return an error in case of invalid command

[hydrargyrum]

% topydo foobar
% echo $?
0

no error message, not even a nonzero status code, it's easy to mistake topydo add foobar for topydo foobar, or topydo done 123 for topydo do 123 and we think it worked but it didn't.

[davesteele]

Note that this matches the behavior of the classic todo.txt cli.

[hydrargyrum]

Ok, but no error message or code is a bad behaviour that is very misleading. Multiple times I forgot the add subcommand and so I "lost" some todo entries because of the absence of a simple feedback telling me no command has been recognized.

In the above example, it could be as simple as error: "foobar" command is not recognized

[davesteele]

Perhaps a message "No tasks found", with maybe an error return, would help.