livewire-material/tests/Browser/CarouselTest.php

<?php

use Illuminate\Support\Facades\Blade;
use Illuminate\Support\Facades\Route;
use Livewire\Component;
use Livewire\Livewire;

/**
 * A Livewire component whose items only the server changes, to watch a carousel through a morph.
 */
class CarouselMorphProbe extends Component
{
    public int $count = 6;

    public function add(): void
    {
        $this->count++;
    }

    public function render(): string
    {
        return <<<'BLADE'
            <div style="padding: var(--md-sys-measurement-space200); width: 600px;">
                <x-carousel label="Server" item-width="200">
                    @foreach (range(1, $count) as $number)
                        <x-carousel-item wire:key="item-{{ $number }}"><div style="width: 100%; height: 100%; background-color: var(--md-sys-color-primary-container);"></div></x-carousel-item>
                    @endforeach
                </x-carousel>
                <button type="button" wire:click="add">Add</button>
            </div>
            BLADE;
    }
}

/**
 * A script run against one carousel of the showcase (0 multi-browse, 1 hero, 2 uncontained,
 * 3 multi-aspect, 4 full-screen), or of another page under `scope`, scrolled into view. `root`,
 * `scroller` and `items` are in scope, with `surface(i)`, `inset(i)` (the mask on each side of
 * item i), `open(i)` (item i is at the largest size any item has here), `snap(i)` (the scroll
 * offset that brings item i into focus) and `at(i)`; the script's value is the result. Pest
 * retries a failing assertion and gives each attempt a second: keep scripts well inside it.
 *
 * `open(i)` rather than a zero inset: M3's 16dp of content padding, the carousel's default,
 * shrinks every keyline near the ends (Compose's
 * createShiftedKeylineListForContentPadding), so a large item resting at the start or the end is
 * masked by that share of the padding — 1.33px on each side in the showcase's first carousel.
 */
function onCarousel(int $index, string $body, string $scope = '#carousel'): string
{
    return <<<JS
        (async () => {
            const root = document.querySelectorAll('{$scope} [x-data="materialCarousel"]')[{$index}]
            const scroller = root.querySelector('[role="region"]')
            const items = [...scroller.querySelectorAll('[data-md-carousel-item]')]
            const gap = parseFloat(getComputedStyle(scroller).columnGap)
            const size = parseFloat(root.style.getPropertyValue('--material-carousel-slot'))
            const surface = (i) => items[i].querySelector('[data-md-carousel-surface]')
            const inset = (i) => parseFloat(surface(i).style.getPropertyValue('--material-carousel-inset'))
            const open = (i) => inset(i) - Math.min(...items.map((_, j) => inset(j))) < 0.5
            const snap = (i) => Math.min(Math.max(i * (size + gap) - parseFloat(items[i].style.scrollMarginInlineStart), 0), scroller.scrollWidth - scroller.clientWidth)
            const at = (i) => Math.abs(Math.abs(scroller.scrollLeft) - snap(i)) < 1.5
            const pause = (ms) => new Promise((resolve) => setTimeout(resolve, ms))
            if (root.getBoundingClientRect().top < 0 || root.getBoundingClientRect().bottom > innerHeight) root.scrollIntoView({ block: 'center' })
            {$body}
        })()
        JS;
}

const FIRST_ITEM = '#carousel [data-md-carousel-item] >> nth=0';

function carouselShowcase(array $options = [])
{
    // Pinned rather than left to the host's own window: at a wide enough viewport the multi-browse
    // row's 8 items (220px each) leave a remainder the keyline math does not reduce to zero the way
    // it does here, so "scroll by exactly 2 slots" no longer lands item 2 on the open keyline.
    return visit('/material/carousel', $options)
        ->resize(1280, 900)
        ->waitForEvent('networkidle')
        ->assertScript("typeof window.Alpine !== 'undefined'");
}

it('masks items by their place between the keylines, and changes the large one as it scrolls', function () {
    $page = carouselShowcase()
        ->assertNoJavaScriptErrors()
        ->assertScript(onCarousel(0, <<<'JS'
            return size > 0 && open(0) && ! open(items.length - 1)
                && getComputedStyle(surface(0)).clipPath.startsWith('inset(')
            JS));

    $page->script(onCarousel(0, "scroller.style.scrollSnapType = 'none'; scroller.scrollTo({ left: 2 * (size + gap), behavior: 'instant' })"));

    $page->assertScript(onCarousel(0, <<<'JS'
        await pause(50)
        return inset(0) > 0.5 && inset(2) < 0.5 && surface(0).style.getPropertyValue('--material-carousel-shift') !== '0.00px'
        JS));

    // Half-way between keylines, an item is part-way between two sizes.
    $page->script(onCarousel(0, "scroller.scrollTo({ left: 2.5 * (size + gap), behavior: 'instant' })"));

    $page->assertScript(onCarousel(0, <<<'JS'
        await pause(50)
        return inset(2) > 0.5 && inset(2) < size / 2 - 1
        JS));
});

it('moves one item with the next and previous buttons', function () {
    $page = carouselShowcase()
        ->assertScript(onCarousel(0, 'return at(0) && root.querySelector(\'[aria-label="Previous"]\').disabled'));

    $page->click('#carousel button[aria-label="Next"] >> nth=0')
        ->assertScript(onCarousel(0, 'return at(1) && inset(1) < 0.5 && !root.querySelector(\'[aria-label="Previous"]\').disabled'));

    $page->click('#carousel button[aria-label="Next"] >> nth=0')
        ->assertScript(onCarousel(0, 'return at(2)'));

    $page->click('#carousel button[aria-label="Previous"] >> nth=0')
        ->assertScript(onCarousel(0, 'return at(1)'));
});

it('moves one item with the arrow keys, and to the ends with Home and End', function () {
    $page = carouselShowcase();

    // M3 puts the tab stop on the item, so the keys are the focused item's and each one moves
    // focus to the item it scrolls to.
    $page->keys(FIRST_ITEM, 'ArrowRight')
        ->assertScript(onCarousel(0, 'return at(1) && document.activeElement === items[1]'));

    $page->keys(':focus', 'ArrowRight')
        ->assertScript(onCarousel(0, 'return at(2)'));

    $page->keys(':focus', 'ArrowLeft')
        ->assertScript(onCarousel(0, 'return at(1)'));

    $page->keys(':focus', 'End')
        ->assertScript(onCarousel(0, 'return Math.abs(scroller.scrollLeft - (scroller.scrollWidth - scroller.clientWidth)) < 1.5 && open(items.length - 1) && root.querySelector(\'[aria-label="Next"]\').disabled'));

    $page->keys(':focus', 'Home')
        ->assertScript(onCarousel(0, 'return at(0)'));
});

it('snaps a scroll that stops between items onto an item', function () {
    $page = carouselShowcase();

    $page->script(onCarousel(0, "scroller.scrollTo({ left: 0.7 * (size + gap), behavior: 'instant' })"));

    $page->assertScript(onCarousel(0, <<<'JS'
        await pause(100)
        return items.some((_, i) => at(i)) && scroller.scrollLeft > 0
        JS));
});

it('brings a partly hidden item into focus when it is pressed, and leaves an open one where it is', function () {
    $page = carouselShowcase()
        ->assertScript(onCarousel(0, 'return open(1) && ! open(4)'));

    // Item 1 rests at the large size, short only of the content padding's share: focusing or
    // pressing it moves nothing.
    $page->script(onCarousel(0, 'items[1].focus(); items[1].querySelector(\'[data-md-carousel-content]\').click()'));

    $page->assertScript(onCarousel(0, <<<'JS'
        await pause(400)
        return scroller.scrollLeft === 0 && open(1)
        JS));

    $page->script(onCarousel(0, 'items[4].querySelector(\'[data-md-carousel-content]\').click()'));

    $page->assertScript(onCarousel(0, 'return open(4) && scroller.scrollLeft > 0'));
});

it('scrolls instantly and leaves every item unmasked under reduced motion', function () {
    // A click, then a separate read-only assertScript: assertScript retries its whole expression
    // on a false result (this file's own comment above), and a click inside it would fire again on
    // every retry, drifting the carousel one further item each time and never recovering. Whether
    // the row had arrived is read in the same task as the click, against the slot size measured
    // before it, and kept, so a retry cannot turn a smooth scroll that finishes later into a pass:
    // under reduced motion it must be instant. (The row re-measures its slot a frame later, so the
    // assertion below reads a fresh size rather than this one.)
    $page = carouselShowcase(['reducedMotion' => 'reduce']);

    $page->script(onCarousel(0, 'root.querySelector(\'[aria-label="Next"]\').click(); window.__arrivedAtOnce = at(1)'));

    $page->assertScript(onCarousel(0, <<<'JS'
        await pause(50)
        return window.__arrivedAtOnce === true && at(1) && items.every((_, i) => inset(i) === 0)
            && items.every((item) => Math.abs(item.getBoundingClientRect().width - size) < 1.5)
        JS));
});

it('brings an item cut off at the row\'s edge into view when it is pressed under reduced motion', function () {
    // Under reduced motion, the row writes a zero inset for every item, so a mask cannot say an
    // item is only partly shown; carousel.js reads the item's box against the row's instead, as
    // for multi-aspect.
    $page = carouselShowcase(['reducedMotion' => 'reduce'])
        ->assertScript(onCarousel(0, <<<'JS'
            const row = scroller.getBoundingClientRect()
            const item = items[4].getBoundingClientRect()
            return scroller.scrollLeft === 0 && item.right > row.right + 1
            JS));

    $page->script(onCarousel(0, 'items[4].querySelector(\'[data-md-carousel-content]\').click()'));

    $page->assertScript(onCarousel(0, <<<'JS'
        await pause(100)
        const row = scroller.getBoundingClientRect()
        const item = items[4].getBoundingClientRect()
        return Math.abs(scroller.scrollLeft) > 0 && item.left >= row.left - 1 && item.right <= row.right + 1
        JS));
});

it('mirrors in a right-to-left page', function () {
    Route::middleware('web')->get('/carousel-rtl-probe', fn () => Blade::render(<<<'BLADE'
        <!DOCTYPE html>
        <html dir="rtl">
            <head>
                <x-theme-script />
                @vite(config('livewire-material.showcase.vite'))
                @livewireStyles
            </head>
            <body style="background-color: var(--md-sys-color-surface);">
                <div style="padding: var(--md-sys-measurement-space200); width: 600px;">
                    <x-carousel label="Right to left" item-width="200" controls>
                        @foreach (range(1, 6) as $number)
                            <x-carousel-item><div style="width: 100%; height: 100%; background-color: var(--md-sys-color-primary-container);"></div></x-carousel-item>
                        @endforeach
                    </x-carousel>
                </div>
                @livewireScripts
            </body>
        </html>
        BLADE));

    $page = visit('/carousel-rtl-probe')->waitForEvent('networkidle')
        ->assertNoJavaScriptErrors()
        ->assertScript(onCarousel(0, 'return size > 0 && at(0) && open(0) && ! open(items.length - 1)', 'body'));

    $page->keys('[data-md-carousel-item] >> nth=0', 'ArrowLeft')
        ->assertScript(onCarousel(0, <<<'JS'
            return scroller.scrollLeft < -1 && at(1) && ! open(0) && open(1)
                && parseFloat(surface(0).style.getPropertyValue('--material-carousel-shift')) < 0
            JS, 'body'));

    $page->click('button[aria-label="Next"]')
        ->assertScript(onCarousel(0, 'return at(2)', 'body'));

    $page->keys('[data-md-carousel-item] >> nth=2', 'ArrowRight')
        ->assertScript(onCarousel(0, 'return at(1)', 'body'));
});

it('measures itself again after a Livewire morph adds an item', function () {
    Livewire::component('carousel-morph-probe', CarouselMorphProbe::class);

    Route::middleware('web')->get('/carousel-morph-probe', fn () => Blade::render(<<<'BLADE'
        <!DOCTYPE html>
        <html>
            <head>
                <x-theme-script />
                @vite(config('livewire-material.showcase.vite'))
                @livewireStyles
            </head>
            <body style="background-color: var(--md-sys-color-surface);">
                <livewire:carousel-morph-probe />
                @livewireScripts
            </body>
        </html>
        BLADE));

    $masked = "(() => { const root = document.querySelector('[x-data=\"materialCarousel\"]'); const items = [...root.querySelectorAll('[data-md-carousel-item]')]; return root.style.getPropertyValue('--material-carousel-slot').endsWith('px') && items.every((item) => item.querySelector('[data-md-carousel-surface]').style.getPropertyValue('--material-carousel-inset').endsWith('px')) && items.length })()";

    $page = visit('/carousel-morph-probe')->waitForEvent('networkidle')
        ->assertNoJavaScriptErrors()
        ->assertScript($masked, 6)
        ->assertAttribute('[data-md-carousel-item] >> nth=5', 'aria-label', '6 of 6');

    $page->click('Add')
        ->assertScript($masked, 7)
        ->assertAttribute('[data-md-carousel-item] >> nth=6', 'aria-label', '7 of 7');

    // Scrolled once the morph has settled, so only the row's own scroll listener can re-mask the
    // items: a row the morph swapped for a copy scrolls with its items' masks left as they were.
    $page->script(onCarousel(0, "await pause(300); scroller.style.scrollSnapType = 'none'; scroller.scrollTo({ left: 2 * (size + gap), behavior: 'instant' })", 'body'));

    $page->assertScript(onCarousel(0, <<<'JS'
        await pause(50)
        return inset(0) > 0.5 && inset(2) < 0.5
        JS, 'body'));
});

/**
 * A script against the showcase's multi-aspect carousel, scoped by its own `data-md-carousel`
 * value rather than a position in the page (fragile if the showcase ever reorders its examples).
 * Nothing masks a multi-aspect item (no `--material-carousel-slot`, no keylines), so
 * `onCarousel()`'s size-based helpers do not apply: this carousel's resting positions come
 * straight off each item's own `getBoundingClientRect()`, as `carousel.js`'s `isMasked()` reads
 * them for `state.measured`.
 */
function onMultiAspectCarousel(string $body): string
{
    return <<<JS
        (async () => {
            const root = document.querySelector('#carousel [data-md-carousel="multi-aspect"]')
            const scroller = root.querySelector('[role="region"]')
            const items = [...scroller.querySelectorAll('[data-md-carousel-item]')]
            const pause = (ms) => new Promise((resolve) => setTimeout(resolve, ms))
            if (root.getBoundingClientRect().top < 0 || root.getBoundingClientRect().bottom > innerHeight) root.scrollIntoView({ block: 'center' })
            {$body}
        })()
        JS;
}

const MULTI_ASPECT_SCOPE = '#carousel [data-md-carousel="multi-aspect"]';

it('moves the multi-aspect carousel one item at a time with the buttons, arrows, Home and End', function () {
    $page = carouselShowcase()
        ->assertNoJavaScriptErrors()
        ->assertScript(onMultiAspectCarousel('return scroller.scrollLeft === 0 && items.length > 2'));

    $page->click(MULTI_ASPECT_SCOPE.' button[aria-label="Next"]')
        ->assertScript(onMultiAspectCarousel(<<<'JS'
            await pause(400)
            return scroller.scrollLeft > 0
            JS));

    $page->click(MULTI_ASPECT_SCOPE.' button[aria-label="Previous"]')
        ->assertScript(onMultiAspectCarousel(<<<'JS'
            await pause(400)
            return scroller.scrollLeft === 0
            JS));

    $page->keys(MULTI_ASPECT_SCOPE.' [data-md-carousel-item] >> nth=0', 'ArrowRight')
        ->assertScript(onMultiAspectCarousel(<<<'JS'
            await pause(400)
            return scroller.scrollLeft > 0 && document.activeElement === items[1]
            JS));

    $page->keys(':focus', 'ArrowLeft')
        ->assertScript(onMultiAspectCarousel(<<<'JS'
            await pause(400)
            return scroller.scrollLeft === 0 && document.activeElement === items[0]
            JS));

    $page->keys(':focus', 'End')
        ->assertScript(onMultiAspectCarousel(<<<'JS'
            await pause(400)
            return document.activeElement === items[items.length - 1]
                && Math.abs(scroller.scrollLeft - (scroller.scrollWidth - scroller.clientWidth)) < 1.5
            JS));

    $page->keys(':focus', 'Home')
        ->assertScript(onMultiAspectCarousel(<<<'JS'
            await pause(400)
            return document.activeElement === items[0] && scroller.scrollLeft === 0
            JS));
});