1.2. Example of IAnnotationTransformer

1.2. Example of IAnnotationTransformer

IAnnotationTransformer is a TestNG allows you to do using its annotation transformation framework. In general annotations are static in nature by design, so any change in the values require recompilation of source files. Since TestNG relies heavily on annotations, it would be nice if one can override its behavior at runtime. 

There are four different ways to achieve this

1.2.1. Example of @Test annotation transformer

1.2.2. Example of @DataProvider annotation transformer

1.2.3. Example of @Factory annotation transformer

1.2.4. Example of Configuration annotation transformer

===========================================================================

1.2.1. Example of @Test annotation transformer

Representation :

 

 In the below example, we configure the @Test annotation.
TestAnnotationTransformerExample is our test class. It contains test methods testcase1, testcase2 and testcase3. Methods testcase1 and testcase2 accept a string parameter but we haven’t provided any DataProvider. The DataProvider will be set on-the-fly in the annotation transformer, based on the method, and also by using Annotation.setEnabled(fasle) will disable the test case. 

TestAnnotationTransformerExample;

 

	package com.IAnnotationTransformer;
	import org.testng.annotations.Test;
	public class TestAnnotationTransformerExample {
	@Test
	public void testcase1(String param) {
	// here param data should read from DataProvider Class when method is equal to testcase1 and it
	// should send the output as apple, banana, mango
	System.out.println("TestAnnotationTransformerExample Method is testcase1, parameter is " + param);
	}
	@Test
	public void testcase2(String param) {
	// here param data should read from DataPrpovider Class when method is equal to testcase2 and it
	// should send the output as a,b,c
	System.out.println("TestAnnotationTransformerExample Method is testcase2, parameter is " + param);
	}
	@Test
	public void testcase3() {
	// This should not display any output as its set diabled in annotation.setEnabled(false);
	System.out.println("TestAnnotationTransformerExample Method is testcase3");
	}
	}

view raw 1TestAnnotationTransformerExample.java hosted with ❤ by GitHub

	TestAnnotationTransformerListener:
	TestAnnotationTransformerListener is test annotation transformer listener. implements IAnnotationTransformer.
	Method transform transforms the annotation.
	It takes four parameters. First parameter is of type ITestAnnotation and it represents @Test annotation.
	Most common use of @Test annotation is at method level but it can also be placed at class or constructor level.
	The last three parameters tell us, on which Java element the annotation was found: a class, a constructor, or a method.
	Only one of them will be non-null.
	You can change the annotation values by calling any of the setters on the ITestAnnotation interface.
	In the below example, we dynamically set the data provider for test method testcase1 and testcase2.
	We also disable the test method if it is testcase3.

view raw 2.TestAnnotationTransformerListener.txt hosted with ❤ by GitHub

	package com.IAnnotationTransformer;
	import java.lang.reflect.Constructor;
	import java.lang.reflect.Method;
	import org.testng.IAnnotationTransformer;
	import org.testng.annotations.ITestAnnotation;
	public class TestAnnotationTransformerListener implements IAnnotationTransformer {
	@Override
	public void transform(ITestAnnotation annotation, Class testClass,
	Constructor testConstructor, Method testMethod) {
	if (testMethod.getName().equals("testcase1")) {
	System.out.println("set data provider for " + testMethod.getName());
	annotation.setDataProviderClass(DataProviderFactory.class);
	annotation.setDataProvider("getDp1");
	} else if (testMethod.getName().equals("testcase2")) {
	System.out.println("set data provider for " + testMethod.getName());
	annotation.setDataProviderClass(DataProviderFactory.class);
	annotation.setDataProvider("getDp2");
	} else if (testMethod.getName().equals("testcase3")) {
	System.out.println("Disable " + testMethod.getName());
	annotation.setEnabled(false);
	}
	}
	}

view raw 3.Example.java hosted with ❤ by GitHub

	DataProviderFactory:
	DataProviderFactory contains the static data providers.
	package com.IAnnotationTransformer;
	import org.testng.annotations.DataProvider;
	public class DataProviderFactory {
	@DataProvider
	public static Object[][] getDp1() {
	return new Object[][]{{"apple"}, {"banana"}, {"mango"}};
	}
	@DataProvider
	public static Object[][] getDp2() {
	return new Object[][]{{"a"}, {"b"}, {"m"}};
	}
	@DataProvider(name="getDp3")
	public static Object[][] getDp3() {
	return new Object[][]{{"river"}, {"book"}, {"bank"}};
	}
	@DataProvider(name="constructorParams")
	public static Object[][] getConstructorParams() {
	return new Object[][]{{"1"}, {"2"}, {"3"}};
	}
	}

view raw 4.DPFactory.java hosted with ❤ by GitHub

	testAnnotationTransformerTestng.xml:
	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
	<suite name="Suite" parallel="false">
	<listeners>
	<listener class-name="com.IAnnotationTransformer.TestAnnotationTransformerListener" />
	</listeners>
	<test name="Test">
	<classes>
	<class name="com.IAnnotationTransformer.TestAnnotationTransformerExample" />
	</classes>
	</test>
	</suite>

view raw 5.testAnnotationTransformerTestng.xml hosted with ❤ by GitHub

	Output :
	set data provider for testcase1
	set data provider for testcase2
	Disable testcase3
	[TestNG] Running:
	TestAnnotationTransformerExample Method is testcase1, parameter is apple
	TestAnnotationTransformerExample Method is testcase1, parameter is banana
	TestAnnotationTransformerExample Method is testcase1, parameter is mango
	TestAnnotationTransformerExample Method is testcase2, parameter is a
	TestAnnotationTransformerExample Method is testcase2, parameter is b
	TestAnnotationTransformerExample Method is testcase2, parameter is m
	===============================================
	Suite
	Total tests run: 6, Failures: 0, Skips: 0
	===============================================

view raw 6.output.txt hosted with ❤ by GitHub

1.2.2. Example of @DataProvider annotation transformer

If we want to modify any TestNG annotation besides @Test then we can make use of  @Dataprovider annotation transformer. In this example, based on the dataProvider, we decide whether it should be used in parallel. If the dataProvider returns a "getDP3", we run it in parallel.

   

	DataProviderAnnotationTransformerExample;
	package com.DPAnnotationTransformer;
	import org.testng.annotations.Test;
	public class DataProviderAnnotationTransformerExample {
	@Test(dataProvider="getDP3", dataProviderClass=DataProviderFactory.class)
	public void largeDataTest(String param) {
	System.out.println("DataProviderAnnotationTransformerExample Method is t3, parameter is " + param + " threadId: "
	+ Thread.currentThread().getId());
	}
	}
	If the annotation name is “getDP3”, the dataProvider annotation is modified to run on a parallel.

view raw 1.DPtransformerexample.java hosted with ❤ by GitHub

	DataProviderFactory:
	DataProviderFactory contains the static data providers.
	package com.IAnnotationTransformer;
	import org.testng.annotations.DataProvider;
	public class DataProviderFactory {
	@DataProvider
	public static Object[][] getDp1() {
	return new Object[][]{{"apple"}, {"banana"}, {"mango"}};
	}
	@DataProvider
	public static Object[][] getDp2() {
	return new Object[][]{{"a"}, {"b"}, {"m"}};
	}
	@DataProvider(name="getDp3")
	public static Object[][] getDp3() {
	return new Object[][]{{"river"}, {"book"}, {"bank"}};
	}
	@DataProvider(name="constructorParams")
	public static Object[][] getConstructorParams() {
	return new Object[][]{{"1"}, {"2"}, {"3"}};
	}
	}

view raw 2.DataProviderFactory.java hosted with ❤ by GitHub

	DataProviderAnnotationTransformerListener:
	package com.DPAnnotationTransformer;
	import java.lang.reflect.Constructor;
	import java.lang.reflect.Method;
	import org.testng.IAnnotationTransformer2;
	import org.testng.annotations.IConfigurationAnnotation;
	import org.testng.annotations.IDataProviderAnnotation;
	import org.testng.annotations.IFactoryAnnotation;
	import org.testng.annotations.ITestAnnotation;
	public class DataProviderAnnotationTransformerListener implements IAnnotationTransformer2 {
	@Override
	public void transform(IDataProviderAnnotation annotation, Method method) {
	if (annotation.getName().equals("getDP3")) {
	System.out.println("In getDP3, run parallely");
	annotation.setParallel(true);
	}
	}
	@Override
	public void transform(ITestAnnotation annotation, Class testClass, Constructor testConstructor, Method testMethod) {
	}
	@Override
	public void transform(IFactoryAnnotation annotation, Method method) {
	}
	@Override
	public void transform(IConfigurationAnnotation annotation, Class testClass, Constructor testConstructor, Method testMethod) {
	}
	}

view raw 3.DataProviderAnnotationTransformerListener.java hosted with ❤ by GitHub

	dataAnnotationTransformerTestng.xml:
	<?xml version="1.0" encoding="UTF-8"?>
	<suite name="Suite" parallel="false">
	<listeners>
	<listener class-name="com.DPAnnotationTransformer.DataProviderAnnotationTransformerListener" />
	</listeners>
	<test name="Test">
	<classes>
	<class name="com.DPAnnotationTransformer.DataProviderAnnotationTransformerExample" />
	</classes>
	</test>
	</suite>

view raw 4.dataAnnotationTransformerTestng.xml hosted with ❤ by GitHub

	Output :
	You can see in the output, each invocation of t3 results in a different threadId, as it is configured to run parallely.
	In getDP3, run parallely
	DataProviderAnnotationTransformerExample Method is t3, parameter is river threadId: 12
	DataProviderAnnotationTransformerExample Method is t3, parameter is Data threadId: 11
	DataProviderAnnotationTransformerExample Method is t3, parameter is book threadId: 10
	===============================================
	Suite
	Total tests run: 3, Failures: 0, Skips: 0
	===============================================

view raw 5.Ouput.txt hosted with ❤ by GitHub

1.2.3. Example of @Factory annotation transformer

In this example, we transform a factory annotation.

FactoryAnnotationTransformerExample is a test class which depends on @Factory annotation for its creation. We will modify the annotation dynamically to set its source to a DataProvider.

  

	//FactoryAnnotationTransformerExample:
	package com.factoryAnnotTransformer;
	import org.testng.annotations.Factory;
	import org.testng.annotations.Test;
	public class FactoryAnnotationTransformerExample {
	private String name;
	@Factory
	public FactoryAnnotationTransformerExample(String name) {
	this.name = name;
	System.out.println("In constructor: " + name);
	}
	@Test
	public void testcase1() {
	System.out.println("Method is testcase1, name is " + name);
	}
	}

view raw 1.FactoryAnnotationTransformerExample.java hosted with ❤ by GitHub

	DataProvider Factory :
	package com.factoryAnnotTransformer;
	import org.testng.annotations.DataProvider;
	public class DataProviderFactory {
	@DataProvider
	public static Object[][] getDp1() {
	return new Object[][]{{"apple"}, {"banana"}, {"mango"}};
	}
	@DataProvider
	public static Object[][] getDp2() {
	return new Object[][]{{"a"}, {"b"}, {"m"}};
	}
	@DataProvider(name="getDp3")
	public static Object[][] getDp3() {
	return new Object[][]{{"river"}, {"book"}, {"bank"}};
	}
	@DataProvider(name="getDP4ConstructorParams")
	public static Object[][] getConstructorParams() {
	return new Object[][]{{"Constructordata 1"}, {"Constructor data 2"}, {"Constructor data 3"}};
	}
	}

view raw 2.DPfactory.java hosted with ❤ by GitHub

	FactoryAnnotationTransformerListener is the factory annotation transformer. In the transform method, we set theDataProvider name and its class.
	FactoryAnnotationTransformerListener:
	package com.factoryAnnotTransformer;
	import java.lang.reflect.Constructor;
	import java.lang.reflect.Method;
	import org.testng.IAnnotationTransformer2;
	import org.testng.annotations.IConfigurationAnnotation;
	import org.testng.annotations.IDataProviderAnnotation;
	import org.testng.annotations.IFactoryAnnotation;
	import org.testng.annotations.ITestAnnotation;
	public class FactoryAnnotationTransformerListener implements IAnnotationTransformer2 {
	@Override
	public void transform(IFactoryAnnotation annotation, Method method) {
	annotation.setDataProvider("getDP4ConstructorParams");
	annotation.setDataProviderClass(DataProviderFactory.class);
	}
	@Override
	public void transform(IConfigurationAnnotation annotation, Class testClass, Constructor testConstructor, Method testMethod) {
	}
	@Override
	public void transform(ITestAnnotation annotation, Class testClass, Constructor testConstructor, Method testMethod) {
	}
	@Override
	public void transform(IDataProviderAnnotation annotation, Method method) {
	}
	}

view raw 3. listener.java hosted with ❤ by GitHub

	<?xml version="1.0" encoding="UTF-8"?>
	<suite name="Suite" parallel="false">
	<listeners>
	<listener class-name="com.factoryAnnotTransformer.FactoryAnnotationTransformerListener" />
	</listeners>
	<test name="Test">
	<classes>
	<class name="com.factoryAnnotTransformer.FactoryAnnotationTransformerExample" />
	</classes>
	</test>
	</suite>

view raw 4.testng.xml hosted with ❤ by GitHub

	Output:
	[TestNGContentHandler] [WARN] It is strongly recommended to add "<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd" >" at the top of your file, otherwise TestNG may fail or not work as expected.
	In constructor: Default test name
	In constructor: Constructordata 1
	In constructor: Constructor data 2
	In constructor: Constructor data 3
	[TestNG] Running:
	Method is testcase1, name is Constructor data 2
	Method is testcase1, name is Constructordata 1
	Method is testcase1, name is Constructor data 3
	===============================================
	Suite
	Total tests run: 3, Failures: 0, Skips: 0
	===============================================

view raw 5.Output.txt hosted with ❤ by GitHub

1.2.4. Example of Configuration annotation transformer

In this example, we will alter the configuration based annotations like @BeforeSuite, @BeforeTest etc.

ConfigurationAnnotationTransformerExample is the test class. It contains some configuration methods with a descriptionattribute.

  

 

 

	ConfigurationAnnotationTransformerExample:
	package com.configAnnotTransformer;
	import org.testng.annotations.AfterMethod;
	import org.testng.annotations.AfterSuite;
	import org.testng.annotations.AfterTest;
	import org.testng.annotations.BeforeMethod;
	import org.testng.annotations.BeforeSuite;
	import org.testng.annotations.BeforeTest;
	import org.testng.annotations.Test;
	public class ConfigurationAnnotationTransformerExample {
	@BeforeSuite(description="before suite annotation")
	public void beforeSuite() {
	System.out.println("Am in beforeSuite");
	}
	@BeforeTest(description="before test annotation")
	public void beforeTest() {
	System.out.println("Am in beforeTest");
	}
	@BeforeMethod(description="before method annotation")
	public void beforeMethod() {
	System.out.println("Am in beforeMethod");
	}
	@Test(description="test method annotation")
	public void t() {
	System.out.println("Am test method");
	}
	@AfterMethod(description="after method annotation")
	public void afterMethod() {
	System.out.println("Am in afterMethod");
	}
	@AfterTest(description="after test annotation")
	public void afterTest() {
	System.out.println("Am in afterTest");
	}
	@AfterSuite(description="after suite annotation")
	public void afterSuite() {
	System.out.println("Am in after suite");
	}
	}

view raw 1.ConfigurationAnnotationTransformerExample.java hosted with ❤ by GitHub

	ConfigurationAnnotationTransformerListener:
	package com.configAnnotTransformer;
	import java.lang.reflect.Constructor;
	import java.lang.reflect.Method;
	import org.testng.IAnnotationTransformer2;
	import org.testng.annotations.IConfigurationAnnotation;
	import org.testng.annotations.IDataProviderAnnotation;
	import org.testng.annotations.IFactoryAnnotation;
	import org.testng.annotations.ITestAnnotation;
	public class ConfigurationAnnotationTransformerListener implements IAnnotationTransformer2 {
	@Override
	public void transform(IConfigurationAnnotation annotation, Class testClass,
	Constructor testConstructor, Method testMethod) {
	System.out.println("Configure annotation " + annotation.getDescription());
	}
	@Override
	public void transform(ITestAnnotation annotation, Class testClass,
	Constructor testConstructor, Method testMethod) {
	}
	@Override
	public void transform(IDataProviderAnnotation annotation, Method method) {
	}
	@Override
	public void transform(IFactoryAnnotation annotation, Method method) {
	}
	}

view raw 2.listener.java hosted with ❤ by GitHub

	configurationAnnotationTransformerTestng.xml
	<?xml version="1.0" encoding="UTF-8"?>
	<suite name="Suite" parallel="false">
	<listeners>
	<listener class-name="com.configAnnotTransformer.ConfigurationAnnotationTransformerListener" />
	</listeners>
	<test name="Test">
	<classes>
	<class name="com.configAnnotTransformer.ConfigurationAnnotationTransformerExample" />
	</classes>
	</test>
	</suite>

view raw 3.configurationAnnotationTransformerTestng.xml hosted with ❤ by GitHub

	Output:
	[TestNGContentHandler] [WARN] It is strongly recommended to add "<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd" >" at the top of your file, otherwise TestNG may fail or not work as expected.
	Configure annotation before suite annotation
	Configure annotation after suite annotation
	Configure annotation before test annotation
	Configure annotation after test annotation
	Configure annotation before method annotation
	Configure annotation after method annotation
	[TestNG] Running:
	Am in beforeSuite
	Am in beforeTest
	Am in beforeMethod
	Am test method
	Am in afterMethod
	Am in afterTest
	Am in after suite
	===============================================
	Suite
	Total tests run: 1, Failures: 0, Skips: 0
	===============================================

view raw 4.output.txt hosted with ❤ by GitHub