TestNG vs JUnit

Updated April 6, 2023

Difference Between TestNG vs JUnit

JUnit and TestNG are the most widely used frameworks for Java developers. TestNG is a framework inspired by JUnit and NUnit. TestNG vs JUnit, both being modern testing framework tools in the Java ecosystem. Depending upon features, frameworks use different annotations and different coding. Compared to Junit, TestNG is advanced in parameterized testing, suite testing, dependency testing.

Unit Testing performs testing unit wise to make sure the application works as expected. TestNG vs JUnit includes comparing their key features, differences and see how these testing frameworks are different from each other.

Head to Head Comparison Between TestNG vs JUnit (Infographics)

Below are the top differences between TestNG and JUnit

Top Key Differences Between TestNG vs JUnit

Let us look at key features of TestNG and Junit,

• TestNG is an open-source testing framework, NG representing NextGeneration and JUnit also an open-source testing framework.
• TestNG and JUnit both support annotations.
• TestNG uses more Java and Object-Oriented features.
• JUnit uses assertions for testing results expected by the business.
• TestNG supports testing of integrated classes, no need to create a test instance.
• JUnit allows writing codes faster, which improves quality.
• TestNG separates compile-time and run-time configuration.
• JUnit can be run automatically, check their own results, and provide immediate feedback, whereas TestNG has run-time configuration flexibility.
• JUnit tests can be organized as test suites with test cases and also test suites.
• Test groups in TestNG compile tests to run all ‘front-end’, ‘fast’, ‘database’, ‘slow’ tests.
• TestNG supports parallel testing, Load testing, partial failures, and multi-threaded testing.
• JUnit shows test progress in the green bar if the test case passes, turns red if it fails.
• TestNG has XML based test configuration and is data-driven
• By default, TestNG provides XML and HTML based reporting.
• JUnit is present in 62% of projects, and TestNG being at 20^th position present in 6% of projects.
• JUnit is an instance of xUnit Architecture, whereas TestNG is similar to JUnit, but it is not a JUnit extension.
• JUnit is developed by Erich Gamma and Kent Beck, whereas Cedric Beust creates TestNG.
• For setting up a Local environment for JUnit and TestNG, JDK should be installed in the machine.
• Both JUnit and TestNG support Annotations, Suite Test, Ignore Test, Exception Test, Timeout, Parameterized Test. JUnit does not support only the Dependency Test.
• Both TestNG and JUnit use 1000 seconds for a timeout.

TestNG vs JUnit Comparison Table

Let’s see some more differences between TestNG vs JUnit through a comparison table for clear understanding:

TestNG	JUnit
TestNG initializes and cleanups at two levels, at method and class levels. Uses @BeforeMethod and @AfterMethod at method level and @BeforeClass and @AfterClass for class level.	JUnit initializes and cleanups at two levels, before and after each method and class. Uses @BeforeEach and @AfterEach for method level and @BeforeAll and @AfterAll for class level.
TestNG uses an XML file to run Suite test.	In JUnit, Test Suite is run using @RunWith and @Suite annotations.
TestNG uses @Test annotation with a Boolean parameter enabled for ignoring Test cases.	JUnit uses @Ignore annotation for ignoring Test cases.
Exception test is used to check which exception is thrown TestNG uses @Test(expectedExceptions = ArithmeticException.class).	JUnit uses @Test(expected = ArithmeticException.class).
Timeout is to terminate a test that takes a longer time. TestNG uses @Test(timeout = 1000).	Time test is used to define if the unit test takes longer than the specified time; if yes, the test will be terminated. JUnit uses @Test(timeout =1000).
In TestNG, @DataProvider or XML file is used to provide a parameter for parameterized testing.	In Junit, @RunWith and @Parameter annotations are used to provide parameter value for the unit test. @Parameter returns List [] and is passed into the class constructor as an argument for parameterized testing.
TestNG supports Dependency Testing; if initial tests fail, subsequent tests will be skipped.	Junit does not support Dependency Testing; if initial tests fail, the subsequent test will also be marked as a fail.
TestNG supports Group Test, which dispatches methods into portions and performs groupings of test methods.	Junit does not support Group Test.
TestNG, by default, generates reports for test execution, which includes HTML and XML output.	Junit provides data in XML format but does not create a report for test executions, which is to be generated separately.
TestNG is better in terms of use as a single module is used to get all TestNG features.	Junit is built on various modules.
TestNG supports Eclipse and IntelliJ with easy integration.	JUnit supports major IDEs, Eclipse and IntelliJ IDEA.
TestNG supports data provider methods.	Supports methods such as Enum, CSV, CSV files, etc., useful in injecting test method input.
TestNG created HTML reports automatically for a test run.	Junit needs an external plugin to generate HTML reports, maven-surefire-report-plugin.
TestNG supports Test Order for ordering test methods according to priority attribute.	Junit does not support Test Order.
TestNG supports Disable Test but limited in functionality.	JUnit supports many other ways to Disable test based on OS properties and JRE.
TestNG supports parallel execution, which is run through XML.	Junit does not support parallel execution.
TestNG supports types of listeners, can be added using annotations.	JUnit supports listeners using LauncherAPI; listeners cannot be added using annotations.

Conclusion

TestNG includes core concepts of Junit4 functionality and hence meant for high level and complex integrations tests, whereas Junit is considered for testing each code unit. Junit provides a flexible and simple framework; the final product’s quality improves with building more unit test cases or suites. Each framework has its strengths and weaknesses, and hence one needs to select the test framework according to business requirements.

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This is a guide to TestNG vs JUnit. Here we discuss the TestNG vs JUnit key differences with infographics and comparison table. You may also have a look at the following articles to learn more –

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