TDD

TDD is a software development approach in which tests are written before the actual code. The process involves iterative cycles: write a small unit test, run it (expecting it to fail initially), then write the code to make the test pass, and finally refactor the code while ensuring that all tests continue to pass. This cycle is often summarized as Red-Green-Refactor.

The reason why TDD is needed is that it enables early detection of defects, helps produce clearer requirements, facilitates incremental development, and enables developers to refactor with confidence.

By writing tests before writing the actual code, developers are forced to consider the desired functionality and potential edge cases. This helps catch defects at an early stage, reducing the cost and effort required for debugging later in the development cycle.

Writing tests before code encourages developers to think through the requirements and expected behavior of the system. This results in clearer and more...