Scala Reactive Programming

What is TDD?

Test-Driven Development (TDD) means test first, code next. This means, with the TDD approach, we first write the unit test before writing any code. Then, we execute that unit test; it will definitely fail (RED) because we have not written any code.

Next, we write the code to match that unit test (test case) and execute that test again; this time, it will pass (GREEN). Next, we write one more test case (unit test) for the same component, then write the code, and so on. Finally, once we finish writing all test cases and code, we finish the development of that component.

We can illustrate this approach with a diagram:

TDD is a unit ...