Prevent postcmd_hook from running when argparse fails

Author: kmvanbrunt

cmd2/cmd2.py

@@ -50,7 +50,7 @@
 from .argparse_custom import CompletionItem, DEFAULT_ARGUMENT_PARSER
 from .clipboard import can_clip, get_paste_buffer, write_to_paste_buffer
 from .decorators import with_argparser
-from .exceptions import EmbeddedConsoleExit, EmptyStatement
+from .exceptions import CmdLineError, EmbeddedConsoleExit, EmptyStatement
 from .history import History, HistoryItem
 from .parsing import StatementParser, Statement, Macro, MacroArg, shlex_split
 from .rl_utils import rl_type, RlType, rl_get_point, rl_set_prompt, vt100_support, rl_make_safe_prompt, rl_warning
@@ -1599,12 +1599,11 @@ def onecmd_plus_hooks(self, line: str, *, add_to_history: bool = True, py_bridge
         stop = False
         try:
             statement = self._input_line_to_statement(line)
-        except EmptyStatement:
+        except (EmptyStatement, ValueError) as ex:
+            if isinstance(ex, ValueError):
+                # Since shlex.split() failed on syntax, let user know what's going on
+                self.perror("Invalid syntax: {}".format(ex))
             return self._run_cmdfinalization_hooks(stop, None)
-        except ValueError as ex:
-            # If shlex.split failed on syntax, let user know what's going on
-            self.pexcept("Invalid syntax: {}".format(ex))
-            return stop
 
         # now that we have a statement, run it with all the hooks
         try:
@@ -1684,8 +1683,8 @@ def onecmd_plus_hooks(self, line: str, *, add_to_history: bool = True, py_bridge
                         # Stop saving command's stdout before command finalization hooks run
                         self.stdout.pause_storage = True
 
-        except EmptyStatement:
-            # don't do anything, but do allow command finalization hooks to run
+        except (CmdLineError, EmptyStatement):
+            # Don't do anything, but do allow command finalization hooks to run
             pass
         except Exception as ex:
             self.pexcept(ex)

cmd2/decorators.py

@@ -4,6 +4,7 @@
 from typing import Callable, List, Optional, Union
 
 from . import constants
+from .exceptions import CmdLineError
 from .parsing import Statement
 
 
@@ -144,7 +145,7 @@ def cmd_wrapper(cmd2_app, statement: Union[Statement, str]):
             try:
                 args, unknown = parser.parse_known_args(parsed_arglist, namespace)
             except SystemExit:
-                return
+                raise CmdLineError
             else:
                 setattr(args, '__statement__', statement)
                 return func(cmd2_app, args, unknown)
@@ -216,7 +217,7 @@ def cmd_wrapper(cmd2_app, statement: Union[Statement, str]):
             try:
                 args = parser.parse_args(parsed_arglist, namespace)
             except SystemExit:
-                return
+                raise CmdLineError
             else:
                 setattr(args, '__statement__', statement)
                 return func(cmd2_app, args)

cmd2/exceptions.py

@@ -2,6 +2,11 @@
 """Custom exceptions for cmd2.  These are NOT part of the public API and are intended for internal use only."""
 
 
+class CmdLineError(Exception):
+    """Custom class for when an error occurred parsing the command line"""
+    pass
+
+
 class EmbeddedConsoleExit(SystemExit):
     """Custom exception class for use with the py command."""
     pass