TestNG

---

✅ 1. What is TestNG?

Answer:

TestNG (Test Next Generation) is a testing framework inspired by JUnit and NUnit. It is widely used in Selenium automation for:

• Managing test cases.

• Setting test priorities.

• Grouping and sequencing tests.

• Generating test reports.

It provides features like @Test, @BeforeMethod, @AfterMethod, @DataProvider, parallel execution, and more.

---

✅ 2. What are the advantages of using TestNG?

Answer:

• Annotations are easier to understand.

• Parallel test execution.

• Detailed HTML test reports.

• Support for grouping and prioritizing test cases.

• Data-driven testing using @DataProvider.

• Dependency and suite-level configuration support.

---

✅ 3. What are TestNG annotations?

Answer:

Annotations in TestNG control test flow. Common ones:

Annotation	Purpose
@Test	Marks a method as a test case
@BeforeMethod	Runs before each @Test method
@AfterMethod	Runs after each @Test method
@BeforeClass	Runs once before all tests in a class
@AfterClass	Runs once after all tests in a class
@BeforeSuite	Runs before any tests in the suite
@AfterSuite	Runs after all tests in the suite

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✅ 4. What is the difference between @BeforeMethod and @BeforeClass?

Answer:

• @BeforeMethod: Runs before every test method.

• @BeforeClass: Runs once before any test method in the class.

Use @BeforeMethod to open browsers or login, and @BeforeClass for setting up heavy configurations.

---

✅ 5. How do you prioritize tests in TestNG?

Answer:

Using the priority attribute in the @Test annotation.

@Test(priority = 1)
public void loginTest() { }
@Test(priority = 2)
public void searchTest() { }

Tests with lower priority numbers execute first.

---

✅ 6. How do you skip a test in TestNG?

Answer:

You can skip a test by:

1. Setting enabled = false:

@Test(enabled = false)
public void skipTest() { }

2. Using throw new SkipException("...") inside the method.

---

✅ 7. What is testng.xml?

Answer:

testng.xml is a configuration file used to define test suites, include/exclude classes or methods, run groups, set parallel execution, and pass parameters.

Example:

<suite name="MySuite">
  <test name="MyTest">
    <classes>
      <class name="tests.LoginTest" />
    </classes>
  </test>
</suite>

---

✅ 8. How do you execute only selected test cases using testng.xml?

Answer:

Use <include> or <exclude> inside the <methods> tag.

<methods>
  <include name="loginTest"/>
  <exclude name="logoutTest"/>
</methods>

---

✅ 9. How do you group tests in TestNG?

Answer:

Use the groups attribute:

@Test(groups = "smoke")
public void loginTest() { }
@Test(groups = {"smoke", "regression"})
public void dashboardTest() { }

In testng.xml:

<groups>
  <run>
    <include name="smoke"/>
  </run>
</groups>

---

✅ 10. What is @DataProvider in TestNG?

Answer:

Used for data-driven testing by passing multiple sets of data to a single test method.

Example:

@DataProvider
public Object[][] loginData() {
  return new Object[][] {
    {"admin", "pass1"},
    {"user", "pass2"}
  };
}
@Test(dataProvider = "loginData")
public void testLogin(String user, String pass) {
  // login test logic
}

---

✅ 11. What is a test suite?

Answer:

A test suite is a collection of test cases or test classes grouped and run together. Defined in testng.xml.

---

✅ 12. How do you run tests in parallel in TestNG?

Answer:

In testng.xml:

<suite name="Suite" parallel="tests" thread-count="2">
  ...
</suite>

Or using parallel attributes like parallel="classes" or methods.

---

✅ 13. What is the difference between soft and hard assertions?

Answer:

• Hard Assert: Fails immediately if the condition is false.

• Soft Assert: Collects all assertions and reports them at the end using assertAll().

Example:

SoftAssert sa = new SoftAssert();
sa.assertEquals(1, 2);
sa.assertAll(); // now reports the failure

---

✅ 14. How do you pass parameters from testng.xml to test methods?

Answer:

Use @Parameters annotation.

<parameter name="browser" value="chrome"/>

In code:

@Parameters("browser")
@Test
public void testBrowser(String browserName) {
  System.out.println(browserName);
}

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✅ 15. How do you generate reports in TestNG?

Answer:

TestNG generates default HTML and XML reports automatically inside the test-output folder. You can also use third-party tools like ExtentReports for advanced reporting.

---

✅ 16. What is dependsOnMethods in TestNG?

Answer:

Used to define test dependencies.

@Test
public void login() { }
@Test(dependsOnMethods = "login")
public void dashboard() { }

If login fails, dashboard is skipped.

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✅ 17. What is the sequence of TestNG annotations?

Answer:

@BeforeSuite
  @BeforeTest
    @BeforeClass
      @BeforeMethod
        @Test
      @AfterMethod
    @AfterClass
  @AfterTest
@AfterSuite

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✅ 18. Can we run TestNG without testng.xml?

Answer:

Yes. You can directly run classes with @Test methods from your IDE or using Maven/Gradle. However, testng.xml is needed for:

• Grouping

• Parallel execution

• Configurations

---

✅ 19. What is InvocationCount in TestNG?

Answer:

It allows a test method to run multiple times.

@Test(invocationCount = 3)
public void repeatTest() {
  System.out.println("Run again");
}

---

✅ 20. How do you ignore a test method in TestNG?

Answer:

Use enabled = false in the @Test annotation:

@Test(enabled = false)
public void skippedTest() { }

---

✅ 21. What is timeout in TestNG?

Answer:

The timeout attribute in TestNG specifies the maximum time a test method is allowed to run.

If the test takes longer, it fails.

@Test(timeOut = 2000) // 2 seconds
public void slowTest() throws InterruptedException {
    Thread.sleep(3000); // This will cause the test to fail
}

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✅ 22. What is alwaysRun in TestNG?

Answer:

alwaysRun = true ensures that the test method will run even if its dependent methods fail.

@Test
public void login() {
    Assert.fail();
}
@Test(dependsOnMethods = "login", alwaysRun = true)
public void dashboard() {
    System.out.println("Runs anyway");
}

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✅ 23. What is parameterization in TestNG?

Answer:

Parameterization is the process of passing data to test methods from external sources, such as:

• testng.xml (using @Parameters)

• @DataProvider

It allows reusability of test logic with different inputs.

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✅ 24. Can we have multiple @DataProvider methods in a class?

Answer:

Yes. You can define multiple @DataProvider methods in the same or different classes and use them via the dataProvider attribute.

@DataProvider(name = "data1")
public Object[][] dp1() { return new Object[][] { ... }; }
@DataProvider(name = "data2")
public Object[][] dp2() { return new Object[][] { ... }; }

Use them:

@Test(dataProvider = "data2")
public void testX(...) { ... }

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✅ 25. How to use a DataProvider from another class?

Answer:

1. Create a separate class with your @DataProvider method.

2. Reference it using dataProviderClass.

Example:

DataProvider class:

public class DataClass {
    @DataProvider(name = "loginData")
    public Object[][] getData() { return ...; }
}

Test class:

@Test(dataProvider = "loginData", dataProviderClass = DataClass.class)
public void testLogin(String user, String pass) { ... }

---

✅ 26. What is invocationCount used for?

Answer:

Used to run the same test method multiple times automatically.

@Test(invocationCount = 5)
public void runMultipleTimes() {
    System.out.println("Running again");
}

---

✅ 27. How do you create test dependencies in TestNG?

Answer:

Use the dependsOnMethods or dependsOnGroups attribute.

@Test
public void openApp() {}
@Test(dependsOnMethods = "openApp")
public void login() {}

This makes login() run only if openApp() passes.

---

✅ 28. Can we have @Test methods without @BeforeMethod or @AfterMethod?

Answer:

Yes, @Test methods can run independently. @BeforeMethod and @AfterMethod are optional and only used for setting pre- and post-test conditions.

---

✅ 29. What is parallel execution in TestNG?

Answer:

TestNG supports running tests in parallel using the parallel attribute in testng.xml. It saves execution time.

Types:

• parallel="tests"

• parallel="classes"

• parallel="methods"

Example:

<suite name="Suite" parallel="methods" thread-count="3">

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✅ 30. Can you pass parameters from command line in TestNG?

Answer:

Yes, using Maven's -D syntax or Jenkins build parameters with @Parameters in code.

Example:

Command:

mvn test -Dbrowser=chrome

Code:

@Parameters("browser")
@Test
public void launch(String browser) { ... }

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✅ 31. What is the difference between @Factory and @DataProvider?

Answer:

• @DataProvider: Runs the same test method with different data.

• @Factory: Runs different test instances, each created with constructor arguments.

@Factory is used when you need different object creation logic for each test.

---

✅ 32. What is ITestListener in TestNG?

Answer:

ITestListener is an interface used to monitor test execution status. You can override its methods to take actions on:

• test success

• test failure

• test skip

• test start and finish

Example use: capture screenshot on test failure.

---

✅ 33. How do you implement ITestListener?

Answer:

1. Create a class that implements ITestListener.

2. Override methods like onTestFailure().

public class MyListener implements ITestListener {
    public void onTestFailure(ITestResult result) {
        System.out.println("Failed: " + result.getName());
    }
}

3. Add the listener:

@Listeners(MyListener.class)
public class TestClass { ... }

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✅ 34. What is IReporter in TestNG?

Answer:

IReporter is an interface that lets you create custom reports after the test suite execution is complete.

You override:

generateReport(List<XmlSuite> xmlSuites, List<ISuite> suites, String outputDirectory)

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✅ 35. What is ISuiteListener?

Answer:

ISuiteListener lets you perform actions before and after a suite is run.

public class MySuiteListener implements ISuiteListener {
    public void onStart(ISuite suite) { ... }
    public void onFinish(ISuite suite) { ... }
}

Useful for starting/stopping servers or initializing suite-wide data.

---

✅ 36. What is thread safety in TestNG?

Answer:

Thread safety ensures that shared resources used in parallel execution do not cause unexpected behavior. You must:

• Avoid static/global variables.

• Use ThreadLocal or synchronized blocks if needed.

• Use proper test data isolation per thread.

---

✅ 37. How to create a base test class in TestNG?

Answer:

A BaseTest class helps to avoid code repetition:

public class BaseTest {
    WebDriver driver;
    @BeforeMethod
    public void setUp() { driver = new ChromeDriver(); }
    @AfterMethod
    public void tearDown() { driver.quit(); }
}

Then extend this class:

public class LoginTest extends BaseTest {
    @Test
    public void login() { ... }
}

---

✅ 38. Can you run failed tests again in TestNG?

Answer:

Yes. TestNG automatically creates a testng-failed.xml in the test-output folder, which includes only failed test cases.

You can re-run this file to retry failed tests.

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✅ 39. How do you rerun failed tests using listeners?

Answer:

Implement IRetryAnalyzer:

public class RetryTest implements IRetryAnalyzer {
    int count = 0;
    public boolean retry(ITestResult result) {
        if (count < 2) {
            count++;
            return true;
        }
        return false;
    }
}

Attach it to your test:

@Test(retryAnalyzer = RetryTest.class)
public void flakyTest() { ... }

---

✅ 40. What is the default order of execution of test methods in TestNG?

Answer:

By default, TestNG runs test methods in alphabetical order, unless you set a priority.

To control order explicitly, use:

@Test(priority = 1)
public void aTest() { }
@Test(priority = 2)
public void bTest() { }

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✅ 41. What is the purpose of @BeforeTest and @AfterTest?

Answer:

• @BeforeTest: Runs once before any test methods in a <test> tag in testng.xml.

• @AfterTest: Runs once after all test methods in that <test> tag.

These are useful for setting up or tearing down test-level configurations such as:

• Connecting to a database.

• Starting/stopping a server.

• Loading common resources.

---

✅ 42. Can we run only one specific test method using TestNG?

Answer:

Yes. You can:

1. Use testng.xml with <include name="methodName" /> to include a single method.

2. Right-click and run the test method directly in your IDE (e.g., Eclipse, IntelliJ).

3. Use groups or filters to isolate test execution.

---

✅ 43. What happens if we don’t use priority in @Test methods?

Answer:

If priority is not defined, TestNG runs test methods in lexicographical (alphabetical) order of method names.

Example:

@Test
public void bTest() {}
@Test
public void aTest() {}

Here, aTest() will run before bTest().

---

✅ 44. What is the use of testng.xml file in Selenium framework?

Answer:

testng.xml helps in:

• Organizing test execution flow.

• Grouping and running multiple test classes/suites.

• Running tests in parallel.

• Passing parameters.

• Including/excluding specific test methods.

It's the central controller for running the test suite in a structured and configurable way.

---

✅ 45. Can we run TestNG tests using Maven?

Answer:

Yes. You can run TestNG tests using the Maven Surefire plugin.

Steps:

1. Add TestNG and Surefire plugin in pom.xml.

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-surefire-plugin</artifactId>
  <version>3.0.0</version>
  <configuration>
    <suiteXmlFiles>
      <suiteXmlFile>testng.xml</suiteXmlFile>
    </suiteXmlFiles>
  </configuration>
</plugin>

2. Run tests:

mvn clean test

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✅ 46. Can we have multiple testng.xml files in one project?

Answer:

Yes. You can create multiple testng.xml files to:

• Run different sets of tests.

• Separate smoke, regression, UAT tests.

• Manage browser-specific suites.

Each XML can be run individually or merged into a master suite.

---

✅ 47. How do you ignore a group of tests in TestNG?

Answer:

In testng.xml, exclude the group using:

<groups>
  <run>
    <exclude name="sanity"/>
  </run>
</groups>

Or in code:

@Test(groups = "sanity", enabled = false)
public void testA() {}

---

✅ 48. Can @DataProvider return different data types?

Answer:

Yes. @DataProvider returns an Object[][], which can contain different data types in each column.

@DataProvider
public Object[][] mixedData() {
  return new Object[][] {
    {"admin", 123, true},
    {"guest", 456, false}
  };
}

The receiving test method must match parameter types:

@Test(dataProvider = "mixedData")
public void test(String username, int id, boolean status) { ... }

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✅ 49. What happens if @Test method throws an exception?

Answer:

If a test throws an unhandled exception, it will fail.

To expect exceptions, use:

@Test(expectedExceptions = ArithmeticException.class)
public void testDivision() {
    int result = 1 / 0;
}

This test will pass because the exception was expected.

---

✅ 50. Can we run TestNG tests in parallel on different browsers?

Answer:

Yes, this is commonly done in Selenium Grid or Cross-Browser frameworks.

Steps:

1. Use @Parameters or @DataProvider to pass browser names.

2. Set parallel execution in testng.xml:

<suite name="CrossBrowserSuite" parallel="tests" thread-count="2">
  <test name="ChromeTest">
    <parameter name="browser" value="chrome" />
    <classes>
      <class name="tests.LoginTest" />
    </classes>
  </test>
  <test name="FirefoxTest">
    <parameter name="browser" value="firefox" />
    <classes>
      <class name="tests.LoginTest" />
    </classes>
  </test>
</suite>

---

✅ 51. How does @Listeners work in TestNG?

Answer:

@Listeners attaches custom listeners (like ITestListener, ISuiteListener) to a test class to monitor and act on events like test pass, fail, skip, etc.

Usage:

@Listeners(MyListener.class)
public class TestClass {
    @Test
    public void testA() { ... }
}

Listeners help in:

• Logging.

• Custom report generation.

• Screenshot capturing on failure.

---

✅ 52. Can we call one test method from another in TestNG?

Answer:

Technically yes, you can call one test method from another like a normal method. But it is not recommended because:

• It breaks the independence of test cases.

• It makes result tracking inaccurate.

Better to use:

@Test(dependsOnMethods = "methodA")

---

✅ 53. Can we define test methods inside @BeforeMethod?

Answer:

No. You cannot write a @Test method inside a @BeforeMethod or any other annotation method.

All @Test methods must be defined as independent public methods in the class.

---

✅ 54. How do you set execution order across multiple classes?

Answer:

Control execution sequence using testng.xml:

<classes>
  <class name="tests.LoginTest" />
  <class name="tests.SearchTest" />
  <class name="tests.PaymentTest" />
</classes>

TestNG will run them in this defined order unless parallel execution is enabled.

---

✅ 55. Can you disable an entire test class in TestNG?

Answer:

Yes. Use @Test(enabled = false) on the class level:

@Test(enabled = false)
public class DisabledTests {
    @Test
    public void testA() { ... }
}

None of the test methods in the class will run.

---

✅ 56. What is a suite-level parameter in TestNG?

Answer:

A suite-level parameter is declared in the <suite> tag in testng.xml and can be used across multiple tests.

<suite name="Suite">
  <parameter name="url" value="https://demoapp.com" />

Used in code:

@Parameters("url")
@Test
public void launchApp(String url) {
    System.out.println("Opening " + url);
}

---

✅ 57. What is the scope of @BeforeSuite and @AfterSuite?

Answer:

• @BeforeSuite: Runs once before all test cases in the entire suite.

• @AfterSuite: Runs once after all test cases are completed.

Good for:

• Initializing suite-wide resources like DB connections or report setup.

• Cleaning up external services after tests.

---

✅ 58. Can we use @Test without public keyword?

Answer:

No. In TestNG, all test methods must be public. If you write a @Test method as private/protected, TestNG will ignore it silently.

---

✅ 59. What are soft assertions and how to use them?

Answer:

Soft assertions allow test execution to continue even if an assertion fails, and collect all errors to report at the end.

Usage:

SoftAssert soft = new SoftAssert();
soft.assertEquals(actual, expected);
soft.assertTrue(condition);
// Collect all
soft.assertAll(); // This triggers the failure report

---

✅ 60. What are factory tests in TestNG?

Answer:

@Factory is used to run multiple test instances with different constructor parameters.

Example:

public class LoginTest {
    private String username;
    public LoginTest(String username) {
        this.username = username;
    }
    @Test
    public void login() {
        System.out.println("Logging in as " + username);
    }
}

public class TestFactory {
    @Factory
    public Object[] createInstances() {
        return new Object[] {
            new LoginTest("admin"),
            new LoginTest("guest")
        };
    }
}

---

✅ 61. What is dependsOnGroups in TestNG?

Answer:

dependsOnGroups is used when a test method depends on an entire group of tests to pass before it runs.

Example:

@Test(groups = "login")
public void loginTest() { ... }
@Test(dependsOnGroups = "login")
public void dashboardTest() { ... }

Here, dashboardTest() will only run after all methods in the login group pass.

---

✅ 62. How do you prioritize tests in TestNG?

Answer:

Use the priority attribute in @Test annotation.

Lower priority number = higher execution order.

@Test(priority = 1)
public void login() {}
@Test(priority = 2)
public void addItem() {}

Note: If multiple methods have the same priority, they execute in alphabetical order.

---

✅ 63. What is the default priority in TestNG?

Answer:

The default priority is 0 if not specified.

@Test
public void aTest() {}  // default priority = 0
@Test(priority = 1)
public void bTest() {}

So aTest() will execute before bTest().

---

✅ 64. What is the difference between @BeforeMethod and @BeforeClass?

Answer:

Annotation	Executes...
@BeforeMethod	Before each test method in the class
@BeforeClass	Once before the first test method in class

Use @BeforeMethod for repeated setup (e.g., login) and @BeforeClass for one-time setup (e.g., browser launch).

---

✅ 65. Can @BeforeMethod and @AfterMethod be used with @DataProvider?

Answer:

Yes. If a test uses @DataProvider, @BeforeMethod and @AfterMethod will run before and after each iteration of the test.

Example:

@DataProvider
public Object[][] loginData() {
    return new Object[][] {
        {"admin", "admin123"},
        {"guest", "guest123"}
    };
}
@BeforeMethod
public void setup() {
    System.out.println("Setup");
}
@AfterMethod
public void tearDown() {
    System.out.println("Teardown");
}
@Test(dataProvider = "loginData")
public void loginTest(String user, String pass) {
    System.out.println("Testing with " + user);
}

Output: Setup → test 1 → Teardown → Setup → test 2 → Teardown

---

✅ 66. Can @DataProvider be in a different class?

Answer:

Yes. Use dataProviderClass to refer to the class containing the data provider.

// In separate class
public class DataUtils {
    @DataProvider(name = "loginData")
    public static Object[][] getLoginData() {
        return new Object[][] {
            {"admin", "admin123"},
            {"user", "user123"}
        };
    }
}

In test class:

@Test(dataProvider = "loginData", dataProviderClass = DataUtils.class)
public void loginTest(String user, String pass) { ... }

---

✅ 67. Can we run specific test methods from the command line?

Answer:

Yes. You can use:

java -cp "path/to/libs/*" org.testng.TestNG testng.xml

Or specify a test method using the -methods option:

java org.testng.TestNG -testclass com.tests.LoginTest -methods loginTest

Maven example:

mvn test -Dtest=LoginTest#loginTest

---

✅ 68. Can @Test methods be overloaded?

Answer:

Yes, but TestNG will only recognize one of them unless you specify @Test for each uniquely.

@Test
public void testLogin(String user) { ... }
@Test
public void testLogin(String user, String pass) { ... } // Invalid: both have same name
// Better:
@Test
public void loginWithUsername() { ... }
@Test
public void loginWithCredentials() { ... }

It's better to keep test method names unique and clear.

---

✅ 69. What is the use of InvocationCount?

Answer:

invocationCount runs the same test multiple times.

@Test(invocationCount = 3)
public void retryTest() {
    System.out.println("Run");
}

Output:

Run
Run
Run

Useful for load testing or flaky tests.

---

✅ 70. What is ThreadPoolSize in TestNG?

Answer:

It specifies how many threads to use when running tests in parallel.

Example:

@Test(invocationCount = 5, threadPoolSize = 2)
public void testThreadPool() {
    System.out.println("Thread: " + Thread.currentThread().getId());
}

Here, 5 executions will run using 2 threads, improving speed in parallel testing.

---

✅ 71. Can we have multiple @DataProvider in the same class?

Answer:

Yes. You can have multiple @DataProvider methods as long as each has a unique name.

@DataProvider(name = "loginData")
public Object[][] login() { ... }
@DataProvider(name = "signupData")
public Object[][] signup() { ... }

Then refer them using dataProvider = "signupData" or loginData.

---

✅ 72. Can we skip a test at runtime?

Answer:

Yes. You can programmatically skip a test using:

throw new SkipException("Skipping this test");

This is useful when:

• A feature is not ready.

• Prerequisite condition is not met.

---

✅ 73. What is the purpose of ITestListener?

Answer:

ITestListener is an interface that allows you to hook into test events like:

• onTestStart

• onTestSuccess

• onTestFailure

• onTestSkipped

Example use cases:

• Take screenshots on failure.

• Send email alerts.

• Custom logging.

---

✅ 74. What is the difference between @Factory and @DataProvider?

Answer:

Feature	@Factory	@DataProvider
Return type	Object[] of test class instances	Object[][] of test data
Used with	Constructors	Test methods
Purpose	Run tests with different objects	Run tests with different data

---

✅ 75. Can we define @Test in an abstract class?

Answer:

Yes, but the concrete subclass must extend it and implement/execute it.

public abstract class BaseTest {
    @Test
    public void commonTest() {
        System.out.println("Common test");
    }
}
public class MyTest extends BaseTest { }

commonTest() will be executed as part of MyTest.

---

✅ 76. Can we parameterize tests using Excel or CSV?

Answer:

Yes, but TestNG doesn’t support it natively.

You can:

1. Use Apache POI to read Excel.

2. Pass the data to @DataProvider.

Example:

@DataProvider
public Object[][] excelData() {
    // read Excel using Apache POI
}

Then feed it to your test method.

---

✅ 77. What is @Parameters vs @DataProvider?

Answer:

Feature	@Parameters	@DataProvider
Source	testng.xml	Java method
Data type	Only Strings	Any object type
Use case	One-time config	Multiple iterations

Use @Parameters for external configuration, @DataProvider for data-driven testing.

---

✅ 78. Can we run TestNG tests without testng.xml?

Answer:

Yes. You can:

• Run from IDE (Eclipse/IntelliJ) directly.

• Run using annotations only.

• Use Maven Surefire with class/method targeting.

However, testng.xml is required for:

• Grouping.

• Parallel testing.

• Parametrization.

---

✅ 79. Can we pass parameters from testng.xml to @DataProvider?

Answer:

No. You cannot directly pass testng.xml parameters to @DataProvider. But you can pass them to the test method via @Parameters, and then combine with @DataProvider.

Alternative:

• Read system/environment values inside @DataProvider.

---

✅ 80. How to create a parallel test framework using TestNG?

Answer:

Steps:

1. Use parallel attribute in testng.xml.

<suite name="ParallelTest" parallel="tests" thread-count="3">
  ...
</suite>

2. Pass browser/device using @Parameters or @DataProvider.

3. Write test methods that launch in separate threads.

4. Ensure thread-safety in WebDriver using ThreadLocal.

---

✅ 81. What is the use of @Listeners annotation in TestNG?

Answer:

@Listeners is used to attach a custom listener class to a test class. This helps capture events during test execution like success, failure, skip, etc.

@Listeners(MyTestListener.class)
public class MyTestClass {
    @Test
    public void sampleTest() { ... }
}

Where MyTestListener implements ITestListener or ISuiteListener.

Common use: capturing screenshots on failure, custom logging, reporting.

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✅ 82. What interfaces are available in TestNG for listeners?

Answer:

TestNG provides multiple listener interfaces:

• ITestListener – for individual test method events (start, success, failure, skip)

• ISuiteListener – for suite-level events (beforeSuite, afterSuite)

• IClassListener – before/after class execution

• IInvokedMethodListener – before/after every method (test/config)

• IReporter – for creating custom reports

• IAnnotationTransformer – to modify annotations at runtime

These are helpful for enhancing test execution tracking and reports.

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✅ 83. What is IAnnotationTransformer in TestNG?

Answer:

IAnnotationTransformer is a listener interface that allows you to modify annotations like @Test, @BeforeMethod, etc. at runtime.

Use case: Enable/disable tests dynamically or set retry logic.

Example:

public class MyTransformer implements IAnnotationTransformer {
    public void transform(TestAnnotation annotation, Class testClass, Constructor testConstructor, Method testMethod) {
        annotation.setEnabled(false); // disables all tests dynamically
    }
}

Register using:

@Listeners(MyTransformer.class)

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✅ 84. What is TestNG.xml file and why is it used?

Answer:

testng.xml is the configuration file for TestNG. It defines:

• Test classes and packages

• Groups and included/excluded tests

• Parallel execution settings

• Parameters

Example:

<suite name="Suite1">
  <test name="LoginTests">
    <classes>
      <class name="com.tests.LoginTest" />
    </classes>
  </test>
</suite>

It provides flexibility and centralized control over test execution.

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✅ 85. How can we exclude specific test methods in testng.xml?

Answer:

Use the <methods> tag with <exclude>:

<class name="com.tests.LoginTest">
  <methods>
    <exclude name="invalidLoginTest" />
  </methods>
</class>

This will skip the invalidLoginTest() during execution.

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✅ 86. Can we pass parameters from testng.xml to test methods?

Answer:

Yes. Use @Parameters and define them in testng.xml.

In test class:

@Parameters({"username", "password"})
@Test
public void login(String user, String pass) { ... }

In XML:

<parameter name="username" value="admin"/>
<parameter name="password" value="admin123"/>

This is helpful for environment-specific testing.

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✅ 87. What happens if a dependent test fails?

Answer:

If a test method depends on another (using dependsOnMethods or dependsOnGroups) and the parent test fails or is skipped, then the dependent test is also skipped.

Example:

@Test
public void loginTest() {
    Assert.fail(); // fails
}
@Test(dependsOnMethods = "loginTest")
public void dashboardTest() {
    // will be skipped
}

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✅ 88. How do you perform soft assertions in TestNG?

Answer:

Use SoftAssert class. Unlike hard assertions, soft assertions don’t stop execution after failure.

SoftAssert softAssert = new SoftAssert();
softAssert.assertEquals(actual, expected);
softAssert.assertTrue(condition);
softAssert.assertAll(); // This will collect and throw all failures

Useful when you want to validate multiple checkpoints in a single test.

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✅ 89. How do you retry failed tests in TestNG?

Answer:

1. Create a class that implements IRetryAnalyzer.

public class RetryAnalyzer implements IRetryAnalyzer {
    private int retryCount = 0;
    private static final int maxRetry = 2;
    public boolean retry(ITestResult result) {
        if (retryCount < maxRetry) {
            retryCount++;
            return true;
        }
        return false;
    }
}

2. Attach it to your test:

@Test(retryAnalyzer = RetryAnalyzer.class)
public void flakyTest() {
    Assert.assertTrue(false);
}

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✅ 90. How to ignore a test method in TestNG?

Answer:

Use enabled = false in the @Test annotation.

@Test(enabled = false)
public void testToSkip() {
    // this test will be ignored
}

Alternatively, exclude it in testng.xml.

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✅ 91. What is grouping in TestNG and why is it useful?

Answer:

Grouping allows you to organize test cases by category or functionality, and run selected groups.

Example:

@Test(groups = "smoke")
public void test1() {}
@Test(groups = "regression")
public void test2() {}

Run only smoke tests via XML:

<groups>
  <run>
    <include name="smoke"/>
  </run>
</groups>

Helps in selective, faster test execution.

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✅ 92. What is alwaysRun = true in TestNG?

Answer:

This ensures the test runs even if its dependencies failed or skipped.

@Test(dependsOnMethods = "login", alwaysRun = true)
public void logout() {
    // will run even if login fails
}

Useful for cleanup, logout, or screenshot-taking tests.

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✅ 93. Can we attach multiple listeners in TestNG?

Answer:

Yes. You can add multiple listeners using:

@Listeners({Listener1.class, Listener2.class})
public class MyTest { ... }

Or define in testng.xml:

<listeners>
  <listener class-name="com.listeners.Listener1"/>
  <listener class-name="com.listeners.Listener2"/>
</listeners>

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✅ 94. How can you set a test to run for a specific time only?

Answer:

Use timeOut attribute.

@Test(timeOut = 5000) // in milliseconds
public void longRunningTest() {
    // must complete in 5 seconds
}

If the method takes longer, it will fail with timeout error.

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✅ 95. What is the order of TestNG annotations?

Answer:

TestNG follows this execution order:

1. @BeforeSuite

2. @BeforeTest

3. @BeforeClass

4. @BeforeMethod

5. @Test

6. @AfterMethod

7. @AfterClass

8. @AfterTest

9. @AfterSuite

This helps in structuring test setup and teardown in an organized way.

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✅ 96. Can we run tests in parallel at method level?

Answer:

Yes. In testng.xml, set:

<suite name="ParallelTest" parallel="methods" thread-count="3">

This runs test methods in parallel, which reduces execution time.

Be sure to manage thread-safety when using shared resources like WebDriver.

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✅ 97. How to run failed tests again automatically in TestNG?

Answer:

1. After test run, TestNG generates a file:
   test-output/testng-failed.xml

2. You can re-run the failed tests using this XML:

   java org.testng.TestNG test-output/testng-failed.xml
   

Also works with Maven or CI tools.

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✅ 98. How to integrate TestNG with Maven?

Answer:

1. Add TestNG dependency in pom.xml:

<dependency>
  <groupId>org.testng</groupId>
  <artifactId>testng</artifactId>
  <version>7.8.0</version>
  <scope>test</scope>
</dependency>

2. Use Surefire plugin to run tests:

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-surefire-plugin</artifactId>
  <version>3.0.0</version>
</plugin>

3. Run:

mvn test

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✅ 99. How to generate HTML reports in TestNG?

Answer:

TestNG generates default HTML reports in the test-output folder.

You can also generate advanced reports using:

• Extent Reports

• Allure Reports

• ReportNG

Example for Extent:

• Add Extent dependency

• Use ExtentHtmlReporter

• Attach it to test events inside a listener

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✅ 100. How to run multiple suites in TestNG?

Answer:

Create a suite-of-suites XML:

<suite name="MasterSuite">
  <suite-files>
    <suite-file path="smoke.xml"/>
    <suite-file path="regression.xml"/>
  </suite-files>
</suite>

Then run the MasterSuite.xml. This helps manage multiple suites in a large project.

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