Welcome to your third unit of this course dedicated to practicing Test Driven Development (TDD) utilizing Scala and ScalaTest. We will begin building a new system; this time, we’ll focus on creating a shopping cart system with a variety of features.

In this course, emphasis is placed on hands-on practice, where you'll receive requirements through tests, one at a time. Your task is to write tests and implement Scala 3 code that makes each test pass, simulating a real-world TDD environment. Unlike previous exercises, where tests were supplied, this time you're in charge!

Remember to utilize the core concepts of the Red-Green-Refactor cycle while working through these exercises. Assistance is available, so don't hesitate to ask for help.

The following requirements outline the foundational functionality of the ShoppingCart class, providing step-by-step guidance to build and test its key features while practicing TDD principles in Scala.

Each requirement focuses on a specific aspect of the shopping cart's behavior, ensuring a comprehensive and modular approach to its development and testing.

• Description: When a new ShoppingCart is created in Scala, it should start without any items, and the total price should be zero.
• Details
  • Initialize a new shopping cart using the ShoppingCart constructor (e.g., val cart = new ShoppingCart()).
  • Ensure the method getItemCount() returns 0 for an empty cart.
  • Verify the method getTotal() returns 0 for the initial state.
• Examples: A newly created cart should have an item count of 0 and a total price of 0.

• Description: Verify that adding a single item to the cart increases the item count and adjusts the total price to include the price of the added item.
• Details
  • Add an item to the cart using the addItem(item: Product) method (or similar).
  • Confirm that getItemCount() reflects the change in the number of items.
  • Ensure getTotal() accurately accounts for the total price of items in the cart.
• Examples: Adding an Item with Id = "1", Name = "Book", and Price = 10 should result in an item count of 1 and a total of 10.