软件测试 Software Tes.ppt

SoftwareTesting Chapter1SoftwareTestingIntroduction Contents 1 1WhySoftwareTestingisNeeded1 2BasicConceptsofSoftwareTesting1 3ReasonofSoftwareDefect1 4RelationshipbetweenSoftwareDevelopmentandTesting1 5SoftwareTestingRules1 6CapabilityforSoftwareTester 1 1WhySoftwareTestingisNeeded 1 1WhySoftwareTestingisNeeded 1 1WhySoftwareTestingisNeeded InfamoussoftwareerrorcasestudiesWorldWarIII Almost 1983 PatriotMissileBug 1991 Killing28soldiersandinjuringaround100otherpeopleMultidataSystems 2000 Atleast8patientsdie whileanother20receiveoverdoses 1 1WhySoftwareTestingisNeeded QualifiedrateofproductsQualifiedrateofairplanemanufacturingindustry Aerobus747 400 aremadeupof1000 000partsQualifiedrateofeverypart 99 9999 Doyouknowthequalifiedrate 99 9999 1000000 36 79 1 1WhySoftwareTestingisNeeded QualifiedrateofproductsQualifiedrateofsoftwareCodingline 99 Write10 000linescodeDoyouknowthequalifiedrate 99 10000 2 25 10 44 1 2BasicConceptsofSoftwareTesting ConceptsrelatedtosoftwaretestingError 错误 occursintheprocessofwritingaprogram Fault 故障 isthemanifestation 表现 ofoneormoreerrors Failure 失效 occurswhenfaultypieceofcodeisexecutedleadingtoanincorrectstatethatpropagates 传播 totheprogram soutput Incident 事故 nomessageisdisplayedwhenfailureoccurs Defect 1 2BasicConceptsofSoftwareTesting Softwaredefect 缺陷 definitionOutofaccordwithuserexpectancy 期望 SoftwarefunctioncanbeexecutedincorrectlyDefectofSoftware BugAllkindsofsoftwareproblemsInconsistency userinterfacefault 1 2BasicConceptsofSoftwareTesting Defectexample Shortcoming runningslowly Inconsistency Ctrl Scan tsaveallapplications Userinterfacedesigndefect anbuttonshouldshow5wordsonit butonly3wordscouldbeseen 1 2BasicConceptsofSoftwareTesting ConceptsrelatedtosoftwaretestingCorrectprogramNosyntaxerrorNoobviouserrorsduringrunningNoimproperstatementsValidinput correctoutputInvalidinput correctoutputAnypossibleinput correctoutput 1 2BasicConceptsofSoftwareTesting ConceptsrelatedtosoftwaretestingTest debugAutomatedtestvs manualoperateDon tknowdetailsareOKvs mustknowdetailsCorrectnessproofandhowtodowithfailurevs correctnessproofonlyCheckingvs reasoningPlan undercontrolvs outofcontrol测试条件已知 规程可定义 结果可预知测试可以计划 过程可控 调试不可控测试是检验 调试是推理过程测试除了表明程序正确还要验证程序如何处理失败 调试表明正确测试可不了解设计细节 调试必须了解设计细节测试可自动化 调试无法自动化 1 2BasicConceptsofSoftwareTesting SoftwaretestingdefinitionSoftwaretestingistheessentialstepwhichisplannedandsystematicWecanknowwhethertheusersexpectationsarerealizedSoftwaretestingisthekeystepofsoftwarequalityassurance 1 2BasicConceptsofSoftwareTesting SoftwaretestpurposeFinderrorsofsoftwareDecreasetheriskofsoftwaredoesn twork 1 3ReasonofSoftwareDefect 1 3ReasonofSoftwareDefect Reasonsofdefect DeviatefromuserrequirementsRequirementreportchangedoftenImplementextrafunctionsFunctionmiss 1 4RelationshipbetweenSoftwareDevelopmentandTesting 1 4RelationshipbetweenSoftwareDevelopmentandTesting Defectscanbeimportedfromanyphraseduringsoftwaredevelopment andtheywillbeamplified 1 5SoftwareTestingRules Infinitetestisimpossible 1 5SoftwareTestingRules Good enough80 20 1 5SoftwareTestingRules Wholetestcases validdata invaliddata PredicttheoutcomeoftestcaseTestindependentlyProblemsgobeyondspecificationcan tbeignoredRegressiontestRandomtestshouldbeavoided 1 5SoftwareTestingRules TestpassingrulesWhetheralltestcasesareexecuted Whetherfunctiondesignisfinished Whetherwegetenoughbugs 1 6CapabilityforSoftwareTester TechniqueabilityCommunicationabilitySuspicionConfidencePatienceAnalysisabilityCooperation SoftwareTesting Chapter2FunctionalTesting Contents 2 1BasicConcepts2 2EquivalencePartitioning2 3BoundaryValueAnalysisTesting2 4CauseEffectGraphing2 5DecisionTables2 6OrthogonalTest 2 1BasicConcepts Whatistestcase Itistestdatadesignedforspecialpurpose Asetofspecialcongregation 集合 relatetotestprocess Thesmallestunittoeffectivelyfindoutsoftwaredefects 2 1BasicConcepts ImportanceoftestcaseEffectiveReusableOrganizeeasilyEvaluativeManageable 2 1BasicConcepts FactorsshouldbeconsideredTypicalReflectsystemdesignCorrectinput errororexceptionalinputandanalysiswhyerroroccursUsers realsituation 2 1BasicConcepts RulestestcasedesignAvoidvaguetestcaseSimilarfunctionsshouldbeabstractedandclassifiedAvoidcomplicatedtestcase 2 1BasicConcepts Black boxtestingisalsocalledfunctionaltesting datadriventesting Itisatestformuser sview Itisappliedtorapiddevelopment software input output 2 1BasicConcepts Functionaltestingintenttofindout FunctionincorrectormissUserinterfaceerrorDatabaseaccesserrorPerformanceerrorInitializationerrorandenderror 2 1BasicConcepts Functionaltestingcananswer Howtotesttheefficiencyoffunction Whatkindofinputwillmakegoodtestcase Whetherthesystemsensitivetosomespecialinputs Howtofindouttheboundaryofdataclasses Howmanydatacanbeenduredbythesystem Thecombinationofspecialdatawillinfluencethesysteminwhatway 2 1BasicConcepts Intheory iffunctionaltestingisusedtofindprogramerrors allkindsofpossibleinputconditionsandoutputconditionsshouldbeneeded Butitisimpossibleforustodothat 2 1BasicConcepts SupposeaprogramPhasinputs XandY andoutput Z Itrunatacomputerwith32bits ifXandYareinteger howmanytimeisneeded 1groupdata ms 232 232 365 24 60 60 1000 5亿年 2 1BasicConcepts TestmethodsEquivalenceclasstestingBoundaryvalueanalysistestingCauseeffectgraphingDecisiontabletestingOrthogonaltestSpeculationScenariotesting 2 2EquivalenceClassTesting EquivalenceclasspartitionmethodAtypicalblack boxtestingmethod Onlyrequirementspecificationisneededtodesigntestcase Partitionallpossibledataintoseveralparts thenusesometypicaldataacquiredfromthemastestcases Sowecanuselessdatatogetbettertestresult 2 2EquivalenceClassTesting EquivalenceclassdefinitionItisthesubcongregationofaninputdomainoranoutputdomain Reasonablesuppose Fortester typicaldataareequaltootherdatainthesameequivalenceclass 2 2EquivalenceClassTesting PartitionsituationvaliddataandinvaliddataareneededatthesametimeValidequivalenceclassForspecification itisacongregationconsistsofreasonableandmeaningfuldata Itcanbeusedtocheckwhethertheapplicationrealizedthepredictedfunctionsandperformance InvalidequivalenceclassForspecification itisacongregationconsistsofunreasonableandmeaninglessdata Itcanbeusedtocheckwhethertheinvaliddataishandledcorrectly 2 2EquivalenceClassTesting PartitionguidelineIftherangeoramountofinputvaluesarerestricted thenwecangetavalidequivalenceclassandtwoinvalidequivalenceclasses Example Inaprogramspecification thereisasentenceaboutinputcondition variablecanchangefrom1to999 thenValidequivalenceclassis 1 variable 999 Twoinvalidequivalenceclassesare variable 1 or variable 999 2 2EquivalenceClassTesting PartitionguidelineIftheinputvaluesarerestrictedor itmustbe thenwecangetavalidequivalenceclassandaninvalidequivalenceclass Example variablemustbeastringwhichbeginwithaletter Thenallstringsbeginwithaletterareinthevalidequivalenceclass othersareintheinvalidequivalenceclass 2 2EquivalenceClassTesting PartitionguidelineIfinputisaBooleanvalue wecangetavalidequivalenceclassandaninvalidequivalenceclass PartitionguidelineIfinputdataareagroupofvaluesandeveryinputvaluemustbedealwithrespectively thenwewillgetavalidequivalenceclassforeveryinputvalueandaninvalidequivalenceclass 2 2EquivalenceClassTesting PartitionguidelineIfinputdatamustconformtoasetofrules thenwecangetavalidequivalenceclassandalotofinvalidequivalenceclasses Example Emailaddressformatavalidequivalenceclass xx xx xxInvalidequivalenceclasses including 2 2EquivalenceClassTesting 规定范围和个数 有效一个无效俩 必须条件布尔量 有效无效一没错 不同输入不同待 有效多来无效单 输入数据有限制 有效单一无效多 等价划分综合断 类中有类细定度 2 2EquivalenceClassTesting weak strong traditional robust Strongrobust Weakrobust Weaktraditional Strongtraditional 2 2EquivalenceClassTesting ThestepsofdesigntestcaseFindoutequivalenceclassesSetupatableandgiveallequivalenceclassesEveryequivalenceclasshasauniqueNo Designanewtestcase trytomakeitincludethoseexclusiveequivalenceclasseswhichdoesn tbeincludednow repeatthisstepuntilallvalidequivalenceclassesareincluded Designanewtestcase trytomakeitincludeaninvalidequivalenceclassonlywhichdoesn tbeincludednow repeatthisstepuntilallinvalidequivalenceclassesareincluded 2 2EquivalenceClassTesting Example1 TriangleproblemItreceivethereintegersa b casinput Ifa b csatisfytheseconditionsbelow C1 1 a 200C4 a b cC2 1 b 200C5 b a cC3 1 c 200C6 c a bFourpossibleoutputs NotaTriangle Scalene 不等边的 Isosceles 等腰的 andEquilateral 等边的 Ifnoinputvalueissatisfiedthentherewillbeamessage Example cisoutofrangeIfa b csatisfytheconditionC1 C2 C3thenwecangetfouroutputexclusively Ifthreesideshavethesamevaluethenoutput equilateral Ifonlytwosideshavethesamevaluethenoutput isosceles Ifanytwosideshavedifferentvaluethenoutput scalene IfoneconditionamongC4 C5andC6isn tbesatisfiedthanoutput notatriangle 2 2EquivalenceClassTesting Step1 findoutequivalenceclassesR1 thetrianglewithsidesa b andcisequilateral R2 thetrianglewithsidesa b andcisisosceles R3 thetrianglewithsidesa b andcisscalene R4 thetrianglewithsidesa b andcnotformatriangle 2 2EquivalenceClassTesting Step2selecttestcases 2 2EquivalenceClassTesting Example2 EquivalenceClassTestCasesfortheNextDateFunctionStep1 findoutequivalenceclassesValidequivalenceclass M1 month 1 month 12 D1 date 1 date 31 Y1 year 1812 year 2012 Invalidequivalenceclass M2 month month12 D2 date date31 Y2 year year2012 2 2EquivalenceClassTesting StrongrobustequivalenceclassforNextDatefunction 2 2EquivalenceClassTesting 练习 前亚利桑那州境内的一位步枪销售商销售密苏里州制造的步枪机 枪托和枪管 枪机 Lock 卖45美元 枪托 Stock 卖30美元 枪管 Barrel 卖25美元 销售商每月至少要销售一支完整的步枪 且生产限额是大多数销售商在一个月内可销售70个枪机 80个枪托和90个枪管 每访问一个镇子之后 销售商都给密苏里州步枪制造商发出电报 说明在那个镇子中售出的枪机 枪托和枪管数量 到了月末 销售商要发出一封很短的电报 通知 1个枪机被售出 这样步枪制造商就知道当月的销售情况 并计算销售商的佣金如下 销售额不到 含 1000美元的部分为10 1000 不含 1800 含 美元的部分为15 超过1800美元的部分为20 佣金程序生成月份销售报告 汇总售出的枪机 枪托和枪管总数 销售商的总销售额以及佣金 2 2EquivalenceClassTesting Exercise commissionproblemtestcaseInputdomainequivalenceclassOutputdomainequivalenceclass 2 2EquivalenceClassTesting Inputequivalenceclass Validequivalenceclass L1 Lock 1 Lock 70 L2 Lock 1 S1 Stock 1 Stock 80 B1 Barrel 1 Barrel 90 Invalidequivalenceclass L3 Lock Lock 0orLock 1 L4 Lock Lock 70 S2 Stock Stock 1 S3 Stock Stock 80 B2 Barrel Barrel 1 B3 Barrel Barrel 90 2 2EquivalenceClassTesting Outputequivalenceclass Sales 45 Lock 30 Stock 25 BarrelS1 Sales 1000 S2 1000 Sales 1800 2 3BoundaryValueAnalysisTesting Basicideaofboundaryvalueanalysisfocusesontheboundaryoftheinputspacetoidentifytestcasesuseinputvariablevaluesattheirminimum justabovetheminimum anominalvalue justbelowtheirmaximum andattheirmaximum 2 3BoundaryValueAnalysisTesting TriangleproblemThreeinputs a b c1 a 2001 b 2001 c 200a 1 2 100 199 200 b 1 2 100 199 200 c 1 2 100 199 200 2 3BoundaryValueAnalysisTesting Triangleproblemtestcase Atminimum Justabovetheminimum Nominalvalue Attheirmaximum Belowtheirmaximum 2 3BoundaryValueAnalysisTesting NextDatefunctionproblemNextDateisafunctionhasthreevariables month date andyear itreturnthenextdatewhichuserinput Month dateandyearareallinteger andsatisfytheseconditionsbelow 1 month 121 date 311812 year 2012month 1 2 6 11 12 date 1 2 15 30 31 year 1812 1813 1912 2011 2012 2 3BoundaryValueAnalysisTesting NextDatefunctiontestcase Atminimum Justabovetheminimum Nominalvalue Attheirmaximum Belowtheirmaximum 2 4Cause EffectGraphing Cause EffectGraphing 因果图 Acause effectgraphisadirectedgraphthatmapsasetofcausestoasetofeffects Cause effectsrelationsareextractedfromtherequirements Thecausesmaybethoughtofastheinputtotheprogram Theeffectsmaybethoughtofastheoutput ThegraphshowsthenodesrepresentingthecausesontheleftsideThenodesrepresentingtheeffectsontherightside 2 4Cause EffectGraphing Therelationsbetweencausesandeffects 1 Imply 等价 ifc1is1 thene1is1also elsee1is0 2 Not 非 ifc1is1 thene1is0 elsee1is1 2 4CauseEffectGraphing Therelationsbetweencausesandeffects 3 Or ifc1orc2orc3is1 thene1is1 elsee1is0 Or mayhavearbitrarynumberofinputs 4 And ifbothc1andc2are1 thene1is1 elsee1is0 mayhavearbitrarynumberofinput 2 4CauseEffectGraphing Constraint 约束 Inpracticalissues theinputstatesalsoexistcertaindependencies calledconstraint Thereareconstraintsamongoutputsstates Thesearerepresentedasedgeslabeledwiththeconstraintsymbolusingadashedline 虚线 2 4CauseEffectGraphing Econstraint Exclusive EitherCaorCb Iconstraint Inclusive AtleastCaorCborCc OconstraintOneandonlyone ofCaandCb Rconstraint Require CarequiresCb 2 4CauseEffectGraphing Mconstraint Mask EamasksEb 2 4Cause EffectGraphing Thestepsofcause effectgraphdesign1 Identifycausesandeffectsbyreadingtherequirements Eachcauseandeffectisassignedauniqueidentifier Notethataneffectcanalsobeacauseforsomeothereffect 2 Expresstherelationshipbetweencausesandeffectsusingacauseeffectgraph 3 Transformthecause effectgraphintoalimitedentrydecisiontable 4 Generatetestcasesfromthedecisiontable table 2 4CauseEffectGraphing Example 有一个处理单价为5角钱的饮料的自动售货机软件测试用例的设计 其规格说明如下 1 若投入5角钱或1元钱的硬币 押下 橙汁 或 啤酒 的按钮 则相应的饮料就送出来 2 若售货机没有零钱找 则一个显示 零钱找完 的红灯亮 这时在投入1元硬币并押下按钮后 饮料不送出来而且1元硬币也退出来 3 若有零钱找 则显示 零钱找完 的红灯灭 在送出饮料的同时退还5角硬币 2 4CauseEffectGraphing Example 1 Analysisthespecificationandfindoutcausesandresultscause 1 售货机有零钱找2 投入1元硬币3 投入5角硬币4 押下橙汁按钮5 押下啤酒按钮建立中间结点 表示处理中间状态11 该找5角 投入1元硬币且押下饮料按钮 12 押下 橙汁 或 啤酒 的按钮13 可找5角 应当找5角零钱并且售货机有零钱找 14 钱已付清effect 21 售货机 零钱找完 灯亮22 退还1元硬币23 找回5角硬币24 送出橙汁饮料25 送出啤酒饮料 2 4CauseEffectGraphing Example 2 DrawCEG Causenodesontheleft effectnodesontheright 3 CEG 4 Because2and3 4and5cannothappenatthesametime sothereareEconstraints 1 2 3 4 5 21 22 23 24 25 14 13 12 11 售货机有零钱找 投入1元硬币 投入5角硬币 押下橙汁按钮 押下啤酒按钮 零钱找完 灯亮 退还1元硬币 找回5角硬币 送出橙汁饮料 送出啤酒饮料 该找5角 押下按钮 钱付清 E E V 可找5角 V 2 4CauseEffectGraphing Example 5 Changetojudgmenttable 2 4CauseEffectGraphing Exercise Thefirstcharacterofinputmustbe or thesecondcharacterofinputmustbenumber Inthiscondition thedocumentwillbemodified Ifthefirstcharacterisn t or thengivetheinformationN ifthesecondcharacterisn tnumberthengivetheinformationM RequestPleasegivethecausesandeffectsFindouttherelationshipbetweencausesandeffectsFindouttherelationshipbetweencauseandcauseDrawcause effectgraphChangethecause effectgraphtojudgmenttableAccordingtothisjudgmenttable designtestcases 2 4CauseEffectGraphing Exercise AnswerCausec1 thefirstcharacteris c2 thefirstcharacteris c3 thesecondcharacterisnumberEffecte1 givetheinformationNe2 modifythedocumente3 givetheinformationM 2 4CauseEffectGraphing Exercise AnswerCause effectgraph 2 4CauseEffectGraphing Exercise 2 4CauseEffectGraphing Exercise Designtestcase 2 5DecisionTableTesting Ofallthefunctionaltestingmethods thosebasedondecisiontablesarethemostrigorous becausedecisiontablesthemselvesenforcelogicalrigor Theyareidealfordescribingsituationsinwhichalotofcombinationsofactionsaretakenundervaryingsetsofconditions 2 5DecisionTableTesting readingguideline decisiontable 2 5DecisionTableTesting Fourportionsofdecisiontable StubportionEntryportionConditionportionActionportionRulesindicatewhichactionsaretakenfortheconditionalcircumstancesindicatedintheconditionportionoftherule 2 5DecisionTableTesting Decisiontable 2 5DecisionTableTesting StepsofconstructsadecisiontableDeterminetherulesnumber iftherearenconditions theremustbe2nrules True False Yes No 0 1 ListallconditionsubsandactionsubsEnterentryconditionsEnteractionconditions ToobtaininitialdecisiontablesimplifydecisiontableIftherearetwomoreruleshavethesameaction andtheconditionsareverysimilar itcouldbemerged TheDon tCareentryhastwomajorinterpretations theconditionisirrelevant ortheconditiondoesnotapply 2 5DecisionTableTesting Decisiontableoftriangleproblem 2 5DecisionTableTesting RefinedDecisionTablefortheTriangleProblem 2 5DecisionTableTesting NextDateFunction FirstTry Equivalenceclasses M1 month monthhas30days M2 month monthhas31days M3 month monthisFebruary D1 day 1 day 28 D2 day day 29 D3 day day 30 D4 day day 31 Y1 year yearisaleapyear Y2 year yearisacommonyear 2 5DecisionTableTesting NextDateFunction SecondTry EquivalenceclassesM1 month monthhas30days M2 month monthhas31days M3 month monthisFebruary D1 day 1 day 28 D2 day day 29 D3 day day 30 D4 day day 31 Y1 year yearis2000 Y2 year yearisaleapyear Y3 year yearisacommonyear 2 5DecisionTableTesting NextDateFunction SecondTryTestCases 2 5DecisionTableTesting DecisiontableofNextDatefunction thirdtimeanalysis M1 month monthhas30days M2 month monthhas31daysper exceptDec M3 month monthisDecember M4 month monthisFebruary D1 day 1 day 27 D2 day day 28 D3 day day 29 D4 day day 30 D5 day day 31 Y1 year yearisaleapyear Y2 year yearisacommonyear Thirdtry 2 5DecisionTableTesting Thirdtry 2 5DecisionTableTesting NextDate函数的决策表测试用例 2 5DecisionTableTesting GuidelinesandobservationsThedecisiontabletechniqueisindicatedforapplicationscharacterizedbyanyofthefollowingprominentIf Then ElselogiclogicalrelationshipsamonginputvariablescalculationsinvolvingsubsetsoftheinputvariablescauseandeffectrelationshipsbetweeninputsandoutputsDecisiontablesdon tscaleupverywellAswithothertechniques iterationhelps Thefirstsetofconditionsandactionsyouidentifymaybeunsatisfactory Useitasasteppingstone andgraduallyimproveonituntilyouaresatisfiedwithadecisiontable 2 6OrthogonalTest ThetypeofexperimentaldesignmethodsComprehensivetestSinglefactortestOrthogonaltest 2 6OrthogonalTest Example Inordertoimproveacertainchemicalproductsconversionrate threefactorswhichmayaffecttheconversionrateareselected Reactiontemperature A Reactiontime B alkaliquantity C andtheexperimentrangeofthemshowbelow A 80 C 90 CB 90min 150minC 5 7 2 6OrthogonalTest Testgoal FindouttheconversionrateisaffectedbyA B andCWhichismaincondition Whichissecondarycondition Determinethemostappropriateproductionconditions 2 6OrthogonalTest ExperimentwithseveralrepresentativevaluesofA BandC A A1 80 A2 85 A3 90 B B1 90min B2 120min B3 150minC C1 5 C2 6 C3 7 SelectedvalueofA B Ciscalled level 2 6OrthogonalTest Two dimensionalforms levelandfactor 2 6OrthogonalTest ComprehensivetestCombinationofallfactorsandlevelsA1B1C1 A1B1C2 A1B1C3 33 27timesexperimentsareneededAdvantagesachievegoodtestresults Disadvantagesiftherearealotoffactorsandlevels thentheexperimenttimesisunacceptable Forexample factoramountis6 andeverylevelofthemare5 thenexperimenttimesis56 15626 2 6OrthogonalTest SinglefactortestformanytimesFixedanumberofoth