What Is Unit Testing?

Unit testing

Unit testing is a software development process in which the smallest testable parts of the system are individually analyzed to guarantee that they’re acting as expected. It’s an important step in the development process, and if done correctly, unit tests can detect early flaws in code, which may be more difficult to find in later testing stages.

Unit tests are typically isolated to ensure a unit doesn’t rely on any external code or functions, which makes us recall one of the principles of functional programming about pure functions. Unit tests should be treated as deliverables in the development process. Moreover, they should be automated to run whenever a new feature is implemented. This way, we’re able to ensure that the current changes haven’t broken the previous features.

How unit tests work

A unit test comprises three stages:

1. Planning: This involves defining the scenarios in which we need to guarantee our code is working ...