+        """
+        命令失败时如果原因只写入 stdout，也需要回传给调用方用于错误提示。
+        """
+        error = subprocess.CalledProcessError(
+            returncode=1,
+            cmd=["pip", "check"],
+            output="demo requires pkg>=2, but you have pkg 1\n",
+            stderr="",
+        )
+
+        with patch("app.utils.system.subprocess.run", side_effect=error):
+            success, message = SystemUtils.execute_with_subprocess(["pip", "check"])
+
+        self.assertFalse(success)
+        self.assertIn("返回码：1", message)
+        self.assertIn("标准输出：demo requires pkg>=2, but you have pkg 1", message)
+
+    def test_execute_with_subprocess_reports_empty_failure_output(self):
+        """
+        命令失败且没有任何输出时，给出明确占位信息，避免错误原因看起来被截断。
+        """
+        error = subprocess.CalledProcessError(
+            returncode=2,
+            cmd=["pip", "check"],
+            output="",
+            stderr="",
+        )
+
+        with patch("app.utils.system.subprocess.run", side_effect=error):
+            success, message = SystemUtils.execute_with_subprocess(["pip", "check"])
+
+        self.assertFalse(success)
+        self.assertIn("返回码：2", message)
+        self.assertIn("无标准输出或错误输出", message)