ImpureStaticPropertyAssignment

An impure function assigns to a static property, which introduces side effects that can make code harder to reason about and test.

Example

<?php
class Counter {
    public static $count = 0;

    public static function increment(): void {
        self::$count++; // Static property modification in function
    }
}

How to fix

Consider using instance properties or dependency injection instead of static properties:

<?php
class Counter {
    private int $count = 0;

    public function increment(): void {
        $this->count++;
    }

    public function getCount(): int {
        return $this->count;
    }
}