Simpler checking, formatting, standard prelude

[simonmichael]

At the start of my justfiles I often put recipes like:

# Constants and recipe arguments will also be available as environment variables
# in recipes, making just code easier to convert to and from shell, so you can
# write $VAR instead of {{ VAR }}. But {{ }} handles multi-word values better.
#set export

# This and all other just invocations assume you are in this justfile's directory,
# since otherwise we must write --justfile {{ justfile() }} or {{ just }} everywhere.

# list this justfile's recipes, optionally filtered by a case-insensitive regexp
@help *PAT:
    if [[ '{{ PAT }}' =~ '' ]]; then just -lu; else just -lu | rg -i '{{ PAT }}'; fi

@_check:
    just --fmt --unstable --check

@_fmt:
    just -q _check || just --fmt --unstable

@_watch:
    watchexec -w {{ justfile() }} -- 'just help; just -q _check && echo format ok || echo non-standard format'

I don't have very concrete suggestions, just

1. I find these handy, others might too
2. The ergonomics could be improved, look at all the verbosity eg to check a justfile. I made these recipes because the command lines were quite hard to discover
3. I appreciate just remaining flexible, yet things like listing recipes as default are such a common need, I wonder if such "prelude" recipes could be built in/easily available somehow

[edvardm]

I like the idea! Linked this in in my post which you might find interesting as well