Test-Driven Development (TDD) is a discipline that can transform the quality of your code. By writing tests before you write the implementation, you clarify your requirements and build a safety net for future refactoring.
This post introduces the “Red-Green-Refactor” cycle and demonstrates how to apply it to a real-world Swift feature. We’ll cover mocking dependencies, writing effective assertions with XCTest, and building confidence in your codebase.