The document compares the Java unit testing frameworks JUnit and TestNG. JUnit was one of the first unit testing frameworks for Java but TestNG was created later to provide more out-of-the-box features. Both frameworks can be used for unit testing but TestNG provides more support for test grouping, parallelization, data-driven and parameterized tests. While JUnit is sufficient for basic unit testing, TestNG has additional features that make it more suitable for integration and acceptance testing scenarios.

1. JUnit vs TestNG:
ceasefire or the end of
the war?
Oleksiy Rezchykov
October 2013

2. Who am I?
• Software Engineer
• Last 6 years working with Java
• XP/Agile/Lean practitioner
• Lazy Pragmatic programmer
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3. 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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4. TDD
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5. 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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6. 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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7. Runners: JUnit
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8. Runners: JUnit
• By default BlockJUnit4ClassRunner is used
• You could add your own features by extending it
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9. 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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10. Cycle: JUnit
Before/after class @BeforeClass/@AfterClas
s (static methods)
Before/after test @Before/@After
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11. Cycle: TestNG
Before/after suite @BeforeSuite/@AfterSuit
e
Before/after class @BeforeClass/@AfterClas
s
Before/after test @BeforeMethod/@AfterM
ethod
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12. Suites: JUnit
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13. Suites: TestNG
Using testng.xml and <suite> tag
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14. Groups: JUnit
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15. Groups: TestNG
@BeforeSuite/@AfterSuite
@BeforeTest/@AfterTest
@BeforeGroups/@AfterGroups
@BeforeClass/@AfterClass
@BeforeMethod/@AfterMethod
All has groups attribute
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16. Groups: TestNG
You can define which groups you want to run using
testng.xml
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17. Test dependencies
JUnit:
Since Junit 4.11
@FixMethodOrder(MethodSorters.JVM)
TestNG:
@Test attributes dependsOnGroups,
dependsOnMethods
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18. Parameterized tests: JUnit
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19. Parameterized tests: TestNG
The values could be passed from testng.xml
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20. Parameterized tests: TestNG
@DataProvider annotation could be used.
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21. Exceptions: JUnit
• Try/catch with fail()
• Expected attribute of the @Test annotation
• ExpectedException as a @Rule
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22. Exceptions: TestNG
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23. @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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24. Test run timeout
• TestNG - attribute in @Test annotation
• JUnit – attribute in @Test annotation
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25. 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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26. 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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27. 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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28. To read
TestNG:
• http://testng.org/
• http://testng.org/doc/book.html
• http://beust.com/
JUnit:
• https://github.com/junit-team/junit/wiki
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29. Presentation and code
• http://www.slideshare.net/mcgray
• https://github.com/mcgray/junit-vs-testng
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30. Questions?
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@twincengray
oleksiy.rezchykov@gmail.com
http://McGray.com.ua