Book Image

Get Your Hands Dirty on Clean Architecture - Second Edition

By : Tom Hombergs
4 (1)
Book Image

Get Your Hands Dirty on Clean Architecture - Second Edition

4 (1)
By: Tom Hombergs

Overview of this book

Building for maintainability is key to keep development costs low (and developers happy). 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. Building upon the success of the first edition, this comprehensive guide explores the drawbacks of conventional layered architecture and highlights the advantages of domain-centric styles such as Robert C. Martin's Clean Architecture and Alistair Cockburn's Hexagonal Architecture. Then, the book dives into hands-on chapters that show you how to manifest a Hexagonal Architecture in actual code. You'll learn in detail about different mapping strategies between the layers of a Hexagonal Architecture and see how to assemble the architecture elements into an application. The later chapters demonstrate how to enforce architecture boundaries, what 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. Whether you're a seasoned developer or a newcomer to the field, "Get Your Hands Dirty on Clean Architecture" will empower you to take your software architecture skills to new heights and build applications that stand the test of time.
Table of Contents (18 chapters)

Testing main paths with system tests

At the top of the pyramid are what I call system tests. A system test starts up the whole application and runs requests against its API, verifying that all our layers work in concert.

Hexagonal Architecture is all about creating a well-defined boundary between our application and the outside world. Doing so makes our application boundaries very testable by design. To test our application locally, we just need to swap out the adapters with mock adapters, as outlined in Figure 8.2.

Figure 8.2 – By replacing the adapters with mocks, we can run and test our application without dependencies on the outside world

Figure 8.2 – By replacing the adapters with mocks, we can run and test our application without dependencies on the outside world

On the left, we can replace the input adapters with a test driver that calls the application’s input ports to interact with it. The test driver can implement certain test scenarios that simulate user behavior during an automated test.

On the right, we can replace the output adapters with mock adapters...