本系列文章主要讨论四个问题：为什么需要单元测试？怎样征服可测性难题？怎样才能高效率测试？怎样保证测试效果？重点阐述单元测试的关键问题，不是一般概念，适合于对单元测试有一定了解的读者。



在选择工具和实施单元测试前，我们应该对相关理论有一个系统的了解，特别是将会遇到哪些难题，如何解决，要心里有数，否则的话，很可能劳民伤财，半途而废。如果只会测试加法函数或者三角形函数之类的独立小程序，就以为可以做单元测试了，那就像一个人刚学会走路，就去长途跋涉。



本文介绍的是针对企业项目的单元测试。企业项目具有两个特点：项目复杂，时间紧张。项目复杂，意味着测试时会遇到很多难题；时间紧张，要求我们不但要保证测试效果，还要尽可能高效率。本文不是泛泛而谈，而是针对企业项目的两个特点，努力揭示本质性的问题，并提出解决办法，对于常识性的问题，将比较简略的带过。-　　This series focuses on four questions: Why do we need unit tests? How to conquer the testability problem? How can high-efficiency test? How to ensure test results? Unit testing focuses on the key issues, not the general concept, suitable for unit testing has some understanding of the reader.



　　In the choice and implementation of unit test tools, we should have a systematic theories to understand, especially the problems will be encountered, how to resolve, to know what s what, otherwise, it is likely a waste of resources by the wayside. If you only test the addition function or triangular function like independent small programs that can be done on the unit test, that learned how to walk like a man, go a long distance.



　　This article is for enterprise project unit test. Enterprise Project has two characteristics: project complexity, time constraints. Complexity of the project, which means the test will encounter many difficulties　time constraints, we are required not o