[Cart Operations] Add virtual product to Cart

[misha-kotov]

As a Magento developer, I need to manipulate the shopping cart via GraphQL so that I can build basic ecommerce experiences for shoppers on the front-end using only GraphQL.

GraphQL needs to provide sufficient mutations (ways to create/update/delete data) for a developer to build out the storefront checkout experience for a shopper.

Use cases:

• Both guest and registered shoppers can add virtual products to cart

Acceptance criteria:

• Cart operations should be useable in both standard Cart and mini-cart
• GraphQL provides the following mutations:
  • addCartItems
• All product types are supported in a modular way (e.g. configurable-related schema and resolvers must be declared in ConfigurableProductGraphQl module and the rest of the system should still work if this module is disabled)
• Depending on token in Authorization header (if any), customer or guest service contract should be used
• Changes are covered with web API functional tests. See \Magento\GraphQl\TestModule\GraphQlMutationTest::testMutation as an example.

Proposed schema

My Account area impacted:

• Cart
• Minicart

[naydav]

#320