What do you mean by Listeners in TestNG?
TestNG Listeners have the capacity to listen to a specific incident. It is
basically an interface that changes the nature of the system. TestNG Listeners are
used for logging purposes and creating reports.
There are two Listeners in Selenium. They are listed below −
TestNG Listeners.
WebDriver Listeners.
TestNG can be configured with the Listeners which can change the default behavior
of the TestNG. TestNG Listeners are known as iTestListener (a TestNG interface). A
java class implements the iTestListeners and at the same time overrides its
methods. Each of these methods trigger an event.
The functions of TestNG listeners are listed below.
iSuiteListener − This consists of methods onStart() and onFinish(). As a java class implements this listener, TestNG shall call the onStart() and onFinish()
methods at the beginning and at the end of the TestNG suite respectively. So
before triggering our test suite for execution, the precondition onStart() test
method is picked for execution by TestNG. Similarly after the execution of
the test suite, post condition onFinish() test method is picked by TestNG.
iTestListener − This is similar in functionality as iSuiteListener. The only difference is that iTestListener is applicable before and after a Test and not
Suite. It has seven methods.
onStart − This test method is invoked when the test begins.
onFinish − This test method is invoked after all the tests have completed
execution.
onTestSuccess − This test method is invoked every time a test is successful.
onTestFailure − This test method is invoked every time a test is unsuccessful.
onTestSkipped − This test method is invoked every time a test is bypassed.
onTestFailedButWithinSuccessPercentage − This test method is invoked
every time a test method annotated with successPercentage is not
successful. But within the requested success percentage.
iInvokedMethodListener − This is similar in functionality as iTestListener and iSuiteListener. The only difference is that iInvokedMethodListener is
applicable before and after every test method. It has two methods.
afterInvocation − This is called after every test method.
beforeInvocation − This is called before every test method.
Example
With iTestListener.
package tutorialspoint;
import org.testng.ITestContext;
import org.testng.ITestListener;
import org.testng.ITestResult;
//ITestListener interface which implements Testng listeners
public class Listener implements ITestListener {
@Override
public void onTestStart(ITestResult result) {
// TODO Auto-generated method stub
}
@Override
public void onTestSuccess(ITestResult result) {
// TODO Auto-generated method stub
}
@Override
public void onTestFailure(ITestResult result) {
// TODO Auto-generated method stub
//screenshot code
System.out.println
("Failed test case name" + result.getName());
}
@Override
public void onTestSkipped(ITestResult result) {
// TODO Auto-generated method stub
}
@Override
public void onTestFailedButWithinSuccessPercentage(ITestResult result) {
// TODO Auto-generated method stub
}
@Override
public void onStart(ITestContext context) {
// TODO Auto-generated method stub
}
@Override
public void onFinish(ITestContext context) {
// TODO Auto-generated method stub
}
}In the Listener java class, onTestFailure() will print the name of the test method
which has failed with the help of result.getName() method.
We can add this Listener class to the Java class file in two ways.
Example
With Listener tag in testng xml file.
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd" >
<suite name = "Tutorialspoint Test">
<listeners>
<listener class-name="tutorialspoint.Listener"/>
</listeners>
<test name = "Test Cycle 1">
<classes>
<class name = "TestQA" />
</classes>
</test>
</suite>
Inside the <listeners> tag we have mentioned the path of the Listener class.
Example
By implementing TestNG listener to the test class.
package TestTutorials;
import org.testng.annotations.Test;
// This code will implement TestNG listeners
@Listeners(tutorialspoint.Listener.class)
public class TestCase {
@Test
public void Login() {
System.out.println("Login is successful");
}
}
Published on 11-Jun-2020 16:26:49
