Building Robust Test Suites with TestNG and Selenium

Building Robust Test Suites with TestNG and Selenium

To speed up testing, improve accuracy, and reduce manual effort in this fast-paced world of application development, the demand for automated testing continues to advance. The reason for this is automation testing allows for detecting and fixing issues early and enhances application quality.

Thus, a robust automation testing framework with easy-to-use features is required to ensure the stability and reliability of applications. Selenium being a powerful tool for automating web testing can greatly improve the efficiency and accuracy of application testing. Therefore testers need to have Selenium knowledge for writing automated test scripts using Selenium so that they can effectively and efficiently perform Selenium testing.

TestNG is a well-known testing framework for Java applications, providing developers with an extensive feature set to build robust test suites for performing automated testing for web applications. It is built on the capabilities of JUnit and NUnit. Selenium, on the other hand, is an extensively used automation testing framework that enables users to automate web browsers. By integrating these two powerful tools developers can create robust automated tests for their web applications.

This article will discuss building a robust test suite using TestNG in Selenium to enhance the overall quality of automated testing. But before moving ahead, we will first learn in brief what the TestNG framework is, what its features are, and the purpose of using TestNG with Selenium. So let’s get started.

What is the TestNG Framework?

In TestNG, the NG stands for ‘Next Generation’. It is a flexible, more powerful, feature-rich testing open-source automation framework for Java, making it a better choice for complex and large test automation projects.

It was created by Cedric Beust, to be efficiently utilized by developers and testers in test case creation because of its ease of using multiple annotations, test grouping, dependencies, prioritization, and parameterization features.

Features of TestNG

Multiple annotations

TestNG Annotations are codes that are written inside the program, ensuring the smooth running of test scripts. These annotations are necessary to run the tests.  Various annotations of TestNG are categorized into before and after annotations. The before annotations are @BeforeSuite,@BeforeTest,@BeforeClass and @BeforeMethod. The after annotations are @After Method, @After Class, @After Test, and @AfterSuite.

Grouping of test cases

TestNg enables the grouping of different test scenarios into logical units by converting them to testing.xml, helping developers and testers execute the particular type of test cases instead of all the test cases. This makes it easy to manage and maintain the test suite. 


Prioritization is a TestNG parameter assigned in @Test annotation to ensure that the Test Suite runs in an orderly way. With priority parameters, the test suite will always run in ascending order. If the Priority of a Test Suite is one, then the other test suites have priority as 2, 3. The test suite with priority 1 will run first followed by 2 and 3. 

Priority can also be zero, negative, and positive value. In case when priority is not assigned to any Test suite then by default it is taken as zero.


Parameterization is a powerful feature in TestNG that allows the writing of more efficient and effective tests by reusing the same test logic with different input sets of data. This feature is useful when it is needed to test a particular functionality with different input values to ensure that it works correctly in all scenarios.

XML File

TestNG contains an XML file that facilitates the smooth execution of multiple test suites together. Before running any Test suite it first needs to convert into an XML file, this makes it easy to understand the codes.

XML file is essential in parallel testing where different test suites are run simultaneously in different browsers and cross-browser testing multiple suites are run in different browsers one by one. In both cases, the code needs to be changed in an XML file.

For performing Assertion where expected and actual results are compared and Grouping where we segregate different types of testing and for each testing type separate Xml files are used.

Emailable report

It also generates HTML-based test reports called emailable reports. Emailable reports are generated after the execution of all the test suites. They are generally HTML reports containing detailed information about the current status of the test suites in a very brief and clear manner like total tests passed and failed, tests skipped, time duration of each test, and the output of all the test methods run.  

All this information will be shown in a sequential order based on the annotations and parameters used in programming code. Automation testers share the emailable report with the QA manager and other members of the team to apprise them about the current status of the project.

All these features make TestNg a very important framework in Selenium for developers and testers to ensure smooth execution of automation test suites  

Purpose of using TestNG in selenium?

Below are some of the reasons for using the TestNG framework in Selenium:

  • Allows testers to easily perform cross-browser testing and parallel testing.
  • Testers can easily understand annotations.
  • Generate the test results in a proper format.
  • Group test cases by converting them to XML files.
  • Include the total number of test cases run with their passed, failed, and skipped status in the report.

The benefits of TestNG in selenium

TestNG provides many advanced and useful features, making it a more robust framework. Some of the features it includes are;

  • Provide a unique set of annotations like @BeforeSuite, AfterSuite, BeforeTest, AfterTest, BeforeMethod, and AfterMethod to customize the tests, and configure them at different levels. Thus enabling the smooth running of Test suites sequentially.
  • Data-driven testing to run the same test case with multiple data sets.
  • Using TestNG in the Page Object Model prevents code repeatability and allows code reusability, as a result saving time.
  • Testing in a sequence that is in a specific order.
  • Allows running tests in parallel, and making Selenium test execution efforts more effective and efficient.
  • Many reporting and logging features with detailed information about test execution, including test results, failures, and errors, to easily identify and debug issues in the tests.
  • Capturing screenshots if there is any failure in any test execution steps.
  • In case of test case failure, it gets redirected to the new block written for the screenshot.

Automation using TestNG with Selenium 

Selenium is an automation testing tool that is used to automate interactions of web applications with web pages and web browsers. TestNG is a robust testing framework, designed to make writing, organizing, and reporting tests easier.

Utilizing TestNG in Selenium provides additional functionality to perform a broad range of tests like unit testing, integration testing, functional testing, and end-to-end testing. TestNG is needed because it allows writing powerful test cases by providing features such as support for parameterized tests, annotations, grouping, parametrizing, flexible test configuration, and the ability to specify dependencies between tests. 

Harnessing the power of TestNG annotations helps in building better, more comprehensive Selenium tests. From interacting with web elements to navigating through pages, leveraging TestNG features such as parameterization, annotations, data providers, and built-in support for grouping tests helps to enhance the maintainability and versatility of Selenium test suites. These features can help in writing more comprehensive and practical tests.

Creating a test suite with Selenium and TestNG 

TestNG allows the creation of easy-to-understand HTML reports, generated automatically, making it easier for developers with limited technical knowledge of programming languages like Java or C# as well as non-professionals who may have just started their career in this field. 

Creating a test suite with TestNG is easy. It first needs to create a testng.xml file and execute it to achieve the goals. This TestNG XML file allows creating and handling multiple test classes in the TestNG framework using the java org.testing. TestNG command-line option. The suitename option can also be used to specify the name of the test suite, making it easier to run multiple test suites all at once.

TestNG also allows specifying the order in which the tests will be run and how they will be grouped. Additionally, the XML file is a targeted file where testers can configure their test suite, set test dependency, include or exclude any test, method, class, or package, and set priority, etc. This makes it easy to create comprehensive test suites and also to run and maintain them efficiently.

Leveraging LambdaTest cloud Selenium Grid for seamless browser testing

TestNG provides many advanced features and reporting, making automated tests more structured, readable, maintainable, and user-friendly. 

LambdaTest is an automation testing solution that provides support for running Selenium tests using TestNG. LambdaTest is an AI-powered test orchestration and execution platform that facilitates automated and manual testing of mobile apps, web testing, and APIs at scale.

LambdaTest maximizes the potential of Selenium for web application testing by allowing performing both real-time and automation testing by providing access to an online Selenium Grid of more than 3000 environments, real mobile devices, and browsers. This is to ensure exceptional user experiences across different browsers, platforms, and network conditions.

LambdaTest cloud Selenium Grid offers several advantages. They include seamless integration of TestNG with cloud Selenium Grid for efficient and scalable cross-browser testing, faster test execution, and better utilization of resources, minimizing the need to maintain additional servers or browsers onsite. 

Testers can automate TestNG test scripts, and ship them quickly by executing them parallely across any combination of web browsers and environments using the online selenium grid to significantly reduce test execution time and improve overall efficiency. Additionally, a Selenium cloud Grid provides advantages in terms of speed, scalability, and enhanced debugging and troubleshooting support.

LambdaTest standout features other than robust API support, and extensive support for both mobile and web testing are-

• Interactive reporting dashboards providing detailed test reports and analytics.

• Various logs to get actionable insights into test results.

• Seamless integrations with various CI/CD and project management tools.

It also provides advanced debugging and monitoring tools to capture detailed performance metrics, network logs, and screenshots during test execution. This helps in identifying and debugging issues easily, and gain valuable insights into the web application’s behavior across multiple browsers and platforms.


In conclusion, it can be said that TestNG is a widely used automation framework by testers and developers, due to its advanced capabilities, and rich features set. It is now a powerful choice for Selenium automation testing because of its flexibility and efficiency. TestNG allows enhancing test structure, organization, and execution, as well as saves time and effort in Selenium automation by eliminating the need to extend classes to define the execution order

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