Justfile Targets

27 Oct 2023 | One-minute read

just is a cross-platform task runner. I use just extensively to define the build tasks for IronPLC, in part so that local builds and the continuous integration builds are as close as possible.

just runs tasks and has no opinion when it comes to what the tasks are.


IronPLC is contained in a single repository that includes the compiler in Rust, the Visual Studio Code integration in TypeScript, the website in reStructuredText (Python), and build task definitions. In fact, some website pages take content directly from the compiler. Keeping things in one repository simplifies the build and test process.

IronPLC builds using GitHub Actions. It is possible to create complex actions, but it is usually better to put any complexity into tasks (scripts) so that they can be run outside of the automated build.

This is the crux of the problem: what are the tasks?

It is possible to define tasks based on each component’s tasks, such as Cargo, NPM or Maven, but those tasks are not inclusive. The Cargo build tasks don’t create the Windows installer. Each component defines tasks slightly differently.


What I needed was a simple vocabulary of tasks that integrations well into with the automated build and is simple enough to not obscure each component’s build system.


I ended up with just a handful of regular build tasks.

The one that I had the most difficulty was build-and-test and ended up calling it exactly what it does.