Test-Driven Development (TDD) FAQs

Question 1

When can I skip TDD using this skill?

Accepted Answer

TDD is mandatory for new features, bug fixes, and refactoring. Exceptions are only made for throwaway prototypes, generated code, or configuration files after consulting with a human partner.

Question 2

What is the 'Refactor' phase in this skill?

Accepted Answer

After the code passes the test (Green), the Refactor phase allows for cleaning up duplication and improving names while ensuring the tests remain passing without adding new behavior.

Question 3

Why must I watch a test fail before writing code?

Accepted Answer

Watching a test fail confirms that the test is valid and actually testing the intended behavior. If a test passes immediately, it proves nothing about the new code's necessity or correctness.

Question 4

How does TDD help with bug fixing?

Accepted Answer

For every bug, you must first write a test that reproduces the failure. This ensures the bug is understood, provides proof of the fix, and prevents future regressions.

Question 5

What is the 'Iron Law' of 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 a test, it should be deleted and rewritten following the TDD cycle.

Test-Driven Development (TDD)

Key Features

Use Cases

Test-Driven Development (TDD)

Key Features

Use Cases