Q1. What is TestNG?
Answer:
TestNG stands for “Test Next Generation”, a powerful open-source testing framework inspired by JUnit and NUnit. It is primarily designed to simplify automated testing for Java developers, especially when working with Selenium WebDriver.
It offers a wide array of features such as:
- Flexible test configuration
- Powerful annotations
- Parallel test execution
- Data-driven testing
- Customizable reports
TestNG makes it easier to manage large test suites with advanced capabilities like grouping, prioritization, and dependency between test cases. It plays a crucial role in enhancing the testing features of Selenium automation.
Q2. What are the advantages of using TestNG?
Answer:
Here are the major advantages of TestNG in Selenium automation:
- Advanced Assertions: Provides a variety of assertions to validate test results.
- Parallel Execution: Enables executing test methods in parallel to save time.
- Test Dependency: Allows defining dependencies among test methods using dependsOnMethods.
- Priority Handling: You can assign custom execution priority using priority attribute.
- Grouping of Tests: Group test cases under Sanity, Regression, Smoke, etc., using groups attribute.
- Data-Driven Testing: Supports parameterization using @DataProvider and @Parameters.
- Built-in Reporting: Automatically generates HTML and XML reports after test execution.
- Cross-Browser Testing: Works seamlessly with cross-browser testing when integrated with Selenium Grid.
TestNG enhances the maintainability and scalability of test automation frameworks.
Q3. How is TestNG different from Selenium WebDriver?
Answer:
Selenium WebDriver is a browser automation tool, while TestNG is a testing framework. Selenium by itself cannot manage test execution flow, logging, reporting, or test grouping.
| Feature | Selenium WebDriver | TestNG |
| Purpose | Automates browser actions | Manages test execution |
| Assertions | Not provided | Available (assertTrue, assertEquals) |
| Reporting | Not available | Built-in reports |
| Test Grouping | Not supported | Fully supported |
| Parallel Execution | Not supported by default | Easily supported |
In essence, Selenium automates interactions with the UI, and TestNG gives the framework to validate, organize, and report on those interactions.
Q4. What is the use of the testng.xml file?
Answer:
The testng.xml file plays a vital role in configuring and running tests in a structured way. It helps define test suites, control test executions, and integrate with CI/CD tools like Jenkins.
Key Features:
- Organize test classes and packages
- Include or exclude test methods
- Set parallel execution mode
- Define groups (e.g., Sanity, Regression)
- Parameterize tests with <parameter> tag
- Attach listeners for logging and reporting
Example snippet:
xml
<suite name=”MySuite”>
<test name=”LoginTests”>
<classes>
<class name=”com.example.LoginTest”/>
</classes>
</test>
</suite>
You can run the testng.xml from IDEs like Eclipse or from command-line using:
bash
java -cp “bin;lib/*” org.testng.TestNG testng.xml
Q5. How can we group test cases like Sanity and Regression in TestNG?
Answer:
TestNG supports grouping test cases using the groups attribute in the @Test annotation. This allows executing only specific test categories like Sanity, Smoke, or Regression.
Example:
java
@Test(groups = {“sanity”})
public void testA() {
// Sanity test logic
}
@Test(groups = {“sanity”, “regression”})
public void testB() {
// Shared logic for both suites
}
To run specific groups, define them in testng.xml:
xml
<groups>
<run>
<include name=”sanity”/>
</run>
</groups>
This feature ensures better test categorization and suite control.
Q6. How can we exclude a test method from executing in the testng.xml file?
Answer:
To exclude specific methods from execution, TestNG allows you to use the <exclude> tag inside the testng.xml.
Example:
xml
<suite name=”Suite1″>
<test name=”Test1″>
<classes>
<class name=”com.example.TestClass”>
<methods>
<exclude name=”testMethodToBeSkipped”/>
</methods>
</class>
</classes>
</test>
</suite>
This is useful when a particular test case is unstable or temporarily needs to be skipped without changing code.
Q7. What are the most commonly used TestNG annotations?
Answer:
TestNG provides several annotations to control the execution flow:
| Annotation | Purpose |
| @Test | Marks a method as a test case |
| @BeforeSuite / @AfterSuite | Executes once before/after entire suite |
| @BeforeTest / @AfterTest | Executes before/after <test> tag block |
| @BeforeClass / @AfterClass | Executes before/after all methods in a class |
| @BeforeMethod / @AfterMethod | Executes before/after each test method |
| @DataProvider | Supplies data for data-driven testing |
| @Parameters | Pass parameters from XML to test methods |
Each annotation controls test behavior at different levels – suite, class, or method – offering high flexibility.
Q8. What is the order of execution of TestNG annotations?
Answer:
TestNG executes annotations in the following hierarchical order:
- @BeforeSuite
- @BeforeTest
- @BeforeClass
- @BeforeMethod
- @Test
- @AfterMethod
- @AfterClass
- @AfterTest
- @AfterSuite
This order ensures the setup and teardown activities are executed around the actual test methods in a structured and predictable way.
Q9. What are some common assertions in TestNG?
Answer:
TestNG provides several built-in assertions for validating test outcomes:
- Assert.assertEquals(actual, expected)
- Assert.assertNotEquals(actual, expected)
- Assert.assertTrue(condition)
- Assert.assertFalse(condition)
- Assert.assertNull(object)
- Assert.assertNotNull(object)
- Assert.fail() – Forces test failure manually
These assertions help verify expected vs actual results, which are fundamental to any automated test case.
Q10. How can we disable a test case in TestNG?
Answer:
You can disable a test method using the enabled=false attribute in the @Test annotation.
Example 1 – Disable a single test:
java
@Test(enabled = false)
public void skippedTest() {
// Will not run
}
Example 2 – Disable a test in a group:
java
@Test(groups = {“smoke”}, enabled = false)
public void disabledSmokeTest() {
// Skipped test logic
}
👉The Next 10 Questions-1: TESTNG
