To ensure a thoroughly tested code base, we must engage in different types of testing. As touched on already, the unit test enables us to test isolated parts, while the various combinations of parts can be tested via either integration, functional, or E2E tests. It's useful first to understand what we mean when we talk about a part or a unit.
When we talk about a unit of code, there is admittedly a fuzziness to the concept. Typically, it will be a piece of code that has a singular responsibility within a system. When a user wishes to perform an action via our software, they will, in fact, be activating a series of parts of our code, all working together to give the user the output they desire. Consider an app in which users can create and share images. A typical user experience (a flow or journey) may involve a few distinct steps that all involve different...
