amare/tests/Feature/PublicSite/FontDeliveryTest.php

<?php

declare(strict_types=1);

namespace Tests\Feature\PublicSite;

use Tests\TestCase;

/**
 * Bunny serves every EB Garamond weight as both woff2 and woff, and the fonts
 * plugin emitted an `@font-face` rule for each — woff2 first, woff second. Two
 * rules with the same family, weight, style and unicode-range mean the later
 * one wins, so browsers rendered from the woff files and discarded the
 * preloaded woff2.
 *
 * The MAN-109 audit measured the cost on the home page: 88 KiB of woff at
 * VeryHigh priority, ahead of the LCP image, plus 74 KiB of preloaded woff2
 * that was fetched and never used. The `amare:fonts-woff2-only` plugin in
 * vite.config.js strips the woff rules; these assertions fail if a plugin
 * upgrade brings them back.
 *
 * Reads the build output because that is where the defect lived — the source
 * config looked correct the whole time. The `feature` job runs `npm run build`
 * before the suite (.github/workflows/ci.yml).
 */
class FontDeliveryTest extends TestCase
{
    public function test_build_ships_woff2_only(): void
    {
        $manifestPath = public_path('build/fonts-manifest.json');

        $this->assertFileExists(
            $manifestPath,
            'Run `npm run build` before this suite — the font manifest is a build artifact.'
        );

        $manifest = json_decode((string) file_get_contents($manifestPath), true);

        $this->assertIsArray($manifest);
        $this->assertNotEmpty($manifest['preloads'] ?? [], 'The critical font weights must still be preloaded.');

        foreach ($manifest['preloads'] as $preload) {
            $this->assertStringEndsWith('.woff2', (string) ($preload['file'] ?? ''));
        }

        foreach ($manifest['families'] ?? [] as $alias => $family) {
            foreach ($family['variants'] ?? [] as $key => $variant) {
                $this->assertNotEmpty($variant['files'] ?? [], "{$alias} {$key} lost every font file.");

                foreach ($variant['files'] as $file) {
                    $this->assertSame(
                        'woff2',
                        $file['format'] ?? null,
                        "{$alias} {$key} declares a {$file['format']} file. Only woff2 is served — a second "
                        .'format with the same family, weight and unicode-range overrides the woff2 rule and '
                        .'doubles the font traffic on the critical path.'
                    );
                }
            }
        }

        $stylesheet = $manifest['style']['file'] ?? null;
        $this->assertIsString($stylesheet);

        $css = (string) file_get_contents(public_path('build/'.$stylesheet));

        $this->assertStringContainsString('format("woff2")', $css);
        $this->assertStringNotContainsString('format("woff")', $css);
    }

    public function test_no_woff_files_are_emitted_into_the_build(): void
    {
        $emitted = glob(public_path('build/assets/*.woff')) ?: [];

        $this->assertSame(
            [],
            array_map('basename', $emitted),
            'The build emitted legacy woff files. They are never requested by a browser that supports woff2, '
            .'which is every browser this site targets.'
        );
    }
}