TestNG Interview Questions

Checkout Vskills Interview questions with answers in TestNG to prepare for your next job role. The questions are submitted by professionals to help you to prepare for the Interview.    

Q.1 What is TestNG?

TestNG (Test Next Generation) is a testing framework designed for testing and running Java applications, particularly for unit and integration testing. It provides various features like parallel execution, test configuration, and reporting.

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Q.2 How do you install TestNG?

You can install TestNG using the following methods: Through Eclipse Marketplace. Using the TestNG Eclipse plug-in update site. Manually downloading the TestNG JAR file and adding it to your project's build path.

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Q.3 Explain the key features of TestNG.?

Key features of TestNG include: Parallel execution of tests. Grouping and prioritizing test methods. Dependency management between test methods. Support for data-driven testing through data providers. Rich configuration and suite setup/teardown.

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Q.4 What is the purpose of the @Test annotation?

The @Test annotation is used to mark a method as a test method that TestNG should execute. It helps TestNG identify which methods to run as part of the test suite.

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Q.5 How do you perform parameterized testing in TestNG?

You can perform parameterized testing using the @DataProvider annotation. This annotation helps in providing different sets of test data to a test method for multiple executions.

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Q.6 Explain the concept of groups in TestNG.?

Groups in TestNG allow you to categorize your test methods. You can include or exclude specific groups when running tests, which helps in selective test execution based on categories.

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Q.7 What is the purpose of the @BeforeTest and @AfterTest annotations?

The @BeforeTest annotation is used to mark a method that should run before any test methods in the current tag. Similarly, the @AfterTest annotation marks a method to run after all test methods in the tag.

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Q.8 How do you run tests in parallel using TestNG?

TestNG provides parallel execution capabilities using the parallel attribute in the or tag. You can set it to methods, tests, classes, or instances to specify the level of parallelism.

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Q.9 Explain the concept of listeners in TestNG.?

Listeners in TestNG are used to customize and enhance test execution behavior. You can create custom listeners to monitor events like test start, test finish, test failure, and more.

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Q.10 What is the purpose of the dependsOnMethods attribute in the @Test annotation?

The dependsOnMethods attribute specifies the dependencies between test methods. A test method with this attribute set will only execute if the listed methods are successfully executed.

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Q.11 How can you ignore a test method in TestNG?

You can ignore a test method by using the @Test(enabled = false) annotation. This will prevent the ignored method from being executed during test runs.

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Q.12 How do you generate HTML reports in TestNG?

TestNG provides built-in reporting features. After test execution, it generates an HTML report that includes details about test results, test methods, and any failures.

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Q.13 What is the purpose of the @DataProvider annotation?

The @DataProvider annotation is used to supply data to a test method. It allows you to separate the test data from the test logic, making it easier to reuse the same test with different data sets.

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Q.14 Explain the difference between @BeforeMethod and @BeforeTest annotations.?

The @BeforeMethod annotation is used to mark a method that runs before each test method within a tag. On the other hand, @BeforeTest is executed once before all test methods within a tag.

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Q.15 How do you define a TestNG suite XML file?

A TestNG suite XML file is used to define the test configuration, including test classes, test methods, and other settings. It is an XML file that specifies the structure of your test suite.

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Q.16 What is the purpose of the @Parameters annotation?

The @Parameters annotation is used to specify parameters that are passed to test methods. These parameters are defined in the suite XML file using the tag.

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Q.17 How can you ensure that a specific set of methods runs before and after all test methods in a suite?

You can achieve this by using the @BeforeSuite and @AfterSuite annotations. Methods annotated with these will run before and after all tests in a suite.

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Q.18 Explain the concept of data-driven testing using @DataProvider.?

Data-driven testing involves executing a test method with different sets of input data. The @DataProvider annotation helps in achieving this by supplying different data sets to the same test method.

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Q.19 What is the role of the testng.xml file?

The testng.xml file is a configuration file that defines how TestNG should run your tests. It includes information about test classes, groups, parameters, parallel execution, and more.

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Q.20 How can you run multiple test classes in parallel using TestNG?

To run multiple test classes in parallel, you can define a tag in the testng.xml file and specify the classes using the tag. Set the parallel attribute to the desired level of parallelism.

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Q.21 What is the significance of the @Test(timeOut = ...) annotation attribute?

The timeOut attribute specifies the maximum time (in milliseconds) that a test method should take to complete. If the test method exceeds this time, it will be marked as failed.

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Q.22 How do you configure TestNG to run tests in a specific order?

TestNG encourages test methods to be independent, but if you need to enforce an order, you can use the dependsOnMethods attribute or priority attribute in the @Test annotation.

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Q.23 Explain the concept of soft assertions in TestNG.?

Soft assertions allow you to continue running a test even after an assertion fails. TestNG's SoftAssert class provides this functionality, and you can assert multiple conditions before finally calling assertAll() to check all assertions.

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Q.24 How do you group test methods using the @Test annotation and XML configuration?

You can group test methods using the groups attribute in the @Test annotation. In the testng.xml file, you can specify which groups to include or exclude when running tests.

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Q.25 What are the benefits of using TestNG over JUnit?

TestNG offers features like parallel execution, flexible test grouping, parameterized testing, and better reporting out of the box. It provides a more intuitive way to handle complex test scenarios.

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Q.26 Explain the purpose of the dependsOnGroups attribute in the @Test annotation.?

The dependsOnGroups attribute specifies that a test method depends on the successful execution of specific groups of test methods. The dependent test will only run if the specified groups have passed.

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Q.27 How can you implement cross-browser testing using TestNG?

You can implement cross-browser testing by parameterizing your test method with browser-related data (e.g., browser type, version) and using a @DataProvider to provide this data. Then, configure the testng.xml to run the test method with different browsers.

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Q.28 Explain the purpose of the @BeforeClass and @AfterClass annotations.?

The @BeforeClass annotation marks a method that runs before the first test method in a test class, while @AfterClass marks a method that runs after all test methods in the class have executed.

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Q.29 How do you configure TestNG to rerun failed tests automatically?

You can use the retryAnalyzer attribute in the @Test annotation to specify a custom retry analyzer class. This class determines whether a failed test should be retried based on your defined logic.

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Q.30 What is the use of the dependsOnGroups attribute in the tag of testng.xml?

The dependsOnGroups attribute in the tag specifies that the current test depends on the successful execution of specific groups of test methods from different classes.

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Q.31 Explain the concept of a TestNG Factory.?

A TestNG Factory allows you to create test instances dynamically. This is useful when you need to create and run tests with different sets of data or configurations.

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Q.32 How can you specify the order of test execution within a single test class?

TestNG recommends making test methods independent, but you can use the priority attribute in the @Test annotation to explicitly define the execution order.

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Q.33 What is the purpose of the @Listeners annotation?

The @Listeners annotation is used to attach custom listeners to your test classes. These listeners can capture and respond to various testing events.

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Q.34 How do you skip a specific test method in TestNG programmatically?

You can skip a test method using the throw keyword with the SkipException class in a test method body or in a custom @BeforeMethod/@AfterMethod annotated method.

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Q.35 Explain the difference between hard and soft assertions in TestNG.?

Hard assertions halt test execution immediately after a failure, while soft assertions (using SoftAssert) allow the test to continue running even after individual assertions fail.

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Q.36 What is the purpose of the @Parameters annotation in a @Test method?

The @Parameters annotation is used to receive parameters from the tag defined in the testng.xml file for a specific test method.

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Q.37 How can you implement grouping of test methods using regular expressions?

You can use regular expressions in the groups attribute of the tag in the testng.xml file to include or exclude test methods based on a pattern.

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Q.38 What is the role of the @Listeners annotation in TestNG?

The @Listeners annotation specifies a class that implements the ITestListener or ISuiteListener interface, enabling custom listeners to listen to and respond to test or suite events.

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Q.39 Explain the concept of parameterization using the @Factory annotation.?

The @Factory annotation is used to create a factory method that generates instances of test classes with different data sets or configurations. This is useful for data-driven testing.

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Q.40 How do you specify the order of execution for test methods across multiple classes?

In the testng.xml file, you can define the execution order of classes by listing them in the desired sequence within the tag.

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Q.41 What is the purpose of the preserve-order attribute in the tag of testng.xml?

The preserve-order attribute ensures that TestNG runs the test methods within a class in the order they are declared, even if parallel execution is enabled.

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Q.42 How can you configure TestNG to run tests in multiple threads with different data sets?

You can achieve this by using the parallel attribute in the tag of the testng.xml file, and combining it with data providers to provide unique data sets to each thread.

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Q.43 Explain the significance of the dependsOnGroups attribute in the tag of testng.xml.?

The dependsOnGroups attribute in the tag specifies that the current test depends on the successful execution of specific groups of test methods within the same class.

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Q.44 How can you handle test dependencies between different test classes using TestNG?

You can handle cross-class test dependencies by using the dependsOnMethods or dependsOnGroups attributes in the @Test annotations, and ensuring that the methods or groups are defined within the same tag in testng.xml.

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Q.45 What is the purpose of the suite() method in TestNG's test factory?

The suite() method is used in a TestNG test factory class to return an array of test classes that should be included in the suite created by the factory.

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Q.46 How can you perform parallel execution of tests at the suite level in TestNG?

To achieve parallel execution at the suite level, you can use the tag's parallel attribute in the testng.xml file. Set it to tests to run entire tags in parallel.

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Q.47 Explain the role of the @BeforeSuite and @AfterSuite annotations.?

The @BeforeSuite annotation marks a method that runs before all tags within a suite. The @AfterSuite annotation marks a method that runs after all tags have completed in the suite.

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Q.48 How can you specify a timeout for all test methods in a test suite?

You can set a global timeout for all test methods by using the timeOut attribute in the tag of the testng.xml file.

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Q.49 What is the purpose of the alwaysRun attribute in the @Test annotation?

The alwaysRun attribute, when set to true, ensures that the annotated method (such as @BeforeMethod or @AfterMethod) always runs even if the dependent methods fail.

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Q.50 How do you configure TestNG to skip a test method if a dependent method fails?

You can use the dependsOnMethods attribute in the @Test annotation to specify dependencies. If a dependent method fails, the test method will be skipped.

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Q.51 Explain the concept of TestNG listeners and their types.?

TestNG listeners are interfaces that allow custom actions to be taken before, during, or after test execution. Some common listener types include ITestListener, ISuiteListener, and IInvokedMethodListener.

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Q.52 How can you exclude specific test methods from being executed in TestNG?

You can exclude test methods by using the tag within the tag in the testng.xml file. Specify the methods you want to exclude using regular expressions.

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Q.53 What is the purpose of the @Factory annotation in TestNG?

The @Factory annotation is used to create a factory method that dynamically generates instances of test classes. This is useful when you need to create multiple instances of a test class with different data or configurations.

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Q.54 Explain how you can pass parameters to a @Factory method in TestNG.?

You can pass parameters to a @Factory method by adding parameters to the factory method and specifying those parameters in the tag in the testng.xml file.

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Q.55 How do you configure TestNG to ignore specific groups during test execution?

You can use the exclude-groups attribute in the tag of the testng.xml file to specify the groups that you want to exclude from execution.

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Q.56 What is the use of the dependsOnMethods attribute in the @Factory annotation?

The dependsOnMethods attribute within a @Factory annotation specifies that the factory method depends on the successful execution of specific test methods before it can create instances of test classes.

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Q.57 How can you parameterize a test method using both a data provider and the @Parameters annotation?

You can achieve this by combining the use of a @DataProvider-annotated method to provide data and the @Parameters annotation on the test method to receive additional parameters from the testng.xml file.

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Q.58 Explain the concept of a TestNG listener and provide an example of its usage.?

A TestNG listener is an interface that allows you to monitor and respond to various testing events. An example is the ITestListener interface, which provides methods like onTestStart, onTestSuccess, and onTestFailure that you can override to customize behavior during test execution.

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Q.59 What is the role of the alwaysRun attribute in the @AfterMethod annotation?

The alwaysRun attribute, when set to true, ensures that the annotated method (e.g., @AfterMethod) runs even if the test method it is associated with fails or is skipped.

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Q.60 How can you configure TestNG to run test methods in random order?

You can set the tag's preserve-order attribute to false in the testng.xml file to enable TestNG to execute test methods in random order.

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Q.61 Explain the concept of a TestNG Data Provider.?

A TestNG Data Provider is a method that supplies data to a test method. It is used to perform data-driven testing by running a test method with different sets of input data.

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Q.62 How can you group test methods across multiple classes in TestNG?

You can group test methods across multiple classes using the tag within the tag in the testng.xml file. This allows you to define a set of test methods from different classes under the same group.

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Q.63 What is the use of the invocationCount attribute in the @Test annotation?

The invocationCount attribute specifies how many times a test method should be invoked. This is useful for running the same test method multiple times with the same data.

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Q.64 Explain the difference between a TestNG configuration method and a test method.?

A TestNG configuration method is annotated with @Before* or @After* annotations and is used for setup or teardown tasks. A test method is annotated with @Test and contains the actual test logic.

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Q.65 How do you configure TestNG to run tests on multiple browsers sequentially?

You can use the tag in the testng.xml file to specify the browser type, and then use a @DataProvider to provide browser-specific data to the test methods.

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Q.66 What is the purpose of the parallel attribute in the tag of testng.xml?

The parallel attribute in the tag allows you to run test methods in parallel within a group. It determines the level of parallelism for methods belonging to the same group.

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Q.67 How can you handle dynamic test data generation using TestNG?

You can use the @DataProvider annotation in combination with the @Test annotation. The data provider method can generate dynamic test data, which is then passed to the test method.

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Q.68 Explain the role of the dataProviderClass attribute in the @Test annotation.?

The dataProviderClass attribute allows you to specify a class containing the data provider method when the data provider method is defined in a different class from the test method.

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Q.69 What is the purpose of the skipFailedInvocations attribute in the tag?

The skipFailedInvocations attribute, when set to true, allows TestNG to skip all remaining invocations of a test method if any invocation fails.

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Q.70 How can you configure TestNG to run tests based on specific criteria, such as environment variables?

You can use the tag's expression attribute in the testng.xml file to define a logical expression based on which tests will be included or excluded from execution.

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Q.71 What is the difference between a test group and a method group in TestNG?

A test group is a collection of test methods from different classes grouped together, while a method group is a collection of test methods within the same class marked with the same group name.

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Q.72 Explain the role of the preserve-order attribute in the tag of testng.xml.?

The preserve-order attribute, when set to true, ensures that TestNG executes test methods in the order they are defined in the code, even if parallel execution is enabled.

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Q.73 What is the purpose of the @Listeners annotation in TestNG?

The @Listeners annotation is used to attach listener classes to your test suite or test class. These listener classes can be used to customize and enhance the test execution process.

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Q.74 How can you configure TestNG to run specific test methods from different classes using regular expressions?

You can use the tag within the tag in the testng.xml file and provide regular expressions to match the desired test methods.

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Q.75 Explain the role of the enabled attribute in the @Test annotation.?

The enabled attribute, when set to false, allows you to disable a specific test method from running during test execution.

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Q.76 What is the purpose of the @BeforeGroups and @AfterGroups annotations?

The @BeforeGroups annotation marks a method that runs before the execution of methods belonging to specific groups. The @AfterGroups annotation marks a method that runs after the execution of methods belonging to specific groups.

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Q.77 How can you implement method-specific data providers in TestNG?

You can use the dataProvider attribute in the @Test annotation to specify a method that provides data for that specific test method, overriding the class-level data provider.

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Q.78 Explain the difference between a TestNG suite and a TestNG test.?

A TestNG suite is a collection of tests, and a TestNG test is a collection of classes. A suite is defined in the testng.xml file and contains one or more test tags, each specifying a class or classes.

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Q.79 What is the purpose of the @BeforeTest and @AfterTest annotations?

The @BeforeTest annotation marks a method that runs before all test methods in a tag. The @AfterTest annotation marks a method that runs after all test methods in a tag.

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Q.80 How can you parameterize the thread count for parallel execution in TestNG?

You can use the tag's thread-count attribute in the testng.xml file to specify the maximum number of threads for parallel execution.

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Q.81 Explain the significance of the enabled attribute in the and tags of testng.xml.?

The enabled attribute, when set to true (default), specifies that the test or group is enabled for execution. Setting it to false disables the test or group.

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Q.82 What is the purpose of the @BeforeTest and @AfterTest annotations when using multiple tags in the same testng.xml file?

When using multiple tags in the same testng.xml file, @BeforeTest methods run before each individual and @AfterTest methods run after each individual .

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Q.83 How can you specify a priority for configuration methods (e.g., @BeforeMethod) in TestNG?

You can set the priority attribute in the configuration method annotations (@BeforeMethod, @AfterMethod, etc.) to specify the order of their execution.

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Q.84 Explain the concept of parallel execution at the method level using the parallel attribute.?

The parallel attribute in the tag of the testng.xml file allows you to specify the degree of parallelism for executing test methods. It can be set to tests, classes, or methods.

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Q.85 How can you configure TestNG to ignore a specific test class during execution?

You can use the tag within the tag in the testng.xml file to exclude specific test classes from execution.

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Q.86 What is the purpose of the @BeforeSuite and @AfterSuite annotations in TestNG?

The @BeforeSuite annotation marks a method that runs before any tag in the testng.xml file. The @AfterSuite annotation marks a method that runs after all tags have completed.

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Q.87 Explain the purpose of the groups attribute in the @Test annotation.?

The groups attribute in the @Test annotation is used to assign one or more group names to a test method. This allows you to categorize and selectively run test methods based on group membership.

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