Book Image

Get Your Hands Dirty on Clean Architecture

By : Tom Hombergs
Book Image

Get Your Hands Dirty on Clean Architecture

By: Tom Hombergs

Overview of this book

Building for maintainability is key to keeping development costs low and processes easy. The second edition of Get Your Hands Dirty on Clean Architecture is here to equip you with the essential skills and knowledge to build maintainable software. With this comprehensive guide, you’ll explore the drawbacks of conventional layered architecture and the advantages of domain-centric styles such as Robert C. Martin's Clean Architecture and Alistair Cockburn's Hexagonal Architecture. Then, you’ll dive into hands-on explanations on how to convert hexagonal architecture into actual code. You'll learn in detail about different mapping strategies between the layers of hexagonal architecture and discover how to assemble the architectural elements into an application. Additionally, you’ll understand how to enforce architecture boundaries, which shortcuts produce what types of technical debt, and how, sometimes, it is a good idea to willingly take on those debts. By the end of this second edition, you'll be armed with a deep understanding of the hexagonal architecture style and be ready to create maintainable web applications that save money and time.
Table of Contents (13 chapters)

How Much Testing is Enough?

A question many project teams I have been part of couldn't answer is how much testing we should do. Is it enough if our tests cover 80% of our lines of code? Should it be higher than that?

Line coverage is a bad metric to measure test success. Any goal other than 100% is completely meaningless because important parts of the codebase might not be covered at all. And even at 100%, we still can't be sure that every bug has been squashed.

I suggest measuring test success by how comfortable we feel to ship the software. If we trust the tests enough to ship after having executed them, we are good. The more often we ship, the more trust we can have in our tests. If we only ship twice a year, no one will trust the tests because they will only prove themselves twice a year.

This requires a leap of faith the first couple of times we ship, but if we make it a priority to fix and learn from bugs in production, we are on the right track.

For each production bug, we should...