Найди ошибки в коде

Необходимо найти ошибки в данном коде, предложить исправления.

phpclass Rectangle
{
    protected int $width;
    protected int $height;

    public function setWidth(int $width): void {
        $this->width = $width;
    }

    public function setHeight(int $height): void {
        $this->height = $height;
    }

    public function calculateArea(): int
    {
        return $this->width * $this->height;
    }
}

class Square extends Rectangle
{
    public function setWidth(int $width): void {
        $this->width = $width;
        $this->height = $width;
    }

    public function setHeight(int $height): void {
        $this->width = $height;
        $this->height = $height;
    }
}

class RectangleTest extends TestCase
{
    public function testCalculateArea()
    {
        // $shape = new Rectangle();
        $shape = new Square();

        $shape->setWidth(10);
        $shape->setHeight(2);

        $this->assertEquals($shape->calculateArea(), 20); // FAILS - 4 != 20

        $shape->setWidth(5);
        $this->assertEquals($shape->calculateArea(), 10); // FAILS - 25 != 10
    }
}