Test-Driven Development (TDD) FAQs

Question 1

When should I use the TDD skill?

Accepted Answer

You should use it for all new features, bug fixes, and refactoring. Exceptions are only made for throwaway prototypes, generated code, or configuration files.

Question 2

Can this skill help fix bugs in existing code?

Accepted Answer

Yes. It requires writing a failing test that reproduces the bug before any fix is implemented, ensuring the bug is truly understood and won't regress.

Question 3

How does this skill handle the 'Refactor' phase?

Accepted Answer

After achieving a 'Green' state (passing test), the skill guides you to clean up duplication and improve names without adding new behavior, ensuring the test remains passing.

Question 4

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

Accepted Answer

The Iron Law states that no production code should be written without a failing test first. If code is written before a test, the methodology requires deleting it and starting over.

Question 5

Why does this skill mandate watching a test fail?

Accepted Answer

Watching a test fail (the Red phase) proves that the test is actually checking the intended behavior and that the failure is due to the missing feature rather than a configuration error.

Test-Driven Development (TDD)

Key Features

Use Cases

Test-Driven Development (TDD)

Key Features

Use Cases