Test-Driven Development

Test-Driven Development (TDD) is perhaps the most important Extreme Programming (XP) rule that we practice.

Business benefits of TDD:

• Deliver more value, faster
• Always ship working software
• Adapt to change quickly

Code benefits of TDD:

• Readable specs and code
• Clean public interfaces
• Decoupled modules

Process benefits of TDD:

• Regression safety net
• Fearless refactoring
• Team trust

At a high level, how to test is very simple:

• Write test first.
• Red-Green-Refactor cycle.