EMOS Framework Article.docx

EMOS Framework Article.docx

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EMOSFrameworkArticle

EMOSFramework:

FunctionalTestingBasedonGUI-Modelling

DeanRajovic

EMOSComputerConsultingGmbH

Oskar-Messter-Str.25

85737IsmaningbyMunich

Germany

ABSTRACT

InthispaperwediscusstheroleofGUI-modellingintheareaoffunctionaltestingandpresentaframeworkforthedevelopmentandexecutionofautomatedfunctionaltestsbasedonsuchmodelling.Themainissuesaddressedbytheframeworkare:

rapidtestdevelopment,intensiveinvolvementofnon-technicalpersonnelintestautomationandmaintainabilityofthetestenvironmentthatscaleswellforlargesystems.

ThemainfeaturesofourapproachtoGUI-modellingarereducingGUIoperationstotheirSET（enter）andCHK（verify）alternativesandcapturingthenavigationasanintrinsicpartofthetestdescription.Throughasimplelinkageconcept,anextremelyhighlevelofreusabilityoftestdataandtestcodeisachieved.

ThetechnicalimplementationisrealisedwiththepopulartesttoolWinRunner®fromMercuryInteractiveandisavailableundertheLesserGeneralPublicLicence（LGPL）.Theconceptisapplicabletopracticallyanyapplicationdesignedforintensivedatamaintenancevia"standard"GUIobjects.Ithasbeensuccessfullyappliedtoseveralhighlycomplextestautomationendeavoursinbrancheslikeinsurance,bankingandtelecommunications.

KEYWORDS:

testing,testautomation,functionaltesting,testframework,WinRunner

1

INTRODUCTION

Therearemanychallengesintestingcomplexsystems.Automatingtestsinsuchenvironmentsreducessomeofthembutintroducesadditionalones.Testswhicharesuitableformanualtestingarenotnecessarilysuitablefortestautomation（providedtheyhavebeenspecified/writtenatall）.Thesheeramountofpossibletestcasescanscareeventhemostexperiencedtestmanager/specialist.Especiallywhensuchtestsaretobecarriedoutwithhopelesslyunderstaffedtestteamsandwithinridiculoustimeframes...[5]Organisingnumeroustestartefactsintoamaintainablecomplexthatsurviveslongenoughtoproveitsusefulnessisaverychallengingtask[3,4,6,7,8].

Themostcommonapproachtofunctionaltestingisbyexercisingtheapplicationthroughitsuserinterface.AutomationoffunctionaltestssimplycannotignoretheGUI-orientedtesttoolsfromvendorssuchasMercuryInteractive,Rational,Segue,Compuware,etc.Althoughthesetoolsarecapableofimplementingverycomplexapproaches,advancedusersseemtobeleftalonetodiscovertheadvancedtechniquesontheirown.

ItdoesnottakemuchbrowsingthroughtheliteratureorintheInternettodiscoverthatmanypeoplefoundtheirownsolutions[1,2,3,8].Thesesolutionsalwaysseemtofollowthesamepath:

fromcapture/replay（record/playback）viascriptinganddata-driventestingtotestframeworks.Duetothelackoffirmtheoreticfundamentsthatcouldguaranteetheiruniversalapplicability（whichisprobablythereasonnoneoftheleadingtoolvendorsoffersuchframeworks）,theseframeworkspairtheirowntestingmethodologywiththetechnicalsupportforit.Nevertheless,theyalltrytosolvethesameproblem:

makethetestautomationmoreeffectiveandmoreefficient.

Whenitcomestotestingviatheapplication'suserinterface,theseframeworksappeartousethesameapproach:

eachmodelsthetestdesigninitsownwayandprovidesaninterfacetoone（ormore）standardGUI-centredtesttoolthatexecutesthetests.ThemostinfluentialtestframeworksofarisprobablytheCMG'sTestFrame®[1].Thisisthepowerfulframeworkbasedonakeyword-drivenseparation（intheirterminology:

"actionwords"）betweenthetestdata（"testclusters"）andthetestscripts.Themostimportantcommonpropertyofalmostalloftheapproachesatthismaturitylevelistheseparationofthetestdatafromthetestscripts.Themoreadvancedtheseparation,themoreadvancedtheconcept（e.g.simpledata-drivenversuskeyword-drivenapproach）.

2THE“BUSINESSCASESYNDROME”

Advancedconceptsattempttoexpressthetestcasesintermsofbusinessprocesses:

thehigh-levelabstractionsthathidetheiractualimplementationasmuchaspossible.Thepromisedbenefitsofsuch"businessmodelling"includetheindependenceoftheparticularuserinterface,increasedcomprehensiontonon-programmersandimprovedrequirements/designcoverage.

Howevertheseparationofscriptsanddatahasitscosts.Thecloserwegettothe"businesslanguage",thebiggerthegaptotheactualtestimplementation.Underthepremisethatweattempttoignoretheparticularuserinterface,itbecomesincreasinglymoredifficulttofindreusablecodepatternsthatrelatetosuch"businesslanguage".Suchpatternshoweverarefundamentaltobridgingthegapbetweenbusinessmodelsandtheirimplementation.

Businessprocessesarerarelysimple.Theproblemisoften"solved"bychunkingbigtransactionsintosmallerpartsand/orbyreducingtheinformationthathasactuallybeentested.Weoftenseefunctionslikeenter_xxx（...）,delete_xxx（...）andmodify_xxx（...）accompaniedwiththeclaimtheytestthegivenbusinessprocesses.Thequestionsiswhethertheyreallydo.

Thetestcodemustbeflexible.Amongotherthingsitshouldbeabletoenterandcheckvalidsituations,provokeerrors,takealternative,unusualorillegalpathsthroughtheapplication,handledynamic（context-sensitive）partsoftheapplicationandcheckthereactionoftheapplicationatmanydifferentplaces.Thepurposeofthiscodeistesting.Itshouldserveasa"playground"forimplementingtestideas.Itshouldbeabletomirrorthebehaviouroftherealhuman（anddestructive）testerasmuchaspossible.Thiscannotbeachievedwithacodeinwhichmanydecisionsarehardcoded.Whenanalternative"route"isneededorwhenthingsgetchanged（astheyinevitablydowithtesting）onemustmakeadaptationssomewheretogetthecodeworking.Questionsthatariseare:

∙Wheretoadapt?

∙Whocanadaptit?

∙Howmuchdoesitcost（time/money）toadapt?

Atestautomationexpert（testprogrammer,toolspecialist）ispermanentlyforcedtomakedecisionsaboutwhatinformationtomakepublic（i.e.makeita"businesscase"）andwhatinformationto"bury"intothetestscripts.Thetradeoffisthattheinformationwhichismadepubliccan（usually）bechangedbynon-programmers（domainexperts,endusers,testers）whereasthe"buried"informationrequiresprogrammingexpertisetochange.Simplechangesintheapplication'suserinterfacecaneasilyaffectplenty（hundreds）oftestcasesiftheinformationisexposedoronlyafewlinesofcodeiftheinformationishidden.Obviously,acarefulbalancemustbefound.However,itisagamble!

Moreoftenthanwewouldlike,changesaffectbothexposedorhiddeninformationregardlessofour"clever"balancing.Thosewhoknowthetricksoftestautomationwillappeartobe"luckier"thantheothers.

Themainbenefitoftestframeworksisinprovidingguidelinesforthosewhousethem（testdesigners,testprogrammers,endusers,systemdesigners,etc.）.Agoodtestframeworkprovidesgoodanswerstomanydifficultquestions.Theareathatstillrequiresplentyofresearchisinfindinganeffectivewayofexpressing（orevengenerating）testcasesthataresufficientlylegibleforhumansaswellasmachines.

3GUIHASITALL

Inourapproach,weconsciouslydigressfromthecommonlyacceptedpracticeofexpressingtestcasesinawaywhichis"independent"oftheparticularuserinterface.Tothecontrary,weconcentrateontheapplication'sinterfaceforthefollowingreasons:

∙itistheaspectthatnoneofthefunctionaltestautomationapproachescanignore,

∙itistheonlycommonplatformfordiscussionssuitabletoallparties,

∙itistheprimaryareaofinteresttomostexpertusersandtestmanagers,and

∙itisindeedsuitableforexpressing（functional）testcases.

Ourexperiencehasshownthatbymodellingtheuserinterfaceweareabletoexpressthe"businesscases"whilepreservingmostoftheotherbenefitsof"businessmodelling"（separationoftestsandscripts,increasedcomprehensiontonon-programmers,maintainability,scalability）andprovidefortheextremelyrapidandrobusttestautomation.Theapproachisparticularlywell-suitedforapplicationswithcomplexuserinterfacefocusedondatamaintenance.Thiscoversaverybroadrangeofbusinessapplicationsinpracticallyallbranches.

Thebasicobjectivesofourapproachare:

∙itmustbesetupquickly,

∙itmustrapidlyevolve（newtestcasesmustbeadoptedquickly）,

∙itmusteventuallyscaletoaccommodatehugesystems,

∙itmustbeableto"live"long（maintainableovermanyproductcycles）,and

∙itmustbeuseful（testwhatwasintendedtobetested）.

OurGUI-modellingideaisbasedonaprettyhereticalhypothesis.Ifthereisaneditfieldontheapplication'sGUI,allthatafunctionaltestwilldowithitistoenter,retrieve/checkorignoreitscontent.（Onemayarguethatthefieldattributes（label,position,enabled/disabled,etc.）alsoneedtobechecked.Thismaybetrue.However,comparedtotheoperationsonthefield'scontent,theoperationsonfield'sattributesarerare.Forthisreason,weconcentrateonthecontent.Nevertheless,wedoknowhowtohandleboth.）

ThesameholdstrueformostoftheotherGUIobjecttypes.Forexample,apushbuttonwillbepressedorignored,acheckboxwillbesetorcheckedwhetheritisset,elementsoflistboxeswillbeselectedorcheckedfortheirpresence,etc.Inotherwords,foreveryGUIobjecttypethereareonlyafewoperationsthatneedtobeappliedinordertoperformmostofthefunctionaltesting.

ThefirstmostimportantconceptofEMOSframeworkisthattheGUIofanapplicationisexercisedwithoperationsineitherSE