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Try for freeTesting is the most critical part of the Software Development Life Cycle(SDLC). Testing is performed at different levels such as Unit Testing, Integration Testing, and Functional Testing. Testing can be performed either manually or through automation. The tools or libraries which are used for test automation vary with the framework that you are using. For example, if you are using a JavaScript framework, you might have to use Jasmine, Jest, etc. The JUnit and TestNG are the most popular Java testing frameworks, so let’s explore JUnit vs TestNG in detail here.
Table Of Contents
JUnit vs TestNG – Overview
What is JUnit?
JUnit happens to be among the most popular unit testing frameworks for Java. It offers a simple and effective solution when it comes to writing and running unit tests for Java code. In JUnit, test cases are generally written as Java classes that have methods to test particular units of code—methods, for example, or classes.
Features of JUnit
Annotations: JUnit uses annotations to define test cases, test suites, and expected exceptions.
Assertions: JUnit provides several different assertion methods, such as assertEquals, assertTrue, and assertFalse, to check the correctness of the results being tested.
Test Runners: JUnit comes with built-in test runners for running tests and reporting results.
Fixtures: JUnit has built-in support for the creation and cleanup of fixture objects.
Test Suites: JUnit enables the creation of test suites so that related tests can be executed together. This is a cleaner and simpler approach.
Check here – Cucumber vs JUnit
What is TestNG?
TestNG is a unit testing framework for Java classes developed to fill in the gaps left by JUnit and NUnit. It introduces some new concepts that were not available in JUnit or NUnit at the time, like groups, flexible configurations for running test cases, and data-driven testing at the test suite level.
Check here – TestNG vs Cucumber
Features of TestNG
Annotations: TestNG uses annotations to define test cases, test suites, and test configurations.
Data-Driven Testing: TestNG supports data-driven testing. It allows running the same test with different data sets.
Parallel Testing: TestNG has the capability to execute tests in parallel, which is advantageous for improving performance for large test suites.
Listeners: TestNG equips listeners to customize the way tests are run and how results are reported.
Dependencies: TestNG allows the specification of dependencies between test methods so that they are executed in the right order.
Check here – Parameterization in TestNG
Similarities Between JUnit and TestNG
The table below shows the similarities between JUnit and TestNG:
| Feature | JUnit | TestNG |
| Core Purpose | Unit testing for Java | Unit testing for Java |
| Annotation-based Testing | Yes | Yes |
| Assertion Mechanisms | Yes | Yes |
| Test Suites | Yes | Yes |
| Test Reporting | Yes | Yes |
| Parameterized Testing | Yes | Yes |
| Dependent Tests | Yes | Yes |
| Data-Driven Testing | Yes | Yes |
| Parallel Test Execution | Yes | Yes |
| Grouping of Tests | Yes | Yes |
| Test Listeners | Yes | Yes |
Top 20 Core Differences between JUnit and TestNG
Check out the core differences in the table below:
| Feature | JUnit | TestNG |
| Open Source | Yes | Yes |
| Setup | Straightforward, minimal configuration | Easy, and to add dependencies |
| User-Friendliness | May require additional integrations (e.g., JUnit Jupiter) for some features | More features out of the box, user-friendly |
| Listener Implementation Read here – Listeners in Selenium | Less intuitive (Listeners API) | More intuitive (annotations) |
| Reporting | No built-in HTML reporting integrates with Maven or other tools | Built-in HTML reporting integrates with Maven |
| Parallel Test Execution | Not supported directly (workarounds possible) | Natively supported (improves efficiency) |
| Dependency Testing | Not supported, tests run independently | Supported, allows tests to depend on others |
| Data-Driven Testing | Supported, but requires more effort | Straightforward, special annotations (@DataProvider) |
| Test Grouping | Supported using tags (may require additional setup) | Seamless, allows organized execution by groups |
| Test Priority/Order | Controllable, but less flexible | Explicit priorities for precise control over execution order |
| Assumptions Support | Yes, tests can be skipped based on conditions | No built-in support focuses on strict execution |
| Parameterized Tests | Supported, but requires additional annotations (e.g., @ParameterizedTest) | Supported, but uses different annotations (@Test(dataProvider = “dataProvider”)) |
| Timeout Support | Supported, allows tests to be terminated after a specified time | Supported, but provides more flexibility with timeout configurations |
| Fixed Suite | Yes, a fixed set of tests is defined in a suite class | No, tests can be dynamically discovered and added |
| Test Configuration | Less flexible, uses @BeforeClass and @AfterClass | More flexible, uses @BeforeMethod, @AfterMethod, @BeforeTest, @AfterTest, etc. |
| Test Annotations | @Test, @BeforeClass, @AfterClass, @Before, @After | @Test, @BeforeMethod, @AfterMethod, @BeforeTest, @AfterTest, @BeforeClass, @AfterClass, and more |
| Configuration Files | Less flexible, uses testng.xml | More flexible, and uses testng.xml and other configuration options. |
| Error Handling | Less granular error handling | More granular error handling with features like soft assertions. |
| Test Retry | Not supported directly | Supported, allows failed tests to be retried a specified number of times. |
| Test Execution Listeners | Supported, but less flexible | Supported, with more granular control over test execution events. |
Why is JUnit More Popular than TestNG?
Junit is most often more popular than TestNG because of its history as one of the first Java testing frameworks. It is simple and easy to use and very highly integrable with widely used IDEs like Eclipse and IntelliJ IDEA.
There are many tutorials available for this, and there is a very large community that supports an ecosystem of plugins and extensions.
The introduction of JUnit 5 has made it more interesting due to new features and flexibility. Besides JUnit 5 close association with the test-driven development (TDD) pattern enforces it as the de facto standard for unit testing in Java.
Can We Use JUnit and TestNG Together?
Even though it is not a common practice, you can use JUnit and TestNG together.
But they are chosen to be used together due to their complementary strengths and widespread adoption within the testing community. While JUnit is renowned for its simplicity and ease of use, TestNG offers advanced features like parameterized testing and parallel execution. Combining both frameworks allows developers to capitalize on the best of both worlds.
Summary
In the comparison of JUnit and TestNG, JUnit is simple, old, and works greatly integrated with IDEs; hence, it is more commonly used for unit testing. On the other hand, TestNG offers advanced features like execution of tests in parallel and dependency testing that are oriented to a more complex test environment.
In the end, however, the choice between the two is an individual thing based on the project and its specific needs as well as the taste of the developer.
Frequently Asked Questions
JUnit vs TestNG, which is better?
This question has no definitive solution because both TestNG and JUnit have advantages and disadvantages. Other additions include flexible test design, data-driven test support, and improved reporting capabilities. On the other hand, JUnit is extensively used and has a large ecosystem of plugins and integrations.
What is the main difference between JUnit and TestNG?
The primary distinction between JUnit and TestNG is their features and capabilities. Other additions include flexible test design, data-driven test support, and improved reporting capabilities. JUnit is extensively used and supported by a large ecosystem of plugins and integrations.
Does TestNG use JUnit?
No, TestNG is a different testing framework that does not use JUnit.
JUnit vs TestNG? What are the advantages of TestNG?
Support for data-driven tests, flexible test setup, richer reporting, and the ability to create dependencies between test methods and groups are all advantages of TestNG over JUnit. Talking about parallel test execution with JUnit Vs TestNG, TestNG also supports parallel tests, which can drastically reduce total test execution time.
