Module loader script for composer

ComposerModuleAutoLoader.php

<?php

namespace App\Support;

class ComposerModuleAutoLoader
{
    public static function load($event)
    {
        $package   = $event->getComposer()->getPackage();
        $base_path = dirname(__DIR__, 2).'/';
        $dirs      = glob(
            $base_path.'modules/*',
            GLOB_ONLYDIR
        );
        $paths = array_map(
            fn($dir) => str_replace($base_path, '', $dir),
            $dirs
        );
        $autoload  = $package->getAutoload();
        $autoload['psr-4'] = array_merge(
            $autoload['psr-4'],
            self::generatePsr4($paths, false)
        );
        $package->setAutoload($autoload);

        $autoloadDev  = $package->getDevAutoload();
        $autoloadDev['psr-4'] = array_merge(
            $autoloadDev['psr-4'],
            self::generatePsr4($paths, true)
        );
        $package->setDevAutoload($autoloadDev);

        $configSource = $event->getComposer()->getConfig()->getConfigSource();
        self::updateComposerJson($configSource, 'autoload', $autoload);
        self::updateComposerJson($configSource, 'autoload-dev', $autoloadDev);
        self::reformatComposerJson($configSource->getName());
    }

    private static function generatePsr4(array $paths, bool $dev): array
    {
        $psr4 = [];
        foreach ($paths as $path) {
            $namespaces        = self::getNamespacesFromPath($path, $dev);
            $psr4 = array_merge(
                $psr4,
                $namespaces
            );
        }
        return $psr4;
    }

    private static function getNamespacesFromPath(string $path, bool $dev): array
    {
        // Get the relative path and the namespace name for each module directory.
        $name = str_replace("modules/", '', $path);
        if (!preg_match('/^[A-Z][\w]*$/', $name)) {
            return [];
        }
        $namespaces = [];
        if (! $dev && file_exists("$path/src") && is_dir("$path/src")) {
            $namespaces["Modules\\$name\\"] = "$path/src";
        }
        if ($dev && file_exists("$path/tests") && is_dir("$path/tests")) {
            $namespaces["Modules\\$name\\Tests\\"] = "$path/tests";
        }
        return $namespaces;
    }

    private static function updateComposerJson($configSource, string $key, array $autoload)
    {
        // Add a placeholder so that the key "autoload" is not removed when removing psr-4.
        $configSource->addLink($key, 'tmp', 'placeholder');
        $configSource->removeLink($key, 'psr-4');
        // Add back psr-4 after changes and remove the placeholder key.
        $configSource->addLink($key, 'psr-4', $autoload['psr-4']);
        $configSource->removeLink($key, 'tmp');
    }

    private static function reformatComposerJson(string $filename)
    {
        // Read the composer.json and re-format it to fix indentation.
        $content = file_get_contents($filename);
        $json    = json_encode(
            json_decode($content, true),
            JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES
        );
        if (!$json) {
            return;
        }
        file_put_contents(
            $filename,
            $json
        );
    }
}