Exit gracefully on Ctrl-C

If we receive SIGINT, exit gracefully: run the clean_up method; don't
print a stacktrace; exit with error code 130 (128 + SIGINT).

Change-Id: I77687133d5482912523814a28e42f4f3a1a146d5
Story: 2008124
Task: 40846

cliff/app.py

@@ -276,11 +276,16 @@ class App(object):
             else:
                 self.LOG.error(err)
             return 1
+        except KeyboardInterrupt:
+            return 130
         result = 1
         if self.interactive_mode:
             result = self.interact()
         else:
-            result = self.run_subcommand(remainder)
+            try:
+                result = self.run_subcommand(remainder)
+            except KeyboardInterrupt:
+                return 130
         return result
 
     # FIXME(dhellmann): Consider moving these command handling methods
@@ -391,6 +396,7 @@ class App(object):
             kwargs['cmd_name'] = cmd_name
         cmd = cmd_factory(self, self.options, **kwargs)
         result = 1
+        err = None
         try:
             self.prepare_to_run_command(cmd)
             full_name = (cmd_name
@@ -398,17 +404,24 @@ class App(object):
                          else ' '.join([self.NAME, cmd_name])
                          )
             cmd_parser = cmd.get_parser(full_name)
-            parsed_args = cmd_parser.parse_args(sub_argv)
+            try:
+                parsed_args = cmd_parser.parse_args(sub_argv)
+            except SystemExit as ex:
+                raise cmd2.exceptions.Cmd2ArgparseError from ex
             result = cmd.run(parsed_args)
         except help.HelpExit:
             result = 0
-        except SystemExit as ex:
-            raise cmd2.exceptions.Cmd2ArgparseError from ex
-        except Exception as err:
+        except Exception as err1:
+            err = err1
             if self.options.debug:
                 self.LOG.exception(err)
             else:
                 self.LOG.error(err)
+        except KeyboardInterrupt as err1:
+            result = 130
+            err = err1
+            raise
+        finally:
             try:
                 self.clean_up(cmd, result, err)
             except Exception as err2:
@@ -416,15 +429,5 @@ class App(object):
                     self.LOG.exception(err2)
                 else:
                     self.LOG.error('Could not clean up: %s', err2)
-            if self.options.debug:
-                # 'raise' here gets caught and does not exit like we want
-                return result
-        else:
-            try:
-                self.clean_up(cmd, result, None)
-            except Exception as err3:
-                if self.options.debug:
-                    self.LOG.exception(err3)
-                else:
-                    self.LOG.error('Could not clean up: %s', err3)
+            del err
         return result

cliff/tests/test_app.py

@@ -51,6 +51,15 @@ def make_app(**kwargs):
     err_command.return_value = err_command_inst
     cmd_mgr.add_command('error', err_command)
 
+    # Register a command that is interrrupted
+    interrupt_command = mock.Mock(name='interrupt_command', spec=c_cmd.Command)
+    interrupt_command_inst = mock.Mock(spec=c_cmd.Command)
+    interrupt_command_inst.run = mock.Mock(
+        side_effect=KeyboardInterrupt
+    )
+    interrupt_command.return_value = interrupt_command_inst
+    cmd_mgr.add_command('interrupt', interrupt_command)
+
     app = application.App('testing interactive mode',
                           '1',
                           cmd_mgr,
@@ -113,6 +122,11 @@ class TestInitAndCleanup(base.TestBase):
         app.run(['mock'])
         app.prepare_to_run_command.assert_called_once_with(command())
 
+    def test_interrupt_command(self):
+        app, command = make_app()
+        result = app.run(['interrupt'])
+        self.assertEqual(result, 130)
+
     def test_clean_up_success(self):
         app, command = make_app()
         app.clean_up = mock.MagicMock(name='clean_up')
@@ -148,6 +162,19 @@ class TestInitAndCleanup(base.TestBase):
         self.assertIsInstance(args[2], RuntimeError)
         self.assertEqual(('test exception',), args[2].args)
 
+    def test_clean_up_interrupt(self):
+        app, command = make_app()
+
+        app.clean_up = mock.MagicMock(name='clean_up')
+        ret = app.run(['interrupt'])
+        self.assertNotEqual(ret, 0)
+
+        app.clean_up.assert_called_once_with(mock.ANY, mock.ANY, mock.ANY)
+        call_args = app.clean_up.call_args_list[0]
+        self.assertEqual(mock.call(mock.ANY, 130, mock.ANY), call_args)
+        args, kwargs = call_args
+        self.assertIsInstance(args[2], KeyboardInterrupt)
+
     def test_error_handling_clean_up_raises_exception(self):
         app, command = make_app()
 
@@ -322,6 +349,19 @@ class TestHelpHandling(base.TestBase):
     def test_deferred_help(self):
         self._test_help(True)
 
+    def _test_interrupted_help(self, deferred_help):
+        app, _ = make_app(deferred_help=deferred_help)
+        with mock.patch('cliff.help.HelpAction.__call__',
+                        side_effect=KeyboardInterrupt):
+            result = app.run(['--help'])
+            self.assertEqual(result, 130)
+
+    def test_interrupted_help(self):
+        self._test_interrupted_help(False)
+
+    def test_interrupted_deferred_help(self):
+        self._test_interrupted_help(True)
+
     def test_subcommand_help(self):
         app, _ = make_app(deferred_help=False)