This PR introduces a new `canonicalizeCandidates` function on the
internal Design System.
The big motivation to moving this to the core `tailwindcss` package is
that we can use this in various places:
- The Raycast extension
- The VS Code extension / language server
- 3rd party tools that use the Tailwind CSS design system APIs
> This PR looks very big, but **I think it's best to go over the changes
commit by commit**. Basically all of these steps already existed in the
upgrade tool, but are now moved to our core `tailwindcss` package.
Here is a list of all the changes:
- Added a new `canonicalizeCandidates` function to the design system
- Moved various migration steps to the core package. I inlined them in
the same file and because of that I noticed a specific pattern (more on
this later).
- Moved `printCandidate` tests to the `tailwindcss` package
- Setup tests for `canonicalizeCandidates` based on the existing tests
in the upgrade tool.
I noticed that all the migrations followed a specific pattern:
1. Parse the raw candidate into a `Candidate[]` AST
2. In a loop, try to migrate the `Candidate` to a new `Candidate` (this
often handled both the `Candidate` and its `Variant[]`)
3. If something changed, print the new `Candidate` back to a string, and
pass it to the next migration step.
While this makes sense in isolation, we are doing a lot of repeated work
by parsing, modifying, and printing the candidate multiple times. This
let me to introduce the `big refactor` commit. This changes the steps
to:
1. Up front, parse the raw candidate into a `Candidate[]` _once_.
2. Strip the variants and the important marker from the candidate. This
means that each migration step only has to deal with the base `utility`
and not care about the variants or the important marker. We can
re-attach these afterwards.
3. Instead of a `rawCandidate: string`, each migration step receives an
actual `Candidate` object (or a `Variant` object).
4. I also split up the migration steps for the `Candidate` and the
`Variant[]`.
All of this means that there is a lot less work that needs to be done.
We can also cache results between migrations. So `[@media_print]:flex`
and `[@media_print]:block` will result in `print:flex` and `print:block`
respectively, but the `[@media_print]` part is only migrated once across
both candidates.
One migration step relied on the `postcss-selector-parser` package to
parse selectors and attribute selectors. I didn't want to introduce a
package just for this, so instead used our own `SelectorParser` in the
migration and wrote a small `AttributeSelectorParser` that can parse the
attribute selector into a little data structure we can work with
instead.
If we want, we can split this PR up into smaller pieces, but since the
biggest chunk is moving existing code around, I think it's fairly doable
to review as long as you go commit by commit.
---
With this new API, we can turn:
```
[
'bg-red-500',
'hover:bg-red-500',
'[@media_print]:bg-red-500',
'hover:[@media_print]:bg-red-500',
'bg-red-500/100',
'hover:bg-red-500/100',
'[@media_print]:bg-red-500/100',
'hover:[@media_print]:bg-red-500/100',
'bg-[var(--color-red-500)]',
'hover:bg-[var(--color-red-500)]',
'[@media_print]:bg-[var(--color-red-500)]',
'hover:[@media_print]:bg-[var(--color-red-500)]',
'bg-[var(--color-red-500)]/100',
'hover:bg-[var(--color-red-500)]/100',
'[@media_print]:bg-[var(--color-red-500)]/100',
'hover:[@media_print]:bg-[var(--color-red-500)]/100',
'bg-(--color-red-500)',
'hover:bg-(--color-red-500)',
'[@media_print]:bg-(--color-red-500)',
'hover:[@media_print]:bg-(--color-red-500)',
'bg-(--color-red-500)/100',
'hover:bg-(--color-red-500)/100',
'[@media_print]:bg-(--color-red-500)/100',
'hover:[@media_print]:bg-(--color-red-500)/100',
'bg-[color:var(--color-red-500)]',
'hover:bg-[color:var(--color-red-500)]',
'[@media_print]:bg-[color:var(--color-red-500)]',
'hover:[@media_print]:bg-[color:var(--color-red-500)]',
'bg-[color:var(--color-red-500)]/100',
'hover:bg-[color:var(--color-red-500)]/100',
'[@media_print]:bg-[color:var(--color-red-500)]/100',
'hover:[@media_print]:bg-[color:var(--color-red-500)]/100',
'bg-(color:--color-red-500)',
'hover:bg-(color:--color-red-500)',
'[@media_print]:bg-(color:--color-red-500)',
'hover:[@media_print]:bg-(color:--color-red-500)',
'bg-(color:--color-red-500)/100',
'hover:bg-(color:--color-red-500)/100',
'[@media_print]:bg-(color:--color-red-500)/100',
'hover:[@media_print]:bg-(color:--color-red-500)/100',
'[background-color:var(--color-red-500)]',
'hover:[background-color:var(--color-red-500)]',
'[@media_print]:[background-color:var(--color-red-500)]',
'hover:[@media_print]:[background-color:var(--color-red-500)]',
'[background-color:var(--color-red-500)]/100',
'hover:[background-color:var(--color-red-500)]/100',
'[@media_print]:[background-color:var(--color-red-500)]/100',
'hover:[@media_print]:[background-color:var(--color-red-500)]/100'
]
```
Into their canonicalized form:
```
[
'bg-red-500',
'hover:bg-red-500',
'print:bg-red-500',
'hover:print:bg-red-500'
]
```
The list is also unique, so we won't end up with `bg-red-500 bg-red-500`
twice.
While the canonicalization itself is fairly fast, we still pay a **~1s**
startup cost for some migrations (once, and cached for the entire
lifetime of the design system). I would like to keep improving the
performance and the kinds of migrations we do, but I think this is a
good start.
The cost we pay is for:
1. Generating a full list of all possible utilities based on the
`getClassList` suggestions API.
2. Generating a full list of all possible variants.
The canonicalization step for this list takes **~2.9ms** on my machine.
Just for fun, if you use the `getClassList` API for intellisense that
generates all the suggestions and their modifiers, you get a list of
**263788** classes. If you canonicalize all of these, it takes
**~500ms** in total. So roughly **~1.9μs** per candidate.
This new API doesn't result in a performance difference for normal
Tailwind CSS builds.
The other potential concern is file size of the package. The generated
`tailwindcss.tgz` file changed like this:
```diff
- 684652 bytes (684.65 kB)
+ 749169 bytes (749.17 kB)
```
So the package increased by ~65 kB which I don't think is the end of the
world, but it is important for the `@tailwindcss/browser` build which we
don't want to grow unnecessarily. For this reason we remove some of the
code for the design system conditionally such that you don't pay this
cost in an environment where you will never need this API.
The `@tailwindcss/browser` build looks like this:
```shell
`dist/index.global.js 255.14 KB` (main)
`dist/index.global.js 272.61 KB` (before this change)
`dist/index.global.js 252.83 KB` (after this change, even smaller than on `main`)
```
This PR fixes an issue where sometimes people try to run the upgrade
tool, reset the changes and then try again.
If this happens, then the `package.json` and/or your lock file will
point to the old Tailwind CSS v3 version, but the actual installed
version will be v4.
This will also cause the upgrade tool to now upgrade from v4 to v4,
which is not what most people want if they were trying to upgrade from
v3 to v4. This in turn will cause some issues because now we won't try
to migrate the config file, or v3-specific classes that also exist in v4
but are only safe to upgrade from v3 to v4.
This PR uses `npm ls tailwindcss` to determine the actual installed
version. This command already errors if there is a mismatch between the
installed version and the version in `package.json` or the lock file.
This also happens to work in pnpm and bun projects (added integration
tests for these).
If for whatever reason we can't determine the expected version, we fall
back to the old behavior of just upgrading. In this scenario, the
changes introduced in
https://github.com/tailwindlabs/tailwindcss/pull/19026 will at least
give you a hint of what version was actually installed.
### Test plan
1. Tested it in a v3 project where I performed the following steps:
1. Run the upgrade tool in full (`npx tailwindcss-upgrade`)
2. Reset the changes (`git reset --hard && git clean -df`)
1. Run the upgrade tool again
This resulted in the following output: <img width="1059" height="683"
alt="image"
src="https://github.com/user-attachments/assets/1d2ea2d1-b602-4631-958f-cc21eb8a633f"
/>
2. Added some integration tests to make sure this also works in pnpm,
bun and normal npm projects.
[ci-all]
This PR adds a bit more information when running the upgrade tool to
know what version of Tailwind CSS you're upgrading from. This will help
users and maintainers when things go wrong.
Will have another PR up soon that errors when the Tailwind CSS version
in package.json and node_modules don't match.
### Test plan
Ran this one one of our older projects and saw the version logged
correctly.
<img width="1055" height="363" alt="image"
src="https://github.com/user-attachments/assets/5cbf4c52-ea0f-42c8-bd55-5bae2ed511de"
/>
This PR fixes an issue where an error such as:
<img width="1702" alt="image"
src="https://github.com/user-attachments/assets/4e6f75c7-3182-4497-939e-96cff08c55ae"
/>
Will be thrown during the upgrade process. This can happen when you are
using `pnpm` and your CSS file includes a `@import "tailwindcss";`. In
this scenario, `tailwindcss` will be loaded from a shared `.pnpm` folder
outside of the current working directory.
In this case, we are also not interested in migrating _that_ file, but
we also don't want the upgrade process to just crash.
I didn't see an option to ignore errors like this, so wrapped it in a
try/catch instead.
It also fixes another issue where if you are using a pnpm workspace and
run the upgrade tool from the root, then it throws you an error that you
cannot add dependencies to the workspace root unless `-w` or
`--workspace-root` flags are passed.
For this, we disable the check entirely using the
`--ignore-workspace-root-check` flag. If we always used the
`--workspace-root` flag, then the dependencies would always be added to
the root, regardless of where you are running the script from which is
not what we want.
## Test plan
Before:
<img width="1816" alt="image"
src="https://github.com/user-attachments/assets/78246876-3eb6-4539-a557-d3d366f1b3a3"
/>
After:
<img width="1816" alt="image"
src="https://github.com/user-attachments/assets/a65e4421-d7c5-4d83-b35d-934708543e25"
/>
Before:
<img width="1816" alt="image"
src="https://github.com/user-attachments/assets/53772661-2c4a-4212-84d9-a556a0ad320f"
/>
After:
<img width="1816" alt="image"
src="https://github.com/user-attachments/assets/5bfaf20e-34b8-44fd-9b59-e72d36738879"
/>
This PR makes the migrations for templates much faster. To make this
work, I also had to move things around a bit (so you might want to check
this PR commit by commit). I also solved an issue by restructuring the
code.
### Performance
For starters, we barely applied any caching when migrating candidates
from α to β. The problem with this is that in big projects the same
candidates will appear _everywhere_, so caching is going to be useful
here.
One of the reasons why we didn't do any caching is that some migrations
were checking if a migration is actually safe to do. To do this, we were
checking the `location` (the location of the candidate in the template).
Since this location is unique for each template, caching was not
possible.
So the first order of business was to hoist the `isSafeMigration` check
up as the very first thing we do in the migration.
If we do this first, then the only remaining code relies on the
`DesignSystem`, `UserConfig` and `rawCandidate`.
In a project, the `DesignSystem` and `UserConfig` will be the same
during the migration, only the `rawCandidate` will be different which
means that we can move all this logic in a good old `DefaultMap` and
cache the heck out of it.
Running the numbers on our Tailwind Plus repo, this results in:
```
Total seen candidates: 2 211 844
Total migrated candidates: 7 775
Cache hits: 1 575 700
```
That's a lot of work we _don't_ have to do. Looking at the timings, the
template migration step goes from ~45s to ~10s because of this.
Another big benefit of this is that this makes migrations _actually_
safe. Before we were checking if a migration was safe to do in specific
migrations. But other migrations were still printing the candidate which
could still result in an unsafe migration.
For example when migrating the `blur` and the `shadow` classes, the
`isSafeMigration` was used. But if the input was `!flex` then the safety
check wasn't even checked in this specific migration.
### Safe migrations
Also made some changes to the `isSafeMigration` logic itself. We used to
start by checking the location, but thinking about the problem again,
the actual big problem we were running into is classes that are short
like `blur`, and `shadow` because they could be used in other contexts
than a Tailwind CSS class.
Inverting this logic means that more specific Tailwind CSS classes will
very likely _not_ cause any issues at all.
For example:
- If you have variants: `hover:focus:flex`
- If you have arbitrary properties: `[color:red]`
- If you have arbitrary values: `bg-[red]`
- If you have a modifier: `bg-red-500/50`
- If you have a `-` in the name: `bg-red-500`
Even better if we can't parse a candidate at all, we can skip the
migrations all together.
This brings us to the issue in #17974, one of the issues was already
solved by just hoisting the `isSafeMigration`. But to make the issue was
completely solved I also made sure that in Vue attributes like
`:active="…"` are also considered unsafe (note: `:class` is allowed).
Last but not least, in case of the `!duration` that got replaced with
`duration!` was solved by verifying that the candidate actually produces
valid CSS. We can compute the signature for this class.
The reason this wasn't thrown away earlier is because we can correctly
parse `duration` but `duration` on its own doesn't exist,
`duration-<number>` does exist as a functional utility which is why it
parsed in the first place.
Fixes: #17974
## Test plan
1. Ran the tool on our Tailwind UI Templates repo to compare the new
output with the "old" behavior and there were no differences in output.
2. Ran the tool on our Tailwind Plus repo, and the template migration
step went from ~45s to ~10s.
3. Added additional tests to verify the issues in #17974 are fixed.
[ci-all] let's run this on all CI platforms...
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 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#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 improves the performance of the `@tailwindcss/postcss` and
`@tailwindcss/vite` implementations.
The issue is that in some scenarios, if you have multiple `.css` files,
then all of the CSS files are ran through the Tailwind CSS compiler. The
issue with this is that in a lot of cases, the CSS files aren't even
related to Tailwind CSS at all.
E.g.: in a Next.js project, if you use the `next/font/local` tool, then
every font you used will be in a separate CSS file. This means that we
run Tailwind CSS in all these files as well.
That said, running Tailwind CSS on these files isn't the end of the
world because we still need to handle `@import` in case `@tailwind
utilities` is being used. However, we also run the auto source detection
logic for every CSS file in the system. This part is bad.
To solve this, this PR introduces an internal `features` to collect what
CSS features are used throughout the system (`@import`, `@plugin`,
`@apply`, `@tailwind utilities`, etc…)
The `@tailwindcss/postcss` and `@tailwindcss/vite` plugin can use that
information to decide if they can take some shortcuts or not.
---
Overall, this means that we don't run the slow parts of Tailwind CSS if
we don't need to.
---------
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
This PR uses the `enhanced-resolve` instead of
`createRequire(…).resolve` which improves the usability when running the
upgrade tool locally using Bun.
While testing, we also noticed that it is not possible to use a
`cjs`-only plugin inside of an `esm` project. It was also not possible
to use an `esm`-only plugin inside of a `cjs` project.
# Test plan
We added integration tests in both the CLI (the CLI is an mjs project)
and in the PostCSS (where we can configure a `cjs` and `esm` PostCSS
config) integration tests where we created an `esm` and `cjs` based
project with 4 plugins (`cjs`-only, `esm`-only, and TypeScript based
plugins: `cts`-only and `mts`-only).
In some local testing we ran the `@tailwindcss/upgrade` command twice in
a row. It would be great to get some feedback that this is not working,
so this PR now checks if it can resolve the installed version of
`tailwindcss` and if it can, it requires it to be < 4 (you can bypass
this check with `--force`).
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
This ensures our glob hoisting mechanism (see #14896) works on Windows
when performing an upgrade.
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
This PR fixes an issue where globs in you `content` configuration escape
the current "root" of the project.
This can happen if you have a folder, and you need to look up in the
tree (e.g.: when looking at another package in a monorepo, or in case of
a Laravel project where you want to look at mail templates).
This applies a similar strategy we already implement on the Rust side.
1. Expand braces in the globs
2. Move static parts of the `pattern` to the `base` of the glob entry
object
---
Given a project setup like this:
```
.
├── admin
│ ├── my-tailwind.config.ts
│ └── src
│ ├── abc.jpg
│ ├── index.html
│ ├── index.js
│ └── styles
│ └── input.css
├── dashboard
│ ├── src
│ │ ├── index.html
│ │ ├── index.js
│ │ ├── input.css
│ │ └── pickaday.css
│ └── tailwind.config.ts
├── package-lock.json
├── package.json
├── postcss.config.js
└── unrelated
└── index.html
7 directories, 14 files
```
If you then have this config:
```ts
// admin/my-tailwind.config.ts
export default {
content: {
relative: true,
files: ['./src/**/*.html', '../dashboard/src/**/*.html'],
// ^^ this is the important part, which escapes
// the current root of the project.
},
theme: {
extend: {
colors: {
primary: 'red',
},
},
},
}
```
Then before this change, running the command looks like this:
<img width="1760" alt="image"
src="https://github.com/user-attachments/assets/60e2dfc7-3751-4432-80e3-8b4b8f1083d4">
After this change, running the command looks like this:
<img width="1452" alt="image"
src="https://github.com/user-attachments/assets/5c47182c-119c-4732-a253-2dace7086049">
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
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 improves the PostCSS migrations to make sure that we install
`@tailwindcss/postcss` in the same bucket as `tailwindcss`.
If `tailwindcss` exists in the `dependencies` bucket, we install
`@tailwindcss/postcss` in the same bucket. If `tailwindcss` exists in
the `devDependencies` bucket, we install `@tailwindcss/postcss` in the
same bucket.
This also contains an internal refactor that normalizes the package
manager to make sure we can install a package to the correct bucket
depending on the package manager.
---------
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
This PR updates the `extractStaticPlugins` function to also emit options as long as these are objects containing of only `string` and `number` values.
While doing this I also cleaned up the `require('custom-plugin')` detector to use a Tree-Sitter query instead of operating on the AST.
Here are the two cases we considered:
```js
import plugin1 from 'plugin1';
export default {
plugins: [
plugin1({
foo: 'bar',
num: 19,
}),
require('./plugin2')({
foo: 'bar',
num: 19,
}),
]
}
```
The test plan also contains a number of scenarios that we do not want to migrate to CSS (because we do not have a CSS API we can use for e.g. nested objects). We do support all types that we also support in the CSS API.
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 attempts to detect simple postcss setups: These are setups that
do not load dynamic modules and are based off the examples we are
[recommending in our
docs](https://tailwindcss.com/docs/installation/using-postcss). We
detect wether a config is appropriate by having it use the object plugin
config and by not requiring any other modules:
```js
module.exports = {
plugins: {
tailwindcss: {},
autoprefixer: {},
},
}
```
When we find such a config file, we will go over it line-by-line and
attempt to:
- Upgrade `tailwindcss:` to `'@tailwindcss/postcss':`
- Remove `autoprefixer` if used
We then attempt to install and remove the respective npm packages based
on the package manger we detect.
And since we now have logic to upgrade packages, this also makes sure to
install `tailwindcss@next` at the end of a sucessful migration.
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.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!;
}
```
