Introduction to unit testing fundamentals

Before getting on to understanding key aspects of JUnit 5, let's try and understand some of the basic concepts around unit testing. In this section, the following will be dealt with:

• What is unit testing?
• Why write unit tests?
• Unit testing naming conventions

What is unit testing?

Simply speaking, unit testing is about testing a block of code in isolation. This essentially means that any dependency within the code will be mocked, and it is just the block of code which will be tested. In case the dependencies are not mocked, the block of code tested along with dependencies forms part of what can be called integration testing. On similar lines, Martin Fowler states that unit...