OptimizeCssCommand.php

<?php

namespace App\Console\Commands;

use RuntimeException;

use Illuminate\Support\Str;
use Illuminate\Console\Command;
use Illuminate\Support\Facades\Storage;

/**
 * Warning: chrome coverage skips @keyframes, @font-face, @media
 * So, need to bundle auto.css with media.css after this command
 */
class OptimizeCssCommand extends Command
{
    protected $signature = 'css:optimize';
    protected $description = 'Optimize css using chrome coverage';

    public function handle()
    {
        $this->optimize('public/css/app.css', 'resources/css/app-desktop-auto.css', 'Coverage-desktop.json');
        $this->optimize('public/css/app.css', 'resources/css/app-mobile-auto.css', 'Coverage-mobile.json');

        $this->info('OK');
    }

    public function optimize(string $from, string $to, string $coverage)
    {
        $disk = Storage::disk('root');

        $file = $disk->get($from);
        $ranges = $this->getCoverageRanges($coverage);

        $bar = $this->output->createProgressBar(count($ranges));

        $bar->start();

        $minified = '';
        $last = '';
        $start = 0;
        while ($range = array_shift($ranges)) {
            if ($range['start'] !== $start) {
                $minified .= $last;
            }
            $start = $range['start'];
            $length = $range['end'] - $start;
            $last = mb_substr($file, $start, $length);
            $bar->advance();
        }

        $bar->finish();
        $this->info('');

        $disk->put($to, $minified);
    }

    protected function getCoverageRanges(string $file): array
    {
        $coverageFile = Storage::disk('local')->get($file);
        $coverage = json_decode($coverageFile, true);

        if (!is_array($coverage)) {
            throw new RuntimeException('Coverage not found');
        }

        foreach ($coverage as $item) {
            if (Str::contains($item['url'], '/css/app.css')) {
                return $item['ranges'];
            }
        }
        throw new RuntimeException('Css not found');
    }
}