Test-driven development (TDD) is a software development process characterized by the practice of writing tests prior to writing the actual code. TDD follows a repeated cycle and relies heavily on automated testing.
The cycle commonly associated with TDD consists of three distinct steps:
Write a Test: Start by writing a test for the new function. This test is initially expected to fail, ensuring that the new code is necessary and that the test is effective.
Write Code: Write the minimum amount of code required to pass the test. This step often leads to simplified and efficient coding.
Refactor: Once the test is passed, refactor the code for improvement, ensuring that it remains efficient, clean, and adheres to coding standards. Repeat the cycle for new functionalities.
Improved Code Quality: By writing tests first, developers focus on the desired functionality without over-engineering, often leading to better code quality.
Early Bug Detection: Tests written beforehand help catch errors early in the development process, reducing debugging time and effort later.
Better Design: TDD encourages thinking about the design and architecture of code from the outset, potentially leading to superior design.