Do not run the shutdown command in debug mode

app/local_system.py

@@ -1,6 +1,8 @@
 import logging
 import subprocess
 
+import flask
+
 logger = logging.getLogger(__name__)
 
 
@@ -22,7 +24,17 @@ def restart():
     return _exec_shutdown(restart_after=True)
 
 
+def _is_debug():
+    return flask.current_app.debug
+
+
 def _exec_shutdown(restart_after):
+    # In debug mode, don't actually shut down or restart the system, as that
+    # would be disruptive to a developer running the app locally.
+    if _is_debug():
+        logger.info('Skipping system shutdown because app is in debug mode')
+        return True
+
     if restart_after:
         param = '--reboot'
     else:

app/local_system_test.py

@@ -0,0 +1,51 @@
+import subprocess
+import unittest
+from unittest import mock
+
+import local_system
+
+
+class ExecShutdownTest(unittest.TestCase):
+
+    def setUp(self):
+        # Run all unit tests with debug mode disabled.
+        is_debug_patch = mock.patch.object(local_system,
+                                           '_is_debug',
+                                           return_value=False)
+        self.addCleanup(is_debug_patch.stop)
+        is_debug_patch.start()
+
+    @mock.patch.object(subprocess, 'run')
+    def test_shutdown_runs_poweroff_command(self, mock_run):
+        mock_run.return_value = subprocess.CompletedProcess(args=[],
+                                                            returncode=0,
+                                                            stdout='',
+                                                            stderr='')
+        self.assertTrue(local_system.shutdown())
+        mock_run.assert_called_once()
+        self.assertIn('--poweroff', mock_run.call_args[0][0])
+
+    @mock.patch.object(subprocess, 'run')
+    def test_restart_runs_reboot_command(self, mock_run):
+        mock_run.return_value = subprocess.CompletedProcess(args=[],
+                                                            returncode=0,
+                                                            stdout='',
+                                                            stderr='')
+        self.assertTrue(local_system.restart())
+        mock_run.assert_called_once()
+        self.assertIn('--reboot', mock_run.call_args[0][0])
+
+
+class DebugModeTest(unittest.TestCase):
+
+    @mock.patch.object(subprocess, 'run')
+    def test_shutdown_does_not_run_command_in_debug_mode(self, mock_run):
+        with mock.patch.object(local_system, '_is_debug', return_value=True):
+            self.assertTrue(local_system.shutdown())
+        mock_run.assert_not_called()
+
+    @mock.patch.object(subprocess, 'run')
+    def test_restart_does_not_run_command_in_debug_mode(self, mock_run):
+        with mock.patch.object(local_system, '_is_debug', return_value=True):
+            self.assertTrue(local_system.restart())
+        mock_run.assert_not_called()