PHP_CodeSniffer: Does not work with readonly classes introduced in PHP 8.2

May be closed by ~#3686~ #3728

Describe the bug In PHP 8.2, “readonly class” feature was introduced. Using readonly classes, we can shorten readonly property declarations as follows:

class Foo {
    public function __construct(
        private readonly string $foo,
        private readonly int $bar,
    ) {
    }
}

equals to:

readonly class Foo {
    public function __construct(
        private string $foo,
        private string $bar,
    ) {
    }
}

However, the latest version of phpcs v3.7.1 does not work on the classes which are marked as “readonly”. (The phpcs error output is in “To reproduce” section)

Code sample

readonly class Foo {
    public function __construct(
        private string $foo,
        private string $bar,
    ) {
    }
}

Custom ruleset N/A

To reproduce Steps to reproduce the behavior:

1. Run phpcs with the default ruleset, with the code sample above.

FILE: /project/Foo.php
----------------------------------------------------------------------
FOUND 0 ERRORS AND 1 WARNING AFFECTING 1 LINE
----------------------------------------------------------------------
 1 | WARNING | A file should declare new symbols (classes, functions,
   |         | constants, etc.) and cause no other side effects, or
   |         | it should execute logic with side effects, but should
   |         | not do both. The first symbol is defined on line 13
   |         | and the first side effect is on line 13.
   |         | (PSR1.Files.SideEffects.FoundWithSymbols)
----------------------------------------------------------------------

Expected behavior A clear and concise description of what you expected to happen.

Versions (please complete the following information):

• OS: macOS Ventura 13.0.1 (Apple M1 Max; aarch64-apple-darwin)
• PHP: 8.2.0
• PHPCS: 3.7.1
• Standard: PSR12

Additional context N/A