TTD (Test-Drive Development) is a special software development technique when the whole development is divided into many small cycles: first, tests are written that cover the desired change, then code is written that passes these tests. After that, this code is refactored, and, if necessary, new tests are written. If a piece of code fails some tests, this is fixed.
One of the most important reasons why programmers switch to TDD is that this methodology improves the coverage of tests with code,
which leads to 40-80% fewer errors in production. In other words, development through testing is a set of unit tests that you can run at any stage to make sure that the software is still working. This takes a load off developers’ hands.
Tools
TDD should be combined with good tools. An IDE is required, such as Eclipse with native JUnit support. Plugins are highly recommended to facilitate the management of unit tests like MoreUnit and Infinitest. The latter automatically performs all unit tests with every code change, which reduces feedback loops, which also lay the foundation for continuous unit tests. Using code templates for unit tests, on the other hand, is an important time-saver in a repeating TDD cycle. At the code level, a Builder design pattern is required to create readable and flexible business objects.
But be careful – TDD is not a panacea. For example, if the development is a sequence of experiments when there is no clear confidence in what is necessary for the end, writing tests will become more of a burden that pulls the team back.
TDD primarily leads to improved code coverage with tests. The reason for this is that we do not start writing the code
for implementing some features until we write a test that checks the correct operation of this future code. Firstly, we write a test. Then we allow it to end with an error. Then we write the code for implementing the opportunity. We are testing the code, we receive an error message, we achieve the correct passing of the tests, we perform refactoring and repeat this process.
