<*arg> / [*arg] syntax returns empty string when no argument is given

[xsnowstorm]

Describe the bug
Commands that use a *arg return an empty string when the argument is not present.

To Reproduce
Steps to reproduce the behavior:

1. Create a command with usage: [*test]
2. Print the arguments when the command executes
3. Run the command without any arguments
4. [''] will be printed to the console

Expected behavior
It should be an empty array

Additional context
This causes the member type to raise an error (fixed)