Why Your Excel VBA Code Can’t Be Tested : And How To Fix It

Why Your VBA Code Can’t Be Tested

Unlock the full potential of VBA development with this comprehensive guide to unit testing and testable code architecture. Whether you’re a seasoned VBA developer or just starting out, this book will show you how to implement best practices like abstractions, interfaces, dependency injection, mocking**, and class factories** to make your code cleaner, more flexible, and easy to test.

You’ll learn how to:
– Write maintainable VBA code that can be tested in isolation.
– Build real-world projects that use **conditional compilation** to switch between production and testing environments seamlessly.
– Structure your code using interfaces*and class factories to separate logic and data, ensuring your VBA applications are adaptable and scalable.
– Implement mocking techniques to simulate dependencies like file systems, APIs, or databases in tests.
– Apply all these concepts to build a robust discount calculator with real and mock data providers.

With hands-on examples, clear explanations, and practical techniques, this book will transform how you write and test your VBA code. Whether you’re working on a small project or large-scale VBA application, this guide will help you build high-quality, reliable, and easily testable code that stands the test of time.

The code for the example project can be downloaded and there is a link to an accompanying video.