In the last chapter, we implemented the main scenario for a single feature: check available groceries. In order to have an app with minimal functionality, at least two other features, and the respective usecases need to be added: add grocery item and remove grocery item.
From an architecture perspective, adding these usecases is pretty straightforward; there are no new business objects (entities) involved; we just need to manipulate the GroceryItems entity by extending its API with the relevant methods, and implement them.
To add each new use case, we add a New Subproject... to the usecases project, with Qt Creator's Qt Unit Test template:
Once the stub source file for the use case test has been created, we modify the first test slot by adding the steps we are going to implement. We have outlined these steps already in Chapter 1, Writing Acceptance Tests and Building a Visual Prototype, as a premise to building the visual prototype. Here is an...