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 integration tests in two ways:
1. Make the integration tests more reliable and thus less flakey
2. Make the integration tests faster (by introducing concurrency)
Tried a lot of different things to make sure that these tests are fast
and stable.
---
The biggest issue we noticed is that some tests are flakey, these are
tests with long running dev-mode processes where watchers are being used
and/or dev servers are created.
To solve this, all the tests that spawn a process look at stdout/stderr
and wait for a message from the process to know whether we can start
making changes.
For example, in case of an Astro project, you get a `watching for file
changes` message. In case of Nuxt project you can wait for an `server
warmed up in` and in case of Next.js there is a `Ready in` message.
These depend on the tools being used, so this is hardcoded per test
instead of a magically automatic solution.
These messages allow us to wait until all the initial necessary work,
internal watchers and/or dev servers are setup before we start making
changes to the files and/or request CSS stylesheets before the server(s)
are ready.
---
Another improvement is how we setup the dev servers. Before, we used to
try and get a free port on the system and use a `--port` flag or a
`PORT` environment variable. Instead of doing this (which is slow), we
rely on the process itself to show a URL with a port. Basically all
tools will try to find a free port if the default port is in use. We can
then use the stdout/stderr messages to get the URL and the port to use.
To reduce the amount of potential conflicts in ports, we used to run
every test and every file sequentially to basically guarantee that ports
are free. With this new approach where we rely on the process, I noticed
that we don't really run into this issue again (I reran the tests
multiple times and they were always stable)
<img width="316" alt="image"
src="https://github.com/user-attachments/assets/b75ddab4-f919-4995-85d0-f212b603e5c2"
/>
Note: these tests run Linux, Windows and macOS in this branch just for
testing purposes. Once this is done, we will only run Linux tests on PRs
and run all 3 of them on the `next` branch.
We do make the tests concurrent by default now, which in theory means
that there could be conflicts (which in practice means that the process
has to do a few more tries to find a free port). To reduce these
conflicts, we split up the integration tests such that Vite, PostCSS,
CLI, … tests all run in a separate job in the GitHub actions workflow.
<img width="312" alt="image"
src="https://github.com/user-attachments/assets/fe9a58a1-98eb-4d9b-8845-a7c8a7af5766"
/>
Comparing this branch against the `next` branch, this is what CI looks
like right now:
| `next` | `feat/improve-integration-tests` |
| --- | --- |
| <img width="594" alt="image"
src="https://github.com/user-attachments/assets/540d21eb-ab03-42e8-9f6f-b3a071fc7635"
/> | <img width="672" alt="image"
src="https://github.com/user-attachments/assets/8ef2e891-08a1-464b-9954-4153174ebce7"
/> |
There also was a point in time where I introduced sequential tests such
that all spawned processes still run after each other, but so far I
didn't run into issues if we keep them concurrent so I dropped that
code.
Some small changes I made to make things more reliable:
1. When relying on stdout/stderr messages, we split lines on `\n` and we
strip all the ANSI escapes which allows us to not worry about special
ANSI characters when finding the URL or a specific message to wait for.
2. Once a test is done, we `child.kill()` the spawned process. If that
doesn't work, for whatever reason, we run a `child.kill('SIGKILL')` to
force kill the process. This could technically lead to some memory or
files not being cleaned up properly, but once CI is done, everything is
thrown away anyway.
3. As you can see in the screenshots, I used some nicer names for the
workflows.
| `next` | `feat/improve-integration-tests` |
| --- | --- |
| <img width="276" alt="image"
src="https://github.com/user-attachments/assets/e574bb53-e21b-4619-9cdb-515431b255b9"
/> | <img width="179" alt="image"
src="https://github.com/user-attachments/assets/8bc75119-fb91-4500-a1d0-bd09f74c93ad"
/> |
They also look a bit nicer in the PR overview as well:
<img width="929" alt="image"
src="https://github.com/user-attachments/assets/04fc71fc-74b0-4e7c-9047-2aada664efef"
/>
The very last commit just filters out Windows and macOS tests again for
PRs (but they are executed on the `next` branch.
---
### Nest steps
I think for now we are in a pretty good state, but there are some things
we can do to further improve everything (mainly make things faster) but
aren't necessary. I also ran into issue while trying it so there is more
work to do.
1. More splits — instead of having a Vite folder and PostCSS folder, we
can go a step further and have folders for Next.js, Astro, Nuxt, Remix,
…
2. Caching — right now we have to run the build step for every OS on
every "job". We can re-use the work here by introducing a setup job that
the other jobs rely on. @thecrypticace and I tried it already, but were
running into some Bun specific Standalone CLI issues when doing that.
3. Remote caching — we could re-enable remote caching such that the
`build` step can be full turbo (e.g.: after a PR is merged in `next` and
we run everything again)
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).
This PR changes how we render `var(...)` calls for theme values,
removing the fallback values we were previously including.
```diff
.text-white {
- color: var(--color-white, #fff);
+ color: var(--color-white);
}
```
We previously included the fallbacks only so you could see the value in
dev tools but this feels like a bad reason to bloat the CSS. I'd rather
just convince the Chrome team to surface this stuff better in dev tools
in the first place.
---------
Co-authored-by: Adam Wathan <4323180+adamwathan@users.noreply.github.com>
We broke this at some point — probably when we tried to optimize
rebuilds in PostCSS by not performing a full auto-source detection scan.
This PR addresses this problem by:
1. Storing a list of found directories
2. Comparing their mod times on every scan
3. If the mod time has changed we scan the directory for new files which
we then store and scan
This PR introduces a new `source(…)` argument and improves on the
existing `@source`. The goal of this PR is to make the automatic source
detection configurable, let's dig in.
By default, we will perform automatic source detection starting at the
current working directory. Auto source detection will find plain text
files (no binaries, images, ...) and will ignore git-ignored files.
If you want to start from a different directory, you can use the new
`source(…)` next to the `@import "tailwindcss/utilities"
layer(utilities) source(…)`.
E.g.:
```css
/* ./src/styles/index.css */
@import 'tailwindcss/utilities' layer(utilities) source('../../');
```
Most people won't split their source files, and will just use the simple
`@import "tailwindcss";`, because of this reason, you can use
`source(…)` on the import as well:
E.g.:
```css
/* ./src/styles/index.css */
@import 'tailwindcss' source('../../');
```
Sometimes, you want to rely on auto source detection, but also want to
look in another directory for source files. In this case, yuo can use
the `@source` directive:
```css
/* ./src/index.css */
@import 'tailwindcss';
/* Look for `blade.php` files in `../resources/views` */
@source '../resources/views/**/*.blade.php';
```
However, you don't need to specify the extension, instead you can just
point the directory and all the same automatic source detection rules
will apply.
```css
/* ./src/index.css */
@import 'tailwindcss';
@source '../resources/views';
```
If, for whatever reason, you want to disable the default source
detection feature entirely, and only want to rely on very specific glob
patterns you define, then you can disable it via `source(none)`.
```css
/* Completely disable the default auto source detection */
@import 'tailwindcss' source(none);
/* Only look at .blade.php files, nothing else */
@source "../resources/views/**/*.blade.php";
```
Note: even with `source(none)`, if your `@source` points to a directory,
then auto source detection will still be performed in that directory. If
you don't want that, then you can simply add explicit files in the globs
as seen in the previous example.
```css
/* Completely disable the default auto source detection */
@import 'tailwindcss' source(none);
/* Run auto source detection in `../resources/views` */
@source "../resources/views";
```
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
Co-authored-by: Adam Wathan <4323180+adamwathan@users.noreply.github.com>
This PR fixes an issue when trying to resolve plugins with `exports` in
their `package.json`, like `@headlessui/tailwindcss`. The missing
`conditionNames` in the enhanced resolver config would cause it to not
properly look up the name.
## Test Plan
I added a test using the `postcss` setup (the existing plugin tests are
inside the CLI setup but the CLI can only ever run in Module JS mode).
To ensure the tests are resolving to the right environment (CJS vs MJS),
I added logging of the `import.meta.url` value to the resolver code.
When run, this was the output:
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
This PR improves the performance of the `@tailwindcss/postcss` plugin.
Before this change we created 2 compiler instances instead of a single
one. On a project where a `tailwindcss.config.ts` file is used, this
means that the timings look like this:
```
[@tailwindcss/postcss] Setup compiler: 137.525ms
⋮
[@tailwindcss/postcss] Setup compiler: 43.95ms
```
This means that with this small change, we can easily shave of ~50ms for
initial PostCSS builds.
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
When your Vite or postcss project has multiple Tailwind CSS roots with
different configs, they should not influence each other (with the
exception of the same candidates being used).
This PR brings `@import` resolution into Tailwind CSS core. This means
that our clients (PostCSS, Vite, and CLI) no longer need to depend on
`postcss` and `postcss-import` to resolve `@import`. Furthermore this
simplifies the handling of relative paths for `@source`, `@plugin`, or
`@config` in transitive CSS files (where the relative root should always
be relative to the CSS file that contains the directive). This PR also
fixes a plugin resolution bug where non-relative imports (e.g. directly
importing node modules like `@plugin '@tailwindcss/typography';`) would
not work in CSS files that are based in a different npm package.
### Resolving `@import`
The core of the `@import` resolution is inside
`packages/tailwindcss/src/at-import.ts`. There, to keep things
performant, we do a two-step process to resolve imports. Imagine the
following input CSS file:
```css
@import "tailwindcss/theme.css";
@import "tailwindcss/utilities.css";
```
Since our AST walks are synchronous, we will do a first traversal where
we start a loading request for each `@import` directive. Once all loads
are started, we will await the promise and do a second walk where we
actually replace the AST nodes with their resolved stylesheets. All of
this is recursive, so that `@import`-ed files can again `@import` other
files.
The core `@import` resolver also includes extensive test cases for
[various combinations of media query and supports conditionals as well
als layered
imports](https://developer.mozilla.org/en-US/docs/Web/CSS/@import).
When the same file is imported multiple times, the AST nodes are
duplicated but duplicate I/O is avoided on a per-file basis, so this
will only load one file, but include the `@theme` rules twice:
```css
@import "tailwindcss/theme.css";
@import "tailwindcss/theme.css";
```
### Adding a new `context` node to the AST
One limitation we had when working with the `postcss-import` plugin was
the need to do an additional traversal to rewrite relative `@source`,
`@plugin`, and `@config` directives. This was needed because we want
these paths to be relative to the CSS file that defines the directive
but when flattening a CSS file, this information is no longer part of
the stringifed CSS representation. We worked around this by rewriting
the content of these directives to be relative to the input CSS file,
which resulted in added complexity and caused a lot of issues with
Windows paths in the beginning.
Now that we are doing the `@import` resolution in core, we can use a
different data structure to persist this information. This PR adds a new
`context` node so that we can store arbitrary context like this inside
the Ast directly. This allows us to share information with the sub tree
_while doing the Ast walk_.
Here's an example of how the new `context` node can be used to share
information with subtrees:
```ts
const ast = [
rule('.foo', [decl('color', 'red')]),
context({ value: 'a' }, [
rule('.bar', [
decl('color', 'blue'),
context({ value: 'b' }, [
rule('.baz', [decl('color', 'green')]),
]),
]),
]),
]
walk(ast, (node, { context }) => {
if (node.kind !== 'declaration') return
switch (node.value) {
case 'red': assert(context.value === undefined)
case 'blue': assert(context.value === 'a')
case 'green': assert(context.value === 'b')
}
})
```
In core, we use this new Ast node specifically to persist the `base`
path of the current CSS file. We put the input CSS file `base` at the
root of the Ast and then overwrite the `base` on every `@import`
substitution.
### Removing the dependency on `postcss-import`
Now that we support `@import` resolution in core, our clients no longer
need a dependency on `postcss-import`. Furthermore, most dependencies
also don't need to know about `postcss` at all anymore (except the
PostCSS client, of course!).
This also means that our workaround for rewriting `@source`, the
`postcss-fix-relative-paths` plugin, can now go away as a shared
dependency between all of our clients. Note that we still have it for
the PostCSS plugin only, where it's possible that users already have
`postcss-import` running _before_ the `@tailwindcss/postcss` plugin.
Here's an example of the changes to the dependencies for our Vite client
✨ :
<img width="854" alt="Screenshot 2024-09-19 at 16 59 45"
src="https://github.com/user-attachments/assets/ae1f9d5f-d93a-4de9-9244-61af3aff1237">
### Performance
Since our Vite and CLI clients now no longer need to use `postcss` at
all, we have also measured a significant improvement to the initial
build times. For a small test setup that contains only a hand full of
files (nothing super-complex), we measured an improvement in the
**3.5x** range:
<img width="1334" alt="Screenshot 2024-09-19 at 14 52 49"
src="https://github.com/user-attachments/assets/06071fb0-7f2a-4de6-8ec8-f202d2cc78e5">
The code for this is in the commit history if you want to reproduce the
results. The test was based on the Vite client.
### Caveats
One thing to note is that we previously relied on finding specific
symbols in the input CSS to _bail out of Tailwind processing
completely_. E.g. if a file does not contain a `@tailwind` or `@apply`
directive, it can never be a Tailwind file.
Since we no longer have a string representation of the flattened CSS
file, we can no longer do this check. However, the current
implementation was already inconsistent with differences on the allowed
symbol list between our clients. Ideally, Tailwind CSS should figure out
wether a CSS file is a Tailwind CSS file. This, however, is left as an
improvement for a future API since it goes hand-in-hand with our planned
API changes for the core `tailwindcss` package.
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
While upgrading a project to Tailwind CSS v4, I forgot to remove the
`tailwindcss` import from the PostCSS config. As a result of this, I was
greeted with the following message:
```
node:internal/process/promises:289
triggerUncaughtException(err, true /* fromPromise */);
^
[Failed to load PostCSS config: Failed to load PostCSS config (searchPath: /Users/philipp/dev/project): [TypeError] Invalid PostCSS Plugin found at: plugins[0]
(@/Users/philipp/dev/project/postcss.config.js)
TypeError: Invalid PostCSS Plugin found at: plugins[0]
```
I don't think this was particularly helpful, so I’m proposing we add a
default function export to the `tailwindcss` package so when it's used
inside PostCSS, we can control the error message. So I changed it to
something along these lines:
```
It looks like you're trying to use the \`tailwindcss\` package as a PostCSS plugin. This is no longer possible since Tailwind CSS v4.
If you want to continue to use Tailwind CSS with PostCSS, please install \`@tailwindcss/postcss\` and change your PostCSS config file.
at w (/Users/philipp/dev/project/node_modules/tailwindcss/node_modules/tailwindcss/dist/lib.js:1:21233)
at Object.<anonymous> (/Users/philipp/dev/project/node_modules/tailwindcss/postcss.config.cjs:3:13)
at Module._compile (node:internal/modules/cjs/loader:1358:14)
at Module._extensions..js (node:internal/modules/cjs/loader:1416:10)
at Module.load (node:internal/modules/cjs/loader:1208:32)
at Module._load (node:internal/modules/cjs/loader:1024:12)
at cjsLoader (node:internal/modules/esm/translators:348:17)
at ModuleWrap.<anonymous> (node:internal/modules/esm/translators:297:7)
at ModuleJob.run (node:internal/modules/esm/module_job:222:25)
at async ModuleLoader.import (node:internal/modules/esm/loader:316:24)
```
This is also a good place to link to the migration guides once we have
them 🙂
---------
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
There are still instances in which CI is flaky after #14332. This PR
applies the same fix (that is, moving the file write into the retrying
block) to all `retryAssertion` callbacks.
When you configure custom content globs inside an `@config` file, we
want to tread these globs as being relative to that config file and not
the CSS file that requires the content file. A config can be used by
multiple CSS configs.
---------
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
In Tailwind v4 the CSS file is the main entry point to your project and
is generally configured via `@theme`. However, given that all v3
projects were configured via a `tailwind.config.js` file we definitely
need to support those. This PR adds support for loading existing
Tailwind config files by adding an `@config` directive to the CSS —
similar to how v3 supported multiple config files except that this is
now _required_ to use a config file.
You can load a config file like so:
```
@import "tailwindcss";
@config "./path/to/tailwind.config.js";
```
A few notes:
- Both CommonJS and ESM config files are supported (loaded directly via
`import()` in Node)
- This is not yet supported in Intellisense or Prettier — should
hopefully land next week
- TypeScript is **not yet** supported in the config file — this will be
handled in a future PR.
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
This PR fixes an issue introduced with the changed candidate cache
behavior in #14187.
Prior to #14187, candidates were cached globally within an instance of
Oxide. This meant that once a candidate was discovered, it would not
reset until you either manually cleared the cache or restarted the Oxide
process. With the changes in #14187 however, the cache was scoped to the
instance of the `Scanner` class with the intention of making the caching
behavior more easy to understand and to avoid a global cache.
This, however, had an unforeseen side-effect in our Vite extension.
Vite, in dev mode, discovers files _lazily_. So when a developer goes to
`/index.html` the first time, we will scan the `/index.html` file for
Tailwind candidates and then build a CSS file with those candidate. When
they go to `/about.html` later, we will _append_ the candidates from the
new file and so forth.
The problem now arises when the dev server detects changes to the input
CSS file. This requires us to do a re-scan of that CSS file which, after
#14187, caused the candidate cache to be gone. This is usually fine
since we would just scan files again for the changed candidate list but
in the Vite case we would only get the input CSS file change _but no
subsequent change events for all other files, including those currently
rendered in the browser_). This caused updates to the CSS file to remove
all candidates from the CSS file again.
Ideally, we can separate between two concepts: The candidate cache and
the CSS input file scan. An instance of the `Scanner` could re-parse the
input CSS file without having to throw away previous candidates. This,
however, would have another issue with the current Vite extension where
we do not properly retain instances of the `Scanner` class anyways. To
properly improve the cache behavior, we will have to fix the Vite
`Scanner` retaining behavior first. Unfortunately this means that for
the short term, we have to add some manual bookkeeping to the Vite
client and retain the candidate cache between builds ourselves.
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
Using the [new integration test
setup](https://github.com/tailwindlabs/tailwindcss/pull/14089), this PR
adds a test for a V4 Next.js setup using the Postcss plugin. It's
testing both a full build and the dev mode (non-turbo for now).
Because of webpack, tests are quite slow which is worrisome since we
probably need to add many more integrations in the future. One idea I
have is that we separate tests in two buckets: _essential_ tests that
run often and are fast and advanced suites that we only run on CI via
custom, non-blocking, jobs.
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
Alternative to #14110
This PR changes the way how we load plugins to be compatible with ES6
async `import`s. This allows us to load plugins even inside the browser
but it comes at a downside: We now have to change the `compile` API to
return a `Promise`...
So most of this PR is rewriting all of the call sites of `compile` to
expect a promise instead of the object.
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
This PR is an umbrella PR where we will add support for the new
`@source` directive. This will allow you to add explicit content glob
patterns if you want to look for Tailwind classes in other files that
are not automatically detected yet.
Right now this is an addition to the existing auto content detection
that is automatically enabled in the `@tailwindcss/postcss` and
`@tailwindcss/cli` packages. The `@tailwindcss/vite` package doesn't use
the auto content detection, but uses the module graph instead.
From an API perspective there is not a lot going on. There are only a
few things that you have to know when using the `@source` directive, and
you probably already know the rules:
1. You can use multiple `@source` directives if you want.
2. The `@source` accepts a glob pattern so that you can match multiple
files at once
3. The pattern is relative to the current file you are in
4. The pattern includes all files it is matching, even git ignored files
1. The motivation for this is so that you can explicitly point to a
`node_modules` folder if you want to look at `node_modules` for whatever
reason.
6. Right now we don't support negative globs (starting with a `!`) yet,
that will be available in the near future.
Usage example:
```css
/* ./src/input.css */
@import "tailwindcss";
@source "../laravel/resources/views/**/*.blade.php";
@source "../../packages/monorepo-package/**/*.js";
```
It looks like the PR introduced a lot of changes, but this is a side
effect of all the other plumbing work we had to do to make this work.
For example:
1. We added dedicated integration tests that run on Linux and Windows in
CI (just to make sure that all the `path` logic is correct)
2. We Have to make sure that the glob patterns are always correct even
if you are using `@import` in your CSS and use `@source` in an imported
file. This is because we receive the flattened CSS contents where all
`@import`s are inlined.
3. We have to make sure that we also listen for changes in the files
that match any of these patterns and trigger a rebuild.
PRs:
- [x] https://github.com/tailwindlabs/tailwindcss/pull/14063
- [x] https://github.com/tailwindlabs/tailwindcss/pull/14085
- [x] https://github.com/tailwindlabs/tailwindcss/pull/14079
- [x] https://github.com/tailwindlabs/tailwindcss/pull/14067
- [x] https://github.com/tailwindlabs/tailwindcss/pull/14076
- [x] https://github.com/tailwindlabs/tailwindcss/pull/14080
- [x] https://github.com/tailwindlabs/tailwindcss/pull/14127
- [x] https://github.com/tailwindlabs/tailwindcss/pull/14135
Once all the PRs are merged, then this umbrella PR can be merged.
> [!IMPORTANT]
> Make sure to merge this without rebasing such that each individual PR
ends up on the main branch.
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
