oh cool, that's a good idea!
Would you be able to help update the FreeBSD port after adding this?

Looks like we can even do it automatically because cmdline parsing is done by clap: https://github.com/clap-rs/clap/tree/master/clap_complete

Sure, I can help you with integrating the completions into the FreeBSD port.

Tested on bash like this:

> bash
bash-5.2$ PATH=$PATH:target/debug
bash-5.2$ source completions/bash/framework_tool 
# Now I can tab complete flags and their values
bash-5.2$ framework_tool --driver portio

How do I test zsh? I can't figure it out

Tested on bash like this:

> bash
bash-5.2$ PATH=$PATH:target/debug
bash-5.2$ source completions/bash/framework_tool 
# Now I can tab complete flags and their values
bash-5.2$ framework_tool --driver portio

How do I test zsh? I can't figure it out

Save the completion file as /usr/local/share/zsh/site-functions/_framework_tool. Then create or edit ~/.zshrc with these lines:

autoload -Uz compinit
compinit

Run source ~/.zshrc then all completions from /usr/local/share/zsh/site-functions should work.

Thanks, that works.