Unit Testing has moved from fringe to mainstream, which is a great thing. Unfortunately, as a side effect developers are creating mountains of unmaintainable tests. I've been fighting the maintenance battle pretty aggressively for years, and I've decided to write a book that captures what I believe is the most effective way to test.
From the Preface
Over a dozen years ago I read Refactoring for the first time; it immediately became my bible. While Refactoring isn’t about testing, it explicitly states: If you want to refactor, the essential precondition is having solid tests. At that time, if Refactoring deemed it necessary, I unquestionably complied. That was the beginning of my quest to create productive unit tests.
Throughout the 12+ years that followed reading Refactoring I made many mistakes, learned countless lessons, and developed a set of guidelines that I believe make unit testing a productive use of programmer time. This book provides a single place to examine those mistakes, pass on the lessons learned, and provide direction for those that want to test in a way that I’ve found to be the most productive.
The book does touch on some theory and definition, but the main purpose is to show you how to take tests that are causing you pain and turn them into tests that you're happy to work with.
For example, the book demonstrates how to go from...
looping test with many (built elsewhere) collaborators
.. to individual tests that expect literals, limit scope, explicitly define collaborators, and focus on readability
.. to fine-grained tests that focus on testing a single responsibility, are resistant to cascading failures, and provide no friction for those practicing ruthless Refactoring.
As of right now, you can read the first 2 chapters for free at https://leanpub.com/wewut/read
I'm currently ~25% done with the book, and it's available now for $14.99. My plan is to raise the price to $19.99 when I'm 50% done, and $24.99 when I'm 75% done. Leanpub offers my book with 100% Happiness Guarantee: Within 45 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks. Therefore, if you find the above or the free sample interesting, you might want to buy it now and save a few bucks.
Buy Now here: https://leanpub.com/wewut