How to Pass Parameters to Test Scripts Using TestNG with Selenium?

When using Selenium with the TestNG framework for automated testing, there are multiple approaches to pass parameters to test scripts, which enhance test flexibility and reusability. Here are some common methods:

1. Using TestNG's @Parameters Annotation

By leveraging TestNG's XML configuration file, parameters can be directly passed to test methods. First, define parameters in the XML file:

xml
<suite name="Suite1">
  <test name="Test1">
    <parameter name="browser" value="Chrome"/>
    <classes>
      <class name="com.example.TestClass">
        <methods>
          <include name="testMethod"/>
        </methods>
      </class>
    </classes>
  </test>
</suite>

Then, use the @Parameters annotation in the test method to receive these parameters:

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

public class TestClass {
  @Parameters("browser")
  @Test
  public void testMethod(String browser) {
    System.out.println("Test running on: " + browser);
    // Initialize different browser drivers based on the browser parameter
  }
}

2. Using TestNG's @DataProvider Annotation

For passing complex parameters or multiple sets of parameters to a test method, @DataProvider is a more suitable choice. First, define a data provider:

java
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;

public class TestClass {
  @DataProvider(name = "dataProviderMethod")
  public Object[][] provideData() {
    return new Object[][] {
      { "Chrome", 80 },
      { "Firefox", 75 }
    };
  }

  @Test(dataProvider = "dataProviderMethod")
  public void testMethod(String browser, int version) {
    System.out.println("Browser: " + browser + ", Version: " + version);
    // Initialize browser drivers based on browser and version
  }
}

This causes testMethod to execute twice, each time with distinct parameters.

Example Application

For instance, when developing a web automation test supporting multiple browsers, either method can pass different browser types as parameters and initialize the corresponding WebDriver in the test script. This enables testing multiple browsers within a single test script, improving code reusability and test coverage.

The key advantage is that it facilitates easy expansion of test cases while maintaining clean, maintainable code. Managing test data through external configuration files also simplifies test management, particularly in multi-environment setups.