JUnit vs TestNG:ceasefire or the end of the war?

Oleksiy RezchykovOctober 2013

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Who am I?• Software Engineer • Last 6 years working with Java• XP/Agile/Lean practitioner• Lazy Pragmatic programmer

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Unit testing• A method to test smallest possible portion of

source code• Tests are independent• Tests are not affecting the state of the application

under test• Main building block of the TDD

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TDD

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JUnit• Canonical unit testing framework for Java• Originated from SUnit (SmallTalk)• One of the first in xUnit family• Developed by Kent Beck and Erich Gamma• First versions at year 2000• Now on GitHub

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TestNG• Test Next Generation• Alternative unit testing tool for Java• Authored by Cédric Beust• First version released in 2004• First version has a lot of out-of-the-box features

which was missing in Junit

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Runners: JUnit

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Runners: JUnit

• By default BlockJUnit4ClassRunner is used• You could add your own features by extending it

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Runners: TestNG• TestRunner is used by default• You can start it with classes or xml configuration

files• Usually you create base class for tests to add

custom features• A variety of interceptor interfaces is at your

service

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Cycle: JUnitBefore/after class @BeforeClass/

@AfterClass (static methods)

Before/after test @Before/@After

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Cycle: TestNGBefore/after suite @BeforeSuite/

@AfterSuite

Before/after class @BeforeClass/@AfterClass

Before/after test @BeforeMethod/@AfterMethod

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Suites: JUnit

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Suites: TestNGUsing testng.xml and <suite> tag

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Groups: JUnit

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Groups: TestNG@BeforeSuite/@AfterSuite@BeforeTest/@AfterTest@BeforeGroups/@AfterGroups@BeforeClass/@AfterClass@BeforeMethod/@AfterMethodAll has groups attribute

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Groups: TestNGYou can define which groups you want to run using testng.xml

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Test dependenciesJUnit:Since Junit 4.11 @FixMethodOrder(MethodSorters.JVM)

TestNG:@Test attributes dependsOnGroups, dependsOnMethods

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Parameterized tests: JUnit

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Parameterized tests: TestNG

The values could be passed from testng.xml

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Parameterized tests: TestNG

@DataProvider annotation could be used.

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Exceptions: JUnit• Try/catch with fail()• Expected attribute of the @Test annotation• ExpectedException as a @Rule

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Exceptions: TestNG

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@Rule• JUnit feature• Supported by runners which extends

BlockJUnit4ClassRunner• Framework extension point• There is a set of implemented rules (e.g.

ExpectedException)

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Test run timeout• TestNG - attribute in @Test annotation• JUnit – attribute in @Test annotation

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Running tests in parallel

JUnit:• Using maven-surefire-plugin• Gradle Test task attribute maxParallelForks TestNG:• <suite> tag has parallel and thread-count

attributes• @Test has threadPoolSize attribute

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Env. Support• Eclipse plugin (does not come out-of-the-box)• IDE plugin (out-of-the-box)

• Gradle support• Maven support

• Framework support

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Conclusion• JUnit has everything for the UNIT testing but

could be extended to do barely everything• TestNG has more stuff out-of-the-box and is more

“QA oriented”

• Feature comparison table (from RebelLabs): http://zeroturnaround.com/wp-content/uploads/2013/07/unit-testing.jpg

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To readTestNG:• http://testng.org/• http://testng.org/doc/book.html• http://beust.com/

JUnit:• https://github.com/junit-team/junit/wiki

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Presentation and code• http://www.slideshare.net/mcgray

• https://github.com/mcgray/junit-vs-testng

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Questions?@twincengray

oleksiy.rezchykov@gmail.com

http://McGray.com.ua