Guide to Test-Driven Development

Test-Driven Development (TDD) is a key component of Extreme Programming (XP) and a core aspect of the PMI-ACP certification exam. In this guide, we cover the basics of TDD, its importance, how it operates, and tips on addressing related test questions.

What is Test-Driven Development?
TDD is an approach to development where tests are written before the code. It involves continuously repeating a very short development cycle where the developer writes an automated test case that defines a new function or improvement.

Why is it Important?
TDD helps to reduce the chances of having bugs in the code. It ensures that the code is tested from the start of the project till the end, which improves code quality. It also makes it easier for developers to refactor the code, knowing that tests will capture any broken functionality.

How does it Work?
First, a test is written for a specific functionality. This test will fail because the function has not yet been created. The developer then writes the minimum amount of code to make the test pass. Finally, the code is refactored, and the process starts over.

Exam Tips: Answering Questions on Test-Driven Development
For exam purposes, remember that in TDD, tests are always written first. Understand the cycle - write a test, write code, refactor. Any question about the process of TDD will adhere to this cycle. Also, TDD emphasizes the minimal amount of code necessary to pass tests, encouraging simpler, cleaner designs.
Take note that in TDD, development is oriented towards satisfying tests, which encourages comprehensive testing from the outset and can lead to better software quality. This is a vital concept to grasp for any question related to the rationale or benefits of TDD.