testing levels nice

8/9/2019 Testing Levels Nice

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LevelsofTesting

AdvancetopicsinComputerScience

PatrickOladimeji

Dr.MarkusRoggenbach

Prof.Dr.Holger Schlingloff

Universityof

Wales

Swansea

Computer

Science

Department


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Contents

1. Differentlevelsoftesting.

2. Importantfactors

on

testing

levels.

o Factorsinfluencingtestscope

o Whytestatdifferentlevels?

3. Testlevels

and

software

life

cycle

models.

o V Model


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DecompositiontreeofSATM

SATMsystem

Manage

Sessions

CentralBank

CommunicationTerminal

I/O

ValidateCard PINEntryManage

Transaction

Close

Session

Screen

Driver

Key

Sensor


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1.DifferentLevelsoftesting

Whatisaleveloftest?

Definedby

agiven

environment

environmentisacollectionofpeople,

hardware,software,

interfaces,

data

etc.

Fig1 Sampleenvironmentvariables

[SystematicSoftwaretesting RickD.CraigandStefanP.Jaskiel2002]


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UnitTesting

IntegrationTesting

SystemTesting

AcceptanceTesting

Regressiontesting

1.Levelsoftesting


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Contents

1. Differentlevels

of

testing.

o UnitTesting

o IntegrationTesting

o SystemTesting

o AcceptanceTesting

o RegressionTesting

2. Importantfactorsontestinglevels.


o Whytest

at

different

levels?

3. Testlevelsandsoftwarelifecyclemodels.

o

V Model


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1.1UnitTesting

Aunitissmallesttestablepieceofsoftware

can

be

compiled,

linked,

loaded

e.g functions/procedures,classes,interfaces

normallydonebyprogrammer

Testcases

written

after

coding

Disadvantage

Test

cases

written

to

suit

programmers

implementation(notnecessarilyspecification)

BettertouseBuddyTesting


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1.1UnitTesting

BuddyTesting

Teamapproachtocodingandtesting

Oneprogrammercodestheothertestsand

viceversa

Testcases

written

by

tester(before coding

starts).Betterthansingleworkerapproach

Objectivity

crosstraining

Modelsprogramspecificationrequirement


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1.1UnitTesting

NormallyinprogrammersIDE(comfortzone)

Findunit

bugs

Wrongimplementationoffunctionalspecs

SATM

Example

Testingfunctionprocedurese.g.theValidatePIN()

procedure


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Contents

1. Differentlevels

of

testing.

o UnitTesting


o SystemTesting

o AcceptanceTesting

o RegressionTesting



o Whytest

at

different

levels?


o

V Model


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1.2Integrationtesting

Testforcorrectinteractionbetweensystemunits

systems

built

by

merging

existing

libraries

modulescodedbydifferentpeople

Mainlyteststheinterfacesamongunits

Bottomupintegrationtesting

Useofdrivers

Topdown

integration

testing

Useofstubs


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1.2Integrationtesting

Whodoesintegrationtestingandwhenisit

done? Donebydevelopers/testers

Testcaseswrittenwhendetailedspecificationisready

Testcontinuous

throughout

project

Whereisitdone?

doneon

programmers

workbench

Whyisitdone?

Discoverinconsistenciesinthecombinationofunits.


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1.2.1StubsandDrivers

SATMsystem

Manage

Sessions

CentralBank

Communication

Terminal

I/O

ValidateCard

ValidatePIN

Manage

Transaction

Close

Session

Screen

Driver

Key

Sensor

GetDigit


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Contents

1. Differentlevels

of

testing.

o UnitTesting


o SystemTesting

o AcceptanceTesting

o RegressionTesting



o Whytest

at

different

levels?


o V Model


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1.3SystemTesting

Testofoverallinteractionofcomponents

Finddisparities

between

implementation

and

specification

Usuallywhere

most

resources

go

to

Involves load,performance,reliabilityand

securitytesting


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1.3SystemTesting

Whoperformssystemtestingandwhenisit

done? Donebythetestteam

Testcaseswrittenwhenhighleveldesignspecis

ready

Whereisitdone?

Doneon

asystem

test

machine

Usuallyinasimulatedenvironmente.g.vmware


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1.3.1Systemvs.Integrationtesting

Whatvs.How

Requirementspec

>what

detaileddesignspec>how

Systemtesting

functional

not

structural


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1.3.2Example:System/IntegrationTesting

SATMsystem

Manage

Sessions

Central

Bank

Communication

Terminal

I/O

ValidateCard

ValidatePIN

Manage

Transaction

Close

Session

Screen

Driver

Key

Sensor

GetDigit


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Contents

1. Differentlevels

of

testing.

o UnitTesting


o SystemTesting

o AcceptanceTesting

o RegressionTesting



o Whytest

at

different

levels?


o V Model


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1.4AcceptanceTesting

Demonstratessatisfactionofuser

Usersare

essential

part

of

process

UsuallymergedwithSystemTesting

Doneby

test

team

and

customer

Doneinsimulatedenvironment/real

environment


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Contents

1. Differentlevels

of

testing.

o UnitTesting


o SystemTesting

o AcceptanceTesting

o RegressionTesting



o Whytest

at

different

levels?


o V Model


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1.5RegressionTesting

Ongoingprocessthroughouttestinglifecycle

Newbug

fix

breaks

previously

tested

units?

Performregressiontestwheneverprogram

changes


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Contents

1. Differentlevels

of

testing.

o UnitTesting


o SystemTesting

o AcceptanceTesting

o RegressionTesting



o Whytest

at

different

levels?


o V Model


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2.1 Factorsinfluencingtestscope

Sizeofproject

Complexityof

project

Budgetforproject

Timescope

for

project

Numberofstaff


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2.2Whytestatdifferentlevels

Softwaredevelopmentnaturallysplitto

phases Easilytrackbugs

Ensuresaworking

subsystem/

component/

library

Softwarereusemorepractical

C t t


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Contents

1. Differentlevels

of

testing.

o UnitTesting


o SystemTesting

o AcceptanceTesting

o RegressionTesting



o Whytest

at

different

levels?


o V Model


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3.1TheV modelandtestlevels

Fig3.1levelsoftesting

[SystematicSoftware

testing

Rick

D.

Craig

and

Stefan

P.

Jaskiel

2002]


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Summary

Differentlevelsoftest

Unittesting

Integrationtesting

Systemtesting

Acceptancetesting

Regressiontesting

Factorsaffectingtestscope

Whytest

at

different

levels

TheV modelandtesting

testing levels nice

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