Extending Jun It

8/6/2019 Extending Jun It

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ExtendingJUnit 4

im Hurne, Systems Architect


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eview of Unit Testing

Unit smallest testable part of an application

Unit Test validate each individual unit of code.


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haracteristics of a good Unit Test

Isolated

Test Single Unit

Fast Dont waste the developers time


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Self Contained

Doesnt rely on external resources that could fail

Independent Doesnt depend on any other tests


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Maintainable

Treat just like any other code

Well documented

i i


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tegration Testing

Test how different units

integrate with each other

Test object interactions

Test interaction with outside

systems

i i i h i


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nit Testing with JUnit 3

Create class that extends TestCase

Provides testing infrastructure Provides assertion methods

Write methods with a name that starts with

test

No Parameter Return void

i i i h i 3


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ublic class HelloWorldTest extends TestCase {

HelloWorld classUnderTest;

public voidsetUp() {

classUnderTest = new HelloWorld();

}

public voidtestHelloWorldReturned() {

assertEquals(Hello World, classUnderTest.sayHello());

}

di JU i 3


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xtending JUnit 3

Extend TestCase

Provide custom assertions

Define custom naming

conventions


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XMLUnit

public class MyXMLTestCase extends XMLTestCase {

. . .

public void testForEquality() throws Exception {

. . .

assertXMLEqual(myControlXML, myTestXML);

assertXMLNotEqual(myControlXML, myTestXML);

}

}

d f JU i 3


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dvantages of JUnit 3

Supports Java 1.4 and earlier

Many extensions already available


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it T ti ith JU it 4


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static import org.junit.Assert.*;

public class HelloWorldTest {

HelloWorld classUnderTest;

@Beforepublic void createTestObject {

classUnderTest = new HelloWorld();

}

@Testpublic void helloWorldReturned() {

assertEquals(Hello World, classUnderTest.sayHello())

}

}

t di JU it 4


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xtending JUnit 4

Create custom test runner

Implement Runner Use the @RunWith annotation

Provide static custom assertion

methods

Take advantage of static imports

Define custom annotations


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d t f JU it 4


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dvantages of JUnit 4

Simplified and easier to use

Doesnt burn up inheritance

Additional capabilities and features

l t t I T h S t


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evelopment at ImageTech Systems

Integrating third-party applications

Connectors Complex Independent Systems

Poorly designed and documented APIs Difficult to incorporate in tests

Missing or inaccurate documentation Need to perform Integration Testing

h P bl ith I t ti T ti


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he Problem with Integration Testing

Variable Test Parameters

Changes from workstation to workstation Requires Configuration

Complex Test Dependencies Cumbersome to create in test code

Same test code, many inputs Many extremes or boundary cases

h t W N d d D t D i T t


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hat We Needed: Data-Driven Tests

Tests are defined by the test code AND the

test data

Test Code separated from Test Data

Q i k A id T ti P tt


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Quick Aside: Testing Patterns

Design Patterns for Testing

Examples The Simple Pass/Fail Test Pattern

The Performance Test Pattern

The Data-Driven Test Pattern

h Fi t S l ti


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he First Solution

Define helper method for each data set

Define separate test for each data set

h S d S l ti P t i d


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he Second Solution: Parameterized

Use JUnit 4 Parameterized

custom test runner

Define data sets in static

method


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MLParametrizedRunner

Custom test runner

Data sets defined in XML file

ML File Format


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ML File Format

Based on Spring bean declaration syntax

Data for each test defined in

element.

ML File Format


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ML File Format

Basic Value Object Parameters:

A String Value

12

JavaBean Parameters:


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plementation

Implements Runner by extending internal

JUnit TestClassRunner

Lists of parameters generated by factory

object (ParameterFactory)

karta Commons Digester


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karta Commons Digester

Default factory object uses Jakarata

Commons Digester to parse XML

High-level API on top of SAX

Pattern matching, rules based API

he JUnit 4 Extensions Project


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he JUnit 4 Extensions Project

Collection of extensions for JUnit 4

Additional Annotations @Prerequisite

@Category

Support for running JUnit 4 with JVM 1.4 or

earlierHome for legacy Swing Test Runner


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lans

Continue to develop the XML format

Provide optional support for Spring and

other application frameworks

Provide support for ignoring tests

nitExt Future Plans


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nitExt - Future Plans

Chainable Test Runners

Testing tools for multi-threading

Migration of JUnit 3 extensions to JUnit 4

esources and Links


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esources and Links

JUnit http://www.junit.org

http://junit.sourceforge.net

JUnit 4 Extensions Project http://www.junitext.org

http://code.google.com/junitext

esources and Links


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esources and Links

XMLUnit http://xmlunit.sourceforge.net/

Jakarta Commons Digester http://jakarta.apache.org/commons/digester/

esources and Links


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esources and Links

Automated Test Patterns http://www.codeproject.com/gen/design/autp5.asp

Robots on Wikipedia http://en.wikipedia.org/wiki/R._Daneel_Olivaw

http://en.wikipedia.org/wiki/Marvin_the_Paranoid_Android

http://en.wikipedia.org/wiki/Johnny_5

http://en.wikipedia.org/wiki/HAL9000

Documents

Extending Jun It