Kevlin Henney
Kevlin Henny is an independent consultant, speaker, writer and trainer. Kevlin has trained a few thousand developers so far. He has contributed to open- and closed-source codebases, been a columnist for a number of magazines and sites and has been on far too many committees. He is co-author of A Pattern Language for Distributed Computing and On Patterns and Pattern Languages, two volumes in the Pattern-Oriented Software Architecture series. He is also editor of 97 Things Every Programmer Should Know and the forthcoming 97 Things Every Java Programmer Should Know. He lives in Bristol and online.


Many developers, teams, and organizations have come to value the feedback that unit tests offer their development. But it’s not always clear that the value they receive matches the full potential that unit tests can deliver. Many test suites suffer from high technical debt and brittle unit tests. Many tests are written for the build process to execute, but not necessarily for developers to understand. Many tests are more of a mystery than a guide to the code they test. This session will highlight common test smells and misunderstandings about unit testing that hold developers back. By considering unit testing to be as much an exercise in communication as verification, this training will outline what makes for good unit tests (GUTs) and illustrate it with code examples in a few languages.