That is a big reason why I use functions. They help me define sane fallbacks, and/or enforce API contracts. Those, in turn, are points where I can enforce "fail and die" behaviour.

Design notes: https://www.evalapply.org/posts/shell-aint-a-bad-place-to-fp...

Example from shite: Hard stop if mandatory front matter for posts is absent: https://github.com/adityaathalye/shite/blob/master/bin/templ...

edit: clarity

It was a bit of a lightbulb moment. I wanted a way to just write HTML templates. What really sealed the deal was the ability to punch content from stdin anywhere within a heredoc's scope using `$(cat -)`: https://github.com/adityaathalye/shite#templating-system