White box testing use knowledge of the code to provide clues as to what should be tested and how to test it.
测试目的：
缺陷disadvantages：
1. 测试者主观性很强
静态白盒
读代码找错
动态白盒
又称为结构测试，利用查看代码功能（做什么）和实现方式（怎么）得到的信息来确定哪些需要测试、哪些不需要测试、如何开展测试。Using information you gain from seeing what the code does and how it works to determine what to test, what not to test, and how to approach the testing
The four areas that dynamic white box testing encompasses are:
1.Directly test the pieces- the low-level functions, procedures,subroutines or libraries.
2. Do top level(整体) testing of the completed program, but choose test cases by knowledge of the code.
3.Directly access variables and state information and force the software to do things.
4. Measure how much of the code has been tested and be able to adjust your tests to remove redundant test cases and add missing ones.
Why dynamic black-box testing is not enough?
It's difficult and sometimes impossibl to figure out exactly what caused the problem
Some bugs hide others, it's impossible to get to the core fault.
单元测试unit testing
测试接口
unit testing cases
要关注接口，本地数据储存，临界条件，
Interface: ensures that information properly flows in and out of the component
local data structures: ensures that data stored temporarily maintains its integrity during execution
boundary conditions: ensures that the component operates properly at boundaries established to limit or restrict processing
independent paths: ensures that all paths in a component have been executed at least once
error-handling paths: ensures that errors are correctly handled
driver（驱动）：下层模块开发完毕，但上层模块没有完成时使用。Drivers hook in exactly the same way that the future real modules will. Drivers are calling Functions in Bottom Up Integration
stub（桩程序）：上层模块开发完毕，但下层模块没有完成时使用。Stubs simulate the behaviors of the low-level modules. Stubs are called Functions in Top Down Integration
整体测试integration testing
bottom up model
优点
Popular approach
Is useful when many of low-level components are general purpose utility routine that are invoked often by others
IntIntegrated test by component driver
Test data and test cases are created easily
缺点
顶部组件问题发现会延时
不易发现设计上的错误
top down model
优点
最重要的组件会被最早测试
应用于顶层设计
不用驱动程序
逻辑结构清晰
缺点
要大量桩程序
很难单独测试各个组件
代码覆盖code coverage
是一种动态白盒测试，检测软件运行时被执行的代码，与测试案例有关
代码覆盖率分析器code coverage analyzer
Statement coverage or line coverage（语句覆盖）
the basic idea:make sure that every statement in the program executes at least once
Branch coverage（判定覆盖或分支覆盖）
The basic idea: make sure that every branch in the program executes at least once
Condition coverage（条件覆盖）
Branch condition coverage（判定﹣条件覆盖）
Condition combination coverage（条件组合覆盖）
Path coverage（路径覆盖）
cfg（control flow graph，控制流图）
要结果所有状态，要用节点的合并
