9 Commits

Author SHA1 Message Date
Philipp Spiess
4200a1ecc4
Fix slow incremental builds (especially on Windows) (#17511)
This PR fixes slow rebuilds on Windows where rebuilds go from ~2s to
~20ms.

Fixes: #16911
Fixes: #17522

## Test plan

1. Tested it on a reproduction with the following results:

Before:


https://github.com/user-attachments/assets/10c5e9e0-3c41-4e1d-95f6-ee8d856577ef

After:


https://github.com/user-attachments/assets/2c7597e9-3fff-4922-a2da-a8d06eab9047

Zooming in on the times, it looks like this:
<img width="674" alt="image"
src="https://github.com/user-attachments/assets/85eee69c-bbf6-4c28-8ce3-6dcdad74be9c"
/>

But with these changes:
<img width="719" alt="image"
src="https://github.com/user-attachments/assets/d89cefda-0711-4f84-bfaf-2bea11977bf7"
/>

We also tested this on Windows with the following results:
Before:
<img width="961" alt="image"
src="https://github.com/user-attachments/assets/3a42f822-f103-4598-9a91-e659ae09800c"
/>

After:
<img width="956" alt="image"
src="https://github.com/user-attachments/assets/05b6b6bc-d107-40d1-a207-3638aba3fc3a"
/>


[ci-all]

---------

Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
2025-04-03 17:13:15 +02:00
Philipp Spiess
156afc6d67
Improve compatibility with Safari 15 (#17435)
This PR improves the compatibility with Tailwind CSS v4 with unsupported
browsers with the goal to greatly improve compatibility with Safari 15.

To make this work, this PR makes the following changes to all code

- Change `oklab(…)` default theme values to use a percentage in the
first place (so instead of `--color-red-500: oklch(0.637 0.237 25.331);`
we now define it as `--color-red-500: oklch(63.7% 0.237 25.331);` since
this syntax has much broader support on Safari).
- Polyfill `@property` with a `@supports` query targeting older versions
of Safari and Firefox *
- Create fallbacks for the `color-mix(…)` function that use _inlined
color values from your theme_ so that they can be computed a compile
time by `lightningcss`. These fallbacks will convert to srgb to increase
compatibility.
- Create fallbacks for the _relative color_ feature used in the new
shadow utilities and using `color-mix(…)` in case _relative color_ is
applied on `currentcolor` (due to limited browser support)
- Create fallbacks for gradient interpolation methods (e.g. to support
`bg-linear-to-r/oklab`)
- Polyfill `@media` queries range syntax.

## A simplified example

Given this example CSS input:

```css
@import 'tailwindcss';
@source inline('from-cyan-500/50 bg-linear-45');
```

Here's the updated output CSS including the newly added polyfills and
updated `oklab` values:

```css
.bg-linear-45 {
  --tw-gradient-position: 45deg;
  background-image: linear-gradient(var(--tw-gradient-stops));
}

@supports (background-image: linear-gradient(in lab, red, red)) {
  .bg-linear-45 {
    --tw-gradient-position: 45deg in oklab;
  }
}

.from-cyan-500\\/50 {
  --tw-gradient-from: oklab(71.5% -.11682 -.08247 / .5);
  --tw-gradient-stops: var(--tw-gradient-via-stops, var(--tw-gradient-position), var(--tw-gradient-from) var(--tw-gradient-from-position), var(--tw-gradient-to) var(--tw-gradient-to-position));
}

@supports (color: color-mix(in lab, red, red)) {
  .from-cyan-500\\/50 {
    --tw-gradient-from: color-mix(in oklab, var(--color-cyan-500) 50%, transparent);
  }
}

:root, :host {
  --color-cyan-500: oklch(71.5% .143 215.221);
}

@supports (((-webkit-hyphens: none)) and (not (margin-trim: 1lh))) or ((-moz-orient: inline) and (not (color: rgb(from red r g b)))) {
  @layer base {
    *, :before, :after, ::backdrop {
      --tw-gradient-position: initial;
      --tw-gradient-from: #0000;
      --tw-gradient-via: #0000;
      --tw-gradient-to: #0000;
      --tw-gradient-stops: initial;
      --tw-gradient-via-stops: initial;
      --tw-gradient-from-position: 0%;
      --tw-gradient-via-position: 50%;
      --tw-gradient-to-position: 100%;
    }
  }
}

@property --tw-gradient-position {
  syntax: "*";
  inherits: false
}

@property --tw-gradient-from {
  syntax: "<color>";
  inherits: false;
  initial-value: #0000;
}

@property --tw-gradient-via {
  syntax: "<color>";
  inherits: false;
  initial-value: #0000;
}

@property --tw-gradient-to {
  syntax: "<color>";
  inherits: false;
  initial-value: #0000;
}

@property --tw-gradient-stops {
  syntax: "*";
  inherits: false
}

@property --tw-gradient-via-stops {
  syntax: "*";
  inherits: false
}

@property --tw-gradient-from-position {
  syntax: "<length-percentage>";
  inherits: false;
  initial-value: 0%;
}

@property --tw-gradient-via-position {
  syntax: "<length-percentage>";
  inherits: false;
  initial-value: 50%;
}

@property --tw-gradient-to-position {
  syntax: "<length-percentage>";
  inherits: false;
  initial-value: 100%;
}
```

## \* A note on `@property` polyfills and CSS modules

On Next.js, CSS module files are required to be _pure_, meaning that all
selectors must either be scoped to a class or an ID. Fortunatnyl for us,
this does not apply to `@property` rules which we've been using before
to initialize CSS variables.

However, since we're now bringing back the `@property` polyfills, that
would cause unexpected rules to be exported from the CSS file as this:

```css
@reference "tailwindcss";

.skew {
  @apply skew-7;
}
```

Would turn to the following file:

```css
.skew {
  /* … */
}
@supports (/*…*/) {
  @layer base {
    *, :before, :after, ::backdrop {
      --tw-gradient-position: initial;
    }
  }
}
@property /* … */ 
```

Notice that this adds a `*` selector which is not considered pure.

Unfortunately there is no way for us to silence this warning or work
around it, as the dependency causing this errors
([`postcss-modules-local-by-default`](https://github.com/css-modules/postcss-modules-local-by-default))
is bundled into Next.js. To work around crashes, these polyfills will
not apply to CSS modules processed by the PostCSS extension for now.

## Testing on tailwindcss.com

To see the changes in effect, take a look at this screencast that
compares tailwindcss.com on iOS 15.5 with a version that has the patches
of this PR applied:

https://github.com/user-attachments/assets/1279d6f5-3c63-4f30-839c-198a789f4292

## Test plan

- Tested on tailwindcss.com via a preview build:
https://tailwindcss-com-git-legacy-browsers-tailwindlabs.vercel.app/
- Updated tests
- Ensure we also test on Chrome 111, Safari 16.4, Firefox 128 to
make sure we have no regressions. Also tested on Safari 16.4, 15.5, 18.0
2025-04-01 13:33:22 +02:00
Robin Malfait
53801091a0
Watch CSS module files for changes (#17467)
This PR is a follow-up PR for:
https://github.com/tailwindlabs/tailwindcss/pull/17433

In the other PR we allow scanning CSS files for extracting usages of CSS
variables. This is important for `.module.css` files that reference
these variables but aren't in the same big AST of the main CSS file.

This PR also makes sure to watch for changes in those registered CSS
files and re-extract the variables when they change.

This PR took a bit longer than expected because I was trying to make
sure that writing to `./dist/out.css` works without infinite-looping
(e.g.: we had issues with this in Tailwind CSS v3 with webpack).

But I couldn't reproduce the issue at all. I did had some code that
tried to detect if the CSS file contained license headers and skip in
(because then it's very likely an output CSS file) but even without it
the tests were fine.

I setup integration tests with `@tailwindcss/cli` itself, and with tools
that use webpack. Added a test for Next.js, and a dedicated webpack test
as well.

Even without tests, locally, I couldn't reproduce an infinite loop due
to changes in an output CSS file...

Eventually dropped the code that tries to detect output CSS files.

One thing to keep in mind is that if you change any of your "main" CSS
files, then we will trigger a full rebuild anyway, so this change is
only required for unrelated CSS files (like CSS module files) that use
CSS variables.

## Test plan

1. Added integration tests for the CLI and Next.js
2. Added new dedicated test for webpack
2025-03-31 18:44:06 +02:00
Philipp Spiess
b38948337d
Make @reference emit variable fallbacks instead of CSS variable declarations (#16774)
Fixes #16725

When using `@reference "tailwindcss";` inside a separate CSS root (e.g.
Svelte `<style>` components, CSS modules, etc.), we have no guarantee
that the CSS variables will be defined in the main stylesheet (or if
there even is one). To work around potential issues with this we decided
in #16676 that we would emit all used CSS variables from the `@theme`
inside the `@reference` block.

However, this is not only a bit surprising but also unexpected in CSS
modules and Next.js that **requires CSS module files to only create
scope-able declarations**. To fix this issue, we decided to not emit CSS
variables but instead ensure all `var(…)` calls we create for theme
values in reference mode will simply have their fallback value added.

This ensures styles work as-expected even if the root Tailwind file does
not pick up the variable as being used or _if you don't add a root at
all_. Furthermore we do not duplicate any variable declarations across
your stylesheets and you still have the ability to change variables at
runtime.

## Test plan

- Updated snapshots everywhere (see diff)
- New Next.js CSS modules integration test
2025-02-25 11:36:43 +01:00
Philipp Spiess
08972f294f
Scan Next.js dynamic route segments with manual @source rules (#16457)
Part of #16287

## Test plan

Added unit and integration tests

---------

Co-authored-by: Robin Malfait <malfait.robin@gmail.com>
2025-02-18 11:51:58 +01:00
Robin Malfait
2a29c29441
Improve integration tests (stability + performance) (#15125)
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)
2024-12-12 13:48:56 +01:00
Philipp Spiess
f028eae75e
Integration tests: Move all file writes into retry block (#14350)
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.
2024-09-06 10:48:49 +02:00
Philipp Spiess
84ebe19da2
Vite: Retain candidates between input CSS updates (#14228)
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>
2024-08-21 12:54:42 +02:00
Philipp Spiess
e10b786437
Add Next.js integration test (#14163)
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>
2024-08-16 15:45:52 +02:00