This PR fixes an issue where embedded Slim templates inside of Ruby
files are not pre processed because we pre process based on a file
extension.
This PR also handles embedded SLIM templates using the following syntax:
```rb
slim_template <<~SLIM
.flex
.flex-1
h1 Hello World
.flex-1
p This is a test
SLIM
```
~~As far as I can tell, this is only a Slim template thing and not a
Haml template thing but I could be wrong here. See:
https://viewcomponent.org/guide/templates.html#interpolations~~
The ViewComponent package handles anything that looks like
`{lang}_template`, so the lang here will be used as the pre processing
language for now.
Fixes: #17334
# Test plan
1. Added test for this
2. Existing tests pass
3. Made sure that the snippet from the issue works as expected:
Added an example where we have a `slim_template` and a `svelte_template`
to prove that it embeds based on the language. I also added a
`html_template` with Svelte syntax to really make sure that that
_doesn't_ work.
<img width="1816" alt="image"
src="https://github.com/user-attachments/assets/35564a32-9c46-4b51-bb1f-e02f4ffe8b01"
/>
This PR fixes an issue where a class shorthand in Pug followed by a `(`
is not properly extracted.
```html
<template lang="pug">
.text-sky-600.bg-neutral-900(title="A tooltip") This div has an HTML attribute.
</template>
```
The `text-sky-600` is extracted, but the `bg-neutral-900` is not.
Fixes: #17313
# Test plan
1. Added test to cover this case
2. Existing tests pass (after a few small adjustments due to _more_
extracted candidates, but definitely not _less_)
3. Verified against the original issue (top is before, bottom is this
PR)
<img width="1307" alt="image"
src="https://github.com/user-attachments/assets/68a0529f-63ad-477d-a342-e3f91c5a1690"
/>
We had this exact same bug in Slim
(https://github.com/tailwindlabs/tailwindcss/pull/17278). Since Pug,
Slim and Haml are the only pre processors we have right now with this
dot-separated class notation I also double checked the Haml
pre-processor if this is an issue or not (and it's already covered
there).
<img width="1263" alt="image"
src="https://github.com/user-attachments/assets/c658168b-d124-46c9-9ec0-9697151a57bf"
/>
<!--
👋 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
-->
This PR fixes an issue where using the class shorthand in Slim
templates, followed by an `(` results in the last class being ignored.
E.g.:
```slim
body.border-t-4.p-8(class="#{body_classes}" data-hotwire-native="#{hotwire_native_app?}" data-controller="update-time-zone")
```
This is because we will eventually extract `p-8` but it's followed by an
invalid boundary character `(`.
To solve this, we make sure to replace the `(` with a space. We already
do a similar thing when the classes are followed by an `[`.
One caveat, we _can_ have `(` in our classes, like `bg-(--my-color)`.
But in my testing this is not something that can be used in the
shorthand version.
E.g.:
```slim
div.bg-(--my-color)
```
Compiles to:
```html
<div --my-color="" class="bg-"></div>
```
So I didn't add any special handling for this. Even when trying to
escape the `(`, `-` and `)` characters, it still doesn't work. E.g.:
```slim
div.bg-\(--my-color\)
```
Compiles to:
```html
<div class="bg-">\(--my-color\)</div>
```
# Test plan
1. Added test for the issue
2. Existing tests pass
3. Verified via the extractor tool:
| Before | After |
| --- | --- |
| <img width="958" alt="image"
src="https://github.com/user-attachments/assets/f72c420e-5429-424f-a01d-12f724062bf2"
/> | <img width="958" alt="image"
src="https://github.com/user-attachments/assets/b0cc8f2f-97a8-4fca-8813-3bb1da8d99a8"
/> |
---
Fixes: #17277
When Tailwind is loaded in a Node Worker thread, it currently causes a
segmentation fault on Linux when the thread exits. This is due to a
longstanding issue in Rust that affects all native modules:
https://github.com/rust-lang/rust/issues/91979. I reported this years
ago but unfortunately it is still not fixed, and seems to have gotten
worse in Rust 1.83.0 and later. Looks like Tailwind recently updated
Rust versions and this issue started appearing when run in tools like
Parcel that use worker threads.
The workaround is to prevent the native module from ever being unloaded.
One way to do that is to always load the native module in the main
thread in addition to workers, but this is hard to enforce.
@Brooooooklyn found another method, which is to use a linker option for
this. I tested this on an Ubuntu system and verified it fixed the issue.
You can test with the following script.
```js
// test.js
const {Worker} = require('worker_threads');
new Worker('./worker.js');
// worker.js
require('@tailwindcss/oxide');
```
Without this change, a segmentation fault will occur.
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
This PR fixes an issue where `<template lang="…">…</template>` in Vue
files should be handled as-if it's the language specified in the `lang`
attribute.
To do this, we added a new Vue pre processor and run the content through
the same pre processor logic as we do for other languages.
Fixes: #17211
# Test plan
1. Added a test to verify this works
2. Existing tests still work
Visually verified against the reproduction in the issue:
| Before | After |
| --- | --- |
| <img width="1273" alt="image"
src="https://github.com/user-attachments/assets/d1accdeb-97cf-48ef-83fb-978832b3e599"
/> | <img width="1273" alt="image"
src="https://github.com/user-attachments/assets/ab7ec19c-b6c4-43be-8845-096ff4e58808"
/> |
---------
Co-authored-by: Adam Wathan <adam.wathan@gmail.com>
This PR fixes an issue where if you use a number with a decimal in a
variant then it wasn't picked up correctly.
E.g.:
```
<div class="2xl:flex 1.5xl:flex"></div>
^^^^^^^^ Picked up
^^^^^^^^^^ Not picket up
```
This PR fixes that behavior by applying the same rules for utilities
where a `.` is valid if it is surrounded by numbers.
# Test plan
1. Added test to ensure this is picked up
2. Existing tests pass
3. Ran the extractor on a real example with the following results:
| Before | After |
| --- | --- |
| <img width="821" alt="image"
src="https://github.com/user-attachments/assets/a77ed5e4-6848-4fe3-8cbf-cf61ff8db41d"
/> | <img width="821" alt="image"
src="https://github.com/user-attachments/assets/61aca66a-e38d-4b61-bf86-e6286a89a3d9"
/> |
They are crossed out just because it's not a default value we know in
the system, but you can see that the `1.` part is also extracted now.
Fixes: #17148
This PR fixes an issue where often people run into issues where they try
to use string interpolation and it doesn't work. Even worse, it could
result in crashes because we will actually generate CSS. This fix only
filters out candidates with a pattern like `${`. If this occurs in a
string position it is fine.
Another solution would be to add a pre processor for JS/TS (and all
thousand file extension combinations) but the problem is that you can
also write JS in HTML files so we would have to pre process HTML as well
which would not be ideal.
# Test plan
1. Added tests to prove this works in arbitrary values, arbitrary
variables in both utilities and variants.
2. Existing tests pass.
3. Some screenshots with before / after situations:
Given this input:
```ts
let color = '#0088cc';
let opacity = 0.8;
let name = 'variable-name';
let classes = [
// Arbitrary Properties
`[color:${color}]`
`[${property}:value]`,
`[--img:url('https://example.com?q=${name}')]`, // WONT WORK BUT VALID CSS
// Arbitrary Values
`bg-[${color}]`,
// Arbitrary Variables
`bg-(--my-${color})`,
`bg-(--my-color,${color})`,
// Arbitrary Modifier
`bg-red-500/[${opacity}]`,
`bg-red-500/(--my-${name})`,
`bg-red-500/(--my-opacity,${opacity})`,
// Arbitrary Variant
`data-[state=${name}]:flex`,
`supports-(--my-${name}):flex`,
`[@media(width>=${value})]:flex`,
];
```
This is the result:
| Before | After |
| --- | --- |
| <img width="908" alt="image"
src="https://github.com/user-attachments/assets/c64d1b16-d39d-48a6-a098-bc4477cb4b0a"
/> | <img width="908" alt="image"
src="https://github.com/user-attachments/assets/d71aaf62-5e13-4174-82bb-690eb81aaeaf"
/> |
Fixes: #17054Fixes: #15853
This PR fixes an issue where some classes weren't properly extracted due
to some incorrect assumptions in the pre processors.
Templating languages such as Haml, Slim and Pug allow you to write
classes in a shorter way that are not properly contained inside of
strings. E.g.:
```slim
p.flex.px-2
```
These candidates are not properly extracted because there are no
bounding characters like quotes. To solve this, we pre-process it and
replace `.` with ` ` characters. This results in something like:
```
p flex px-2
```
However, this has some challenges on its own. Candidates like `px-2.5`
cannot be written in this shorthand form, instead they need to be in
strings. Now we _cannot_ replace the `.` because otherwise we would
change `px-2.5` to `px-2 5` which is wrong.
The next problem is that we need to know when they are in a "string".
This has another set of problems because these templating languages
allow you to write normal text that will eventually be the contents of
the HTML tags.
```haml
.text-red-500.text-3xl
| This text can't should be red
^ Wait, is this the start of a string now???
```
In this example, if we consider the `'` the start of a string, when it's
clearly not, how would we know it's for _sure_ not a string?
This ended up as a bit of a rabbit hole, but we came up with another
approach entirely if we think about the original problem we want to
solve which is when do we change `.` to ` ` characters.
One of the rules in our current extractor is that a `.` has to be
between 2 numbers. Which works great in a scenario like: `px-2.5`.
However, if you look at Haml or Slim syntax, this is also allowed:
```slim
p.bg-red-500.2xl:flex
^^^ Uh oh...
```
In this scenario, a `.` is surrounded by numbers so we shouldn't replace
it with a space. But as you can see, we clearly do... so we need another
heuristic in this case.
Luckily, one of the rules in Tailwind CSS is that a utility cannot start
with a number, but a variant _can_. This means that if we see a scenario
like `<digit>.<digit>` then we can just check if the value after the `.`
is a valid variant or not.
In this case it is a valid variant so we _do_ want to replace the `.`
with a ` ` even though we do have the `<digit>.<digit>` format.
🥴
# Test plan
1. Added additional tests.
2. Existing tests still pass
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
Closes#17128
This PR prevents extraction of links inside square brackets as valid
candidate:
```
[https://example/]
```
We do this by throwing out arbitrary properties when the value starts
with a slash (`/`).
## Test plan
- Added unit test
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
This PR adds a small JSON pre processor to improve parsing JSON files.
Due to the sheer amount of potential `[` and `]` brackets, it could be
that parsing JSON files are way slower than they need to be.
We saw this while debugging this issue:
https://github.com/tailwindlabs/tailwindcss/issues/17092
# Test plan
1. Added test to verify the pre processing works
2. Existing tests still pass
Closes#17092
After a lot of spelunking we found one specific reason for the very slow
builds in the repro from #17092: Turns our we are needlessly scanning
the binary `.node` extension for class names 😬. This PR adds `.wasm` and
`.node` to the list of known binary extensions.
## Test plan
- Check out the repro from `#17092`
- Delete the `.gitignore` file
- Observe that builds are very slow (`527.79s`)
- Add a _pnpm override_ to load local versions of Oxide
- `pnpm build` now completes in ~50s
This PR implements the state machines using the type state pattern at
compile time (via generic types) instead of a runtime state variable.
There is no runtime check to see what state we are in, instead we
transition to the new state when it's necessary.
This has some nice performance improvements for some of the state
machines, e.g.:
```diff
- ArbitraryVariableMachine: Throughput: 744.92 MB/s
+ ArbitraryVariableMachine: Throughput: 1.21 GB/s
```
We also don't have to store the current state because each machine runs
to completion. It's during execution that we can move to a new state if
necessary.
Unfortunately the diff is a tiny bit annoying to read, but essentially
this is what happened:
### The `enum` is split up in it's individual states as structs:
```rs
enum State {
A,
B,
C,
}
```
Becomes:
```rs
struct A;
struct B;
struct C;
```
### Generics
The current machine will receive a generic `State` that we can default
to the `IdleState`. Then we use `PhantomData` to "use" the type because
the generic type is otherwise not used as a concrete value, it's just a
marker.
```rs
struct MyMachine {}
```
Becomes:
```rs
struct MyMachine<State = Idle> {
_state: std::marker::PhantomData<State>
}
```
### Split
Next, the `next` function used to match on the current state, but now
each match arm is moved to a dedicated implementation instead:
```rs
impl Machine for MyMachine {
fn next(&mut self) -> MachineState {
match self.state {
State::A => { /* … */ },
State::B => { /* … */ },
State::C => { /* … */ },
}
}
}
```
Becomes:
```rs
impl Machine for MyMachine<A> {
fn next(&mut self) -> MachineState {
/* … */
}
}
impl Machine for MyMachine<B> {
fn next(&mut self) -> MachineState {
/* … */
}
}
impl Machine for MyMachine<C> {
fn next(&mut self) -> MachineState {
/* … */
}
}
```
It's a bit more verbose, but now each state is implemented in its own
block. This also removes 2 levels of nesting which is a nice benefit.
This PR fixes an issue in Slim templates where a single quote `'` at the
start of the line (excluding white space) is considered a line indicator
for verbatim text. It is not considered a string in this scenario.
So something like this:
```slim
div
'Foo'
```
Will compile to:
```html
<div>Foo'</div>
```
Fixes: #17081
This PR fixes an issue where candidates inside `>…<` were not always
correctly extracted. This happens in XML-like languages where the
classes are inside of these boundaries.
E.g.:
```html
<!-- Fluid template language -->
<f:variable name="bgStyle">
<f:switch expression="{data.layout}">
<f:case value="0">from-blue-900 to-cyan-200</f:case>
<!-- ^^^^^^^^^^^^^^^^^^^^^^^^^ -->
<f:case value="1">from-cyan-600 to-teal-200</f:case>
<f:defaultCase>from-blue-300 to-cyan-100</f:defaultCase>
</f:switch>
</f:variable>
```
Fixes: https://github.com/tailwindlabs/tailwindcss/issues/17088
# Test plan
1. Added a new test
2. Existing tests pass
This PR fixes an issue where candidates are not properly extractor when
they end in `\`. This can happen if you embed a programming language
like JS inside another language like PHP where you need to escape some
strings.
Here is an example of Livewire flux:
```blade
@php
if ($sidebarIsStashable) {
$attributes = $attributes->merge([
'x-init' => '$el.classList.add(\'-translate-x-full\'); $el.classList.add(\'transition-transform\')',
// ^ ^
]);
}
@endphp
<div x-data {{ $attributes->class('border-r w-64 p-4 min-h-dvh max-h-dvh top-0 fixed left-0') }}>
{{ $slot }}
</div>
```
Where the `\'` is causing some issues.
Another solution might be to add a custom pre processor for blade files
where we drop the escaped characters, but that felt overkill for now
because some escapes are still valid.
Fixes: #17023
# Test plan
1. Added a test to cover this case.
2. Existing tests still pass
This PR fixes an issue in Razor template files where `@sm:flex` doesn't
work and `@@sm:flex` is required.
In Tailwind CSS v3, some people used a custom transform to replace `@@`
with just `@`. But in Tailwind CSS v4 we don't have this.
However, we can add a pre processor for `.cshtml` and `.razor` files.
Fixes: #17022
This PR cleans up the boundary character checking by using similar
classification techniques as we used for other classification problems.
For starters, this moves the boundary related items to its own file,
next we setup the classification enum.
Last but not least, we removed `}` as an _after_ boundary character, and
instead handle that situation in the Ruby pre processor where we need
it. This means the `%w{flex}` will still work in Ruby files.
---
This PR is a followup for
https://github.com/tailwindlabs/tailwindcss/pull/17001, the main goal is
to clean up some of the boundary character checking code. The other big
improvement is performance. Changing the boundary character checking to
use a classification instead results in:
Took the best score of 10 runs each:
```diff
- CandidateMachine: Throughput: 311.96 MB/s
+ CandidateMachine: Throughput: 333.52 MB/s
```
So a ~20MB/s improvement.
# Test plan
1. Existing tests should pass. Due to the removal of `}` as an after
boundary character, some tests are updated.
2. Added new tests to ensure the Ruby pre processor still works as
expected.
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
This PR fixes an issue where strings in the Pug and Slim pre-processor
were handled using the `string_machine`. However, the `string_machine`
is not for strings inside of Tailwind CSS classes which means that
whitespace is invalid.
This means that parts of the code that _are_ inside strings will not be
inside strings and parts of the code that are not inside strings will be
part of a potential string. This is a bit confusing to wrap your head
around, but here is a visual representation of the problem:
```
.join(' ')
^ 3. start of new string, which means that the `)` _could_ be part of a string if a new `'` occurs later.
^ 2. whitespace is not allowed, stop string
^ 1. start of string
```
Fixes: #16998
# Test plan
1. Added new test
2. Existing tests still pass
3. Added a simple test helper to make sure that we can extract the
correct candidates _after_ pre-processing
This PR fixes an issue in Slim templates where the start of attributes
causes some candidates to be missing.
```slim
.text-xl.text-red-600[
data-foo="bar"
]
| This line should be red
```
Because of the `[` attached to the `text-red-600`, the `text-red-600`
was not extracted because `[` is not a valid boundary character.
To solve this, we copied the Pug pre processor and created a dedicated
Slim pre processor. Next, we ensure that we replace `[` with ` ` in this
scenario (by also making sure that we don't replace `[` where it's
important).
Additionally, we noticed that `.` was also replaced inside of arbitrary
values such as URLs. This has been fixed for both Pug and Slim.
Fixes: #16975
# Test plan
1. Added failing tests
2. Existing tests still pass
Closes#16982
Handle the case of variants looking like this: `@[32rem]:flex`.
## Test plan
Added regression tests
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
Fixes#16978, and also added support for dash.
Classes like `text-theme1-primary` or `text-theme1_primary` should be
treated as valid.
If this approach is not aligned with the project’s direction or there
are any concerns, please feel free to close or edit this PR 😃
<br/>
### As is
Classes conatining number followed by dash or underscore (e.g.
`bg-theme1-primary`, `text-title1_strong`) are ignored, and utility
classes are not generated.
### To be
Classes conatining number followed by dash or underscore (e.g.
`bg-theme1-primary`, `text-title1_strong`) are treated as valid
tailwindcss classes
---------
Co-authored-by: Philipp Spiess <hello@philippspiess.com>
This PR fixes an issue where named utilities that contain double dashes
`--` are not extracted correctly.
Some people use `--` in the middle of the utility to create some form of
namespaced utility.
Given this input:
```js
let x = 'foo--bar'
```
The extracted candidates before this change:
```js
[ "let", "x", "--bar" ]
```
The extracted candidates after this change:
```js
[ "let", "x", "foo--bar", "--bar" ]
```
The reason `--bar` is still extracted in both cases is because of the
CSS variable machine. We could improve its extraction by checking its
boundary characters but that's a different issue.
For now, the important thing is that `foo--bar` was extracted.
# Test plan
1. Added new test
2. Existing tests pass
This PR improves the internal DX when working with `u8` classification
into a smaller enum. This is done by implementing a `ClassifyBytes` proc
derive macro. The benefit of this is that the DX is much better and
everything you will see here is done at compile time.
Before:
```rs
#[derive(Debug, Clone, Copy, PartialEq)]
enum Class {
ValidStart,
ValidInside,
OpenBracket,
OpenParen,
Slash,
Other,
}
const CLASS_TABLE: [Class; 256] = {
let mut table = [Class::Other; 256];
macro_rules! set {
($class:expr, $($byte:expr),+ $(,)?) => {
$(table[$byte as usize] = $class;)+
};
}
macro_rules! set_range {
($class:expr, $start:literal ..= $end:literal) => {
let mut i = $start;
while i <= $end {
table[i as usize] = $class;
i += 1;
}
};
}
set_range!(Class::ValidStart, b'a'..=b'z');
set_range!(Class::ValidStart, b'A'..=b'Z');
set_range!(Class::ValidStart, b'0'..=b'9');
set!(Class::OpenBracket, b'[');
set!(Class::OpenParen, b'(');
set!(Class::Slash, b'/');
set!(Class::ValidInside, b'-', b'_', b'.');
table
};
```
After:
```rs
#[derive(Debug, Clone, Copy, PartialEq, ClassifyBytes)]
enum Class {
#[bytes_range(b'a'..=b'z', b'A'..=b'Z', b'0'..=b'9')]
ValidStart,
#[bytes(b'-', b'_', b'.')]
ValidInside,
#[bytes(b'[')]
OpenBracket,
#[bytes(b'(')]
OpenParen,
#[bytes(b'/')]
Slash,
#[fallback]
Other,
}
```
Before we were generating a `CLASS_TABLE` that we could access directly,
but now it will be part of the `Class`. This means that the usage has to
change:
```diff
- CLASS_TABLE[cursor.curr as usize]
+ Class::TABLE[cursor.curr as usize]
```
This is slightly worse UX, and this is where another change comes in. We
implemented the `From<u8> for #enum_name` trait inside of the
`ClassifyBytes` derive macro. This allows us to use `.into()` on any
`u8` as long as we are comparing it to a `Class` instance. In our
scenario:
```diff
- Class::TABLE[cursor.curr as usize]
+ cursor.curr.into()
```
Usage wise, this looks something like this:
```diff
while cursor.pos < len {
- match Class::TABLE[cursor.curr as usize] {
+ match cursor.curr.into() {
- Class::Escape => match Class::Table[cursor.next as usize] {
+ Class::Escape => match cursor.next.into() {
// An escaped whitespace character is not allowed
Class::Whitespace => return MachineState::Idle,
// An escaped character, skip ahead to the next character
_ => cursor.advance(),
},
// End of the string
Class::Quote if cursor.curr == end_char => return self.done(start_pos, cursor),
// Any kind of whitespace is not allowed
Class::Whitespace => return MachineState::Idle,
// Everything else is valid
_ => {}
};
cursor.advance()
}
MachineState::Idle
}
}
```
If you manually look at the `Class::TABLE` in your editor for example,
you can see that it is properly generated at compile time.
Given this input:
```rs
#[derive(Clone, Copy, ClassifyBytes)]
enum Class {
#[bytes_range(b'a'..=b'z')]
AlphaLower,
#[bytes_range(b'A'..=b'Z')]
AlphaUpper,
#[bytes(b'@')]
At,
#[bytes(b':')]
Colon,
#[bytes(b'-')]
Dash,
#[bytes(b'.')]
Dot,
#[bytes(b'\0')]
End,
#[bytes(b'!')]
Exclamation,
#[bytes_range(b'0'..=b'9')]
Number,
#[bytes(b'[')]
OpenBracket,
#[bytes(b']')]
CloseBracket,
#[bytes(b'(')]
OpenParen,
#[bytes(b'%')]
Percent,
#[bytes(b'"', b'\'', b'`')]
Quote,
#[bytes(b'/')]
Slash,
#[bytes(b'_')]
Underscore,
#[bytes(b' ', b'\t', b'\n', b'\r', b'\x0C')]
Whitespace,
#[fallback]
Other,
}
```
This is the result:
<img width="1244" alt="image"
src="https://github.com/user-attachments/assets/6ffd6ad3-0b2f-4381-a24c-593e4c72080e"
/>
This PR adds a new candidate[^candidate] extractor with 2 major goals in
mind:
1. It must be way easier to reason about and maintain.
2. It must have on-par performance or better than the current candidate
extractor.
### Problem
Candidate extraction is a bit of a wild west in Tailwind CSS and it's a
very critical step to make sure that all your classes are picked up
correctly to ensure that your website/app looks good.
One issue we run into is that Tailwind CSS is used in many different
"host" languages and frameworks with their own syntax. It's not only
used in HTML but also in JSX/TSX, Vue, Svelte, Angular, Pug, Rust, PHP,
Rails, Clojure, .NET, … the list goes on and all of these have different
syntaxes. Introducing dedicated parsers for each of these languages
would be a huge maintenance burden because there will be new languages
and frameworks coming up all the time. The best thing we can do is make
assumptions and so far we've done a pretty good job at that.
The only certainty we have is that there is at least _some_ structure to
the possible Tailwind classes used in a file. E.g.: `abc#def` is
definitely not a valid class, `hover:flex` definitely is. In a perfect
world we limit the characters that can be used and defined a formal
grammar that each candidate must follow, but that's not really an option
right now (maybe this is something we can implement in future major
versions).
The current candidate extractor we have has grown organically over time
and required patching things here and there to make it work in various
scenarios (and edge cases due to the different languages Tailwind is
used in).
While there is definitely some structure, we essentially work in 2
phases:
1. Try to extract `0..n` candidates. (This is the hard part)
2. Validate each candidate to make sure they are valid looking classes
(by validating against the few rules we have)
Another reason the current extractor is hard to reason about is that we
need it to be fast and that comes with some trade-offs to readability
and maintainability.
Unfortunately there will always be a lot of false positives, but if we
extract more classes than necessary then that's fine. It's only when we
pass the candidates to the core engine that we will know for sure if
they are valid or not. (we have some ideas to limit the amount of false
positives but that's for another time)
### Solution
Since the introduction of Tailwind CSS v4, we re-worked the internals
quite a bit and we have a dedicated internal AST structure for
candidates. For example, if you take a look at this:
```html
<div class="[@media(pointer:fine)]:data-[state=pending]:hover:text-red-500/(--my-opacity)"></div>
```
<details>
<summary>This will be parsed into the following AST:</summary>
```json
[
{
"kind": "functional",
"root": "text",
"value": {
"kind": "named",
"value": "red-500",
"fraction": null
},
"modifier": {
"kind": "arbitrary",
"value": "var(--my-opacity)"
},
"variants": [
{
"kind": "static",
"root": "hover"
},
{
"kind": "functional",
"root": "data",
"value": {
"kind": "arbitrary",
"value": "state=pending"
},
"modifier": null
},
{
"kind": "arbitrary",
"selector": "@media(pointer:fine)",
"relative": false
}
],
"important": false,
"raw": "[@media(pointer:fine)]:data-[state=pending]:hover:text-red-500/(--my-opacity)"
}
]
```
</details>
We have a lot of information here and we gave these patterns a name
internally. You'll see names like `functional`, `static`, `arbitrary`,
`modifier`, `variant`, `compound`, ...
Some of these patterns will be important for the new candidate extractor
as well:
| Name | Example | Description |
| -------------------------- | ----------------- |
---------------------------------------------------------------------------------------------------
|
| Static utility (named) | `flex` | A simple utility with no inputs
whatsoever |
| Functional utility (named) | `bg-red-500` | A utility `bg` with an
input that is named `red-500` |
| Arbitrary value | `bg-[#0088cc]` | A utility `bg` with an input that
is arbitrary, denoted by `[…]` |
| Arbitrary variable | `bg-(--my-color)` | A utility `bg` with an input
that is arbitrary and has a CSS variable shorthand, denoted by `(--…)` |
| Arbitrary property | `[color:red]` | A utility that sets a property to
a value on the fly |
A similar structure exist for modifiers, where each modifier must start
with `/`:
| Name | Example | Description |
| ------------------ | --------------------------- |
---------------------------------------- |
| Named modifier | bg-red-500`/20` | A named modifier |
| Arbitrary value | bg-red-500`/[20%]` | An arbitrary value, denoted by
`/[…]` |
| Arbitrary variable | bg-red-500`/(--my-opacity)` | An arbitrary
variable, denoted by `/(…)` |
Last but not least, we have variants. They have a very similar pattern
but they _must_ end in a `:`.
| Name | Example | Description |
| ------------------ | --------------------------- |
------------------------------------------------------------------------
|
| Named variant | `hover:` | A named variant |
| Arbitrary value | `data-[state=pending]:` | An arbitrary value,
denoted by `[…]` |
| Arbitrary variable | `supports-(--my-variable):` | An arbitrary
variable, denoted by `(…)` |
| Arbitrary variant | `[@media(pointer:fine)]:` | Similar to arbitrary
properties, this will generate a variant on the fly |
The goal with the new extractor is to encode these separate patterns in
dedicated pieces of code (we called them "machines" because they are
mostly state machine based and because I've been watching Person of
Interest but I digress).
This will allow us to focus on each pattern separately, so if there is a
bug or some new syntax we want to support we can add it to those
machines.
One nice benefit of this is that we can encode the rules and handle
validation as we go. The moment we know that some pattern is invalid, we
can bail out early.
At the time of writing this, there are a bunch of machines:
<details>
<summary>Overview of the machines</summary>
- `ArbitraryPropertyMachine`
Extracts candidates such as `[color:red]`. Some of the rules are:
1. There must be a property name
2. There must be a `:`
3. There must ba a value
There cannot be any spaces, the brackets are included, if the property
is a CSS variable, it must be a valid CSS variable (uses the
`CssVariableMachine`).
```
[color:red]
^^^^^^^^^^^
[--my-color:red]
^^^^^^^^^^^^^^^^
```
Depends on the `StringMachine` and `CssVariableMachine`.
- `ArbitraryValueMachine`
Extracts arbitrary values for utilities and modifiers including the
brackets:
```
bg-[#0088cc]
^^^^^^^^^
bg-red-500/[20%]
^^^^^
```
Depends on the `StringMachine`.
- `ArbitraryVariableMachine`
Extracts arbitrary variables including the parentheses. The first
argument must be a valid CSS variable, the other arguments are optional
fallback arguments.
```
(--my-value)
^^^^^^^^^^^^
bg-red-500/(--my-opacity)
^^^^^^^^^^^^^^
```
Depends on the `StringMachine` and `CssVariableMachine`.
- `CandidateMachine`
Uses the variant machine and utility machine. It will make sure that 0
or more variants are directly touching and followed by a utility.
```
hover:focus:flex
^^^^^^^^^^^^^^^^
aria-invalid:bg-red-500/(--my-opacity)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
Depends on the `VariantMachine` and `UtilityMachine`.
- `CssVariableMachine`
Extracts CSS variables, they must start with `--` and must contain at
least one alphanumeric character or, `-`, `_` and can contain any
escaped character (except for whitespace).
```
bg-(--my-color)
^^^^^^^^^^
bg-red-500/(--my-opacity)
^^^^^^^^^^^^
bg-(--my-color)/(--my-opacity)
^^^^^^^^^^ ^^^^^^^^^^^^
```
- `ModifierMachine`
Extracts modifiers including the `/`
- `/[` will delegate to the `ArbitraryValueMachine`
- `/(` will delegate to the `ArbitraryVariableMachine`
```
bg-red-500/20
^^^
bg-red-500/[20%]
^^^^^^
bg-red-500/(--my-opacity)
^^^^^^^^^^^^^^^
```
Depends on the `ArbitraryValueMachine` and `ArbitraryVariableMachine`.
- `NamedUtilityMachine`
Extracts named utilities regardless of whether they are functional or
static.
```
flex
^^^^
px-2.5
^^^^^^
```
This includes rules like: A `.` must be surrounded by digits.
Depends on the `ArbitraryValueMachine` and `ArbitraryVariableMachine`.
- `NamedVariantMachine`
Extracts named variants regardless of whether they are functional or
static. This is very similar to the `NamedUtilityMachine` but with
different rules. We could combine them, but splitting things up makes it
easier to reason about.
Another rule is that the `:` must be included.
```
hover:flex
^^^^^^
data-[state=pending]:flex
^^^^^^^^^^^^^^^^^^^^^
supports-(--my-variable):flex
^^^^^^^^^^^^^^^^^^^^^^^^^
```
Depends on the `ArbitraryVariableMachine`, `ArbitraryValueMachine`, and
`ModifierMachine`.
- `StringMachine`
This is a low-level machine that is used by various other machines. The
only job this has is to extract strings that start with double quotes,
single quotes or backticks.
We have this because once you are in a string, we don't have to make
sure that brackets, parens and curlies are properly balanced. We have to
make sure that balancing brackets are properly handled in other
machines.
```
content-["Hello_World!"]
^^^^^^^^^^^^^^
bg-[url("https://example.com")]
^^^^^^^^^^^^^^^^^^^^^
```
- `UtilityMachine`
Extracts utilities, it will use the lower level `NamedUtilityMachine`,
`ArbitraryPropertyMachine` and `ModifierMachine` to extract the utility.
It will also handle important markers (including the legacy important
marker).
```
flex
^^^^
bg-red-500/20
^^^^^^^^^^^^^
!bg-red-500/20 Legacy important marker
^^^^^^^^^^^^^^
bg-red-500/20! New important marker
^^^^^^^^^^^^^^
!bg-red-500/20! Both, but this is considered invalid
^^^^^^^^^^^^^^^
```
Depends on the `ArbitraryPropertyMachine`, `NamedUtilityMachine`, and
`ModifierMachine`.
- `VariantMachine`
Extracts variants, it will use the lower level `NamedVariantMachine` and
`ArbitraryValueMachine` to extract the variant.
```
hover:focus:flex
^^^^^^
^^^^^^
```
Depends on the `NamedVariantMachine` and `ArbitraryValueMachine`.
</details>
One important thing to know here is that each machine runs to
completion. They all implement a `Machine` trait that has a
`next(cursor)` method and returns a `MachineState`.
The `MachineState` looks like this:
```rs
enum MachineState {
Idle,
Done(Span)
}
```
Where a `Span` is just the location in the input where the candidate was
found.
```rs
struct Span {
pub start: usize,
pub end: usize,
}
```
#### Complexities
**Boundary characters:**
When running these machines to completion, they don't typically check
for boundary characters, the wrapping `CandidateMachine` will check for
boundary characters.
A boundary character is where we know that even though the character is
touching the candidate it will not be part of the candidate.
```html
<div class="flex"></div>
<!-- ^ ^ -->
```
The quotes are touching the candidate `flex`, but they will not be part
of the candidate itself, so this is considered a valid candidate.
**What to pick?**
Let's imagine you are parsing this input:
```html
<div class="hover:flex"></div>
```
The `UtilityMachine` will find `hover` and `flex`. The `VariantMachine`
will find `hover:`. This means that at a certain point in the
`CandidateMachine` you will see something like this:
```rs
let variant_machine_state = variant_machine.next(cursor);
// MachineState::Done(Span { start: 12, end: 17 }) // `hover:`
let utility_machine_state = utility_machine.next(cursor);
// MachineState::Done(Span { start: 12, end: 16 }) // `hover`
```
They are both done, but which one do we pick? In this scenario we will
always pick the variant because its range will always be 1 character
longer than the utility.
Of course there is an exception to this rule and it has to do with the
fact that Tailwind CSS can be used in different languages and
frameworks. A lot of people use `clsx` for dynamically applying classes
to their React components. E.g.:
```tsx
<div
class={clsx({
underline: someCondition(),
})}
></div>
```
In this scenario, we will see `underline:` as a variant, and `underline`
as a utility. We will pick the utility in this scenario because the next
character is whitespace so this will never be a valid candidate
otherwise (variants and utilities must be touching). Another reason this
is valid, is because there wasn't a variant present prior to this
candidate.
E.g.:
```tsx
<div
class={clsx({
hover:underline: someCondition(),
})}
></div>
```
This will be considered invalid, if you do want this, you should use
quotes.
E.g.:
```tsx
<div
class={clsx({
'hover:underline': someCondition(),
})}
></div>
```
**Overlapping/covered spans:**
Another complexity is that the extracted spans for candidates can and
will overlap. Let's take a look at this C# example:
```csharp
public enum StackSpacing
{
[CssClass("gap-y-4")]
Small,
[CssClass("gap-y-6")]
Medium,
[CssClass("gap-y-8")]
Large
}
```
In this scenario, `[CssClass("gap-y-4")]` starts with a `[` so we have a
few options here:
1. It is an arbitrary property, e.g.: `[color:red]`
2. It is an arbitrary variant, e.g.: `[@media(pointer:fine)]:`
When running the parsers, both the `VariantMachine` and the
`UtilityMachine` will run to completion but end up in a
`MachineState::Idle` state.
- This is because it is not a valid variant because it didn't end with a
`:`.
- It's also not a valid arbitrary property, because it didn't include a
`:` to separate the property from the value.
Looking at the code as a human it's very clear what this is supposed to
be, but not from the individual machines perspective.
Obviously we want to extract the `gap-y-*` classes here.
To solve this problem, we will run over an additional slice of the
input, starting at the position before the machines started parsing
until the position where the machines stopped parsing.
That slice will be this one: `[CssClass("gap-y-6")]` (we already skipped
over the whitespace). Now, for every `[` character we see, will start a
new `CandidateMachine` right after the `[`'s position and run the
machines over that slice. This will now eventually extract the `gap-y-6`
class.
The next question is, what if there was a `:` (e.g.:
`[CssClass("gap-y-6")]:`), then the `VariantMachine` would complete, but
the `UtilityMachine` will not because not exists after it. We will apply
the same idea in this case.
Another issue is if we _do_ have actual overlapping ranges. E.g.: `let
classes = ['[color:red]'];`. This will extract both the `[color:red]`
and `color:red` classes. You have to use your imagination, but the last
one has the exact same structure as `hover:flex` (variant + utility).
In this case we will make sure to drop spans that are covered by other
spans.
The extracted `Span`s will be valid candidates therefore if the outer
most candidate is valid, we can throw away the inner candidate.
```
Position: 11112222222
67890123456
↓↓↓↓↓↓↓↓↓↓↓
Span { start: 17, end: 25 } // color:red
Span { start: 16, end: 26 } // [color:red]
```
#### Exceptions
**JavaScript keys as candidates:**
We already talked about the `clsx` scenario, but there are a few more
exceptions and that has to do with different syntaxes.
**CSS class shorthand in certain templating languages:**
In Pug and Slim, you can have a syntax like this:
```pug
.flex.underline
div Hello World
```
<details>
<summary>Generated HTML</summary>
```html
<div class="flex underline">
<div>Hello World</div>
</div>
```
</details>
We have to make sure that in these scenarios the `.` is a valid boundary
character. For this, we introduce a pre-processing step to massage the
input a little bit to improve the extraction of the data. We have to
make sure we don't make the input smaller or longer otherwise the
positions might be off.
In this scenario, we could simply replace the `.` with a space. But of
course, there are scenarios in these languages where it's not safe to do
that.
If you want to use `px-2.5` with this syntax, then you'd write:
```pug
.flex.px-2.5
div Hello World
```
But that's invalid because that technically means `flex`, `px-2`, and
`5` as classes.
You can use this syntax to get around that:
```pug
div(class="px-2.5")
div Hello World
```
<details>
<summary>Generated HTML</summary>
```html
<div class="px-2.5">
<div>Hello World</div>
</div>
```
</details>
Which means that we can't simply replace `.` with a space, but have to
parse the input. Luckily we only care about strings (and we have a
`StringMachine` for that) and ignore replacing `.` inside of strings.
**Ruby's weird string syntax:**
```ruby
%w[flex underline]
```
This is valid syntax and is shorthand for:
```ruby
["flex", "underline"]
```
Luckily this problem is solved by the running the sub-machines after
each `[` character.
### Performance
**Testing:**
Each machine has a `test_…_performance` test (that is ignored by
default) that allows you to test the throughput of that machine. If you
want to run them, you can use the following command:
```sh
cargo test test_variant_machine_performance --release -- --ignored
```
This will run the test in release mode and allows you to run the ignored
test.
> [!CAUTION]
> This test **_will_** fail, but it will print some output. E.g.:
```
tailwindcss_oxide::extractor::variant_machine::VariantMachine: Throughput: 737.75 MB/s over 0.02s
tailwindcss_oxide::extractor::variant_machine::VariantMachine: Duration: 500ns
```
**Readability:**
One thing to note when looking at the code is that it's not always
written in the cleanest way but we had to make some sacrifices for
performance reasons.
The `input` is of type `&[u8]`, so we are already dealing with bytes.
Luckily, Rust has some nice ergonomics to easily write `b'['` instead of
`0x5b`.
A concrete example where we had to sacrifice readability is the state
machines where we check the `previous`, `current` and `next` character
to make decisions. For a named utility one of the rules is that a `.`
must be preceded by and followed by a digit. This can be written as:
```rs
match (cursor.prev, cursor.curr, cursor.next) {
(b'0'..=b'9', b'.', b'0'..=b'9') => { /* … */ }
_ => { /* … */ }
}
```
But this is not very fast because Rust can't optimize the match
statement very well, especially because we are dealing with tuples
containing 3 values and each value is a `u8`.
To solve this we use some nesting, once we reach `b'.'` only then will
we check for the previous and next characters. We will also early return
in most places. If the previous character is not a digit, there is no
need to check the next character.
**Classification and jump tables:**
Another optimization we did is to classify the characters into a much
smaller `enum` such that Rust _can_ optimize all `match` arms and create
some jump tables behind the scenes.
E.g.:
```rs
#[derive(Debug, Clone, Copy, PartialEq)]
enum Class {
/// ', ", or `
Quote,
/// \
Escape,
/// Whitespace characters
Whitespace,
Other,
}
const CLASS_TABLE: [Class; 256] = {
let mut table = [Class::Other; 256];
macro_rules! set {
($class:expr, $($byte:expr),+ $(,)?) => {
$(table[$byte as usize] = $class;)+
};
}
set!(Class::Quote, b'"', b'\'', b'`');
set!(Class::Escape, b'\\');
set!(Class::Whitespace, b' ', b'\t', b'\n', b'\r', b'\x0C');
table
};
```
There are only 4 values in this enum, so Rust can optimize this very
well. The `CLASS_TABLE` is generated at compile time and must be exactly
256 elements long to fit all `u8` values.
**Inlining**:
Last but not least, sometimes we use functions to abstract some logic.
Luckily Rust will optimize and inline most of the functions
automatically. In some scenarios, explicitly adding a
`#[inline(always)]` improves performance, sometimes it doesn't improve
it at all.
You might notice that in some functions the annotation is added and in
some it's not. Every state machine was tested on its own and whenever
the performance was better with the annotation, it was added.
### Test Plan
1. Each machine has a dedicated set of tests to try and extract the
relevant part for that machine. Most machines don't even check boundary
characters or try to extract nested candidates. So keep that in mind
when adding new tests. Extracting inside of nested `[…]` is only handled
by the outer most `extractor/mod.rs`.
2. The main `extractor/mod.rs` has dedicated tests for recent bug
reports related to missing candidates.
3. You can test each machine's performance if you want to.
There is a chance that this new parser is missing candidates even though
a lot of tests are added and existing tests have been ported.
To double check, we ran the new extractor on our own projects to make
sure we didn't miss anything obvious.
#### Tailwind UI
On Tailwind UI the diff looks like this:
<details>
<summary>diff</summary>
```diff
diff --git a/./main.css b/./pr.css
index d83b0a506..b3dd94a1d 100644
--- a/./main.css
+++ b/./pr.css
@@ -5576,9 +5576,6 @@ @layer utilities {
--tw-saturate: saturate(0%);
filter: var(--tw-blur,) var(--tw-brightness,) var(--tw-contrast,) var(--tw-grayscale,) var(--tw-hue-rotate,) var(--tw-invert,) var(--tw-saturate,) var(--tw-sepia,) var(--tw-drop-shadow,);
}
- .\!filter {
- filter: var(--tw-blur,) var(--tw-brightness,) var(--tw-contrast,) var(--tw-grayscale,) var(--tw-hue-rotate,) var(--tw-invert,) var(--tw-saturate,) var(--tw-sepia,) var(--tw-drop-shadow,) !important;
- }
.filter {
filter: var(--tw-blur,) var(--tw-brightness,) var(--tw-contrast,) var(--tw-grayscale,) var(--tw-hue-rotate,) var(--tw-invert,) var(--tw-saturate,) var(--tw-sepia,) var(--tw-drop-shadow,);
}
```
</details>
The reason `!filter` is gone, is because it was used like this:
```js
getProducts.js
23: if (!filter) return true
```
And right now `(` and `)` are not considered valid boundary characters
for a candidate.
#### Catalyst
On Catalyst, the diff looks like this:
<details>
<summary>diff</summary>
```diff
diff --git a/./main.css b/./pr.css
index 9f8ed129..4aec992e 100644
--- a/./main.css
+++ b/./pr.css
@@ -2105,9 +2105,6 @@
.outline-transparent {
outline-color: transparent;
}
- .filter {
- filter: var(--tw-blur,) var(--tw-brightness,) var(--tw-contrast,) var(--tw-grayscale,) var(--tw-hue-rotate,) var(--tw-invert,) var(--tw-saturate,) var(--tw-sepia,) var(--tw-drop-shadow,);
- }
.backdrop-blur-\[6px\] {
--tw-backdrop-blur: blur(6px);
-webkit-backdrop-filter: var(--tw-backdrop-blur,) var(--tw-backdrop-brightness,) var(--tw-backdrop-contrast,) var(--tw-backdrop-grayscale,) var(--tw-backdrop-hue-rotate,) var(--tw-backdrop-invert,) var(--tw-backdrop-opacity,) var(--tw-backdrop-saturate,) var(--tw-backdrop-sepia,);
@@ -7141,46 +7138,6 @@
inherits: false;
initial-value: solid;
}
-@property --tw-blur {
- syntax: "*";
- inherits: false;
-}
-@property --tw-brightness {
- syntax: "*";
- inherits: false;
-}
-@property --tw-contrast {
- syntax: "*";
- inherits: false;
-}
-@property --tw-grayscale {
- syntax: "*";
- inherits: false;
-}
-@property --tw-hue-rotate {
- syntax: "*";
- inherits: false;
-}
-@property --tw-invert {
- syntax: "*";
- inherits: false;
-}
-@property --tw-opacity {
- syntax: "*";
- inherits: false;
-}
-@property --tw-saturate {
- syntax: "*";
- inherits: false;
-}
-@property --tw-sepia {
- syntax: "*";
- inherits: false;
-}
-@property --tw-drop-shadow {
- syntax: "*";
- inherits: false;
-}
@property --tw-backdrop-blur {
syntax: "*";
inherits: false;
```
</details>
The reason for this is that `filter` was only used as a function call:
```tsx
src/app/docs/Code.tsx
31: .filter((x) => x !== null)
```
This was tested on all templates and they all remove a very small amount
of classes that aren't used.
The script to test this looks like this:
```sh
bun --bun ~/github.com/tailwindlabs/tailwindcss/packages/@tailwindcss-cli/src/index.t -- -i ./src/styles/tailwind.css -o pr.css
bun --bun ~/github.com/tailwindlabs/tailwindcss--main/packages/@tailwindcss-cli/src/index.t -- -i ./src/styles/tailwind.css -o main.css
git diff --no-index --patch ./{main,pr}.css
```
This is using git worktrees, so the `pr` branch lives in a `tailwindcss`
folder, and the `main` branch lives in a `tailwindcss--main` folder.
---
### Fixes:
- Fixes: https://github.com/tailwindlabs/tailwindcss/issues/15616
- Fixes: https://github.com/tailwindlabs/tailwindcss/issues/16750
- Fixes: https://github.com/tailwindlabs/tailwindcss/issues/16790
- Fixes: https://github.com/tailwindlabs/tailwindcss/issues/16801
- Fixes: https://github.com/tailwindlabs/tailwindcss/issues/16880 (due
to validating the arbitrary property)
---
### Ideas for in the future
1. Right now each machine takes in a `Cursor` object. One potential
improvement we can make is to rely on the `input` on its own instead of
going via the wrapping `Cursor` object.
2. If you take a look at the AST, you'll notice that utilities and
variants have a "root", these are basically prefixes of each available
utility and/or variant. We can use this information to filter out
candidates and bail out early if we know that a certain candidate will
never produce a valid class.
3. Passthrough the `prefix` information. Everything that doesn't start
with `tw:` can be skipped.
### Design decisions that didn't make it
Once you reach this part, you can stop reading if you want to, but this
is more like a brain dump of the things we tried and didn't work out.
Wanted to include them as a reference in case we want to look back at
this issue and know _why_ certain things are implemented the way they
are.
#### One character at a time
In an earlier implementation, the state machines were pure state
machines where the `next()` function was called on every single
character of the input. This had a lot of overhead because for every
character we had to:
1. Ask the `CandidateMachine` which state it was in.
2. Check the `cursor.curr` (and potentially the `cursor.prev` and
`cursor.next`) character.
3. If we were in a state where a nested state machine was running, we
had to check its current state as well and so on.
4. Once we did all of that we could go to the next character.
In this approach, the `MachineState` looked like this instead:
```rs
enum MachineState {
Idle,
Parsing,
Done(Span)
}
```
This had its own set of problems because now it's very hard to know
whether we are done or not.
```html
<div class="hover:flex"></div>
<!-- ^ -->
```
Let's look at the current position in the example above. At this point,
it's both a valid variant and valid utility, so there was a lot of
additional state we had to track to know whether we were done or not.
#### `Span` stitching
Another approach we tried was to just collect all valid variants and
utilities and throw them in a big `Vec<Span>`. This reduced the amount
of additional state to track and we could track a span the moment we saw
a `MachineState::Done(span)`.
The next thing we had to do was to make sure that:
1. Covered spans were removed. We still do this part in the current
implementation.
2. Combine all touching variant spans (where `span_a.end + 1 ==
span_b.start`).
3. For every combined variant span, find a corresponding utility span.
- If there is no utility span, the candidate is invalid.
- If there are multiple candidate spans (this is in theory not possible
because we dropped covered spans)
- If there is a candidate _but_ it is attached to another set of spans,
then the candidate is invalid. E.g.: `flex!block`
4. All left-over utility spans are candidates without variants.
This approach was slow, and still a bit hard to reason about.
#### Matching on tuples
While matching against the `prev`, `curr` and `next` characters was very
readable and easy to reason about. It was not very fast. Unfortunately
had to abandon this approach in favor of a more optimized approach.
In a perfect world, we would still write it this way, but have some
compile time macro that would optimize this for us.
#### Matching against `b'…'` instead of classification and jump tables
Similar to the previous point, while this is better for readability,
it's not fast enough. The jump tables are much faster.
Luckily for us, each machine has it's own set of rules and context, so
it's much easier to reason about a single problem and optimize a single
machine.
[^candidate]: A candidate is what a potential Tailwind CSS class _could_
be. It's a candidate because at this stage we don't know if it will
actually produce something but it looks like it could be a valid class.
E.g.: `hover:bg-red-500` is a candidate, but it will only produce
something if `--color-red-500` is defined in your theme.
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
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
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 statically links the C runtime on Windows builds so we no longer
require installing Visual Studio redistributables.
## Test plan
Relying on CI here to not break anything for Windows.
<!--
👋 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 <4323180+adamwathan@users.noreply.github.com>
Fixes a crash found in Dockerfiles when a build takes place at the root
directory. It's not a good practice to keep your application logic in
`/`, but it probably shouldn't cause a crash either.
I found this particularly difficult to write tests for because it would
involve either running a glob on my real filesystem starting from `/` or
mocking the calls to `fs` which as far as I can tell isn't supported in
the codebase and would be out of scope to try to do here.
Fixes#15987
Fixes#15632Fixes#15740
This PR fixes a number of Oxide scanner bugs reported over various
channels, specifically:
- When using the Svelte class shorthand split over various lines, we
weren't extracting class names properly:
```svelte
<div
class:underline={isUnderline}>
</div>
```
- We now extract classes when using the class shortcut in Angular:
```html
<div [class.underline]=\"bool\"></div>
```
- We now validate parentheses within arbitrary candidates so that we
don't consume invalid arbitrary candidates anymore which allows us to
parse the following case properly:
```js
const classes = [wrapper("bg-red-500")]
```
## Test plan
Added unit tests
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
Right now, when Oxide is scanning for files, it considers ignore files
in the "root" directory it is scanning as well as all parent
directories.
We honor .gitignore files even when not in a git repo as an optimization
in case a project has been created, contains a .gitignore, but no repo
has actually been initialized. However, this has an unintended side
effect of including ignore files _ouside of a repo_ when there is one.
This means that if you have a .gitignore file in your home folder it'll
get applied even when you're inside a git repo which is not what you'd
expect.
This PR addresses this by checking to see the folder being scanned is
inside a repo and turns on a flag that ensures .gitignore files from the
repo are the only ones used (global ignore files configured in git still
work tho).
This still needs lots of tests to make sure things work as expected.
Fixes#15876
---------
Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
