Added validation of subcommand handler attributes

1 files changed, 5 insertions, 1 deletions

diff --git a/cmd2/cmd2.py b/cmd2/cmd2.py
index adf797bf..f6a5251c 100644
--- a/cmd2/cmd2.py
+++ b/cmd2/cmd2.py
@@ -637,10 +637,14 @@ class Cmd(cmd.Cmd):
 
         # iterate through all matching methods
         for method_name, method in methods:
-            subcommand_name = getattr(method, constants.SUBCMD_ATTR_NAME)
+            subcommand_name = getattr(method, constants.SUBCMD_ATTR_NAME)  # type: str
             full_command_name = getattr(method, constants.SUBCMD_ATTR_COMMAND)  # type: str
             subcmd_parser = getattr(method, constants.CMD_ATTR_ARGPARSER)
 
+            subcommand_valid, errmsg = self.statement_parser.is_valid_command(subcommand_name, is_subcommand=True)
+            if not subcommand_valid:
+                raise CommandSetRegistrationError('Subcommand {} is not valid: {}'.format(str(subcommand_name), errmsg))
+
             command_tokens = full_command_name.split()
             command_name = command_tokens[0]
             subcommand_names = command_tokens[1:]