This PR introduces a vastly improved upgrade migrations system, to
migrate your codebase and modernize your utilities to make use of the
latest variants and utilities.
It all started when I saw this PR the other day:
https://github.com/tailwindlabs/tailwindcss/pull/17790
I was about to comment "Don't forget to add a migration". But I've been
thinking about a system where we can automate this process away. This PR
introduces this system.
This PR introduces upgrade migrations based on the internal Design
System, and it mainly updates arbitrary variants, arbitrary properties
and arbitrary values.
## The problem
Whenever we ship new utilities, or you make changes to your CSS file by
introducing new `@theme` values, or adding new `@utility` rules. It
could be that the rest of your codebase isn't aware of that, but you
could be using these values.
For example, it could be that you have a lot of arbitrary properties in
your codebase, they look something like this:
```html
<div class="[color-scheme:dark] [text-wrap:balance]"></div>
```
Whenever we introduce new features in Tailwind CSS, you probably don't
keep an eye on the release notes and update all of these arbitrary
properties to the newly introduced utilities.
But with this PR, we can run the upgrade tool:
```console
npx -y @tailwindcss/upgrade@latest
```
...and it will upgrade your project to use the new utilities:
```html
<div class="scheme-dark text-balance"></div>
```
It also works for arbitrary values, for example imagine you have classes
like this:
```html
<!-- Arbitrary property -->
<div class="[max-height:1lh]"></div>
<!-- Arbitrary value -->
<div class="max-h-[1lh]"></div>
```
Running the upgrade tool again:
```console
npx -y @tailwindcss/upgrade@latest
```
... gives you the following output:
```html
<!-- Arbitrary property -->
<div class="max-h-lh"></div>
<!-- Arbitrary value -->
<div class="max-h-lh"></div>
```
This is because of the original PR I mentioned, which introduced the
`max-h-lh` utilities.
A nice benefit is that this output only has 1 unique class instead of 2,
which also potentially reduces the size of your CSS file.
It could also be that you are using arbitrary values where you (or a
team member) didn't even know an alternative solution existed.
E.g.:
```html
<div class="w-[48rem]"></div>
```
After running the upgrade tool you will get this:
```html
<div class="w-3xl"></div>
```
We can go further though. Since the release of Tailwind CSS v4, we
introduced the concept of "bare values". Essentially allowing you to
type a number on utilities where it makes sense, and we produce a value
based on that number.
So an input like this:
```html
<div class="border-[123px]"></div>
```
Will be optimized to just:
```html
<div class="border-123"></div>
```
This can be very useful for complex utilities, for example, how many
times have you written something like this:
```html
<div class="grid-cols-[repeat(16,minmax(0,1fr))]"></div>
```
Because up until Tailwind CSS v4, we only generated 12 columns by
default. But since v4, we can generate any number of columns
automatically.
Running the migration tool will give you this:
```html
<div class="grid-cols-16"></div>
```
### User CSS
But, what if I told you that we can keep going...
In [Catalyst](https://tailwindcss.com/plus/ui-kit) we often use classes
that look like this for accessibility reasons:
```html
<div class="text-[CanvasText] bg-[Highlight]"></div>
```
What if you want to move the `CanvasText` and `Highlight` colors to your
CSS:
```css
@import "tailwincdss";
@theme {
--color-canvas: CanvasText;
--color-highlight: Highlight;
}
```
If you now run the upgrade tool again, this will be the result:
```html
<div class="text-canvas bg-highlight"></div>
```
We never shipped a `text-canvas` or `bg-highlight` utility, but the
upgrade tool uses your own CSS configuration to migrate your codebase.
This will keep your codebase clean, consistent and modern and you are in
control.
Let's look at one more example, what if you have this in a lot of
places:
```html
<div class="[scrollbar-gutter:stable]"></div>
```
And you don't want to wait for the Tailwind CSS team to ship a
`scrollbar-stable` (or similar) feature. You can add your own utility:
```css
@import "tailwincdss";
@utility scrollbar-stable {
scrollbar-gutter: stable;
}
```
```html
<div class="scrollbar-stable"></div>
```
## The solution — how it works
There are 2 big things happening here:
1. Instead of us (the Tailwind CSS team) hardcoding certain migrations,
we will make use of the internal `DesignSystem` which is the source of
truth for all this information. This is also what Tailwind CSS itself
uses to generate the CSS file.
The internal `DesignSystem` is essentially a list of all:
1. The internal utilities
2. The internal variants
3. The default theme we ship
4. The user CSS
1. With custom `@theme` values
2. With custom `@custom-variant` implementations
3. With custom `@utility` implementations
2. The upgrade tool now has a concept of `signatures`
The signatures part is the most interesting one, and it allows us to be
100% sure that we can migrate your codebase without breaking anything.
A signature is some unique identifier that represents a utility. But 2
utilities that do the exact same thing will have the same signature.
To make this work, we have to make sure that we normalize values. One
such value is the selector. I think a little visualization will help
here:
| UTILITY | GENERATED SIGNATURE |
| ---------------- | ----------------------- |
| `[display:flex]` | `.x { display: flex; }` |
| `flex` | `.x { display: flex; }` |
They have the exact same signature and therefore the upgrade tool can
safely migrate them to the same utility.
For this we will prefer the following order:
1. Static utilities — essentially no brackets. E.g.: `flex`,
`grid-cols-2`
2. Arbitrary values — e.g.: `max-h-[1lh]`, `border-[2px]`
3. Arbitrary properties — e.g.: `[color-scheme:dark]`, `[display:flex]`
We also have to canonicalize utilities to there minimal form.
Essentially making sure we increase the chance of finding a match.
```
[display:_flex_] → [display:flex] → flex
[display:_flex] → [display:flex] → flex
[display:flex_] → [display:flex] → flex
[display:flex] → [display:flex] → flex
```
If we don't do this, then the signatures will be slightly different, due
to the whitespace:
| UTILITY | GENERATED SIGNATURE |
| ------------------ | ------------------------- |
| `[display:_flex_]` | `.x { display: flex ; }` |
| `[display:_flex]` | `.x { display: flex; }` |
| `[display:flex_]` | `.x { display: flex ; }` |
| `[display:flex]` | `.x { display: flex; }` |
### Other small improvements
A few other improvements are for optimizing existing utilities:
1. Remove unnecessary data types. E.g.:
- `bg-[color:red]` -> `bg-[red]`
- `shadow-[shadow:inset_0_1px_--theme(--color-white/15%)]` ->
`shadow-[inset_0_1px_--theme(--color-white/15%)]`
This also makes use of these signatures and if dropping the data type
results in the same signature then we can safely drop it.
Additionally, if a more specific utility exists, we will prefer that
one. This reduced ambiguity and the need for data types.
- `bg-[position:123px]` → `bg-position-[123px]`
- `bg-[123px]` → `bg-position-[123px]`
- `bg-[size:123px]` → `bg-size-[123px]`
2. Optimizing modifiers. E.g.:
- `bg-red-500/[25%]` → `bg-red-500/25`
- `bg-red-500/[100%]` → `bg-red-500`
- `bg-red-500/100` → `bg-red-500`
3. Hoist `not` in arbitrary variants
- `[@media_not_(prefers-color-scheme:dark)]:flex` →
`not-[@media_(prefers-color-scheme:dark)]:flex` → `not-dark:flex` (in
case you are using the default `dark` mode implementation
4. Optimize raw values that could be converted to bare values. This uses
the `--spacing` variable to ensure it is safe.
- `w-[64rem]` → `w-256`
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
This PR improves the upgrade tooling at tiny bit to make sure that as
long as we didn't change any of the stylesheets, that we also don't sort
internal nodes and/or format the stylesheet at all.
This is important in case the Prettier rules are different or if a
totally different formatter is used.
Essentially, if we didn't have to change the stylesheets because of a
migration, we don't want to change it due to a formatter either.
While working on another PR I noticed that some variants were re-printed
in an odd way.
Specifically, this PR fixes an issue where variants using the `@`-root
were incorrectly printed.
- `@lg` was printed as `@-lg`
- `@[400px]` was printed as `@-[400px]`
This is now special cased where the `-` is not inserted for `@`-root
variants.
## Test plan
1. Added a test to ensure the `@`-root variants are printed correctly.
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]
This PR adds a new source detection feature: `@source not "…"`. It can
be used to exclude files specifically from your source configuration
without having to think about creating a rule that matches all but the
requested file:
```css
@import "tailwindcss";
@source not "../src/my-tailwind-js-plugin.js";
```
While working on this feature, we noticed that there are multiple places
with different heuristics we used to scan the file system. These are:
- Auto source detection (so the default configuration or an `@source
"./my-dir"`)
- Custom sources ( e.g. `@source "./**/*.bin"` — these contain file
extensions)
- The code to detect updates on the file system
Because of the different heuristics, we were able to construct failing
cases (e.g. when you create a new file into `my-dir` that would be
thrown out by auto-source detection, it'd would actually be scanned). We
were also leaving a lot of performance on the table as the file system
is traversed multiple times for certain problems.
To resolve these issues, we're now unifying all of these systems into
one `ignore` crate walker setup. We also implemented features like
auto-source-detection and the `not` flag as additional _gitignore_ rules
only, avoid the need for a lot of custom code needed to make decisions.
High level, this is what happens after the now:
- We collect all non-negative `@source` rules into a list of _roots_
(that is the source directory for this rule) and optional _globs_ (that
is the actual rules for files in this file). For custom sources (i.e
with a custom `glob`), we add an allowlist rule to the gitignore setup,
so that we can be sure these files are always included.
- For every negative `@source` rule, we create respective ignore rules.
- Furthermore we have a custom filter that ensures files are only read
if they have been changed since the last time they were read.
So, consider the following setup:
```css
/* packages/web/src/index.css */
@import "tailwindcss";
@source "../../lib/ui/**/*.bin";
@source not "../../lib/ui/expensive.bin";
```
This creates a git ignore file that (simplified) looks like this:
```gitignore
# Auto-source rules
*.{exe,node,bin,…}
*.{css,scss,sass,…}
{node_modules,git}/
# Custom sources can overwrite auto-source rules
!lib/ui/**/*.bin
# Negative rules
lib/ui/expensive.bin
```
We then use this information _on top of your existing `.gitignore`
setup_ to resolve files (i.e so if your `.gitignore` contains rules e.g.
`dist/` this line is going to be added _before_ any of the rules lined
out in the example above. This allows negative rules to allow-list your
`.gitignore` rules.
To implement this, we're rely on the `ignore` crate but we had to make
various changes, very specific, to it so we decided to fork the crate.
All changes are prefixed with a `// CHANGED:` block but here are the
most-important ones:
- We added a way to add custom ignore rules that _extend_ (rather than
overwrite) your existing `.gitignore` rules
- We updated the order in which files are resolved and made it so that
more-specific files can allow-list more generic ignore rules.
- We resolved various issues related to adding more than one base path
to the traversal and ensured it works consistent for Linux, macOS, and
Windows.
## Behavioral changes
1. Any custom glob defined via `@source` now wins over your `.gitignore`
file and the auto-content rules.
- Resolves#16920
3. The `node_modules` and `.git` folders as well as the `.gitignore`
file are now ignored by default (but can be overridden by an explicit
`@source` rule).
- Resolves#17318
- Resolves#15882
4. Source paths into ignored-by-default folders (like `node_modules`)
now also win over your `.gitignore` configuration and auto-content
rules.
- Resolves#16669
5. Introduced `@source not "…"` to negate any previous rules.
- Resolves#17058
6. Negative `content` rules in your legacy JavaScript configuration
(e.g. `content: ['!./src']`) now work with v4.
- Resolves#15943
7. The order of `@source` definitions matter now, because you can
technically include or negate previous rules. This is similar to your
`.gitingore` file.
9. Rebuilds in watch mode now take the `@source` configuration into
account
- Resolves#15684
## Combining with other features
Note that the `not` flag is also already compatible with [`@source
inline(…)`](https://github.com/tailwindlabs/tailwindcss/pull/17147)
added in an earlier commit:
```css
@import "tailwindcss";
@source not inline("container");
```
## Test plan
- We added a bunch of oxide unit tests to ensure that the right files
are scanned
- We updated the existing integration tests with new `@source not "…"`
specific examples and updated the existing tests to match the subtle
behavior changes
- We also added a new special tag `[ci-all]` that, when added to the
description of a PR, causes the PR to run unit and integration tests on
all operating systems.
[ci-all]
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
Prepare the 4.0.16 release.
~~Also added a commit to mark the `--value('…')` and `--modifier('…')`
with literals strings as an experimental feature (aka not shipped in
this PR). But we can revert that commit if we still want to ship it in
4.0.16 instead of 4.1.~~
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
<!--
👋 Hey, thanks for your interest in contributing to Tailwind!
**Please ask first before starting work on any significant new
features.**
It's never a fun experience to have your pull request declined after
investing a lot of time and effort into a new feature. To avoid this
from happening, we request that contributors create an issue to first
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https://github.com/tailwindcss/tailwindcss/blob/master/.github/CONTRIBUTING.md
-->
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.
<!--
👋 Hey, thanks for your interest in contributing to Tailwind!
**Please ask first before starting work on any significant new
features.**
It's never a fun experience to have your pull request declined after
investing a lot of time and effort into a new feature. To avoid this
from happening, we request that contributors create an issue to first
discuss any significant new features. This includes things like adding
new utilities, creating new at-rules, or adding new component examples
to the documentation.
https://github.com/tailwindcss/tailwindcss/blob/master/.github/CONTRIBUTING.md
-->
---------
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
This PR fixes an issue where installing a specific version of
`@tailwindcss/postcss` and `tailwindcss` could still result in a version
mismatch. This is because we were relying on `^4.0.6` for example
instead of `4.0.6`.
This PR now pins all these versions to prevent this:
```
❯ pnpm why tailwindcss
devDependencies:
@tailwindcss/postcss 4.0.5
├─┬ @tailwindcss/node 4.0.6
│ └── tailwindcss 4.0.6
└── tailwindcss 4.0.5
```
Closes#16171
This PR handles `darkMode` variant configs containing braces (so
creating sub-rules) the same way we handle it in the interop layer.
Since the interop layer runs inside the `addVariant` API that we do not
run here, I instead oped to copy the one liner.
## Test plan
Updated one of the migration tests to include a rule that wasn't working
before. Ensured the new output works via
https://play.tailwindcss.com/nR99uhKtv3
Closes#16391
Like the title suggest this PR adds error reporting when the `npm
install` or `npm remove` commands fail.
## Test plan
Tested by swapping out the command for `echo "bla"; exit 1` and
capturing the output from the integration tests:
<img width="792" alt="Screenshot 2025-02-13 at 14 33 02"
src="https://github.com/user-attachments/assets/d1288114-106a-4ac6-a54b-d02b74c98f35"
/>
<img width="761" alt="Screenshot 2025-02-13 at 14 31 05"
src="https://github.com/user-attachments/assets/6d5b9427-457f-4e67-9723-4e340da61749"
/>
Decided not to add a new test for this since it's unlikely we'll do big
changes here and the upgrade integration tests are already quite slow.
This PR bumps the Prettier dependencies, and also pins the version.
Noticed that a PR with a single empty commit started failing at the time
of writing this
(https://github.com/tailwindlabs/tailwindcss/pull/16306). This is
because prettier released a new minor version which results in slightly
different output.
Let's bump prettier and handle the differences, but also pin the version
to avoid this in the future.
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---------
Co-authored-by: Adam Wathan <4323180+adamwathan@users.noreply.github.com>
Resolves#16170
This PR fixes an issue where the previously opted-out escaping of the
first argument for the `var(…)` function was not unescaped at all. This
was introduced in https://github.com/tailwindlabs/tailwindcss/pull/14776
where the intention was to not require escaping of underscores in the
var function (e.g. `ml-[var(--spacing-1_5)]`). However, I do think it
still makes sense to unescape an eventually escaped underline for
consistency.
## Test plan
The example from #1670 now parses as expected:
<img width="904" alt="Screenshot 2025-02-03 at 13 51 35"
src="https://github.com/user-attachments/assets/cac0f06e-37da-4dcb-a554-9606d144a8d5"
/>
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
This PR fixes the upgrade tool by properly migrating the
`leading-[<number>]` classes.
The issue is that `leading-[<number>]` maps to the number directly, but
if you use a bare value, then it's a multiplier for based on the
`--spacing` value.
E.g.:
*leading-[2]*:
```css
.leading-\[2\] {
--tw-leading: 2;
line-height: 2;
}
@property --tw-leading {
syntax: "*";
inherits: false;
}
```
*leading-2*:
```css
.leading-2 {
--tw-leading: calc(var(--spacing) * 2);
line-height: calc(var(--spacing) * 2);
}
@property --tw-leading {
syntax: "*";
inherits: false;
}
```
This PR will now prevent migrating arbitrary values to bare values for
`leading-*` utilities.
That said, this does introduce a small improvement where `leading-[1]`
is migrated to `leading-none`.
Fixes: https://github.com/tailwindlabs/tailwindcss/issues/15924
Closes#15220
This PR fixes an issue where the upgrade tool would not be able to load
some JavaScript config files across different drive letters on Windows.
The issue in detail is that `path.relative(…)` tries to build a relative
path but if the file is inside the same folder, it won't start the
relative path with a `./` so we manually appended it in case that it
isn't there. The issue on Windows specifically is that
`file.relative(…)` can also return a legit absolute path, e.g. when the
file is on a different drive. In this case we obviously don't want to
prefix a path with `./`.
## Test plan
To reproduce this issue, I checked out a Tailwind v3 project _on a
different drive letter than my Windows installation_. In that case, I
was adding a repo inside `D:` while `npm` was installed in `C:`. I then
run `npx @tailwindcss/upgrade` to reproduce the issue.
The fix was validated with a local `bun` run of the upgrade tool:

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 upgrade tool to make sure that newly upgraded
`--spacing(2)` CSS functions is pretty printed to prevent unambiguous
looking classes (even though it compiles correctly).
If you have a class such as `m-[calc(100dvh-theme(spacing.2))]`, then we
used to convert it to `m-[calc(100dvh-calc(var(--spacing)*2))]`. But
recently we introduced the `--spacing(2)` CSS function which means that
the output now looks like this instead: `m-[calc(100dvh---spacing(2))]`.
The triple `-` is valid because the first `-` is the minus sign, the
next two `-` characters are from the function.
One solution is to introduce spaces via underscores:
```
m-[calc(100dvh_-_--spacing(2))]
```
But a simpler solution, is to wrap the `--spacing(2)` in parens to
remove the underscores and improve the readability of the `---`
characters.
```
m-[calc(100dvh-(--spacing(2)))]
```