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TestNG: a powerful testing framework for Java
What is TestNG ?
TestNG is a powerful testing framework for Java that is designed to support a variety of test types, including unit, functional, integration, and end-to-end tests. It provides a number of features that make the testing process easier and more efficient.
TestNG is inspired by JUnit and NUnit with new introductory features that make it more powerful and easier to use. NG stands for Next Generation, which refers to the new features that TestNG brings. From simple unit testing to complex integrated testing, it is designed to simplify all your testing requirements such as functional testing, regression testing, end-to-end testing and more. It is an open-source and free tool.
Before we learn how to use TestNG, let’s take a look at some of the benefits of using this testing framework.
What is TestNG used for?
- To test the functionality of a web application: The TestNG can be used to test whether the web application correctly processes input data, displays correct information and responds to user actions.
- To test mobile app performance: TestNG can be used to test how fast a mobile app launches, how quickly it responds to user input, and how efficiently it uses device resources.
- To test desktop application security: TestNG can be used to test whether a desktop application is resistant to attacks such as SQL injection or cross-site scripting.
- To test the integration of cloud services: The TestNG can be used to test whether cloud services are communicating properly with each other and providing the right functionality.
Benefits of TestNG
- Simplified TestNG annotations: The annotations have been simplified, making it easier for testers to understand them.
- Results in HTML: Generates reports in HTML.
- TestNG Parallel Execution: Using the TestNG Suite (testing.xml), which is basically an xml file, testers can execute multiple test cases at the same time. In this xml file, users must specify the number of classes and test cases they want to execute.
- Running failed test cases: TestNG can also be used to run failed test cases. This is one of the most important advantages of TestNG over JUnit.
- Enables grouping: TestNG supports grouping. With this feature, testers can group test cases without much effort, which was not possible with JUnit.
- Allows execution in multiple browsers: TestNG allows testers to execute and run a single script in multiple browsers.
- Parameterized Testing: In most cases, testers have to perform a large number of different tests, mainly due to the nature of their business logic. However, this lengthy process can be eliminated because parametric testing allows you to run the same test multiple times by simply changing the values. Allows you to pass parameters to test methods in two ways: parameter and @dataprovider.
- Pass or ignore test cases: This feature is useful if you don’t want to execute specific test cases. In such cases, TestNG allows you to disable or bypass specific test cases using the @Test(enabled = false) annotation.
- Reporter class generates logs: In TestNG, users can use the Reporter class to log messages for a test. Let’s say you’re running a test-case and you want to record related information.
- Expected Exceptions: Allows you to keep track of exception handling in your code. When writing code, there may be situations where testers want to verify that an exception is thrown when the code is executed. This method will give you details of the exceptions that are expected to be presented for that method. Use this method with @Test annotation.
- Dependency method: TestNG supports the “dependency” method. We can have a dependency as an attribute of a method, for example if one method is dependent on another. This is not available in JUnit.
- Priority of tests: We can execute test cases in a certain order. To achieve this, we define the ranking in the @Test annotation.
Disadvantages of TestNG
- Learning curve: The TestNG has a fairly steep learning curve. This means that you need to learn a lot of new concepts and annotations in order to start writing tests. This can be challenging for beginners.
- Complexity:TestNG is a fairly complex testing framework. This means that there are many options and configurations that can be set up. This can lead to difficulties in test maintenance, especially for new testers.
- Performance: TestNG can be more performance intensive than some other testing frameworks This is due to the fact that TestNG is quite complex and uses multiple resources.
- Lack of documentation: The TestNG has some documentation gaps. This can be frustrating for beginners as it can be difficult to find the information they need.
TestNG documentation
If you want to read more about TestNG and find out what features it offers, be sure to read the documentation on their official website.
TestNG tutorial
If you don’t want to waste time with documentation and want to see how TestNG works, check out one of the following tutorials and try TestNG in practice.
Alternatives to TestNG
- JUnit is another popular testing framework for Java. It is simpler than TestNG, but does not provide the same feature set. JUnit is a good choice for beginners who want to learn the basics of testing.
- Selenium is a testing framework for automating web applications. It can also be used to test software that is not a web application. Selenium is a good choice for testers who need to automate web application testing.
- Appium is a testing framework for mobile application automation. Appium is a good choice for testers who need to automate mobile app testing.
- Cucumber is a testing framework for automating software testing using natural language. Cucumber is a good choice for testers who want to write tests in natural language that is easy to understand.
- Pytest – Pytest is a testing framework for Python. Pytest is a good choice for testers who need a testing framework for Python.
- RubyUnit – RubyUnit is a testing framework for Ruby. RubyUnit is a good choice for testers who need a testing framework for Ruby.
- NUnit – NUnit is a testing framework for C#. NUnit is a good choice for testers who need a testing framework for C#.
- xUnit – xUnit is a testing framework for C++. xUnit is a good choice for testers who need a testing framework for C++.
TestNG vs JUNIT
- TestNG supports the group concept, while JUnit does not.
- Parameter testing is possible in TestNG, but cannot be done in JUnit.
- TestNG provides special annotations, such as @Before/AfterSuite and @Before/AfterTest.
- In TestNG it is possible to change the name of the method. However, JUnit does not allow this.
- TestNG supports the “dependency” method. It is not available in JUnit.
TestNG vs Maven
- Maven is a project management tool, while TestNG is a testing framework.
- Maven is used to manage the dependencies and build cycle of the project, while TestNG is used to write and execute tests.
- Maven is required to run TestNG. TestNG comes with a Maven plugin that makes it easy to run tests from Maven.
- TestNG can be used with or without Maven. TestNG can also be run without Maven, but it is less convenient.
TestNG vs Selenium
- Selenium is a testing framework for web application automation, while TestNG is a general testing framework.
- Selenium is designed specifically to automate web applications, while TestNG can be used to automate any type of software.
- Selenium can be used with TestNG. There are several ways to use Selenium with TestNG, including using Selenium WebDriver with TestNG or using Selenium Grid with TestNG.
- TestNG is available for Java, while Selenium is available for Java, C#, Python, Ruby and more.
TestNG vs Cucumber
- Cucumber is a testing framework primarily used for behavior-driven development (BDD). TestNG is a testing framework for Java, designed to simplify a wide range of testing needs, from unit tests to integration tests.
- Cucumber scripts are written in Gherkin syntax, which uses keywords such as
Given,When,Then,And, andButto describe behavior in human-readable form, while TestNG uses Java annotations to define test methods, settings, and procedures before and after tests. - Cucumber interprets feature files and executes scenarios described in the Gherkin syntax. Test execution is driven by feature files and corresponding step definitions, while TestNG executes Java test methods based on annotations.
- Cucumber typically generates HTML or JSON reports, TestNG provides built-in HTML reports and integrates with other reporting tools such as ExtentReports and Allure for detailed test reporting.
- Cucumber integrates with various programming languages and testing frameworks (e.g. Java with JUnit or TestNG, Ruby with RSpec) and TestNG can also be integrated with various frameworks such as Eclipse, IntelliJ IDEA, etc.
Installing TestNG in Eclipse
1. Go to the Eclipse application. If you don’t have it yet, you can download it from this page. Here you can find detailed instructions on how to install Eclipse on Windows.
2. Click “Help” in the top bar.
3. Select “Eclipse Marketplace”.
4. Search for “TestNG” in the Search section.
5. Install TestNG for Eclipse by clicking on “Install”.
6. You can check if TestNG is installed correctly by clicking on “Window” and then “Preferences”. You will see this window and if you see TestNG in the sidebar, the installation was successful.
Conclusion
TestNG is a powerful and flexible testing framework for Java that is designed to support a wide range of testing scenarios from simple unit tests to complex end-to-end testing. With its rich set of features such as parameterized tests, group testing and support for multiple test cases at once, TestNG enables efficient and effective software testing, improving the quality and reliability of development projects.
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