TestNG Interview Questions and Answers for experienced

0
100 TestNG Interview Questions and Answers

  1. What is TestNG?

    • Answer: TestNG is a testing framework inspired by JUnit and NUnit but introduces several improvements. It's designed to simplify the creation of robust and reliable tests for Java applications. Key features include annotations for test management, support for parallel testing, powerful reporting, and integration with various tools.

  2. Explain the difference between @Test, @BeforeTest, @AfterTest, @BeforeClass, and @AfterClass annotations.

    • Answer: `@Test`: Marks a method as a test method. `@BeforeTest`: Executes once before each test method in a test class. `@AfterTest`: Executes once after each test method in a test class. `@BeforeClass`: Executes once before all test methods in a test class. `@AfterClass`: Executes once after all test methods in a test class. The `@BeforeClass` and `@AfterClass` methods must be declared `static`.

  3. What are TestNG's different assertion methods?

    • Answer: TestNG provides various assertion methods through the `Assert` class, including `assertEquals()`, `assertNotEquals()`, `assertTrue()`, `assertFalse()`, `assertNull()`, `assertNotNull()`, `assertSame()`, `assertNotSame()`, `fail()` and many more. These methods verify expected outcomes against actual results during test execution.

  4. How do you handle exceptions in TestNG?

    • Answer: Use the `@Test(expectedExceptions = {ExceptionType.class})` annotation to verify that a specific exception is thrown. Alternatively, you can use a `try-catch` block within your test method to handle exceptions gracefully and perform additional actions like logging.

  5. Explain the concept of TestNG Suites.

    • Answer: TestNG suites allow you to group multiple test classes or individual test methods into a single execution unit. This enables running specific sets of tests together, improving test organization and management. Suites are defined in XML files.

  6. How do you parameterize your tests in TestNG?

    • Answer: Use the `@DataProvider` annotation to supply test data to your test methods. The `@DataProvider` method returns an `Object[][]` array containing the test data. The `@Test` method then receives this data as parameters.

  7. What is the purpose of the `@Listeners` annotation?

    • Answer: The `@Listeners` annotation allows you to specify custom listener classes to monitor and interact with TestNG's test execution lifecycle. Listeners can perform actions like logging, reporting, and modifying test behavior.

  8. How do you implement parallel testing in TestNG?

    • Answer: Configure parallel testing in the `testng.xml` file using the `` tag's `parallel` attribute (e.g., `parallel="methods"` or `parallel="tests"`) and the `thread-count` attribute to specify the number of threads. This allows running tests concurrently, reducing overall test execution time.

  9. Explain the difference between hard assertions and soft assertions in TestNG.

    • Answer: Hard assertions (using `Assert` class) stop test execution immediately upon failure. Soft assertions (using `SoftAssert` class) collect all assertion failures and report them at the end of the test method, allowing the test to continue even if some assertions fail.

  10. How can you generate TestNG reports?

    • Answer: TestNG generates HTML reports automatically after test execution. You can customize the reporting further by using listener classes or integrating with external reporting tools.

  11. How to skip a test method conditionally in TestNG?

    • Answer: Use the `@Test(enabled = false)` annotation to skip a test method. Alternatively, use a conditional statement within the test method itself (e.g., `if (condition) { ... } else { Assert.skip("Skipping test due to condition"); }` )

  12. Explain the use of groups in TestNG.

    • Answer: Groups allow you to logically categorize your test methods. You can then run specific groups of tests together using the `testng.xml` file, improving test organization and selective execution.

  13. How to handle dependent test methods in TestNG?

    • Answer: Use the `dependsOnMethods` attribute within the `@Test` annotation to specify that a test method depends on the successful execution of other methods. If a dependent method fails, the dependent method will be skipped.

  14. What is the purpose of the `@Factory` annotation?

    • Answer: The `@Factory` annotation allows creating multiple instances of a test class dynamically, providing a way to run the same test with different parameters without using `@DataProvider`.

  15. How to integrate TestNG with Maven?

    • Answer: Add the TestNG dependency in your `pom.xml` file and use the Maven Surefire plugin to run TestNG tests. This allows for seamless integration into a build system.

  16. How to integrate TestNG with Selenium?

    • Answer: Use Selenium WebDriver to interact with web browsers within your TestNG test methods. TestNG provides the framework for running the tests, while Selenium handles browser automation.

  17. Explain the concept of TestNG's ITestListener interface.

    • Answer: `ITestListener` is an interface that provides methods to listen to different events during TestNG's test execution lifecycle. Implementing this interface allows you to create custom listeners for reporting or other purposes.

  18. How to use TestNG to test REST APIs?

    • Answer: Use libraries like RestAssured or HttpClient to make HTTP requests to your REST APIs within your TestNG test methods. TestNG then verifies the responses.

  19. What is the difference between `@BeforeSuite` and `@BeforeTest`?

    • Answer: `@BeforeSuite` runs once before the entire suite of tests, while `@BeforeTest` runs once before each test in a test class within the suite.

Thank you for reading our blog post on 'TestNG Interview Questions and Answers for experienced'.We hope you found it informative and useful.Stay tuned for more insightful content!