TestNG Framework Tutorial: A Comprehensive Guide, with Examples & Best Practices

  • Learning Hub
  • TestNG Framework Tutorial: A Comprehensive Guide, with Examples & Best Practices


It is a Java-based open-source test automation framework. It covers a broader range of test categories: unit, functional, end-to-end, integration, etc. This framework is quite popular among developers and testers for test creation due to its useful features like grouping, dependence, prioritization, ease of using multiple annotations, etc. Another reason for its popularity is that it helps them organize tests in a structured way and enhances the scripts' maintainability and readability.

Though, it is developed on the same lines as NUnit and JUnit. But, its advanced features make it a much more robust framework in comparison to its peers.In this TestNG framework tutorial we will dive deeper into all aspects of TestNG.


Choosing The Right Selenium Java Framework

New generation frameworks are emerging today with multiple advantages that can mark a shift in how applications are created and used. Of course, the best framework depends on you, your team, and the goals you're trying to hit. But if your ideal choice is TestNG this TestNG framework tutorial will guide you so that you can test anything quickly and easily.

So check out this article to know why you should choose TestNG framework.


JUnit 5 vs TestNG

JUnit and TestNG are the most popular Java frameworks for automated Selenium testing. You should choose the one that suits your requirements best.

Let us get to the core differences between JUnit 5 vs TestNG.

  • Junit is an open-source unit testing framework for java, while TestNG is also a Java-based framework but has wider scope for different types of testing like functional, end-to-end, unit, etc.
  • Coming to Annotations of Junit 5 & TestNG, TestNG annotations can be used easily & has a more significant number of annotations that can be used in the test scripts.
  • Dependency Tests are supported for TestNG only. These are tests where one method will not run unless the dependent method runs & passes.

These were some key differences highlighted in our TestNG framework tutorial. You can read about additional differences & parallel execution in our JUnit 5 vs TestNG blog.

Getting started with TestNG

This section of the TestNG framework tutorial will help you get started with running automation tests with TestNG Framework.

Installing TestNG in Eclipse

Installing TestNG in Eclipse is a used to develop & test code. There are numerous ways to install TestNG in Eclipse. We have discussed various ways to install TestNG in Eclipse. They include installing TestNG plugin in Eclipse -

  • Through the marketplace.
  • Without marketplace.
  • By downloading the library.

We have explained few steps in brief in this TestNG framework tutorial to get deeper insights into how to set up TestNG Eclipse tests from your existing Java, checkout our blog about Installing TestNG in Eclipse to understand in detail.

Create TestNG Project in Eclipse

Learn how to create a TestNG project from scratch and write your very first test script. There are some prerequisites required for getting started they are Eclipse IDE & downloading Selenium WebDriver and Client for Java.

These are the next steps which are to be followed -

  • Create TestNG project in Eclipse
  • Adding Selenium JAR files To Selenium TestNG Project
  • Creating a TestNG class in Eclipse
  • Writing Our First Test Case Using Selenium
  • Creating a TestNG class in Eclipse and TestNG
  • Generating TestNG Reports

This is a part of our TestNG framework tutorial, you can understand the steps in detail through our blog on creating a TestNG project in Eclipse.

Running Tests with TestNG

This section of the TestNG framework tutorial will act as your step-by-step guide to successfully running tests with TestNG.

Automation TestNG with Selenium

Let's understand automation through this TestNG framework tutorial. TestNG being popular option for automation engineers, who can rely on its in-built features and know that they have an active community of developers behind their back.

Dive into the practical demonstration of automation using TestNG. We will cover the installation process using 2 of the most used IDEs Eclipse and IntelliJ.

To understand the automation process better we have stressed on annotations and attributes. Annotations are used to provide meaning to any function in the test script and describe its behavior. Attributes are part of annotations that help in making our tests more defined.

Apart from this we have emphasized on TestNG assertions, DataProviders & priorities. To learn in detail read the complete blog on automation using TestNG.

Parallel Test Execution in TestNG

The traditional approach of manual testing is already overtaken by automation testing. One widely adopted automation testing strategy is the shift from sequential testing to parallel testing.

To save time and ensure maximum coverage, QA teams shift from testing sequentially to testing in parallel. Tests can be run on multiple devices, browsers, and OS combinations. You can test an app or a component of an app.

Understand parallel test execution in Selenium using configuration of TestNG XML and learn how to perform parallel testing in TestNG on cloud grid.

In this TestNG framework tutorial you can refer to the below video of parallel testing or read our blog on parallel test execution in TestNG for the detailed execution of tests.

Creating TestNG XML File

Running a single test at a time will not be very effective when you use a Selenium Grid. You need to execute multiple test cases in parallel to make the most of it.

One way to execute multiple test files from a single file is to use the TestNG XML file. This file allows you to specify which test files to run and provides additional control over the execution of your tests. By using this file, you can easily manage and run multiple test files.

Dive deeper in this blog of creating TestNG XML file to know about why & how to create TestNG XML file, and learn how to run TestNG XML file along with its parallel execution.


Automation with Selenium, Cucumber & TestNG

Get ready to run your first Cucumber script and leverage TestNG capabilities to perform parallel testing.

Cucumber is a BDD framework used to write and run tests for behavior-driven development (BDD) frameworks. It allows tests to be written in a natural language that is easily understandable by developers and non-technical stakeholders.

This helps to improve communication and collaboration among team members and ensures that the system being built will meet the requirements and expectations of its users.

Deep dive through our blog on automation with Selenium, Cucumber & TestNG as TestNG provides an easier configuration and additional capabilities.

Run JUnit Selenium Tests using TestNG

JUnit is a unit testing framework for Java, while TestNG is a Java framework having a broader scope than unit testing. Both JUnit and TestNG can be used to run unit tests, but they have some differences in their approach and functionality.

TestNG framework supports tests in more categories than JUnit, making it easier to migrate test cases from JUnit to TestNG. One advantage of using TestNG to run JUnit tests is that it allows you to avoid completely rewriting the test scenarios that were originally written using the JUnit framework. It can save time and effort and enable you to take advantage of TestNG's features.

Get started with running your parallel and regular tests by reading our blog on how to run JUnit Selenium tests using TestNG.

Deep diving into Advanced Use Cases for TestNG

In this section of the TestNG framework tutorial, you will learn more about the TestNG testing frameworks by deep diving into the use cases for TestNG.

Group Test Cases in TestNG

In TestNG, a group is a set of test methods that share a common characteristic. Groups are used to selectively run or exclude specific tests from a test run. This allows you to organize your tests into logical units and easily include or exclude them from a test run based on your needs.

For example, you could create groups for different types of tests, such as unit tests and integration tests, and then run only the unit tests in a test suite by specifying the unit test group.

TestNG also allows you to define dependencies between groups, so that tests in one group will only be run if tests in another group have been run and passed. This can be useful for ensuring that certain tests are run only after certain preconditions have been met.

Learn more about it by checking out this blog on grouping test cases in TestNG

Prioritizing Tests in TestNG

Let's understand prioritizing tests in this TestNG framework tutorial. In TestNG, tests can be prioritized using the priority attribute in the @Test annotation. This allows you to specify the order in which the tests should be executed. Tests with a lower priority value will be executed before tests with a higher priority value.

This is especially useful when defining a sequence for the test case execution or when assigning precedence to some methods over others. You can also specify that certain tests should be ignored. This can be useful if you want to temporarily disable a test without deleting it.

By using the priority attributes, you can control the order in which tests are executed and selectively ignore specific tests in TestNG. Learn more about this by checking out this blog on prioritizing tests in TestNG

Assertions in TestNG

TestNG is a popular testing framework for Java. One of the key features of TestNG is the ability to use assertions within your test cases.

Assertions are a way to verify that the output of a piece of code matches what you expect. For example, if you are testing a method that calculates the sum of two numbers, you can use an assertion to verify that the output of the method is the expected sum. If the output does not match the expected value, the test will fail.

There are various types of assertions available in TestNG, including the ability to check if a value is true or false, if two objects are equal, and if an object is null. You can also use custom messages with assertions to provide more detailed information about why a test failed.

Overall, assertions in TestNG are a powerful tool for verifying the correctness of your code. They can help you identify problems with your code and ensure that it is working as expected. Check out this blog to learn about assertions in TestNG.

DataProviders in TestNG

DataProvider in TestNG allows us to pass multiple parameters to a single test using only one execution cycle. This can be helpful when we need to pass multiple values to a test in just one execution cycle.

To use a DataProvider in TestNG, you first need to define a method that returns an array of objects containing the data that you want to pass to the test method. This method should be annotated with the @DataProvider annotation. Then, in the test method, you can specify which DataProvider to use by referencing its name in the @Test annotation.

When the test is executed, TestNG will call the DataProvider method and pass the data it returns to the test method. The test method can then use this data to perform its tests. This allows you to test a piece of code with multiple different sets of input data. They can help you ensure that your code is working correctly with different types of input, and can help you identify any problems or issues with your code.

Hope you have understood DataProviders from this TestNG framework tutorial. Read this blog on DataProviders in TestNG to dive deeper.

Parameterization in TestNG

If most of your tests are likely to have similar actions, then Parameterization may be the right tool for you. We can use Parameterization in our automation scripts, depending on the framework we're using.

When your application involves inputting different types of user interactions, Parameterization is the way to go. Parameterizing your tests allows you to write fewer tests and still achieve the same coverage.

In this blog, we'll examine different ways of parameterization in TestNG tests and how to use these parameters in Selenium automation testing scripts.

TestNG Listeners in Selenium WebDriver

TestNG Listeners allow you to customize test results and provide valuable information on your tests. Selenium WebDriver's TestNG Listeners are modules that listen to certain events and keep track of the test execution while performing some action at every stage of test execution.

TestNG Listeners are classes that can be used to listen to events that occur during the execution of a TestNG test. They allow you to add additional functionality to your tests and can be used to perform a wide range of tasks, such as logging test results, generating reports, or sending notifications. Listeners can be implemented in your tests by annotating your test class with the@Listeners annotation and specifying the listener class or classes to be used.

Learn in this blog about TestNG listeners and how they can be useful for providing additional insights, information about your tests, and can be an essential part of a comprehensive testing strategy.

TestNG Annotations

Annotations were first added to the Java language in JDK 5. TestNG annotations can be added to your code to control how TestNG executes your tests. These annotations are used to identify the different components of your tests, such as test methods, groups, and configurations.

TestNG includes a wide range of annotations that can be used to control various aspects of your tests, such as the order in which they are run, the conditions under which they are executed, and how they are organized into groups.

Annotations can be added to your code for different test methods, there are various types of annotations. Using annotations can make it easier to manage and organize your tests, and can help you create more maintainable and reliable test code.

This was a brief idea about annotations in this TestNG framework tutorial, learn in detail about execution sequence & attribute of annotation in our TestNG Annotations blog.

TestNG Reporter Log in Selenium

The TestNG reporter log is a feature of the TestNG testing framework that allows you to generate detailed reports about the execution of your Selenium tests. The reporter log provides information about the tests that were run, including the number of tests that passed and failed, the time taken to run each test, and any exceptions or errors that were thrown.

This information can be very useful for understanding the results of your tests and identifying any potential issues or problems.The reporter log can help you get a better understanding of your Selenium tests and improve the quality of your test code.

Overall TestNG Reporter Class, allows us to create reports that are informative and helpful without relying on third-party software, improving efficiency and analysis of information. Check out this blog on TestNG Reporter Log in Selenium to learn further in detail.


TestNG Reports in Jenkins

TestNG reports can be integrated with Jenkins to provide additional insights and information about the results of your Selenium tests. Jenkins is an open-source automation server that can be used to automate a wide range of tasks, including building, testing, and deploying software.

By integrating TestNG with Jenkins, you can create a continuous integration (CI) pipeline that automatically runs your tests as part of your build process and generates reports about the results.

To use TestNG reports in Jenkins you need to configure the plug-in once done, Jenkins will automatically generate TestNG reports for your Selenium tests as part of your build process, providing valuable insights into the quality of your code.

Want to know how you can generate, install and share TestNG reports in Jenkins, check out this detailed guide on how to generate TestNG reports in Jenkins.

Frequently Asked Questions (FAQs)

What is a TestNG framework?

TestNG is an open-source Java test automation framework developed by Cedric Beust that is similar to JUnit and NUnit. TestNG has additional advanced features, which makes it a more substantial framework than its counterparts. The letters 'NG'in TestNG stands for 'Next Generation'.

Why is TestNG used in Selenium?

TestNG is used in Selenium due to its ability to perform broad range of tests like unit testing,integration testing, functional testing & end-to-end testing. It provides features such as support for parameterized tests, flexible test configuration, and the ability to specify dependencies between tests.

What is Selenium vs TestNG?

Selenium is a browser automation tool used to automate interactions with web pages and applications in a web browser. While TestNG is a testing framework designed to make it easier to write, organize, report tests, and perform tests like functional, unit, E2E, and integration testing. Selenium can be used to drive the execution of tests written using TestNG. They are not the same and serve different roles in the testing process.

Try LambdaTest Now !!

Get 100 minutes of automation test minutes FREE!!

Next-Gen App & Browser Testing Cloud

Did you find this page helpful?