软件测试---学习笔记
错误分类
Software Fault：A static defect in thesoftware，静态存在于软件中的缺陷（如code写错了）。---程序中的错误代码。
Software Error：An incorrect internalstate that is the manifestation of some fault，软件运行时，运行到fault触发产生错误的中间状态。---错误代码导致的错误状态
Software Failure：External, incorrectbehavior with respect to the requirements or other description of the expected behavior，Error传到软件外部，使得用户或测试人员观测到失效的行为。---错误状态表现出来后被感知
测试能够发现的错误只有Failure级别，即表现出来的错误。程序中处于Error和Fault级别的错误单靠测试难以发现。需要开发自己做白盒测试尽量避免Fault的出现。
PIE模型
1. Execution/Reachability : The location orlocations in the program that contain the fault must be reached，执行必须通过错误的代码。
2. Infection : The state of the programmust be incorrect ，在执行错误代码时必须触发一个错误的中间状态。
3. Propagation : The infected state mustpropagate to cause some output of the program to be incorrect，错误的中间状态必须传播到最后输出，使得观测到的输出结果和预期结果不一致，即失效。
产生fault的程序，可能在测试时不会触发错误的中间状态。同理，触发错误的中间状态可能不会使测试人员观察到失效的行为。
Verification
“The evaluation of whether or not aproduct, service, or system complies with a regulation, requirement,specification, or imposed condition. It is often an internal process.”
Validation
“The assurance that a product, service, orsystem meets the needs of the customer and other identified stakeholders. Itoften involves acceptance and suitability with external customers.”
图覆盖准则
• Syntactic reach : A path exists in thegraph。
• Semantic reach : A test exists that canexecute that path。
语义可行的一定语法可行，但语法可行的不一定语义可行
测试路径Test Path: A path that starts at an initialvertex and ends at a final vertex。Each test executes one and only one testpath
测试准则Test Criteria
• Test Requirements (TR) :Describe properties of test paths
• Test Criterion :Rules that define test requirements
• Satisfaction:Given a set TR of test requirements for acriterion C, a set of tests T satisfies C on a graph if and only if for everytest requirement in TR, there is a test path in path(T) that meets the testrequirement tr。
结构覆盖StructuralCoverage
Vertex Coverage (VC) 点覆盖：Test set T satisfies vertex coverage ongraph G if and only if for every syntactically reachable vertex v in V, thereis a path p in path(T) such that p covers v.
Edge Coverage (EC) 边覆盖：Test set T satisfies vertex coverage ongraph G if and only if for every syntactically reachable edge e in E, there isa path p in path(T) such that p covers e.
Edge-Pair Coverage (EPC) 边对覆盖：TR contains each reachable path of lengthto up 2, inclusive, in G.
Complete Path Coverage (CPC) : TR containsall paths in G.
n-Path Coverage (nPC) : TR contains each reachable path of length up to n, inclusive, in G.
控制流图ControlFlow Graph
•A control flow graph (CFG) is a representation,using graph notation, of all paths that might be traversed through a programduring its execution.
if 、if-return、while、do 、 for 、 break and continue 、 switch。
数据流覆盖DataFlow Coverage
Sets of Def and Use
• def (n) or def (e) :
The set of variables that are defined by node n or edge e
• use (n) or use (e) :
The set of variables that are used by node n or edge e
DU pair :
A pair of locations (li, lj) such that avariable v is defined at li and used at lj
• Def-clear :
A path from li to lj is def-clear with respect to variable v if v is not given another value on any of the nodes or edges in the path
• Reach :
If there is a def-clear path from li to lj with respect to v, the def of v at li reaches the use at lj
• du-path :
A simple subpath that is def-clear with respect to v from a defof v to a use of v
• du (ni, nj, v)
the set of du-paths from ni to nj
• du (ni, v)
the set of du-paths that start at ni
All-defs coverage (ADC) :
For each set of du-paths S = du (n, v), TRcontains at least one path d in S.--全定义覆盖，所有定义的地方都覆盖过
All-uses coverage (AUC) :
For each set of du-paths to uses S = du(ni, nj, v), TR contains at least one path d in S.--全引用覆盖，所有引用的地方都覆盖过，包括所有的定义也都覆盖过
All-du-paths coverage (ADUPC) :
For each set S = du (ni, nj, v), TR contains every path d in S.--全部定义引用覆盖，所有的定义和引用之间的路径都覆盖过
随机测试RandomTesting
Test cases are generated purely at random[SWEBOK v3.0]
–Input domain must be known
–Pick random points within input domain
–Automation
Problems in RT
• Define input domain
• Random mechanism 随机机制
• Randomness and IntegrityService(random.org) 随机性和完整性
自适应随机测试
ART Algorithm
- randomly generate an input t, run t, add tto T
- ·while (stop criteria not reached)
- randomlygenerate k candidate input c1, … ck
- for eachcandidate ci
- compute min distance di to T
- end for
- select onecandidate t with min distance
- run t, add t toT
- end while
Problems in ART
• Distance用例距离
• Sampling用例分布
Anti-Random Testing Process:
1 . Select one test case randomly 选择一条测试用例
2. Select a test case with the maximum Sum of Hamming Distance to existed test cases 从所有可能的测试用例中，选择一条使其与已有测试用例的海明距离之和最大
3. Repeat。。重复第二步，直至发现问题或测试用例总量满足需求或用例耗尽。
EquivalencePartitioning 等价类划分
等价类的划分原则
• 完备性 Complete –等价类的并集应涵盖整个输入域
• 无冗余 NoRedundant –等价类之间互不相交
Boundary-ValueAnalysis 边界值分析
An input variable with equivalent class[Min, Max]
Select
– Min
– Min+
– Nom
– Max-
– Max
CombinatorialTesting 组合测试
- Fixed strength combinatorial testing
- Pair-wise Testing
- t-wise/t-ways Combinatorial Testing
- Variable strength combinatorial testing
Key issue：
- Sampling in all combinations
- Do not consider special information of inputs
DecisionTables 决策表
Decision tables represent logicalrelationships between conditions (roughly, inputs) and actions (roughly,outputs). Test cases are systematically derived … [SWEBOK v3.0]
• 决策表的优点：能够将复杂的问题按照各种可能的情况全部列举出来，简明并避免 遗漏。因此，利用决策表能够设计出完整的测试用例集合。
• 在一些数据处理问题当中，某些操作的实施依赖于多个逻辑条件的组合，即：针对不同逻辑条件的组合值，分别执行不同的操作。决策表很适合于处理这类问题。
决策表的组成
• 决策表通常由以下4部分组成：
– 条件桩—列出问题的所有条件
– 条件项—针对条件桩中条件列出所有可能的取值
– 动作桩—列出问题规定的可能采取的操作
– 动作项—指出条件项各取值情况下应采取的动作
条件桩 条件项
动作桩 动作项
任何一个条件组合的特定取值及相应要执行的动作为一条规则。在决策表中贯穿条件项和动作项的一列是一条规则。
决策表的生成
构造决策表的5个步骤：
（1）确定规则的个数（每个条件取真、假值）
（2）列出所有的条件桩和动作桩
（3）填入条件项
（4）填入动作项，得到初始决策表
（5）简化决策表，合并相似规则
若表中有两条以上规则具有相同的动作，并且在条件项之间存在极为相似的关系，便可以合并
合并后的条件项用符号“-”表示，说明执行的动作与该条件的取值无关，称为无关条件
探索性测试
分类：
1、自由式探索
2、基于场景的探索
3、基于策略的探索
4、基于反馈的探索。
https://www.jianshu.com/p/39a837590a9f
