In this tutorial, We will learn how to install and configure TestNG with Eclipse to use TestNG framework in automating scripts using Selenium WebDriver.

In case you are not aware of TestNG, follow the link - TestNG Introduction

1. Launch Eclipse.
2. On the menu bar, click Help.
3. Choose the "Eclipse Marketplace..." option.

  

In this tutorial, I am going to cover the Introduction to TestNG and its uses in Selenium.

TestNG is a testing framework which is used to design and maintain test scripts efficiently and generate test execution results in the form of HTML report. It covers a wide range of testing from Unit testing to end-to-end testing.

Advantages - 

1. It provides effective HTML report that explains test execution result.
2. It allows parallel execution of test cases.
3. It supports parameterization using @parameters annotation.
4. It provides flexibility to prioritize test cases.
5. It provides flexibility to ignore the execution of test cases.
6. It provides assertions to examine the expected and actual outcome.
7. It supports grouping of test cases.
8. It supports Data Driven Testing using @DataProvider annotation.

Annotations in TestNG – 

1. @BeforeSuite – Method under this annotation will execute before the execution of all the tests in the suite.
2. @AfterSuite – Method under this annotation will execute after the execution of all the tests in the suite.
3. @BeforeClass – Method under this annotation will execute before the execution of first @test annotation.
4. @AfterClass – Method under this annotation will execute after the execution of all @test annotation.
5. @BeforeMethod – Method under this annotation will execute before the execution of each @test annotation.
6. @AfterMethod – Method under this annotation will execute after the execution of each @test annotation.
7. @Test – Defines a particular functionality of the application.
8. @BeforeTest – Method under this annotation will execute before the execution of first @test annotation.
9. @AfterClass – Method under this annotation will execute after the execution of all @test annotation.

JUnit

It is also a testing framework like TestNG. However, TestNG has some more useful features compared to JUnit. So we can say TestNG is the enhanced version of JUnit.


Similarities between JUnit and TestNG

• Annotations - Both have similar annotations(@Test, @BeforeClass, @AfterClass), Almost similar annotations(TestNG has @BeforeMethod and @AfterMethod, similarly JUnit has @Before and @After).
• Annotation to set TimeOut - Both have @Test(timeOut = 1000) in miliseconds.
• Annotation to Ignore Test - TestNG has @Test(enabled=true) and JUnit has @Ignore.
• Annotation for Exception - TestNG has @Test(expectedExpecptions=ExceptionName.class) and JUnit has @Test(expected=ExceptionName.class)

Dis-similarities between JUnit and TestNG

• Annotations - Unlike TestNG, JUnit does not provide @BeforeSuite, @AfterSuite, @BeforeTest and @AfterTest annotations.
• TestNG provides Grouping of test cases whereas JUnit does not.
• TestNG provides parallel execution of test cases whereas JUnit does not.
• Achieving Parametrization in JUnit is more complex than that of TestNG.
• TestNG provides Dependency of a method on other methods functionality of test cases whereas JUnit does not.