XML-based Representation of Test Cases for Distributed Systems

XML-based Representation of Test Cases for Distributed Systems

Alexander Kraas

7. October 2008

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Alexander KraasOct 2007

www.esk.fraunhofer.dewww.esk.fraunhofer.de

Contents

1. Motivation

2. Toolchain and Workflow

3. Design Goals

4. Structure and Mapping of XTR Test Cases

5. Conclusion & Future work

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MotivationActual situation

Many commercial and academic tools for the model-based test generation

Different solutions for test case specification:

- Using the same language for programming the SUT and writing test cases

- Specification of test cases with scripting languages, e.g. TCL

- Utilization of specialized testing languages, for example TTCN-3

Only a small number of test generation tools support several target languages

Motivation for using an abstract representation format

A test representation format can facilitates:

- The exchange of test cases between different tools

- The implementation of adapters for different target languages

Advantages of using XML for test case representation:

- XML documents can be formalized by XML Schemata (XSD)

- XML is human-readable

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Toolchain and Workflow (1)

Test CaseGenerator 1

Test CaseGenerator N...

Test CaseSelection Module

(optional)

Test Data Generator(optional)

XML Test Representation (XTR)

TTCN-3Language Adapter

JUnitLanguage Adapter

Adapters for other Languages(optional)

Exemplarily architecture of a tool chain which utilizes the XTR format

Different test case generators and other optional modules

Adaptors for different target languages

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Toolchain and Workflow (2)

Workflow of test case generation with the XTR format

1. Test Case Generator produces test cases in the XTR format

2. Optional modules can be used for post-processing of XTR test cases

3. A Language Adapter transforms XTR test cases into a target language,e.g. TTCN-3 or JUnit

Test CaseGenerator 1

UML Model

XMI

Test CaseSelection Module

Test Data Generator

Language Adapter

XTR XTR XTR

TargetLanguage

XMIXMI

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Design Goals

The design of the XTR format rests on following main objectives

Representation of black-box test cases for the test of distributed communication systems

Support of concurrency and asynchronous communication

Usage of a simplified test architecture (without communication ports)

Powerful data type concept for representing user-defined as well as object-oriented data types

Providing only a minimal set of test interactions, because only automatic generated test cases should be represented

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Structure and Mapping of XTR Test Cases (1)

The structure of a XTR test suite consists of four different element groups

<typeDefinitions>

- Containing all data types used by the test cases

- Definitions can consists of simple as well as complex data types

<templateDefinitions>

- Optional template definitions for data types.

- Templates can represent pre-defined values or matching expressions

<testArchitecture>

- Specification of an abstract test architecture

- The architecture have to be used by all test cases of a XTR test suite.

<testCases>

- This element contains all test cases of a XTR test suite

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Data type definitions and their mapping to TTCN-3

<class name="ExampleClass" baseType="class" parameter="false"> <attributes> <attribute name="name" typeName="string" baseType="string"/> </attributes> <methods> <method name="setName" typeName="void" baseType="void"> <parameter name="parName" typeName="string" baseType="string"/> </method> <exception name="exceptionCause" typeName="string" baseType="string" </methods></class>


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type record attrib_ExampleClass {

charstring name }

signature setName_ExampleClass (inout charstring par1)

exception (charstring);

Data type definitions and their mapping to TTCN-3

<class name="ExampleClass" baseType="class" parameter="false"> <attributes> <attribute name="name" typeName="string" baseType="string"/> </attributes> <methods> <method name="setName" typeName="void" baseType="void"> <parameter name="parName" typeName="string" baseType="string"/> </method> <exception name="exceptionCause" typeName="string" baseType="string" </methods></class>


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Test architecture


Abstract Test Architecture

TestComponent 1

SUT

Objects Under Test

Protocolxy

Protocol Under Test

Test Component 2

a b c

A XTR test architecture can consists of:

Test components for protocol tests

Test components for API tests

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Test architecture


Abstract Test Architecture

TestComponent 1

SUT

Objects Under Test

Protocolxy

Protocol Under Test

Test Component 2

a b c

<testArchitecture> <globalParameters/> <testComponent name="Component_1"> <api> <object name="sutObj_a" type="Class_A"> <object name="sutObj_b" type="Class_B"> <object name="sutObj_c" type="Class_C"> </api> </testComponent> <testComponent name="Component_2"> <protocol protocolName="protocol_xy"/> </testComponent></testArchitecture>

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Test architecture


<testArchitecture> <globalParameters/> <testComponent name="Component_1"> <api> <object name="sutObj_a" type="Class_A"> <object name="sutObj_b" type="Class_B"> <object name="sutObj_c" type="Class_C"> </api> </testComponent> <testComponent name="Component_2"> <protocol protocolName="protocol_xy"/> </testComponent></testArchitecture>

testcase TC_1() runs on mtcType {

//creating parallel testComponents:

var t_Component_1 Component_1 :=

Component_1.create;

var t_Component_2 Component_2 :=

Component_2.create;

// mapping to System Ports

map (Component_1.pco1:system.pco1);

map (Component_2.pco2:system.pco2);

// starting Components behaviour

Component_1.start(testBehaviour_1());

Component_2.start(testBehaviour_2());

}

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Specification of a XTR test case


<testCase name="TC_1"> <testBehaviour testComponent="Component_1"> … </testBehaviour> <testBehaviour testComponent="Component_2"> <variables> <variable name="timeOutTimer" type="Timer"/> <variable name="waitTimer" type="Timer"/> </variables> <testInteraction> <send> // send testInteraction with a fixed value <message> <value typeName="aStructure"> ... </value> </message> </send> </testInteraction> <timerOperation type="start" timer="timeOutTimer"/> <testInteraction> <receive verdict="pass"> // testInteraction <message> // using a template <template templateName="aTemplate"/> </message> </receive> <timeout timer="timeOutTimer" verdict="fail"/> </testInteraction> <timerOperation type="stop" timer="timeOutTimer"/> <synchronize/> // => Synchronization of test </testBehaviour> // components</testCase>

Concurrent test behavior:

Expressed by different groups of <testBehavior> elements

Running on different testComponents

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<testInteraction> elements are used to specify different interactions with the SUT:

For message-based communication <send> and <receive>

For procedure-based communication <call>, <return> and <catch>

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Values for test interactions can be assigned in three different ways:

Fixed inline values

Templates

Dynamic values from local variables

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Test verdict is determined by the result of

<receive>,

<return> or

<catch> test interactions.

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function testBehaviour_2 () runs on

Component_2 {

timer timeOutTimer := 15.0;

timer waitTimer := 15.0;

{

pco2.send(...) // sending a fixed value

timeOutTimer.start;

alt {

[]pco2.receive(aTemplate) {

setverdict(pass);

timeOutTimer.stop;}

[]pco2.receive(?) {

setverdict(fail);

timeOutTimer.stop;}

[] timeOutTimer.timeout{

setverdict(fail);}

}

synchronize(); // Waiting for other

testcomponents

}

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Conclusion & Future work

Summary

The XTR format has been designed in order to represent test cases for distributed communicating systems

Support for asynchronous communication and concurrency

Mappings to different target languages

XTR is independent from any test generation tool

Open Issues

Further refinements of the XTR format specification

Applicability of the XTR format for representing large test cases

Integration of different test case generators

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Any Questions?

XML-based Representation of Test Cases for Distributed Systems

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