Add max validation failures check of command arguments

nonebot/command/__init__.py

@@ -73,6 +73,7 @@ class Command:
                     session.current_key is not None:
                 # argument-level filters are given, use them
                 arg = session.current_arg
+                config = session.bot.config
                 for f in session.current_arg_filters:
                     try:
                         res = f(arg)
@@ -81,9 +82,21 @@ class Command:
                         arg = res
                     except ValidateError as e:
                         # validation failed
+                        if config.MAX_VALIDATION_FAILURES > 0:
+                            # should check number of validation failures
+                            session.state['__validation_failure_num'] = \
+                                session.state.get(
+                                    '__validation_failure_num', 0) + 1
+
+                            if session.state['__validation_failure_num'] >= \
+                                    config.MAX_VALIDATION_FAILURES:
+                                # noinspection PyProtectedMember
+                                session.finish(render_expression(
+                                    config.TOO_MANY_VALIDATION_FAILURES_EXPRESSION
+                                ), **session._current_send_kwargs)
+
                         failure_message = e.message
                         if failure_message is None:
-                            config = session.bot.config
                             failure_message = render_expression(
                                 config.DEFAULT_VALIDATION_FAILURE_EXPRESSION
                             )

nonebot/default_config.py

@@ -28,14 +28,22 @@ DEBUG: bool = True
 
 SUPERUSERS: Container[int] = set()
 NICKNAME: Union[str, Iterable[str]] = ''
+
 COMMAND_START: Iterable[Union[str, Pattern]] = {'/', '!', '／', '！'}
 COMMAND_SEP: Iterable[Union[str, Pattern]] = {'/', '.'}
+
 SESSION_EXPIRE_TIMEOUT: Optional[timedelta] = timedelta(minutes=5)
 SESSION_RUN_TIMEOUT: Optional[timedelta] = None
 SESSION_RUNNING_EXPRESSION: Expression_T = '您有命令正在执行，请稍后再试'
-SESSION_CANCEL_EXPRESSION = '好的'
+
 SHORT_MESSAGE_MAX_LENGTH: int = 50
+
+SESSION_CANCEL_EXPRESSION = '好的'
+
 DEFAULT_VALIDATION_FAILURE_EXPRESSION: Expression_T = '您的输入不符合要求，请重新输入'
+MAX_VALIDATION_FAILURES = 3
+TOO_MANY_VALIDATION_FAILURES_EXPRESSION: Expression_T = \
+    '您输入错误太多次啦，如需重试，请重新触发本功能'
 
 APSCHEDULER_CONFIG: Dict[str, Any] = {
     'apscheduler.timezone': 'Asia/Shanghai'