The just Command Runner is an Neat Tool

I came across the tool just.

It’s a tool for running commands/scripts.

My initial impression was “that’s it?”.

I might describe it slightly differently, compared to other common workflows:

• It’s common to see make used with a bunch of .PHONY: targets. The point of a make is to describe how some target is built. But since people will often want to run tasks (e.g. run tests with make test), a ‘phony’ target is a task where the target isn’t a file that gets built.
  • Compared to “use make with a bunch of .PHONY targets”, just has some nice quality of life features.
    • e.g. with just, you don’t have to indent the definitions using Tabs.
    • e.g. just can list the targets in its justfile.
• In the NodeJS ecosystem, its package.json files often contain a scripts property, which is used to describe common tasks that will be run when working with the project.
  • Compared to this, a justfile is more expressive / less constrained.
    • e.g. ‘make with .PHONY targets’ is more expressive than package.json’s scripts`.
• It’s common to have a ‘script directory’ where you keep a bunch of scripts for common functionality.
  • Compared to this, just allows for a consistent starting point, some quality of life features (e.g. by-default always starting scripts with starting directory being the justfile’s directory) and allow for integration with editors.

Overall, I find that quite persuasive: it’s more polished/tailored than make for a particular use case; and that use case is something which developers definitely make use of.

There is the downside that just isn’t a standard tool that you can hope to find on most systems (in contrast to e.g. python, bash, or maybe awk or make).
But, installing packages isn’t all that hard. (And just is available in many places).
And I use nix, so it’s especially easy to ensure it’s available when I want it.

I think this is a good example of “sometimes better isn’t MUCH better; it’s merely slightly better”.