TestNG

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TestNG is a powerful test automation framework for Java that provides powerful features for writing and executing unit tests, such as test configuration, test grouping, test dependency management, and parallel test execution. Test configuration allows you to specify the test order, the test timeout, and the test data. With TestNG, you organize your tests into logical groups, define test dependencies, and easily configure test parameters and data providers. You use TestNG to organize your tests into groups based on the feature they are testing. It also supports various annotations and assertions for test readability and validations.

TestNG Examples

• Running a basic test with TestNG

import org.testng.annotations.Test;

public class MyTest {
    @Test
    public void testMethod() {
        // Test logic here
    }
}
  

• Parameterized test with TestNG

import org.testng.annotations.Test;
import org.testng.annotations.Parameters;

public class MyTest {
    @Test
    @Parameters({"param1", "param2"})
    public void testMethod(String param1, int param2) {
        // Test logic with parameters here
    }
}
  

• Test dependency management with TestNG

import org.testng.annotations.Test;

public class MyTest {
    @Test
    public void setup() {
        // Set up test environment
    }

    @Test(dependsOnMethods = "setup")
    public void testMethod() {
        // Test logic here
    }
}
  

• Parallel test execution with TestNG

import org.testng.annotations.Test;

public class MyTest {
    @Test
    public void testMethod1() {
        // Test logic here
    }

    @Test
    public void testMethod2() {
        // Test logic here
    }
}
  

Tips for TestNG

• Use TestNG annotations such as `@Test`, `@BeforeTest`, and `@AfterTest` to define the test methods, test setup and test teardown logic.
• Leverage TestNG's grouping feature to categorize and execute tests selectively based on different criteria, such as sanity tests, regression tests, or specific feature tests.
• Use TestNG's data provider feature to supply test data from various sources, such as Excel files or databases, enabling data-driven testing.
• Use TestNG's parallel execution capabilities to speed up test execution by running tests in parallel across multiple threads or test instances.

FAQ (interview questions and answers)

1. Is TestNG only for Java-based projects?
   Yes, but there are also integrations available for other programming languages like Scala and Groovy.
2. What is the difference between TestNG and JUnit?
   TestNG and JUnit are both test automation frameworks, but TestNG offers more advanced features such as test configuration, parallel execution, and dependency management, while JUnit is simpler and widely used for unit testing in Java.
3. Can you integrate TestNG with other tools?
   Yes, TestNG provides integration capabilities with various tools and frameworks such as Maven, Jenkins, and Selenium WebDriver, allowing you to incorporate TestNG tests into the existing development and testing workflows.
4. Can you run TestNG tests from the command line?
   Yes, using TestNG command-line interface (CLI). It is useful for automation and continuous integration purposes.

Remember to just comment if you have any doubts or queries.

TestNG short tutorial