est-Driven Development (TDD) is a popular approach to writing software that helps ensure code quality and correctness by writing tests before the actual code. A key concept in TDD is the 3 A’s: Arrange, Act, and Assert. These three steps guide you in writing clear, organized, and effective tests. Let’s break them down:

1. Arrange: Set the Stage

Before you can test anything, you need to set up the scenario. This step involves initializing objects, configuring the environment, and preparing the conditions required for the test. Think of it as getting all your pieces in place before starting the action.

2. Act: Perform the Action

In this step, you perform the action that you want to test. It could be calling a method, sending an input, or triggering some functionality in the code. This is the moment where the system under test does its job.

3. Assert: Check the Results

Finally, you assert that the expected result matches the actual result. This step verifies whether the code behaves as expected, ensuring that your test either passes or fails based on the correctness of the code.