Cannot add items to cart

[LarryBarker]

• Bazar Version: ^0.8.2
• Laravel Version: 8
• PHP Version: 8.1
• Database Driver & Version: MySQL 8

Description:

Following the docs trying to add an item to the cart and I get this error back: Column 'price' cannot be null

$item = Cart::addItem($variant->product, 1, [
            'price' => $variant->prices->format('USD.default')
        ]);
        ```
        
Also note I initially tried adding the variant to the cart which failed because `addItem` expects an instance of `Product` to be passed. This is strange to me but nevertheless I can work around it.

I'm not exactly sure how or where to pass the price? 

Also, I cannot seem to find where the logic for `addItem` actually lives? 

[LarryBarker]

@iamgergo I just upgraded to v0.9 and am having the same issue with the exception I can pass an instance of Variant to addItem. Still have the error about null price.

[LarryBarker]

@iamgergo Related to another ticket I commented on about array to string conversion error, addItem is now failing if the item is added with an empty array of properties:

$item = Cart::addItem($variant, 1, []);

This will insert an item into the database with [] as the properties. Later, the InteractsWithItems trait will throw an error here:

        return $this->items->first(static function (Item $item) use ($attributes): bool {
            return empty(array_diff(
                Arr::dot($attributes),
                Arr::dot($item->withoutRelations()->toArray())
            ));
        });
        ```
        
   This is because of how `array_diff` handles empty arrays for some reason.