TestNG Listener - customise output with ITestListener

TestNG provides many listeners (as interfaces) which you can customise to your need to get output more readable.

Here are the listeners –

IAnnotationTransformer
IAnnotationTransformer2
IHookable
IInvokedMethodListener
IMethodInterceptor
IReporter
ISuiteListener
ITestListener

From this above listeners, in this post we will see ITestListener

ITestListener interface has the following methods to implement

void onStart(ITestContext context)
Invoked after the test class is instantiated and before any configuration method is called.

void onFinish(ITestContext context)
Invoked after all the tests have run and all their Configuration methods have been called.

onTestFailure(ITestResult result)
Invoked each time a test fails.

onTestSkipped(ITestResult result)
Invoked each time a test is skipped.

onTestStart(ITestResult result)
Invoked each time before a test will be invoked.

onTestSuccess(ITestResult result)
Invoked each time a test succeeds.

Let’s see the implementation –

Create a new Maven project (com.testNG and projectName – TestNGSample)

Know more about creating maven project with testNG

Create a testNG class with Passed, Failed and Skipped scenario

TestNG1.java

package mypkg;

import org.testng.SkipException;
import org.testng.annotations.Test;

public class TestNG1 {
	
	@Test(description = "Desc - Passing a scenario")
	public void passTestMethod() {
		System.out.println("Inside PassTestMethod");
	}
	
	@Test(description = "Desc - Failing a scenario")
	public void failTestMethod() {
		int a = 9/0;
		System.out.println("Inside FailTestMethod");
	}

	@Test(description = "Desc - Skipping a scenario")
	public void skipTestMethod() {
		throw new SkipException("Intentionally skipping");
	}
}

Create another testNG class – TestNG2.java

package mypkg;

import org.testng.Assert;
import org.testng.annotations.Test;

public class TestNG2 {

    @Test
    public void Test1_2(){
        System.out.println("This is Test1_2: TESTNG3");
        Assert.fail();
    }

    @Test
    public void Test2_2(){
        System.out.println("This is Test2_2: TESTNG2");
    }
}

Let’s see the output for these 2 testNG classes with out listener

java.lang.ArithmeticException: / by zero

	at testNG.TList.iTestList.TestNG1.failTestMethod(TestNG1.java:19)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:134)
    ...


Inside PassTestMethod


Test ignored.

===============================================
Default Suite
Total tests run: 3, Passes: 1, Failures: 1, Skips: 1
===============================================

This is Test1_2: TESTNG3

java.lang.AssertionError: null

	at org.testng.Assert.fail(Assert.java:97)
	at org.testng.Assert.fail(Assert.java:102)
	at testNG.TList.iTestList.TestNG2.Test1_2(TestNG2.java:13)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    ...
    
    
This is Test2_2: TESTNG2

===============================================
Default Suite
Total tests run: 2, Passes: 1, Failures: 1, Skips: 0
===============================================

Now, create a class TestListenerManager.java which will implement ITestListener

package mypkg;

import org.testng.ITestContext;
import org.testng.ITestListener;
import org.testng.ITestResult;

public class ITestListManager implements ITestListener {

    @Override
    public void onTestStart(ITestResult result) {

        System.out.println("--------- Test case '"+ result.getMethod().getMethodName() +"' started ---------");
    }

   @Override
    public void onTestSuccess(ITestResult result) {
        System.out.println("Testcase '" + result.getMethod().getMethodName() + "' passed");
    }

    @Override
    public void onTestFailure(ITestResult result) {
        System.out.println("Testcase '" + result.getMethod().getMethodName() +
                "' failed, because of " + result.getThrowable());

    }

    @Override
    public void onTestSkipped(ITestResult result) {
        System.out.println("Testcase '" + result.getMethod().getMethodName() +
                "' skipped, because of " + result.getThrowable());
    }

    @Override
    public void onTestFailedButWithinSuccessPercentage(ITestResult result) {

    }

    @Override
    public void onTestFailedWithTimeout(ITestResult result) {

    }

    @Override
    public void onStart(ITestContext context) {
        System.out.println("Context start- " + context.getName());
    }

    @Override
    public void onFinish(ITestContext context) {
        System.out.println("Context finish- " + context.getName());
    }
}

Now we have 3 class files,

TestNG1.java

TestNG2.java

ITestListManager.java

But we didn’t create relationship between them, means we dint connect the listener class with the actual testNG class

We have 3 ways to integrate

Class level
Suite level
pom.xml using sure-fire plugin

Class level

Each testNG class (TestNG1.java & TestNG2.java), we have to specific the listener as asn example –

@Listeners(mypkg.ITestListManager.class) public class TestNG2 { ....

@Listeners(mypkg.ITestListManager.class)
public class TestNG2 {
....

Then individually we need to run the testNG classes to see the custom output

Suite level

Listeners can be specified on the testng.xml, so all the tests mentioned under the suite or test tag will be covered

<listeners>
    <listener class-name="mypkg.ITestListManager"/>
</listeners>

Example – testng.xml

<!DOCTYPE suite SYSTEM "https://testng.org/testng-1.0.dtd" >

<suite name="MySuite For List" verbose="1" >
    <listeners>
        <listener class-name="mypkg.ITestListManager"/>
    </listeners>
    
    <test name="Regression1"   >
       <classes>
           <class name="mypkg.TestNG1"/>
       </classes>
    </test>
    
    <test name="Functional"   >
        <classes>
            <class name="mypkg.TestNG2"/>
        </classes>
    </test>

</suite>

Run the testng.xml – Right click on the xml > Run As > TestNG Suite

OutPut –

Context start- Regression1

--------- Test case 'failTestMethod' started ---------

java.lang.ArithmeticException: / by zero

	at testNG.TList.iTestList.TestNG1.failTestMethod(TestNG1.java:19)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    ...

Testcase 'failTestMethod' failed, because of java.lang.ArithmeticException: / by zero


--------- Test case 'passTestMethod' started ---------
Inside PassTestMethod

Testcase 'passTestMethod' passed


--------- Test case 'skipTestMethod' started ---------

Test ignored.
Testcase 'skipTestMethod' skipped, because of org.testng.SkipException: Intentionally skipping

Context finish- Regression1



Context start- Functional

--------- Test case 'Test1_2' started ---------
This is Test1_2: TESTNG3

java.lang.AssertionError: null

	at org.testng.Assert.fail(Assert.java:97)
	at org.testng.Assert.fail(Assert.java:102)
	at testNG.TList.iTestList.TestNG2.Test1_2(TestNG2.java:13)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    ...

Testcase 'Test1_2' failed, because of java.lang.AssertionError: null


--------- Test case 'Test2_2' started ---------
This is Test2_2: TESTNG2

Testcase 'Test2_2' passed

Context finish- Functional

===============================================
MySuite For List
Total tests run: 5, Passes: 2, Failures: 2, Skips: 1
===============================================

Now you can observe the customised output, as compared to the raw output we have seen at beginning of this post, this one is more readable.

pom.xml : sure-fire plugin

<plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>3.0.0-M5</version>
                <configuration>
                    <!--suiteXmlFiles>
                        <suiteXmlFile>testng.xml</suiteXmlFile>
                    </suiteXmlFiles-->
                    <includes>
                        <include>*.*</include>
                    </includes>
                    <properties>
                        <property>
                            <name>listener</name>
                            <value>testNgLearning.listeners.ITestListManager</value>
                        </property>
                    </properties>
                </configuration>
            </plugin>

Under your pom.xml, add the sure-fire plugin > properties > property > name as listener and value as ITestListManager or which ever class implemented the ITestListener interface

reference –

https://maven.apache.org/surefire/maven-surefire-plugin/examples/testng.html

Now you can run any testng class or method by right click or even we can use mvn test to run the tests, testngListener will automatically applied to each test methods.

To run the tests using maven command in commandline –

mvn test -Dtest=mypkg.TestNG2

If this post is useful, then refer IReporter listener for more customisations.

Reference – TestNG listeners

Here are the listeners –

Class level

Suite level

pom.xml : sure-fire plugin

Author: sunil patro

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TestNG Listener – customise output with ITestListener

Here are the listeners –

Class level

Suite level

pom.xml : sure-fire plugin

Author: sunil patro

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