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 <[email protected]>
<!--
👋 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 <[email protected]>
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 <[email protected]>
Co-authored-by: Adam Wathan <[email protected]>
Co-authored-by: Robin Malfait <[email protected]>
This PR adds a new standalone client: A single-binary file that you can
use to run Tailwind v4 without having a node setup. To make this work we
use Bun's single-binary build which can properly package up native
modules and the bun runtime for us so we do not have to rely on any
expand-into-tmp-folder-at-runtime workarounds.
When running locally, `pnpm build` will now standalone artifacts inside
`packages/@tailwindcss-standalone/dist`. Note that since we do not build
Oxide for other environments in the local setup, you won't be able to
use the standalone artifacts for other platforms in local dev mode.
Unfortunately Bun does not have support for Windows ARM builds yet but
we found that using the `bun-baseline` runtime for Windows x64 would
make the builds work fine in ARM emulation mode:
Some Bun related issues we faced and worked around:
- We found that the regular Windows x64 build of `bun` does not run on
Windows ARM via emulation. Instead, we have to use the `bun-baseline`
builds which emulate correctly.
- When we tried to bundle artifacts with [embed
directories](https://bun.sh/docs/bundler/executables#embed-directories),
node binary dependencies were no longer resolved correctly even though
they would still be bundled and accessible within the [`embeddedFiles`
list](https://bun.sh/docs/bundler/executables#listing-embedded-files).
We worked around this by using the `import * as from ... with { type:
"file" };` and patching the resolver we use in our CLI.
- If you have an import to a module that is used as a regular import
_and_ a `with { type: "file" }`, it will either return the module in
both cases _or_ the file path when we would expect only the `with {
type: "file" }` import to return the path. We do read the Tailwind CSS
version via the file system and `require.resolve()` in the CLI and via
`import * from './package.json'` in core and had to work around this by
patching the version resolution in our CLI.
```ts
import packageJson from "./package.json"
import packageJsonPath from "./package.json" with {type: "file"}
// We do not expect these to be equal
packageJson === packageJsonPath
```
- We can not customize the app icon used for Windows `.exe` builds
without decompiling the binary. For now we will leave the default but
one workaround is to [use tools like
ResourceHacker](https://github.com/tailwindlabs/tailwindcss/pull/14270/commits/698d9c4bd182391adb4b236f19a539aff13f78f9)
to decompile the binary first.
---------
Co-authored-by: Jordan Pittman <[email protected]>
Co-authored-by: Robin Malfait <[email protected]>
This PR bumps dependencies
We also make some dependencies `catalog:` dependencies, which allows us
to keep
the version in sync. E.g.: `lightningcss` and `@types/node`.
Bumped `turbo` to the latest version + enabled the new UI
Fixed a bug in the tests now that `lightningcss` outputs the correct
value.
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 <[email protected]>
Co-authored-by: Jordan Pittman <[email protected]>
Co-authored-by: Adam Wathan <[email protected]>
* run `pnpm update --recursive`
* update tests to reflect lightningcss bump
It looks like it's mainly (re-)ordering properties. Not 100% sure why
though.
* add `@tailwindcss/optimize` as a separate package
* remove lightningcss from `tailwindcss`
* import `optimizeCss` from `@tailwindcss/optimize`
* ensure we use `src/` files in development
* move `devDependencies` after `dependencies`
Just for consistency
* inline `optimizeCss` in leaf packages
Instead of introducing a custom `@tailwindcss/optimize` package
* update changelog
* fix changelog
* move `cli` to its own package `@tailwindcss/cli`
* minify builds when using `tsup`
* prefer tsup cli flag over tsup.config.ts file
* add `--clean`, to make sure `dist/` folders are cleaned before building
* make CLI esm only
* use version of `tailwindcss` instead of the version of `@tailwindcss/cli`
