System test cases from use cases

SYSTEM TEST CASES FROM USE CASES Ja ie J. Gu ié ez, Ma ía J. Escalona, Manuel Mejías, Jesús To es Uni e si y o Se illa, A d. Reina Me cedes sn. Se illa, Spain {ja ie j, escalona, iso o, j o es}@lsi.us.es Keywo ds: Sys em es ing, use cases, gene a ion o es cases. Abs ac : Use cases ha e become a widely used echnique o de ine he unc ionali y o a so wa e sys em. This pape desc ibes a new, o mal and sys ema ic app oach o gene a ing sys em es cases om use cases. This p ocess has been designed specially o es ing he sys em om he poin o iew o he ac o s, h ough i g aphical use in e aces. 1 INTRODUCTION Sys em es ing is a black-box echnique which e i ies he sa is ac ion o he equi emen s o he sys em unde es (SUT) (Bu ns ein, 2003). Ea ly es ing is he gene a ion o es cases in ea ly de elopmen phases. This is no a new idea. Two su eys (Denge , 2003) and (Gu ié ez, 2004) (22 di e en app oaches in o al) expose ha he e a e many lacks in he exi ing app oaches. One lack is he absence o a o mal p ocess and he absence o ee a ailable ools. Ano he lack is ha app oaches a e no comple e; his means ha hey desc ibe how o gene a e pa ial es cases, mainly es ac ions, wi hou desc ibing o he impo an elemen s such as es da a, expec ed esul , execu able es sc ip s, o es co e age. In a p e ious wo k i was desc ibed how o gene a e es cases om use cases o web applica ion using exis ing app oaches (Gu ié ez, 2005). This pape ies o esol e bo h lacks o e ing a o mal app oach o ob ain execu able es sc ip s om use cases. I has been specially designed o be used in ea ly de elopmen phases. I also uses UML and UML Tes ing P o ile (OMG, 2002) (called UMLTP om now). Rela ed wo ks may be ound in (Denge , 2003) and (Gu ié ez, 2004). 2 A PROCESS TO GENERATE TEST CASES FROM USE CASES This es p ocess is ocused on es ing use cases whose p incipal ac o is human. A es case is composed o h ee elemen s: es ac ion, es alues and expec ed esul s. Tes ac ions a e he ac ions de eloped by he es case o e he sys em unde es (SUT). Tes alues a e he in o ma ion needed by he es case. Expec ed esul s a e he esponses o he sys em ha allows e alua ing whe he he es is sa is ied o ailed. The esul s o his p ocess a e: es objec i es, a se o es cases o e i y each objec i e and es sc ip s. Tes cases a e exp essed using models and g aphical no a ion de ined in UMLTP when possible. 2.1 Tes ing Models The models used o s o e he in o ma ion abou es cases a e: es objec i e model, es da a model, in e ace model and e en model. 1. Tes objec i e models. A es objec i e is an elemen named acco ding o he desc ip ion o wha should be es ed. The UMLTP does no de ine any no a ion o ep esen es objec i es. Thus, we use ac i i y diag ams. A es objec i e is a pa h h ough he ac i i y diag am. Tes objec i es migh be au oma ically ex ac ed om he ac i i y diag am applying a co e age c i e ion, like all-edges and all- ansi ions. E e y es objec i e will ha e a leas one es case o e i y i . An example is shown in able 4. 2. Tes da a model. Tes da a model desc ibes he s uc u e and alues o he es da a. The i s ask is o iden i y ope a ional a iables (o simply a iables) o a use case. An ope a ional a iable is an explici inpu o ou pu , an en i onmen al condi ion o a ep esen a ion o he 283 SUT (Binde , 1999). The domain o e e y a iable is di ided in o da a pa i ions. UMLTP uses class diag ams and s e eo ypes o desc ibe he hie a chy o da a pa i ions. A e ha , es alues a e gene a ed o e e y da a pa i ion. Case s udy shows an example o da a s uc u es, pa i ions and es alues in igu e 4. 3. In e ace model. Ou aim is o es he unc ionali y h oughou a g aphical in e ace, no o es he g aphical in e ace i sel . The objec i e o his model is o desc ibe he in e ace used o he es case o in e ac wi h he sys em. Since his p ocess has been designed o be applied in ea ly de elopmen phases, his model ep esen s a high abs ac desc ip ion o he GUI. UML Tes ing P o ile, and UML in gene al, does no include any speci ic no a ion o GUI, so i will be used class and objec diag ams o ep esen he componen s and s a es o a GUI. Figu e 1: Example o componen s o in e ace models. Figu e 1 shows a class diag am wi h some elemen s om an in e ace model. 4. E en model. F equen ly, ac o ac i i ies om a es objec i e a e oo abs ac o be di ec ly ansla ed in o a es sc ip . I is p oposed o build up an e en model o add ess o his complexi y. A se o e en s desc ibes how o pe o m ac o ac i i ies iden i ied in he es objec i e model. I an ac i i y needs o supply in o ma ion o he sys em, his in o ma ion should ha e been de ined in he es da a model. This pape in oduces a simple se o messages o exp ess e en s. These messages a e lis ed in able 1. Due o hei simplici y, he messages migh be easily ex ended. E en model also includes an asse message ( able 1). This message is sen by he es case o i sel o e i y an a ibu e o he GUI. This message allows codi ying he expec ed esul s in o a es sc ip , an example is shown in case s udy. Table 1: Messages o e en model. Message Meaning ClickOn(componen ) Pe o m a one-click e en o e he indica ed GUI componen . Sc een(sc een) Sea ch o he indica e GUI sc een and se he ocus o e i . Se Field( ield, alue) Se he indica ed alue in o he ield objec . Asse (componen . a ibu e, alue) Ve i y ha he a ibu e o he componen indica ed ma ches wi h he alue. 2.2 S eps o Gene a e Tes Cases We sugges a p ocess o six s eps o gene a e es models and o ob ain execu able es sc ip s. These s eps a e shown in he ac i i y diag am in igu e 2 and desc ibed in he ollowing pa ag aphs. Figu e 2: Ac i i ies o gene a e es cases. The i s s ep is o build up a es objec i e model om a use case, as desc ibed in poin 2.1. The second one is o build up he es da a model as desc ibed in poin 2.1. In he hi d s ep, es cases a e gene a ed combining es objec i es wi h es alues. The numbe o es cases is de e mined by he es objec i es and he di e en pa i ions o he a iables in ol ed in ha es objec i e. In he ou h s ep, in e ace model is gene a ed, as desc ibed in poin 2.1. In he i h s ep e en model is gene a ed. Finally, e en messages, es alues and asse ions a e ansla ed in o es sc ip s, comple ed wi h es ha ness (Binde , 1999) and execu ed o e he eal SUT. ICSOFT 2006 - INTERNATIONAL CONFERENCE ON SOFTWARE AND DATA TECHNOLOGIES 284 3 CASE STUDY This sec ion applies he p ocess desc ibed in sec ion 2 o e a eal sys em o gene a e es cases. The sys em unde es is an implemen a ion o a classic no epad. The use case selec ed o gene a e es cases is Open File ( able 2). Table 2: Templa e o use case "Open File". Desc ip ion Load documen om ile P econdi ion No Main scena io 1 Use selec “Open ile” op ion. 2 Sys em asks o he ile o open. 3 Use selec s a ile. 4 Sys em loads he ile and shows he documen . Al e na i e / e o s 3 Use may cancel he loading ope a ion a any ime. 4 I ile does no exis o he e is an e o , sys em shows an e o message. Pos condi ion No. A ull co e age o he use case is selec ed. This means ha a leas one es case o e e y iden i ied es objec i e will be gene a ed. 3.1 Gene a ion o Tes Objec i es Fi s o all, he es objec i e model is buil ( igu e 3). Ac i i ies 01 and 03 a e de eloped by he use and ac i i ies 02, 04, 04.1 and 04.2 a e pe o med by he sys em. S ep 4 ( able 4) has been di ided in o ac i i ies 04, 04.1 and 04.2, and due o hei esul s hey may be di e en i he e is an e o when opening he ile. Figu e 3: Tes objec i e model. Table 4 shows es objec i es ob ained by a e sing igu e 3. 3.2 Gene a ion o Tes Values Fi s ly he a iables in ol ed in he use case a e iden i ied. Tes objec i e model in igu e 3 e eals ha he e a e, a leas , wo a iables ( he same numbe as decision nodes). Va iables and domains a e esumed in able 3. Table 3: Va iables and domains. Va iable Domain Use -Op ion Op ions a ailable o he use : load ile o cancel. File File o open Use -Op ion is a a iable o an enume a ed ype. Howe e , File is a a iable o a complex ype. Fo he es ing pu pose he e mus be known, a leas , he name o he ile, i s con en and i s a ibu es. Figu e 4: Tes da a. Now, we di ide he domains in o da a pa i ions. Finally, a leas one es alue is gene a ed o each pa i ion. Objec diag am in igu e 4 shows es s alues. 3.3 Build Tes Cases A es case is a es objec i e wi h a conc e e alue o i s a iables. Va iables and hei pa i ions a e added o he es objec i es, as shown in able 4. Table 4: Tes objec i es wi h a iables and pa i ions. Tes objec i es 1 01, 02, 03( 01: Wi hou -E o s, op01:LoadOp ion), 04, 04.1 2 01, 02, 03( 02: Wi h-E o s, op02:LoadOp ion), 04, 04.1 3 01, 02, 03( 03: *, op03:CancelOp ion), 04, 04.1 3.4 Gene a e In e ace Model I is assumed ha he sys em unde es is no buil ye . So, i is gene a ed an abs ac desc ip ion o he use in e ace wi h he minimum se o componen s o pe o m he use case. S udying he use case, we ealize ha he e a e h ee sc eens in ol ed: he main sc een, whe e use ac o clicks on open op ion, he ile selec ion sc een, SYSTEM TEST CASES FROM USE CASES 285 whe e use ac o selec s he ile o open, and he e o sc een whe e sys em shows he e o message, i any. The in e ace model is shown in he objec diag am in igu e 5. Figu e 5: In e ace model. 3.5 Gene a e E en Models and Expec ed Resul s Fi s , each use ac i i y is e ined using messages lis ed in able 1 and he use in e ace, de ined in poin 3.4. The e en model o e i y he main scena io is desc ibed as UML sequence diag am in igu e 6. Figu e 6: E en model. Valida ion ac ions a e implemen ed using he asse p oposi ion shown in able 1 and ac i i ies diag ams as p oposed in he UMLTP. Due hei simplici y, he ha e been omi ed. The p ocess has ended. The e ha e been gene a ed es ac ions (shown in he e en model), es alues (shown in he es alue model) and expec ed esul s (shown in he e en model oo) ha commi s ou es objec i es (shown in he es objec i e model). Up o now, we ha e no needed he design o he code o he sys em. 3.6 Building Tes Sc ip s The in o ma ion ob ained in he poin s be o e, migh be au oma ically ansla ed in o execu able es sc ip s. De ails o he implemen a ion and es ool a e needed o pe o m his s ep. I is used a eal implemen a ion o he no epad, called S ylepad, o gene a e es sc ip s. The S ylepad is dis ibu ed in he Ja a De elope Ki . I has been used an open sou ce ool called Abbo o codi y execu able sc ip s. 4 CONCLUSIONS This pape has shown a p ocess o he ea ly- es ing o use cases. Al hough his p ocess has been designed o es use cases om he pe spec i e o human ac o s, i can be also used o es o he ac o s. This p ocess can be applied in ea ly de elopmen s ages. In ac , in case s udy desc ibed in sec ion 3, all es cases ha e been gene a ed be o e choosing a eal implemen a ion o es . REFERENCES Binde R.V. 1999. Tes ing Objec -O ien ed Sys ems. Addison-Wesley. USA. Bu ns ein, I. 2003. P ac ical so wa e Tes ing. Sp inge P o essional Compu ing. USA. Denge , C. Medina M. 2003. Tes Case De i ed om Requi emen Speci ica ions. F aunho e IESE Repo . Escalona M.J. 2004. Models and Techniques o he Speci ica ion and Analysis o Na iga ion in So wa e Sys ems. Ph. Eu opean Thesis. Depa men o Compu e Language and Sys ems. Uni e si y o Se ille. Se ille, Spain. Gu ié ez, J.J., Escalona M.J., Mejías M., To es, J. 2004. Compa a i e Analysis o Me hodological P oposes o Sys ema ic Gene a ion o Sys em Tes Cases. 3º Wo kshop on Sys em Tes ing and Valida ion. Pa is. F ance. Gu ié ez J.J., Escalona M.J., Mejías M., To es J. 2005. A p ac ical app oach o Web Sys em Tes ing. Ad ances in In o ma ion Sys ems De elopmen . Ed. Sp inge Ve lag Ka ls ad, Sweeden. Objec Managemen G oup. 2002. The UML 2.0 Tes ing P o ile. www.omg.o g ICSOFT 2006 - INTERNATIONAL CONFERENCE ON SOFTWARE AND DATA TECHNOLOGIES 286