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JUnit/NUnit – Unittesting frameworks
…based on the xUnit architecture
MEI 2003/2004 Nuno Flores
What is JUnit?Open Source Java testing framework used to writeand run repeatable tests.Instance of the xUnit Architecture for unit testingframeworks.Features:
Assertions for testing expected resultsTest fixtures for sharing common test dataTest Suites for easily organizing and running testsGraphical and textual test runners
Originally written by Erich Gamma and Kent Beck
JUnit(xUnit) traceback…xUnit first incarnation: SUnit (SmallTalk)JUnit: “Test infected – Programmers Love WritingTests”Extreme Programming, “Embrace Change”
Kent Beck, Martin Fowler, Ron Jeffries, Erich GammaLightweight development philosophyValues: Simplicity, Courage, Communication, FeedbackBest Practices: Pair-Programming, Small Iterations, Colaborative Ownership, Integrate Often, Refactor Often, KISS, DNO, Test-driven programming
XP Practices Overview
Test-Driven ProgrammingSimplicityMinimalist approachTest-First
During Development - When you need to add new functionality to the system, write the tests first. Then, you will be done developing when the test runs. During Debugging - When someone discovers a defect in your code, first write a test that will succeed if the code is working. Then debug until the test succeeds.
Focus on needed functionality
Test-Driven ProgrammingPractical Guidelines
You are forced to define precisely what a method does.You know where to begin writing a method.You know when you are done writing a method.You know the minimal scaffolding needed to run a method.You know when you are done.
“Once you get them running, make sure they stay running”
xUnit ArchitectureObject-Oriented architecture for development of unit testingframeworks.
Have an object (TestCase) manage the execution of a singletest. Each test should be isolated from the others, so it creates all itsdata before executing and destroys it when it's done (setUp() andtearDown()). Composites of tests (TestSuite) allow many tests to be runtogether. Passing a CollectingParameter (TestResult) to the testsas they run allows the collection of statistics. That's the framework--three objects (TestCase, TestSuite, TestResult).
RudyUnit, SUnit, CppUnit, Unit++, PerlUnit, VbUnit, NUnit, PyUnit, SQLUnit, XMLUnit, ...XUnit Online: www.xprogramming.com/software
JUnit Architecture
JUnit Testing
Regression, Modularity, Simplicity“Keep the bar green to keep the code clean”SimpleTest Example
Class declaration and Constructorimport java.util.*; import junit.framework.*;
public class SimpleTest extends TestCase { public SimpleTest(String name) {
super(name);}
}
JUnit Testing
SimpleTest ExampleDeclaring a test method
Creating a test suite
public static Test suite() { return new TestSuite(SimpleTest.class);
}
public void testEmptyCollection() { Collection collection = new ArrayList(); assertTrue(collection.isEmpty());
}
JUnit Testing
SimpleTest ExampleTest execution
public static void main(String args[]) { junit.textui.TestRunner.run(suite());//junit.swingui.TestRunner.run(suite());
}
JUnit TestingTestCase (descends from Assert, implements Test)
Setup()TearDown()assertEquals()assertFalse(), assertTrue()assertSame(), assertNotSame()fail()
TestSuiteaddTest(Test)
JUnit Testing
Demonstration
JUnit TestingTesting Exceptions (expected and unexpected)
public void testIndexOutOfBoundsException() { ArrayList emptyList = new ArrayList(); try {
Object o = emptyList.get(0); fail("Should raise an IndexOutOfBoundsException");
} catch (IndexOutOfBoundsException success) {}
}
public void testIndexOutOfBoundsExceptionNotRaised() throws IndexOutOfBoundsException { ArrayList emptyList = new ArrayList(); Object o = emptyList.get(0);
}
NUnit – xUnit for .NETUnit-testing framework for all .Net languages.Initially ported from JUnit, the current version, 2.1 is
the third major release of this xUnit based unittesting tool for Microsoft .NET. It is written entirely in C# and has been completelyredesigned to take advantage of many .NET language features, for example custom attributesand other reflection related capabilities. NUnit brings xUnit to all .NET languages.
NUnit – xUnit for .NET
AttributesTestFixture (instead of TestCase)TestSetup()/Teardown()Expected ExceptionSuiteIgnore
NUnit – xUnit for .NET
TestFixtureC# VB.NET
namespace NUnit.Tests { using System; using NUnit.Framework;
[TestFixture] public class SuccessTests {
// ... }
}
Imports SystemImports Nunit.Framework
Namespace Nunit.Tests
<TestFixture()> Public Class SuccessTests' ...
End ClassEnd Namespace
NUnit – xUnit for .NET
Testnamespace NUnit.Tests { using System; using NUnit.Framework;
[TestFixture] public class SuccessTests {
[Test] public void Add() { /* ... */
} public void TestSubtract() {
/* backwards compatibility*/
} }
}
Imports SystemImports Nunit.Framework
Namespace Nunit.Tests
<TestFixture()> Public Class SuccessTests<Test()> Public Sub Add()
' ... End SubPublic Sub testAdd()
‘ backwards compatibilityEnd Sub
End Class
End Namespace
NUnit – xUnit for .NET
Setup/TearDown (C#) (I)namespace NUnit.Tests { using System; using NUnit.Framework;
[TestFixture] public class SuccessTests {
[TestFixtureSetUp] public void Init() { /* ... */
} [TestFixtureTearDown] public void Dispose() {
/* ... */ } [Test] public void Add() { /* ... */ }
} }
NUnit – xUnit for .NET
Setup/TearDown (C#) (II)namespace NUnit.Tests {
using System; using NUnit.Framework;
[TestFixture] public class SuccessTests { [SetUp] public void Init() {
/* ... */ } [TearDown] public void Dispose() {
/* ... */ } [Test] public void Add() {
/* ... */ } }
}
NUnit – xUnit for .NET
Expected Exception (C#)namespace NUnit.Tests {
using System; using NUnit.Framework;
[TestFixture] public class SuccessTests {
[Test] [ExpectedException(typeof(InvalidOperationException))] public void ExpectAnException() {
/* ... */ }
} }
NUnit – xUnit for .NET
Expected Exception (VB.NET)
Imports SystemImports Nunit.Framework
Namespace Nunit.Tests
<TestFixture()> Public Class SuccessTests<Test(), ExpectedException(GetType(Exception))> Public Sub ExpectAnException()
' ... End Sub
End ClassEnd Namespace
NUnit – xUnit for .NET
Suite (C#) namespace NUnit.Tests { using System; using NUnit.Framework;
public class AllTests { [Suite] public static TestSuite Suite {
get { TestSuite suite = new TestSuite("All Tests"); suite.Add(new OneTestCase()); suite.Add(new Assemblies.AssemblyTests()); suite.Add(new AssertionTest()); return suite;
} }
} }
NUnit – xUnit for .NET
IgnoreC# VB.NET
namespace NUnit.Tests { using System; using NUnit.Framework;
[TestFixture] [Ignore("Ignore a fixture")] public class SuccessTests {
// ... }
}
Imports SystemImports Nunit.Framework
Namespace Nunit.Tests
<TestFixture(), Ignore("Ignore a fixture")> Public Class SuccessTests
' ... End Class
End Namespace
NUnit – xUnit for .NET
Demonstration
Mock ObjectsMock objects make it possible to test an objectwithout its knowledge. keep stub testing coding out of the real classCharacteristics:
is easily created is easily set up is quick is deterministic has easily caused behaviourhas no direct user interface is directly queriable
Mock Objects
ApplicationsUnit test your application independently of theproduction infrastructure.Anticipate a set of preconditions andpostconditionsDevelopers do not need access to a real database to run the unit tests.Simulate states that may be difficult or time-consuming to realize in a runtime environment.
Mock Objects
ExampleAsserting the right calling order
Mock ClassPublic class MyMockObject extends MyObject {
public boolean methodCalled = false;protected boolean propagateChanges = false;public void mockMethod(int args) {
if (propagateChanges) {//call parent method
}methodCalled = true;
}}
Mock Objects
Test Class [TestFixture] public class TestClass {MyMockObject mock;[Setup] public void Init() {
mock = new MyMockObject();}
[Test] public void testRightProcCalling() {// trigger calling…assertTrue(mock.methodCalled);
}[Test] public void testProcFunc() {
mock.propagateEvents = true;// trigger calling…// assert funcionality
}}
ApontadoresExtreme Programming
www.extrememprogramming.orgwww.xprogramming.com
JUnitwww.junit.org
NUnitwww.nunit.orgnunit.sourceforge.org
Mock Objectswww.mockobjects.com
Referências“Endo-Testing: Unit Testing with MockObjects”Tim Mackinnon, Steve Freeman, PhilipCraig 2000“XUnit Testing – A plea for assertEquals” Tim Mackinnon“Test Infected – Programmers Love WritingTests” Erich Gamma, Kent Beck, online athttp://junit.sourceforge.net/doc/testinfected/testing.htmJUnit.org website, online at http://www.junit.orgNUnit.org website, online at http://www.nunit.orgwww.extremeprogramming.org site
Referências
“Extreme Programming explained: Embrace Change”. Kent Beck, Addison-Wesley, 1999
