Composer 把 App\ 映射到 src/。找出会破坏 PSR-4 加载的命名空间与大小写不匹配。
php
<?php
// File: src/Service/TaxCalculator.php
namespace App\Services;
final class TaxCalculator {}
namespace App\Checkout;
use app\Services\TaxCalculator;
final class Checkout
{
public function tax(): TaxCalculator
{
return new TaxCalculator();
}
}