Refactoring with readonly classes in PHP 8.2

Marian Kostadinov (stochnagara on Twitter) replied to Friday's email about DTOs and value objects to tell me about readonly classes, which can be done in PHP 8.2.

Looking at the previous class:

class AccountDetails {

  public function __construct(
    public readonly string $accountNumber,
    public readonly string $sortCode,
  ) {}

}

Instead of setting each property as readonly, the whole class can instead be marked as readonly:

readonly class AccountDetails {

  public function __construct(
    public string $accountNumber,
    public string $sortCode,
  ) {}

}

Thanks for the suggestion, Marian!