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)

The test pyramid

Let’s start the discussion about testing along the lines of the test pyramid1 in Figure 8.1, which is a metaphor that helps us to decide on how many tests of which type we should aim for.

1 The test pyramid can be traced back to Mike Cohn’s book Succeeding with Agile from 2009.

Figure 8.1 – According to the test pyramid, we should create many cheap tests and fewer expensive ones

Figure 8.1 – According to the test pyramid, we should create many cheap tests and fewer expensive ones

The basic statement of the pyramid is that we should have high coverage of fine-grained tests that are cheap to build, easy to maintain, fast-running, and stable. These are unit tests that verify that a single unit (usually a class) works as expected.

Once tests combine multiple units and go across unit boundaries, architectural boundaries, or even system boundaries, they tend to become more expensive to build, slower to run, and more brittle (failing due to some configuration error instead of a functional error). The pyramid...