Wanna unit-test a function, but constructor gives error

I am trying to unit test a function which is in an entity class, and it is stored in my DB by the use of a constructor. Each time I am trying to test this function it is giving me that error

ArgumentCountError: Too few arguments to function App\Entity\Deal::__construct(), 0 passed in /var/www/html/casus/tests/dealsEntityFunctionsTest.php on line 10 and exactly 1 expected

It is obvious I think, but I am really new with unit testing and that stuff so I couldn’t find the answer. Could you please help me?

My code is

class Deal
{
    private bool $isNewToday

    public function __construct($deal)
    {
        $this->isNewToday = $deal['is_new_today'];
    }

    public function getIsNewToday(): ?bool
    {
        return $this->isNewToday;
    }

    public function setIsNewToday(bool $isNewToday): self
    {
        $this->isNewToday = $isNewToday;

        return $this;
    }
}

And my unit test is

class test extends TestCase
{
    public function testIsNewTodayIsTrue()
    {
        $deal = new Deal();
        $deal->setIsForSale(true);
        $this->assertTrue($deal->getIsForSale(), true);
    }
}

>Solution :

As brombeer suggested, new Deal entity requires parameter.
This parameter looks like an array, with key ‘is_new_today’. So, sth like this below should help with constructor error.

class test extends TestCase
{
    public function testIsNewTodayIsTrue()
    {
        $deal = new Deal(['is_new_today' => true]);
        $deal->setIsForSale(true);
        $this->assertTrue($deal->getIsForSale(), true);
    }
}