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>
When migrating a project from Tailwind CSS v3 to Tailwind CSS v4, then
we started the migration process in the following order:
1. Migrate the JS/TS config file
2. Migrate the source files (found via the `content` option)
3. Migrate the CSS files
However, if you have a setup where you have multiple CSS root files
(e.g.: `frontend` and `admin` are separated), then that typically means
that you have an `@config` directive in your CSS files. These point to
the Tailwind CSS config file.
This PR changes the migration order to do the following:
1. Build a tree of all the CSS files
2. For each `@config` directive, migrate the JS/TS config file
3. For each JS/TS config file, migrate the source files
If a CSS file does not contain any `@config` directives, then we start
by filling in the `@config` directive with the default Tailwind CSS
config file (if found, or the one passed in). If no default config file
or passed in config file can be found, then we will error out (just like
we do now)
---------
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
This PR adds a codemod that ensures that the border styles from Tailwind CSS v3 work as expected once your project is migrated to Tailwind CSS v4.
In Tailwind CSS v3, the default border color is `colors.gray.200` and in Tailwind CSS v4 the default border color is `currentColor`.
Similarly in Tailwind CSS v3, DOM elements such as `input`, `select`, and `textarea` have a border width of `0px`, in Tailwind CSS v4, we don't change the border width of these elements and keep them as `1px`.
If your project happens to already use the same value for the default border color (`currentColor`) as we use in Tailwind CSS v4, then nothing happens. But this is very unlikely, so we will make sure that we honor your `borderColor.DEFAULT` value.
If you didn't change the default values in your `tailwind.config.js`, then we will inject compatibility CSS using the default Tailwind CSS v3 values to ensure the default color and width are applied correctly.
This PR implements the first version of JS config file migration to CSS.
It is based on the most simple config setups we are using in the
Tailwind UI templates Commit, Primer, Radiant, and Studio.
The example we use in the integration test is a config that looks like
this:
```js
import { type Config } from 'tailwindcss'
import defaultTheme from 'tailwindcss/defaultTheme'
module.exports = {
darkMode: 'selector',
content: ['./src/**/*.{html,js}'],
theme: {
boxShadow: {
sm: '0 2px 6px rgb(15 23 42 / 0.08)',
},
colors: {
red: {
500: '#ef4444',
},
},
fontSize: {
xs: ['0.75rem', { lineHeight: '1rem' }],
sm: ['0.875rem', { lineHeight: '1.5rem' }],
base: ['1rem', { lineHeight: '2rem' }],
},
extend: {
colors: {
red: {
600: '#dc2626',
},
},
fontFamily: {
sans: 'Inter, system-ui, sans-serif',
display: ['Cabinet Grotesk', ...defaultTheme.fontFamily.sans],
},
borderRadius: {
'4xl': '2rem',
},
},
},
plugins: [],
} satisfies Config
```
As you can see, this file only has a `darkMode` selector, custom
`content` globs, a `theme` (with some theme keys being overwriting the
default theme and some others extending the defaults). Note that it does
not support `plugins` and/or `presets` yet.
In the case above, we will find the CSS file containing the existing
`@tailwind` directives and are migrating it to the following:
```css
@import 'tailwindcss';
@source './**/*.{html,js}';
@variant dark (&:where(.dark, .dark *));
@theme {
--box-shadow-*: initial;
--box-shadow-sm: 0 2px 6px rgb(15 23 42 / 0.08);
--color-*: initial;
--color-red-500: #ef4444;
--font-size-*: initial;
--font-size-xs: 0.75rem;
--font-size-xs--line-height: 1rem;
--font-size-sm: 0.875rem;
--font-size-sm--line-height: 1.5rem;
--font-size-base: 1rem;
--font-size-base--line-height: 2rem;
--color-red-600: #dc2626;
--font-family-sans: Inter, system-ui, sans-serif;
--font-family-display: Cabinet Grotesk, ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
--border-radius-4xl: 2rem;
}
```
This replicates all features of the JS config so we can even delete the
existing JS config in this case.
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
This PR injects a `@config "…"` in the CSS file if a JS based config has
been found.
We will try to inject the `@config` in a sensible place:
1. Above the very first `@theme`
2. If that doesn't work, below the last `@import`
3. If that doesn't work, at the top of the file (as a last resort)
When a stylesheet is imported with `@import “…” layer(utilities)` that
means that all classes in that stylesheet and any of its imported
stylesheets become candidates for `@utility` conversion.
Doing this correctly requires us to place `@utility` rules into separate
stylesheets (usually) and replicate the import tree without layers as
`@utility` MUST be root-level. If a file consists of only utilities we
won't create a separate file for it and instead place the `@utility`
rules in the same stylesheet.
Been doing a LOT of pairing with @RobinMalfait on this one but I think
this is finally ready to be looked at
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
In order to properly migrate your Tailwind CSS v3 project to v4, we need
access to the JavaScript configuration object. This was previously only
required for template migrations, but in this PR we're making it so that
this is also a prerequisite of the CSS migrations. This is because some
migrations, like `@apply`, also need to convert candidates that to the
v4 syntax and we need the full config in order to properly validate
them.
In addition to requiring a JS config, we also now attempt to
automatically find the right configuration file inside the current
working directory. This is now matching the behavior of the Tailwind CSS
v3 CLI where it will find the config automatically if it's in the
current directory and called `tailwind.conf.js`.
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
This PR fixes an issue where CSS that existed before a layer:
```css
.foo {
color: red;
}
@layer components {
.bar {
color: blue;
}
}
```
Was turned into an `@layer` without a name:
```css
@layer {
.foo {
color: red;
}
}
@utility bar {
color: blue;
}
```
But in this case, it should stay as-is:
```css
.foo {
color: red;
}
@utility bar {
color: blue;
}
```
This PR adds a new migration that can migrate Tailwind CSS v3 style
prefixes into Tailwind CSS v4.
The migration is split into three separate pieces of work:
1. Firstly, we need to read the full JavaScript config to get the _old_
prefix option. This is necessary because in v4, we will not allow things
like custom-separators for the prefix. From this option we will then try
and compute a new prefix (in 90% of the cases this is going to just
remove the trailing `-` but it can also work in more complex cases).
2. Then we migrate all Candidates. The important thing here is that we
need to operate on the raw candidate string because by relying on
`parseCandidate` (which we do for all other migrations) would not work,
as the candidates are not valid in v4 syntax. More on that in a bit.
3. Lastly we also make sure to update the CSS config to include the new
prefix. This is done by prepending the prefix option like so:
```css
@import "tailwindcss" prefix(tw);
```
### Migrating candidates
The main difference between v3 prefixes and v4 prefixes is that in v3,
the prefix was _part of the utility_ where as in v4 it is _always in
front of the CSS class.
So, for example, this candidate in v3:
```
hover:-tw-mr-4
```
Would be converted to the following in v4:
```
tw:hover:-mr-4
```
Since the first example _won't parse as a valid Candidate in v4, as the
`tw-mr` utility does not exist, we have to operate on the raw candidate
string first. To do this I created a fork of the `parseCandidate`
function _without any validation of utilities or variants_. This is used
to identify part of the candidate that is the `base` and then ensuring
the `base` starts with the old prefix. We then remove this to create an
"unprefixed" candidate that we validate against a version of the
DesignSystem _with no prefixes configured_. If the variant is valid this
way, we can then print it again with the `DesignSystem` that has the new
prefix to get the migrated version.
Since we set up the `DesignSystem` to include the new prefix, we can
also be certain that migrations that happen afterwards would still
disqualify candidates that aren't valid according to the new prefix
policy. This does mean we need to have the prefix fixup be the first
step in our pipeline.
One interesting bit is that in v3, arbitrary properties did not require
prefixes where as in v4 they do. So the following candidate:
```
[color:red]
```
Will be converted to:
```
tw:[color:red]
```
This PR inserts the `@import` in a more sensible location when running
codemods.
The idea is that we replace `@tailwind base; @tailwind components;
@tailwind utilities;` with the much simple `@import "tailwindcss";`. We
did this by adding the `@import` to the top of the file.
While this is correct, this means that the diff might not be as clear.
For example, if you have a situation where you have a license comment:
```css
/**! My license comment */
@tailwind base;
@tailwind components;
@tailwind utilities;
```
This resulted in:
```css
@import "tailwindcss";
/**! My license comment */
```
While it is not wrong, it feels weird that this behaves like this. In
this commit we make sure that it is injected in-place (the first
`@tailwind` at-rule we find) and fixup the position if we can't inject
it in-place.
The above example results in this:
```css
/**! My license comment */
@import "tailwindcss";
```
However, there are scenario's where you can't replace the `@tailwind`
directives directly. E.g.:
```css
/**! My license comment */
html {
color: red;
}
@tailwind base;
@tailwind components;
@tailwind utilities;
```
If we replace the `@tailwind` directives in-place, it would look like
this:
```css
/**! My license comment */
html {
color: red;
}
@import "tailwindcss";
```
But this is invalid CSS, because you can't have CSS above an `@import`
at-rule. There are some exceptions like:
- `@charset`
- `@import`
- `@layer foo, bar;` (just the order, without a body)
- comments
In this scenario, we inject the import in the nearest place where it is
allowed to. In this case:
```css
/**! My license comment */
@import "tailwindcss";
@layer base {
html {
color: red;
}
}
```
Additionally, we will wrap the existing CSS in an `@layer` of the first
Tailwind directive we saw. In this case an `@layer base`. This ensures
that utilities still win from the default styles.
Also note that the (license) comment is allowed to exist before the
`@import`, therefore we do not put the `@import` above it. This also
means that the diff doesn't touch the license header at all, which makes
the diffs cleaner and easier to reason about.
---------
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.
This PR adds some initial tooling for codemods. We are currently only
interested in migrating CSS files, so we will be using PostCSS under the
hood to do this. This PR also implements the "migrate `@apply`" codemod
from #14412.
The usage will look like this:
```sh
npx @tailwindcss/upgrade
```
You can pass in CSS files to transform as arguments:
```sh
npx @tailwindcss/upgrade src/**/*.css
```
But, if none are provided, it will search for CSS files in the current
directory and its subdirectories.
```
≈ tailwindcss v4.0.0-alpha.24
│ No files provided. Searching for CSS files in the current
│ directory and its subdirectories…
│ Migration complete. Verify the changes and commit them to
│ your repository.
```
The tooling also requires the Git repository to be in a clean state.
This is a common convention to ensure that everything is undo-able. If
we detect that the git repository is dirty, we will abort the migration.
```
≈ tailwindcss v4.0.0-alpha.24
│ Git directory is not clean. Please stash or commit your
│ changes before migrating.
│ You may use the `--force` flag to override this safety
│ check.
```
---
This PR alsoo adds CSS codemods for migrating existing `@apply`
directives to the new version.
This PR has the ability to migrate the following cases:
---
In v4, the convention is to put the important modifier `!` at the end of
the utility class instead of right before it. This makes it easier to
reason about, especially when you are variants.
Input:
```css
.foo {
@apply !flex flex-col! hover:!items-start items-center;
}
```
Output:
```css
.foo {
@apply flex! flex-col! hover:items-start! items-center;
}
```
---
In v4 we don't support `!important` as a marker at the end of `@apply`
directives. Instead, you can append the `!` to each utility class to
make it `!important`.
Input:
```css
.foo {
@apply flex flex-col !important;
}
```
Output:
```css
.foo {
@apply flex! flex-col!;
}
```
