During the migration process, a lot of changes to the CSS file happen.
Some parts are converted, some parts are deleted and some new CSS is
added.
To make sure we are generating a sensible and good looking CSS file, we
will sort the final CSS and pretty print it.
The order we came up with looks like this:
```css
/* Imports */
@import "tailwindcss";
@import "../other.css";
/* Configuration */
@config "../path/to/tailwindcss.config.js";
@plugin "my-plugin-1";
@plugin "my-plugin-2";
@source "./foo/**/*.ts";
@source "./bar/**/*.ts";
@variant foo {}
@variant bar {}
@theme {}
/* Border compatibility CSS */
@layer base {}
/* Utilities */
@utility foo {}
@utility bar {}
/* Rest of your own CSS if any */
```
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
This PR adds a codemod that ensures that some parts of your stylesheet
are wrapped in an `@layer`.
This is a follow-up PR of #14411, in that PR we migrate `@tailwind`
directives to imports.
As a quick summary, that will turn this:
```css
@tailwind base;
@tailwind components;
@tailwind utilities;
```
Into:
```css
@import 'tailwindcss';
```
But there are a few issues with that _if_ we have additional CSS on the
page. For example let's imagine we had this:
```css
@tailwind base;
body {
background-color: red;
}
@tailwind components;
.btn {}
@tailwind utilities;
```
This will now be turned into:
```css
@import 'tailwindcss';
body {
background-color: red;
}
.btn {}
```
But in v4 we use real layers, in v3 we used to replace the directive
with the result of that layer. This means that now the `body` and `.btn`
styles are in the incorrect spot.
To solve this, we have to wrap them in a layer. The `body` should go in
an `@layer base`, and the `.btn` should be in an `@layer components` to
make sure it's in the same spot as it was before.
That's what this PR does, the original input will now be turned into:
```css
@import 'tailwindcss';
@layer base {
body {
background-color: red;
}
}
@layer components {
.btn {
}
}
```
There are a few internal refactors going on as well, but those are less
important.
