《测试驱动开发》(中文版)设想把编程看成是转动曲柄从井里提一桶水上来的过程。如果水桶比较小，那么仅需一个能自由转动的曲柄就可以了。如果水桶比较大而且装满水，那么还没等水桶全部被提上来你就会很累了。你需要一个防倒转的装置，以保证每转一次可以休息一会儿。水桶越重，防倒转的棘齿相距越近。测试驱动开发中的测试程序就是防倒转装置上的棘齿。一旦我们的某个测试程序能工作了，你就知道，它从现在开始并且以后永远都可以工作了。相比于测试程序没有通过，你距离让所有的测试程序都工作又近了一步。现在我们的工作是让下一个测试程序工作，然后再下一个，就这样一直进行。分析表明，要编程解决的问题越难，每次测试所覆盖的范围就应该越小。

Foreword by Kent Beck "The authors of this book have led a revolution in the craft of programming by controlling the environment in which software grows." --Ward Cunningham "At last, a book suffused with code that exposes the deep symbiosis between TDD and OOD. This one's a keeper." --Robert C. Martin "If you want to be an expert in the state of the art in TDD, you need to understand the ideas in this book."--Michael Feathers Test-Driven Development (TDD) is now an established technique for delivering better software faster. TDD is based on a simple idea: Write tests for your code before you write the code itself. However, this "simple" idea takes skill and judgment to do well. Now there's a practical guide to TDD that takes you beyond the basic concepts. Drawing on a decade of experience building real-world systems, two TDD pioneers show how to let tests guide your development and "grow" software that is coherent, reliable, and maintainable. Steve Freeman and Nat Pryce describe the processes they use, the design principles they strive to achieve, and some of the tools that help them get the job done. Through an extended worked example, you'll learn how TDD works at multiple levels, using tests to drive the features and the object-oriented structure of the code, and using Mock Objects to discover and then describe relationships between objects. Along the way, the book systematically addresses challenges that development teams encounter with TDD--from integrating TDD into your processes to testing your most difficult features. Coverage includes * Implementing TDD effectively: getting started, and maintaining your momentum throughout the project * Creating cleaner, more expressive, more sustainable code * Using tests to stay relentlessly focused on sustaining quality * Understanding how TDD, Mock Objects, and Object-Oriented Design come together in the context of a real software development project * Using Mock Objects to guide object-oriented designs * Succeeding where TDD is difficult: managing complex test data, and testing persistence and concurrency