Test-Driven Development (TDD) FAQs

Question 1

How does the Red-Green-Refactor cycle work here?

Accepted Answer

First, you write a failing test (Red). Second, you write the minimal code necessary to make that test pass (Green). Finally, you clean up and optimize the code while keeping the tests passing (Refactor).

Question 2

Does this skill work with existing codebases?

Accepted Answer

Yes. While it prioritizes TDD for new features, it provides guidance on adding tests for existing code to facilitate safe improvements and refactoring.

Question 3

Why does this skill insist on writing tests before code?

Accepted Answer

Writing tests first ensures you are testing the required behavior rather than just confirming the implementation you already wrote. It proves the test is capable of catching a failure before any code is added.

Question 4

Can I use this TDD skill for bug fixes?

Accepted Answer

Yes. When a bug is found, you first write a failing test that reproduces the issue. You then follow the TDD cycle to implement the minimal fix, which also prevents future regressions.

Question 5

What is the 'Iron Law' enforced by this skill?

Accepted Answer

The Iron Law states: 'No production code without a failing test first.' If code is written before a test, the skill advises deleting it and starting over to ensure the integrity of the TDD process.

Test-Driven Development (TDD)

主な機能

ユースケース

Test-Driven Development (TDD)

主な機能

ユースケース