条件覆盖和判定.PPT

7.5 Glass-Box Unit-Testing Techniques We will examine Statement coverage (语句覆盖) Branch coverage (分支覆盖) Term Coverage(条件覆盖) Branch Coverage plus Term Coverage(分支/条件覆盖) Term combination Coverage (条件组合覆盖) Path coverage (路径覆盖) Statement coverage: Running a set of test cases in which every statement is executed at least once (运行一系列测试用例,使每个语句最少执行一次) A CASE tool needed to keep track Statement coverage (cont) 2. Branch Coverage (分支覆盖) Running a set of test cases in which every branch is executed at least once (分支覆盖,又称判定覆盖,即运行一系列测试用例,使每个分支最少执行一次) Branch Coverage(cont) Running a set of test cases in which every term is executed at least once (运行一系列测试用例,使每个条件最少执行一次) Term Coverage(cont) Term Coverage(cont) Running a set of test cases in which every term is executed at least once and every branch is executed at least once too (判定／条件覆盖就是设计足够的测试用例，使得判定中的每个条件都取到各种可能的值，而且每个判定表达式也都取到各种可能的结果) Branch Coverage plus Term Coverage(cont) Running a set of test cases in which every term’s combination is executed at least once (条件组合覆盖就是设计足够的测试用例，使得每个判定中的条件的各种可能组合都至少出现一次。) 6. Path Coverage (路径覆盖) Running a set of test cases in which every path is executed at least once (设计足够的测试用例，使得每个路径都至少执行一次。) Problem: The number of paths may be very large 显然，满足条件组合覆盖的测试数据，也一定满足判定覆盖、条件覆盖和判定／条件覆盖标准。 但是，满足条件组合覆盖标准的测试数据并不一定覆盖了程序中的每条路径，例如，利用上述四组测试数据就遗漏了路径P4（acd）。 7.6 Code Walkthroughs and Inspections (代码走查和审查) Code reviews lead to rapid and thorough fault detection Up to 95 percent reduction in maintenance costs Slide 7.* 1. Statement coverage (语句覆盖) 程序段中共有4条路径： P1（ace）、P2（abd）、 P3（abe）、P4（acd）。 语句覆盖不能发现判断中的逻辑运算中的错误。第一个判断中的逻辑运算符“”若错写成了“||”，利用上面的输入数据则检查不出这个错误。 P1正好满足语句覆盖的条件。可以设计如下的输入数据： A＝2，B＝0，x＝4 Both statements can be executed w