3.1.0 fails scanning `.slim` templates for purging

[ledermann]

What version of Tailwind CSS are you using?

v3.1.0

What build tool (or framework if it abstracts the build tool) are you using?

webpack@5.73.0, postcss@8.4.14

What version of Node.js are you using?

v18.3.0

What browser are you using?

Not relevant here

What operating system are you using?

Not relevant here

---

In a Ruby on Rails application, I'm using Slim templates which look like this:

p.bg-red-500.text-sm
  'This is a paragraph
  small.italic.text-gray-500 
    '(Look mom, no closing tag!)

With Tailwind CSS v3.0.24 this works fine, which means that Tailwind recognizes the classes correctly.

But after upgrading to v3.1.0 this is broken - maybe because of the dots instead of spaces (see #8553 for a similar issue). Classes defined this way are purged from the resulting stylesheet.

I've built this workaround by transforming to HTML:

// tailwind.config.js
var execSync = require('child_process').execSync;

// Converts Slim to HTML
function compileToHTML(source) {
  return execSync(`slimrb --stdin --erb`, {
    input: source,
  }).toString();
}

module.exports = {
  ...

  content: {
    files: [
      './app/**/*.{html,html.erb,rb,html.slim}',
      './app/javascript/**/*.js',
    ],
    transform: {
      slim: (content) => compileToHTML(content),
    },
  },

  ...
};

This works, but seems like a hack. Is there a chance for an official fix?