TypeError attempting to save new product without price

[mattstein]

Description

When attempting to save a new product without entering its price, a type error is returned instead of the validation error I’d expect:

TypeError Return value of craft\digitalproducts\elements\Product::getPrice() must be of the type float, string returned

Looks like it needs to be cast as a float for MySQL or that a null value needs to be accounted for.

Steps to reproduce

1. Install Craft with Craft Commerce + Digital Products plugins and create a Product Type.
2. Choose Digital Products → Products → + New Product.
3. Enter some garbage input, specifically leaving Price empty, and choose Save.
4. Observe the resulting type error.
5. Go back and add a numeric value for Price, then choose Save.
6. Observe the element detail view (as expected) where the empty SKU has a validation error (“Sku cannot be blank.”) as expected.
7. Add the SKU and save, just for good feels and a sense of completion.

Additional info

• Craft version: 3.5.15.1
• PHP version: 7.3.20, 7.4.8
• Database driver & version: MySQL 5.5.5
• Plugins & versions: Digital Products 2.4.1, Commerce 3.2.10.1

[mattstein]

^ Tested + submitted a stunning PR.