# Test-Driven Development

In test-driven development you write a failing test first, then just enough code to pass it, then tidy up. Follow three short cycles that build a shipping calculator.

![Cheat sheet: Test-Driven Development](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/11/44559d960e9143509abea7e252063d30.webp)

- Category: C#
- Level: Apprentice
- Tags: "Red", "Green", "Refactor", c-sharp, Passing and Failing Tests, Test-Driven Development, unit testing
- Updated: November 3, 2026

Source: https://www.ask-codey.com/cheat-sheets/unit-testing-with-mstest-test-driven-development-cheat-sheet