This PR bumps all Tailwind CSS related dependencies when running the
upgrade tool _if_ the dependency exists in your package.json file.
E.g.: if you have `tailwindcss` and `@tailwindcss/vite` in your
package.json, then both will be updated to the latest version.
This PR is not trying to be smart and skip updating if you are already
on the latest version. It will just try and update the dependencies and
your package manager will do nothing in case it was already the latest
version.
## Test plan
Ran this on one of my personal projects and this was the output:
<img width="1023" alt="image"
src="https://github.com/user-attachments/assets/a189fe7a-a58a-44aa-9246-b720e7a2a892"
/>
Notice that I don't have `@tailwindcss/vite` logs because I am using
`@tailwindcss/postcss`.
This PR ensures that the `@tailwindcss/upgrade` tool works on existing
Tailwind CSS v4 projects. This PR also ensures that the upgrade tool is
idempotent, meaning that it can be run multiple times and it should
result in the same output.
One awesome feature this unlocks is that you can run the upgrade tool on
your codebase at any time and upgrade classes if you still have some
legacy syntaxes, such as `bg-[var(--my-color)]`, in your muscle memory.
One small note: If something changed in the first run, re-running will
not work immediately because your git repository will not be clean and
the upgrade tool requires your git repo to be clean. But once you
verified and committed your changes, the upgrade tool will be
idempotent.
Idempotency is guaranteed by ensuring that some migrations are skipped
by checking what version of Tailwind CSS you are on _before_ the version
is upgraded.
For the Tailwind CSS version: We will resolve `tailwindcss` itself to
know the _actual_ version that is installed (the one resolved from
`node_modules`). Not the one available in your package.json. Your
`package.json` could be out of sync if you reverted changes but didn't
run `npm install` yet.
Back to Idempotency:
For example, we have migrations where we change the variant order of
stacked variants. If we would run these migrations every time you run
the upgrade tool then we would be flip-flopping the order every run.
See: https://tailwindcss.com/docs/upgrade-guide#variant-stacking-order
Another example is where we rename some utilities. For example, we
rename:
| Before | After |
| ----------- | ----------- |
| `shadow` | `shadow-sm` |
| `shadow-sm` | `shadow-xs` |
Notice how we have `shadow-sm` in both the `before` and `after` column.
If we would run the upgrade tool again, then we would eventually migrate
your original `shadow` to `shadow-sm` (first run) and then to
`shadow-xs` (second run). Which would result in the wrong shadow.
See: https://tailwindcss.com/docs/upgrade-guide#renamed-utilities
---
The order of upgrade steps changed a bit as well to make the internals
are easier to work with and reason about.
1. Find CSS files
2. Link JS config files (if you are in a Tailwind CSS v3 project)
3. Migrate the JS config files (if you are in a Tailwind CSS v3 project)
4. Upgrade Tailwind CSS to v4 (or the latest version at that point)
5. Migrate the stylesheets (we used to migrate the source files first)
6. Migrate the source files
This is done so that step 5 and 6 will always operate on a Tailwind CSS
v4 project and we don't need to check the version number again. This is
also necessary because your CSS file will now very likely contain
`@import "tailwindcss";` which doesn't exist in Tailwind CSS v3.
This also means that we can rely on the same internals that Tailwind CSS
actually uses for locating the source files. We will use
`@tailwindcss/oxide`'s scanner to find the source files (and it also
keeps your custom `@source` directives into account).
This PR also introduces a few actual migrations related to recent
features and changes we shipped.
1. We migrate deprecated classes to their new names:
| Before | After |
| --------------------- | --------------------- |
| `bg-left-top` | `bg-top-left` |
| `bg-left-bottom` | `bg-bottom-left` |
| `bg-right-top` | `bg-top-right` |
| `bg-right-bottom` | `bg-bottom-right` |
| `object-left-top` | `object-top-left` |
| `object-left-bottom` | `object-bottom-left` |
| `object-right-top` | `object-top-right` |
| `object-right-bottom` | `object-bottom-right` |
Introduced in:
- https://github.com/tailwindlabs/tailwindcss/pull/17378
- https://github.com/tailwindlabs/tailwindcss/pull/17437
2. We migrate simple arbitrary variants to their dedicated variant:
| Before | After |
| ----------------------- | ------------------- |
| `[&:user-valid]:flex` | `user-valid:flex` |
| `[&:user-invalid]:flex` | `user-invalid:flex` |
Introduced in:
- https://github.com/tailwindlabs/tailwindcss/pull/12370
3. We migrate `@media` variants to their dedicated variant:
| Before | After |
| ----------------------------------------------------- |
------------------------- |
| `[@media_print]:flex` | `print:flex` |
| `[@media(prefers-reduced-motion:no-preference)]:flex` |
`motion-safe:flex` |
| `[@media(prefers-reduced-motion:reduce)]:flex` | `motion-reduce:flex`
|
| `[@media(prefers-contrast:more)]:flex` | `contrast-more:flex` |
| `[@media(prefers-contrast:less)]:flex` | `contrast-less:flex` |
| `[@media(orientation:portrait)]:flex` | `portrait:flex` |
| `[@media(orientation:landscape)]:flex` | `landscape:flex` |
| `[@media(forced-colors:active)]:flex` | `forced-colors:flex` |
| `[@media(inverted-colors:inverted)]:flex` | `inverted-colors:flex` |
| `[@media(pointer:none)]:flex` | `pointer-none:flex` |
| `[@media(pointer:coarse)]:flex` | `pointer-coarse:flex` |
| `[@media(pointer:fine)]:flex` | `pointer-fine:flex` |
| `[@media(any-pointer:none)]:flex` | `any-pointer-none:flex` |
| `[@media(any-pointer:coarse)]:flex` | `any-pointer-coarse:flex` |
| `[@media(any-pointer:fine)]:flex` | `any-pointer-fine:flex` |
| `[@media(scripting:none)]:flex` | `noscript:flex` |
The new variants related to `inverted-colors`, `pointer`, `any-pointer`
and `scripting` were introduced in:
- https://github.com/tailwindlabs/tailwindcss/pull/11693
- https://github.com/tailwindlabs/tailwindcss/pull/16946
- https://github.com/tailwindlabs/tailwindcss/pull/11929
- https://github.com/tailwindlabs/tailwindcss/pull/17431
This also applies to the `not` case, e.g.:
| Before | After |
| --------------------------------------------------------- |
----------------------------- |
| `[@media_not_print]:flex` | `not-print:flex` |
| `[@media_not(prefers-reduced-motion:no-preference)]:flex` |
`not-motion-safe:flex` |
| `[@media_not(prefers-reduced-motion:reduce)]:flex` |
`not-motion-reduce:flex` |
| `[@media_not(prefers-contrast:more)]:flex` | `not-contrast-more:flex`
|
| `[@media_not(prefers-contrast:less)]:flex` | `not-contrast-less:flex`
|
| `[@media_not(orientation:portrait)]:flex` | `not-portrait:flex` |
| `[@media_not(orientation:landscape)]:flex` | `not-landscape:flex` |
| `[@media_not(forced-colors:active)]:flex` | `not-forced-colors:flex` |
| `[@media_not(inverted-colors:inverted)]:flex` |
`not-inverted-colors:flex` |
| `[@media_not(pointer:none)]:flex` | `not-pointer-none:flex` |
| `[@media_not(pointer:coarse)]:flex` | `not-pointer-coarse:flex` |
| `[@media_not(pointer:fine)]:flex` | `not-pointer-fine:flex` |
| `[@media_not(any-pointer:none)]:flex` | `not-any-pointer-none:flex` |
| `[@media_not(any-pointer:coarse)]:flex` |
`not-any-pointer-coarse:flex` |
| `[@media_not(any-pointer:fine)]:flex` | `not-any-pointer-fine:flex` |
| `[@media_not(scripting:none)]:flex` | `not-noscript:flex` |
For each candidate, we run a set of upgrade migrations. If at the end of
the migrations the original candidate is still the same as the new
candidate, then we will parse & print the candidate one more time to
pretty print into consistent classes. Luckily parsing is cached so there
is no real downside overhead.
Consistency (especially with arbitrary variants and values) will reduce
your CSS file because there will be fewer "versions" of your class.
Concretely, the pretty printing will apply changes such as:
| Before | After |
| ---------------------- | ----------------- |
| `bg-[var(--my-color)]` | `bg-(--my-color)` |
| `bg-[rgb(0,_0,_0)]` | `bg-[rgb(0,0,0)]` |
Another big important reason for this change is that these classes on
their own
would have been migrated _if_ another migration was relevant for this
candidate.
This means that there are were some inconsistencies. E.g.:
| Before | After | Reason |
| ----------------------- | ---------------------- |
------------------------------------ |
| `!bg-[var(--my-color)]` | `bg-(--my-color)!` | Because the `!` is in
the wrong spot |
| `bg-[var(--my-color)]` | `bg-[var(--my-color)]` | Because no
migrations rand |
As you can see, the way the `--my-color` variable is used, is different.
This
changes will make sure it will now always be consistent:
| Before | After |
| ----------------------- | ---------------------- |
| `!bg-[var(--my-color)]` | `bg-(--my-color)!` |
| `bg-[var(--my-color)]` | `bg-(--my-color)` |
Yay!
Of course, if you don't want these more cosmetic changes, you can always
ignore the upgrade and revert these changes and only commit the changes
you want.
# Test plan
- All existing tests still pass.
- But I had to delete 1 test (we tested that Tailwind CSS v3 was
required).
- And had to mock the `version.isMajor` call to ensure we run the
individual migration tests correctly.
- Added new tests to test:
1. Migrating Tailwind CSS v4 projects works
1. Idempotency of the upgrade tool
[ci-all]
This PR is an internal refactor of the codemods package structure that
will make a few follow-up PRs easier.
Essentially what happens is:
1. Moved `./src/template/` into `src/codemods/template/`
2. Moved `./src/codemods` into `./src/codemods/css` (because the CSS
related codemods already)
3. Moved the migration files for the JS config, PostCSS config and
Prettier config into `./src/codemods/config/`.
4. Made filenames with actual migrations consistent by prefixing them
with `migrate-`.
5. Made sure that all the migration functions also use `migrate…`
When looking at this PR, go commit by commit, it will be easier. In a
lot of cases, it's just moving files around but those commits also come
with changes to the code just to update the imports.
[ci-all]
Closes#16945
This PR changes the `--theme(…)` function now return CSS `var(…)`
definitions unless used in places where `var(…)` is not valid CSS (e.g.
in `@media (width >= theme(--breakpoint-md))`):
```css
/* input */
@theme {
--color-red: red;
}
.red {
color: --theme(--color-red);
}
/* output */
:root, :host {
--color-red: red;
}
.red {
color: var(--color-red);
}
```
Furthermore, this adds an `--theme(… inline)` option to the `--theme(…)`
function to force the resolution to be inline, e.g.:
```css
/* input */
@theme {
--color-red: red;
}
.red {
color: --theme(--color-red inline);
}
/* output */
.red {
color: red;
}
```
This PR also changes preflight and the default theme to use this new
`--theme(…)` function to ensure variables are prefixed correctly.
## Test plan
- Added unit tests and a test that pulls in the whole preflight under a
prefix theme.
This PR replaces `@variant` with `@custom-variant` for registering
custom variants via your CSS.
In addition, this PR introduces `@variant` that can be used in your CSS
to use a variant while writing custom CSS.
E.g.:
```css
.btn {
background: white;
@variant dark {
background: black;
}
}
```
Compiles to:
```css
.btn {
background: white;
}
@media (prefers-color-scheme: dark) {
.btn {
background: black;
}
}
```
For backwards compatibility, the `@variant` rules that don't have a body
and are
defined inline:
```css
@variant hocus (&:hover, &:focus);
```
And `@variant` rules that are defined with a body and a `@slot`:
```css
@variant hocus {
&:hover, &:focus {
@slot;
}
}
```
Will automatically be upgraded to `@custom-variant` internally, so no
breaking changes are introduced with this PR.
---
TODO:
- [x] ~~Decide whether we want to allow multiple variants and if so,
what syntax should be used. If not, nesting `@variant <variant> {}` will
be the way to go.~~ Only a single `@variant <variant>` can be used, if
you want to use multiple, nesting should be used:
```css
.foo {
@variant hover {
@variant focus {
color: red;
}
}
}
```
This PR improves the codemod tool to simplify 2 things:
1. Whenever you have a `theme(…)` call, we try to change it to a
`var(…)`, but if that doesn't work for some reason, we will make sure to
at least convert it to the more modern `--theme(…)`.
2. When converting `theme(spacing.2)`, we used to convert it to
`calc(var(--spacing)*2)`, but now we will convert it to `--spacing(2)`
instead.
This PR ensures that when we inject `layer(…)` into an `@import` that it
always gets inserted as the first param. The `layer(…)` has to come
first by spec.
Input:
```css
@import "./foo" supports(--foo);
```
Before:
```css
@import "./foo" supports(--foo) layer(utilities);
```
After:
```css
@import "./foo" layer(utilities) supports(--foo);
```
Closes#15071
This PR reverts the changes in #15036 which add consistent base styles
for buttons and form controls to Preflight.
While this felt like a good idea (for the reasons explained in that PR),
practically this is just too disruptive of a change for people upgrading
from v3 to v4.
While updating some of our projects to v4 we found ourselves adding
classes to undo styles more often than we expected, and it also felt
inconsistent to have to use a different set of classes to style a link
or a button when we wanted them to look the same.
We also decided it feels a little strange that you could change the
border color of an element without ever specifying that it should have a
border, for example this just feels a little wrong:
```html
<button class="border-blue-500">
```
We also needed to set a default `color-scheme` value for any of this
stuff to work which breaks the ability to use the `color-scheme` meta
tag.
Since this change was a fairly major breaking change and we aren't
feeling much benefit from it, it doesn't feel worth making this change
for v4.
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
While testing the latest alpha release across Tailwind v3 projects, we
noticed one regression in relation to the default color of `<button>`
elements. In v3, the reset would change the default to `inherit` but in
v4 we would _not include it in the reset snippet inserted by the upgrade
too_.
This PR changes the upgrade snippet to include it:
```diff
/*
In Tailwind CSS v4, basic styles are applied to form elements by default. To
maintain compatibility with v3, the following resets have been added:
*/
@layer base {
input,
textarea,
select,
button {
border: 0px solid;
border-radius: 0;
padding: 0;
+ color: inherit;
background-color: transparent;
}
}
```
This PR also ensures that there's a newline between the two code
snippets.
## Test Plan
### Before
### After
<img width="1354" alt="Screenshot 2024-11-21 at 15 42 58"
src="https://github.com/user-attachments/assets/9a4503fe-683f-4d08-abf2-7dd111ed5428">
This PR introduces consistent base styles for buttons and form controls
in Tailwind CSS v4.
## Motivation
In v3, form elements lack default styles, which can be
confusing—especially when certain elements, like a text input without a
placeholder or value, are rendered completely invisible on the page.
The goal of this change is to provide reasonable default styles for
buttons, inputs, selects, and textareas that are (mostly) consistent
across all browsers while remaining easy to customize with your own
styles.
This improvement should make Tailwind more accessible for developers new
to the framework and more convenient in scenarios where you need to
quickly create demos (e.g., using Tailwind Play).
## Light and dark mode support
These styles support both light and dark mode, achieved using the
`light-dark()` CSS function. While browser support for this function is
still somewhat limited, Lightning CSS transpiles it to a CSS
variable-based approach that works in older browsers.
For this approach to function correctly, a default `color-scheme` must
be set in your CSS (as explained in [the Lightning CSS
documentation](https://lightningcss.dev/transpilation.html#light-dark()-color-function)).
This PR addresses this requirement by setting the `color-scheme` to
`light` on the `html` element in Preflight.
<img width="1712" alt="image"
src="https://github.com/user-attachments/assets/dba56368-1427-47b3-9419-7c2f6313a944">
<img width="1709" alt="image"
src="https://github.com/user-attachments/assets/3d84fcd2-9606-4626-8e03-164a1dce9018">
## Breaking changes
While we don’t expect these changes to significantly impact v3 users
upgrading to v4, there may be minor differences for those relying on the
simpler v3 styles.
For example, Preflight now applies a `border-radius` to buttons and form
controls. If you weren’t explicitly setting the border radius to `0` in
your project, you’ll need to do so to restore the previous look.
Thankfully, reverting to the v3 styles is straightforward—just add the
following reset to your CSS:
```css
@layer base {
input,
textarea,
select,
button {
border: 0px solid;
border-radius: 0;
padding: 0;
background-color: transparent;
}
}
```
It’s worth noting that this reset doesn't touch the
`::file-selector-button` styles that were added in this PR. This is
because it's not possible to reliably "undo" these styles and restore
the original user-agent styles (which is what was used in v3), as these
are different in each browser. However, these new styles actually match
the defaults in most browsers pretty closely, so hopefully this just
won't be an issue.
## Codemod
This PR includes a codemod that automatically inserts the above
mentioned v3 reset to help avoid breaking changes during the upgrade.
The codemod will insert the following CSS:
```css
/*
In Tailwind CSS v4, basic styles are applied to form elements by default. To
maintain compatibility with v3, the following resets have been added:
*/
@layer base {
input,
textarea,
select,
button {
border: 0px solid;
border-radius: 0;
padding: 0;
background-color: transparent;
}
}
```
## Testing
These changes have been tested across a wide range of browsers,
including Chrome, Safari, Firefox, Edge, and Opera on macOS and Windows,
as well as Safari, Chrome, Firefox, and several lesser-known browsers on
iOS and Android.
However, some quirks still exist in certain mobile browsers, such as iOS
Safari, which adds too much bottom padding below date and time inputs:
<img width="1548" alt="Screenshot 2024-11-20 at 3 57 20 PM"
src="https://github.com/user-attachments/assets/507c7724-ac41-4634-a2b3-61ac4917ebce">
The only reliable way to address these issues is by applying
`appearance: none` to these form controls. However, this felt too
opinionated for Preflight, so we’ve opted to leave such adjustments to
user-land implementations.
---------
Co-authored-by: Jonathan Reinink <jonathan@reinink.ca>
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
We noticed that in the current alpha 34 release, the `package.json` file
of the `@tailwindcss/node` package only defines `tailwindcss` as a dev
dependency. This makes it very easy for version mismatches to happen
when a v3 version (or an earlier v4 alpha for that matter) was installed
in the same project:
```json
{
"name": "@tailwindcss/node",
"version": "4.0.0-alpha.34",
"description": "A utility-first CSS framework for rapidly building custom user interfaces.",
"license": "MIT",
"repository": {
"type": "git",
"url": "https://github.com/tailwindlabs/tailwindcss.git",
"directory": "packages/@tailwindcss-node"
},
"bugs": "https://github.com/tailwindlabs/tailwindcss/issues",
"homepage": "https://tailwindcss.com",
"files": [
"dist/"
],
"publishConfig": {
"provenance": true,
"access": "public"
},
"exports": {
".": {
"types": "./dist/index.d.ts",
"import": "./dist/index.mjs",
"require": "./dist/index.js"
},
"./require-cache": {
"types": "./dist/require-cache.d.ts",
"default": "./dist/require-cache.js"
},
"./esm-cache-loader": {
"types": "./dist/esm-cache.loader.d.mts",
"default": "./dist/esm-cache.loader.mjs"
}
},
"devDependencies": {
"tailwindcss": "4.0.0-alpha.34"
},
"dependencies": {
"enhanced-resolve": "^5.17.1",
"jiti": "^2.0.0-beta.3"
},
"scripts": {
"build": "tsup-node",
"dev": "pnpm run build -- --watch"
}
}
```
Furthermore, we were trying to fix issues where our integration test
setup could not install `tailwindcss@3` because of how we did pnpm
overrides.
This PR fixes this by:
- Ensuring every client that calls into `tailwindcss` core marks it as a
version-pinned dependency. You are still required to install
`tailwindcss` in your project along side a client (e.g.
`@tailwindcss/vite`) but we now only use your installed version for
importing the respective `.css` files. For the core logic, we are now
requiring each package to use `tailwindcss` at the same version. This
should help resolve issues like
https://github.com/tailwindlabs/tailwindcss/discussions/14652
- We tried to eliminate the dependency on `tailwindcss` from the
`@tailwindcss/upgrade` package. Unfortunately this is not possible to do
right now because we need to load the CSS files from v4 to create the
right environment. In a future version we could bundle the required CSS
files with `@tailwidncss/upgrade` but it doesn't seem necessary for now.
- We then changed our integration test overrides to only override the
`tailwindcss` package that are dependencies of the known list of
packages that we have `tailwindcss` dependencies on: `@tailwindcss/node`
and `@tailwindcss/upgrade`. This ensures that we can install v3 of
`tailwindcss` in the integration tests and it will work. Something we
want to do for some upgrade tests.
# Test plan
Integration work again. Furthermore we added a quick setup with the CLI
using the local tarballs and ensured it works:
```bash
pnpm init
pnpm install ../../tailwindcss/dist/tailwindcss-cli.tgz
pnpm install ../../tailwindcss/dist/tailwindcss.tgz
echo '@import "tailwindcss";' > index.css
echo '<div class="underline"></div>' > index.html
pnpm tailwindcss -i index.css -o out.css
cat out.css
```
This PR fixes an issue where imports above Tailwind directives didn't
get a `layer(…)` argument.
Given this CSS:
```css
@import "./typography.css";
@tailwind base;
@tailwind components;
@tailwind utilities;
```
It was migrated to:
```css
@import "./typography.css";
@import "tailwindcss";
```
But to ensure that the typography styles end up in the correct location,
it requires the `layer(…)` argument.
This PR now migrates the input to:
```css
@import "./typography.css" layer(base);
@import "tailwindcss";
```
Test plan:
---
Added an integration test where an import receives the `layer(…)`, but
an import that eventually contains `@utility` does not receive the
`layer(…)` argument. This is necessary otherwise the `@utility` will be
nested when we are processing the inlined CSS.
Running this on the Commit template, we do have a proper `layer(…)`
<img width="585" alt="image"
src="https://github.com/user-attachments/assets/538055e6-a9ac-490d-981f-41065a6b59f9">
This PR fixes an issue where an `@config` was injected in a strange
location if you have multiple CSS files with Tailwind directives.
Let's say you have this setup:
```css
/* ./src/index.css */
@import "./tailwind-setup.css";
/* ./src/tailwind-setup.css */
@import "./base.css";
@import "./components.css";
@import "./utilities.css";
/* ./src/base.css */
@tailwind base;
/* ./src/components.css */
@tailwind components;
/* ./src/utilities.css */
@tailwind utilities;
```
In this case, `base.css`, `components.css`, and `utilities.css` are all
considered Tailwind roots because they contain Tailwind directives or
imports.
Since there are multiple roots, the nearest common ancestor should
become the tailwind root (where `@config` is injected). In this case,
the nearest common ancestor is `tailwind-setup.css` (not `index.css`
because that's further away).
Before this change, we find the common ancestor between `base.css` and
`components.css` which would be `index.css` instead of
`tailwind-setup.css`.
In a next iteration, we compare `index.css` with `utilities.css` and
find that there is no common ancestor (because the `index.css` file has
no parents). This resulted in the `@config` being injected in
`index.css` and in `utilities.css`.
Continuing with the rest of the migrations, we migrate the `index.css`'s
`@config` away, but we didn't migrate the `@config` from
`utilities.css`.
With this PR, we don't even have the `@config` in the `utilities.css`
file anymore.
Test plan
---
1. Added an integration test with a non-migrateable config file to
ensure that the `@config` is injected in the correct file.
2. Added an integration test with a migrateable config file to ensure
that the CSS config is injected in the correct file. h/t @philipp-spiess
3. Ran the upgrade on the https://commit.tailwindui.com project and
ensured that
1. The `@config` does not exist in the `utilities.css` file (this was
the first bug we solved)
2. The `@config` is replaced in the `tailwind.css` file correctly.
<img width="592" alt="image"
src="https://github.com/user-attachments/assets/02e3f6ea-a85d-46c2-ac93-09f34ac4a4b8">
<img width="573" alt="image"
src="https://github.com/user-attachments/assets/e372eb5f-5732-4052-ab39-096ba7970ff6">
This PR fixes an issue where we migrated classes such as `rounded` to
`rounded-sm` (see:
https://github.com/tailwindlabs/tailwindcss/pull/14875)
However, if you override the values in your `tailwind.config.js` file,
then the migration might not be correct.
This PR makes sure to only migrate the classes if you haven't overridden
the values in your `tailwind.config.js` file.
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
This PR reverts a change we made for v4 that added borders to inputs by
default. It feels like we have to go further than this for this to
actually be useful to anyone, and since there were no borders in v3 it's
also a breaking change.
If we wanted to make form elements look more "normal" out of the box I
think we need to do something more like this:
https://play.tailwindcss.com/icCwFLVp4z?file=css
But it's a huge rabbit hole and there are so many stupid details to get
right that it feels like an insurmountable task, and if we can't go all
the way with it it's better to just maximize compatibility with v3.
---------
Co-authored-by: Adam Wathan <4323180+adamwathan@users.noreply.github.com>
We noticed an issue that the `theme()` function wourld not properly
parse in CSS if you split the argument list over multiple lines. This is
fixed by treating `\n` and `\t` the same as space:
```css
.custom-font {
font-family: theme(
fontFamily.unknown,
Helvetica Neue,
Helvetica,
sans-serif
);
}
```
## Test plan
Added tests, but also tried it in the Vite example:
<img width="1995" alt="Screenshot 2024-11-08 at 13 46 09"
src="https://github.com/user-attachments/assets/f9bf94b0-3f9b-4334-8911-9190987e2df5">
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 replaces the default spacing scale (`--spacing-*`) with a
generative system based on a default spacing _unit_.
Instead of the default theme containing values like `--spacing-4`,
`--spacing-6`, `--spacing-8`, etc., instead we just define a single
`--spacing` value:
```css
@theme {
--spacing: 0.25rem;
}
```
Utilities like `px-4` are derived from this unit by multiplying it by
the value in the utility (4 in this case):
```css
.px-4 {
padding-inline: calc(var(--spacing) * 4);
}
```
The biggest consequence of this change is that every value is available
now, rather than just the explicitly configured values.
This means utilities like `px-42` will work now, whereas prior to this
PR only `px-40` and `px-44` were valid utilities. I personally found it
very difficult to know which values actually existed at the higher end
of the scale without IntelliSense, and in practice even when working
with a skilled designer like [Steve](https://x.com/steveschoger) who
helped design Tailwind's default spacing scale, I'd very often need to
break out of it to implement a design, and trying to round to a value
that was in the scale made the design worse, not better.
This PR allows you to use any whole number, as well as decimal numbers
that are multiples of `0.25` to ensure classes like `px-1.5` continue to
work. While this means you can now technically do things like
`pt-97.25`, I think the presence of the fractional value will be enough
of a signal to developers that they are doing something a little
unusual, and they can use their judgment as to whether they are making
the right decision or not.
I'll update this PR with a lot more detail when I have a chance, as
there are a few other things to explain like:
- Unifying all of the values for
width/min-width/max-width/height/min-height/max-height utilities
- Deriving numeric line-height values from the spacing multiplier
instead of a separate line-height scale
- Using `--spacing: initial` to disable the multiplier
- How you can still use an explicit spacing scale and ignore this change
- How we plan to use IntelliSense to surface a more curated set of
spacing values even if smaller increments work when you type them
explicitly
---------
Co-authored-by: Adam Wathan <4323180+adamwathan@users.noreply.github.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 fixes an issue where `layer(…)` next to imports were removed
where they shouldn't have been removed.
The issue exists if _any_ of the `@import` nodes in a file contains
`@utility`, if that's the case then we removed the `layer(…)` next to
_all_ `@import` nodes.
Before we were checking if the current sheet contained `@utility` or in
any of its children (sub-`@import` nodes).
This fixes that by looping over the `@import` nodes in the current
sheet, and looking for the `@utility` in the associated/imported file.
This way we update each node individually.
Test plan:
---
Added a dedicated integration test to make sure all codemods together
result in the correct result. Input:
96e8908378/integrations/upgrade/index.test.ts (L2076-L2108)
Output:
96e8908378/integrations/upgrade/index.test.ts (L2116-L2126)
This PR improves where we inject the border compatibility CSS. Before
this change we injected it if it was necessary in one of these spots:
- Above the first `@layer base` to group it together with existing
`@layer base` at-rules.
- If not present, after the last `@import`, to make sure that we emit
valid CSS because `@import` should be at the top (with a few
exceptions).
However, if you are working with multiple CSS files, then it could be
that we injected the border compatibility CSS multiple times if those
files met one of the above conditions.
To solve this, we now inject the border compatibility CSS with the same
rules as above, but we also have another condition:
The border compatibility CSS is only injected if the file also has a
`@import "tailwindcss";` _or_ `@import "tailwindcss/preflight";` in the
current file.
---
Added integration tests to make sure that we are generating what we
expect in a real environment. Some of the integration tests also use the
old `@tailwind` directives to make sure that the order of migrations is
correct (first migrate to `@import` syntax, then inject the border
compatibility CSS).
---------
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
When we implemented the CSS import resolution system, we found out a
detail about CSS imports in that files without a relative path prefix
would still be relative to the source file. E.g.:
```css
@import 'foo.css';
```
Should first look for the file `foo.css` in the same directory. To make
this cost as cheap as possible, we limited this by a heuristics to only
apply the auto-relative imports for files with a file extension.
Naturally, while testing v4 on more templates, we found that it's common
for people to omit the file extension when loading css file. The above
could also be written as such:
```css
@import 'foo';
```
To improve this, we have two options:
- We either remove the heuristics, making every `@import` more expensive
because we have to check for relative files.
- We upgrade our codemods to rewrite `@import` statements to be
explicitly relative.
Because we really care about performance, we opted to go with the latter
option. This PR adds the codemod and removes the heuristics so we
resolve CSS files similar to how you would resolve JS files.
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
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 adds a codemod for migrating the old `@screen` directive from Tailwind
CSS v2 that also worked in Tailwind CSS v3 but wasn't documented anymore.
Internally, this first migrates `@screen md` to `@media screen(md)`, then we rely on the existing migration that migrates the `screen(…)` function.
Input:
```css
@screen md {
.foo {
color: red;
}
}
```
Output (IR):
```css
@media screen(md) {
.foo {
color: red;
}
}
```
Output:
```css
@media theme(--breakpoint-md) {
.foo {
color: red;
}
}
```
This PR migrates the `@variants` and `@responsive` directives.
In Tailwind CSS v2, these were used to generate certain variants of responsive variants for the give classes. In Tailwind CSS v3, these still worked but were implemented as a no-op such that these directives don't end up in your final CSS.
In Tailwind CSS v4, these don't exist at all anymore, so we can safely get rid of them by replacing them with their contents.
Input:
```css
@variants hover, focus {
.foo {
color: red;
}
}
@responsive {
.bar {
color: blue;
}
}
```
Output:
```css
.foo {
color: red;
}
.bar {
color: blue;
}
```
This PR extends our JS configuration to CSS migration by also allowing `plugins` with options.
An example of such config would be:
```js
import { type Config } from 'tailwindcss'
import myPlugin from "./myPlugin";
export default {
plugins: [
myPlugin({
class: "tw",
}),
],
} satisfies Config;
```
If the option object contains only values allowed in our CSS API, we can convert this to CSS entirely:
```css
@plugin './myPlugin' {
class: 'tw';
}
```
This PR is a follow up from https://github.com/tailwindlabs/tailwindcss/pull/14664 migrates all the `theme(…)` calls in your CSS to `var(…)` if we can.
In at-rules, like `@media` we can't use `var(…)` so we have to use the modern version of `theme(…)`.
In declarations, we can convert to `var(…)` unless there is a modifier used in the `theme(…)` function, then we can only convert to the new `theme(…)` syntax without dot notation.
Input:
```css
@media theme(spacing.4) {
.foo {
background-color: theme(colors.red.900);
color: theme(colors.red.900 / 75%); /* With spaces around the `/` */
border-color: theme(colors.red.200/75%); /* Without spaces around the `/` */
}
}
```
Output:
```css
@media theme(--spacing-4) {
/* ^^^^^^^^^^^^^^^^^^ Use `theme(…)` since `var(…)` is invalid in this position*/
.foo {
background-color: var(--color-red-900); /* Converted to var(…) */
color: theme(--color-red-900 / 75%); /* Convert to modern theme(…) */
border-color: theme(--color-red-200 / 75%); /* Convert to modern theme(…) — pretty printed*/
}
}
```
Imagine the following setup:
```css
/* src/input.css */
@import "tailwindcss";
@config "../tailwind.config.ts";
@theme {
--color-red-500: #ef4444;
}
```
```ts
/* tailwind.config.ts */
export default {
theme: {
colors: {
red: {
600: '#dc2626'
}
},
extend: {
colors: {
400: '#f87171'
}
}
}
}
```
Since the theme object in the JS config contains `colors` in the
non-`extends` block, you would expect this to _not pull in all the
default colors imported via `@import "tailwindcss";`_. This, however,
wasn't the case right now since all theme options were purely _additive_
to the CSS.
This PR makes it so that non-`extend` theme keys _overwrite default CSS
theme values_. The emphasis is on `default` here since you still want to
be able to overwrite your options via `@theme {}` in user space.
This now generates the same CSS that our upgrade codemods would also
generate as this would apply the new CSS right after the `@import
"tailwindcss";` rule resulting in:
```css
@import "tailwindcss";
@theme {
--color-*: initial;
--color-red-400: #f87171;
--color-red-600: #dc2626;
}
@theme {
--color-red-500: #ef4444;
}
```
## Keyframes
This PR also adds a new core API to unset keyframes the same way. We
previously had no option of doing that but while working on the above
codemods we noticed that keyframes should behave the same way:
```css
@import "tailwindcss";
@theme {
--keyframes-*: initial;
@keyframes spin {
to {
transform: rotate(361deg);
}
}
}
```
To do this, the keyframes bookeeping was moved from the main Tailwind
CSS v4 file into the `Theme` class.
_I’m not sure super of the API yet but we would need a way for the
codemods to behave the same as out interop layer here. Option B is that
we don't reset keyframes the same way we reset other theme variables_.
This PR builds on top of the new [JS config to CSS
migration](https://github.com/tailwindlabs/tailwindcss/pull/14651) and
extends it to support migrating _static_ plugins.
What are _static_ plugins you might ask? Static plugins are plugins
where we can statically determine that these are coming from a different
file (so there is nothing inside the JS config that creates them). An
example for this is this config file:
```js
import typographyPlugin from '@tailwindcss/typography'
import { type Config } from 'tailwindcss'
export default {
content: ['./src/**/*.{js,jsx,ts,tsx}'],
darkMode: 'selector',
plugins: [typographyPlugin],
} satisfies Config
```
Here, the `plugins` array only has one element and it is a static import
from the `@tailwindcss/typography` module. In this PR we attempt to
parse the config file via Tree-sitter to extract the following
information from this file:
- What are the contents of the `plugins` array
- What are statically imported resources from the file
We then check if _all_ entries in the `plugins` array are either static
resources or _strings_ (something I saw working in some tests but I’m
not sure it still does). We migrate the JS config file to CSS if all
plugins are static and we can migrate them to CSS `@plugin` calls.
## Todo
This will need to be rebased after the updated tests in #14648
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>
This PR adds a codemod that migrates the `@media screen(…)` to the
properly expanded `@media (…)` syntax.
```css
@media screen(md) {
.foo {
color: red;
}
}
```
Will be converted to:
```css
@media (width >= 48rem) {
.foo {
color: red;
}
}
```
If you happen to have custom screens (even complex ones), the screen
will be converted to a custom media query.
```css
@media screen(foo) {
.foo {
color: red;
}
}
```
With a custom `tailwind.config.js` file with a config like this:
```js
module.exports = {
// …
theme: {
screens: {
foo: { min: '100px', max: '123px' },
},
}
}
```
Then the codemod will convert it to:
```css
@media (123px >= width >= 100px) {
.foo {
color: red;
}
}
```
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 extracts all _candidate migrations_ from the existing _template
migrations_ and reuses these in the `@apply` CSS migration. Seems like
this _JustWorks✨_.
---------
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
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 fixes an issue where a CSS rule with a selector that contains
multiple selectors lost everything but the last selector.
While testing the `npx @tailwindcss/upgrade` codemods on real world
projects, I noticed that we lost one of the selectors in the
`docker/docs` repository.
```diff
diff --git a/assets/css/toc.css b/assets/css/toc.css
index 91ff92d7cd..3b2432e913 100644
--- a/assets/css/toc.css
+++ b/assets/css/toc.css
@@ -2,7 +2,7 @@
#TableOfContents {
.toc a {
@apply block max-w-full truncate py-1 pl-2 hover:font-medium hover:no-underline;
- &[aria-current="true"],
+
&:hover {
@apply border-l-2 border-l-gray-light bg-gradient-to-r from-gray-light-100 font-medium text-black dark:border-l-gray-dark dark:from-gray-dark-200 dark:text-white;
}
```
This PR fixes the issue by not overriding the `node.selector` internally
with the last selector we handled. Instead, we let the selector parser
handle it entirely.
When CSS exists between two tailwind directives, then the CSS will be
wrapped in an `@layer` to ensure it all ends up in the correct location
in the final CSS file.
However, if the only thing between two tailwind directives is a comment,
then the comment will also be wrapped in an `@layer` directive.
E.g.:
```css
@tailwind base;
/* This is a comment */
@tailwind components;
/* This is another comment */
@tailwind utilities;
```
Results in:
```css
@import "tailwindcss";
@layer base {
/* This is a comment */
}
@layer components {
/* This is another comment */
}
```
In this case, the layers don't matter, so this can be simplified to:
```css
@import "tailwindcss";
/* This is a comment */
/* This is another comment */
```
This PR fixes an issue where some `@import` at-rules had an empty
`layer()` attached at the end of the `@import` string.
We should only add that if a Tailwind directive or Tailwind import such
as `@tailwind base` or `@import "tailwindcss/base"` preceded the current
`@import` at-rule. If there was no Tailwind directive, the `lastLayer`
will be empty and we don't need to attach it to the `@import` string.
This PR improves the missing layers codemod where everything after the
last Tailwind directive can stay as-is without wrapping it in a `@layer`
directive.
The `@layer` at-rules are only important for CSS that exists between
Tailwind directives.
E.g.:
```css
@tailwind base;
html {}
@tailwind components;
.btn {}
@tailwind utilities;
.foo {}
.bar {}
```
Was transformed into:
```css
@import "tailwindcss";
@layer base {
html {}
}
@layer components {
.btn {}
}
@layer utilities {
.foo {}
.bar {}
}
```
But the last `@layer utilities` is already in the correct spot, so we
can simplify this to just this instead:
```css
@import "tailwindcss";
@layer base {
html {}
}
@layer components {
.btn {}
}
.foo {}
.bar {}
```
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 CSS codemods for migrating existing `@layer utilities` to
`@utility` directives.
This PR has the ability to migrate the following cases:
---
The most basic case is when you want to migrate a simple class to a
utility directive.
Input:
```css
@layer utilities {
.foo {
color: red;
}
.bar {
color: blue;
}
}
```
Output:
```css
@utility foo {
color: red;
}
@utility bar {
color: blue;
}
```
You'll notice that the class `foo` will be used as the utility name, the
declarations (and the rest of the body of the rule) will become the body
of the `@utility` definition.
---
In v3, every class in a selector will become a utility. To correctly
migrate this to `@utility` directives, we have to register each class in
the selector and generate `n` utilities.
We can use nesting syntax, and replace the current class with `&` to
ensure that the final result behaves the same.
Input:
```css
@layer utilities {
.foo .bar .baz {
color: red;
}
}
```
Output:
```css
@utility foo {
& .bar .baz {
color: red;
}
}
@utility bar {
.foo & .baz {
color: red;
}
}
@utility .baz {
.foo .bar & {
color: red;
}
}
```
In this case, it could be that you know that some of them will never be
used as a utility (e.g.: `hover:bar`), but then you can safely remove
them.
---
Even classes inside of `:has(…)` will become a utility. The only
exception to the rule is that we don't do it for `:not(…)`.
Input:
```css
@layer utilities {
.foo .bar:not(.qux):has(.baz) {
display: none;
}
}
```
Output:
```css
@utility foo {
& .bar:not(.qux):has(.baz) {
display: none;
}
}
@utility bar {
.foo &:not(.qux):has(.baz) {
display: none;
}
}
@utility baz {
.foo .bar:not(.qux):has(&) {
display: none;
}
}
```
Notice that there is no `@utility qux` because it was used inside of
`:not(…)`.
---
When classes are nested inside at-rules, then these classes will also
become utilities. However, the `@utility <name>` will be at the top and
the at-rules will live inside of it. If there are multiple classes
inside a shared at-rule, then the at-rule will be duplicated for each
class.
Let's look at an example to make it more clear:
Input:
```css
@layer utilities {
@media (min-width: 640px) {
.foo {
color: red;
}
.bar {
color: blue;
}
@media (min-width: 1024px) {
.baz {
color: green;
}
@media (min-width: 1280px) {
.qux {
color: yellow;
}
}
}
}
}
```
Output:
```css
@utility foo {
@media (min-width: 640px) {
color: red;
}
}
@utility bar {
@media (min-width: 640px) {
color: blue;
}
}
@utility baz {
@media (min-width: 640px) {
@media (min-width: 1024px) {
color: green;
}
}
}
@utility qux {
@media (min-width: 640px) {
@media (min-width: 1024px) {
@media (min-width: 1280px) {
color: yellow;
}
}
}
}
```
---
When classes result in multiple `@utility` directives with the same
name, then the definitions will be merged together.
Input:
```css
@layer utilities {
.no-scrollbar::-webkit-scrollbar {
display: none;
}
.no-scrollbar {
-ms-overflow-style: none;
scrollbar-width: none;
}
}
```
Intermediate representation:
```css
@utility no-scrollbar {
&::-webkit-scrollbar {
display: none;
}
}
@utility no-scrollbar {
-ms-overflow-style: none;
scrollbar-width: none;
}
```
Output:
```css
@utility no-scrollbar {
&::-webkit-scrollbar {
display: none;
}
-ms-overflow-style: none;
scrollbar-width: none
}
```
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
