This is a sequenced workflow used in [[Test Driven Development (TDD)|TDD]] for creating tests and the application code.
The red, green, refactor approach helps developers compartmentalize their focus into three phases: [^fn1]
[^fn1]: [REdGreenRefactor TDD](https://www.codecademy.com/article/tdd-red-green-refactor)
- Red — think about _what_ you want to develop. You implement the test case and ensure it fails. This checks that you haven't a bug in your test which would allow it to allows pass
- Green — think about _how_ to make your tests pass. You implement the application code being tested and ensure your test case passes.
- Refactor — think about _how_ to improve your existing implementation.