Writing the tests

This is the initial step of the technique, where you have to write the tests that describe a component or feature to be developed. The component can be the user interface, business rule or logic, data persistence routine, or a method implementing a specific user requirement. The tests need to be brief and should contain the required data input and desired outcome expected by the component being tested.

While writing the tests, technically you have solved half of the development task, because the design of the code is usually conceived through the thought pattern and process put into writing the tests. It becomes easier to tackle the difficult code after the easier code, which is the test that has been written. At this point, as a TDD newcomer, the tests are not expected to be 100% perfect or have full code coverage, but with continuous practice and adequate refactoring, this can be achieved.