Testing in Extreme Programming

By Mong-Hang Vo

CS 240 Software ProjectMaster of Science in Computer

ScienceSan Jose State University

December 03, 2003Professor Badrul Sarwar

Agenda

Testing in XP Overview JUnit Framework

Rules and Practices of XP Planning Designing Coding

Code the unit tests first Testing

Coding The Unit Tests First Create one test to define some small

aspect of the problem Then create the simplest code that will

make that test pass Then create a second test Add to the code you just created to make

this new test pass … Continue until there is nothing left to

test.

Coding The Unit Tests First Give a better idea of what features

need to be in a class Immediate feedback Easier and faster to create your

code No need to create them after the

code Save you a lot of time.

Testing in XP Unit Tests Acceptance Tests.

Testing in XP All code must have unit tests All code must pass unit tests

before it can released When a bug is found tests are

created Acceptance tests are run often and

the score is published.

Unit Tests Majority of the testing in XP is unit

testing Unit tests XP style

Download a unit test framework to be able to create automated unit tests suites

Test all classes in the system Create your tests first before coding

Unit tests are released into the code repository along with the code they test.

Unit tests

Enable Collective Code Ownership Enable refactoring.

Collective Code Ownership Everyone in the development team

owns all the code When a change is required, any

programmer can make the change at any time

More reliable than putting a single person in charge of specific classes.

Refactoring Removing redundant and unused

code Keep the design simple.

Acceptance Tests

Created from user stories provided by the customers

Are black box system tests Should be automated so it can be

run often The implementation and running of

acceptance tests can be done by the Software QA team.

Quality assurance (QA) An essential part of the XP process Can be done by a separate group Can be integrated into the

development team XP requires development to have

much closer relationship with QA

Unit Tests Framework Download

www. XProgramming.com JUnit Framework

http://www.junit.org Developed by Luckily Erich Gamma

and Kent Beck The standard for unit testing in Java.

JUnit Framework A set of classes that allows you to

easily create and run a set of unit tests.

Run unit tests Command line mode JUnit GUI

A test case is usually implemented as a subclass of junit.framework.TestCase

JUnit Framework The execution of a test method in

JUnit follows the model: setUp(); test<method_name>(); tearDown();

Junit distinguishes errors from failures. Failures are anticipated by the assert methods.

These methods compare actual result with expected results.

JUnit Framework If a test fails, execution of the current

test method is aborted. A test case repeats the above model,

using reflection to find all test methods.

Test methods must be public, void, take no arguments, and have a name that starts with "test" (so that reflection can determine which methods to call).

JUnit Framework

JUnit Framework

JUnit Framework Automate unit testing of Java

classes Test code should be documented

with Javadocs. Easier to maintain well-documented

test cases Is an easy-to-use framework.

References http://www.extremeprogramming.org Unit tests Samples in JUnit installation Unit Testing: Test Early, Test Often by

Michael Olan Test first, code later: a guide to

integrating JUnit into development process by Thomas Hammell and Robert Nettleton (sjlibray.org)

Thank You!