Test-Driven Development (TDD) FAQs

Question 1

When should I use the TDD skill?

Accepted Answer

You should use it for almost every coding task, including new features, bug fixes, refactoring, and behavior changes, to ensure code reliability and systematic documentation.

Question 2

Can I use mocks with this TDD skill?

Accepted Answer

The skill encourages testing real code and behavior whenever possible. Mocks are supported but should only be used when dependencies make direct testing unavoidable.

Question 3

What is the 'Iron Law' in this TDD skill?

Accepted Answer

The Iron Law dictates that no production code should be written without a failing test first; if code is written before the test, the skill mandates deleting that code and starting fresh.

Question 4

What is the Red-Green-Refactor cycle?

Accepted Answer

It is a three-step process: Write a failing test (Red), write the minimal amount of code to make the test pass (Green), and then clean up the code (Refactor) without changing its behavior.

Question 5

Why is writing the test before the code so important?

Accepted Answer

Writing tests first ensures the test actually works (by watching it fail), defines the desired behavior instead of the current implementation, and prevents the developer from testing only what they remembered to build.

Test-Driven Development (TDD)

Key Features

Use Cases

Test-Driven Development (TDD)

Key Features

Use Cases