## Test-Driven Development (TDD) The goal of TDD is to have a detailed specification of the code you're going to write, which helps to clarify the requirements and design before you start coding. It also leads to a robust suite of unit tests that can help prevent future regressions. 1. **Write a test:** Before you write functional code, you write a test for the functionality you want to implement. At this point, the test will fail because the functionality doesn't exist yet. 2. **Write the code:** You then write the minimum amount of code necessary to pass the test. This might not be the perfect or final version of the code, but it's enough to pass the test. 3. **Refactor:** Once the test passes, you refine and optimize the code while ensuring that the test still passes. This step allows you to improve the code's structure and performance without changing its behavior. 4. **Repeat:** The cycle then repeats for the next piece of functionality.