cssbundling-rails VS puma-dev

See the issue I opened on Github. [EDIT: closed by DHH recently]

In the Procfile.dev that's currently generated by the cssbundling-rails and jsbundling-rails gems, we can see that they write the web process like:

The functionality comes from https://github.com/rails/jsbundling-rails and https://github.com/rails/cssbundling-rails -- both come with Rails 7 and all you have to do is generate your app with the choices you want such as -j esbuild --css tailwind.

TailwindCSS from CSS Bundling for Rails - (this post)

Maybe https://github.com/rails/cssbundling-rails does what you want? For CSS only, afaik it's perfectly fine to mix different approaches for CSS and JS within one Rails app, so you could still use importmaps for JS.

The docs at https://github.com/rails/cssbundling-rails clearly state that

Install cssbundling-rails gem.

Propshaft has a smaller scope than sprockets and requires you to rely on the js-bundling and css-bundling gems to handle the building of CSS and JS assets. Read the docs for an extensive upgrade guide.

As you may know there's also a [CSS bundling](https://github.com/rails/cssbundling-rails). However, I've only upgraded a trivial project, don't know how involved that would be.

Puma-dev: A fast, zero-config development server for macOS and Linux - https://github.com/puma/puma-dev

Developing a rails application with subdomains is much more difficult on Linux than on MacOS. On Mac it requires nothing more than installing puma-dev and following the installation guide, which also covers linux but we don't understand why that works, or how, and so we close our minds to whats beyond that rabbit hole.

Check out puma-dev. It's intended to be a successor of sorts.

you can also use them with puma-dev

You develop using this approach by running the bundler in watch mode in a terminal with yarn build:css --watch (and your Rails server in another, if you're not using something like puma-dev). Whenever the bundler detects changes to any of the stylesheet files in your project, it'll bundle app/assets/stylesheets/application.[bundler].css into app/assets/builds/application.css. This build output takes over from the regular asset pipeline default file. So you continue to refer…

I will describe the installation for macOS, for Linux you can use https://github.com/puma/puma-dev#linux-support.