Importance of TestNG and its Advantages

TestNG introduces the entire new set of features which makes it more powerful and useful. TestNG is a user-friendly automation framework that overcomes the drawbacks and limitations of the java unit. The automated testing Framework helps in the elimination of numerous limitations of the older framework.

TestNG Framework

• TestNG is a testing framework designed for unit testing, nowadays it is used for every kind of testing
• it is an open source framework which is inspired by the Java platform(JUnit) and NET platform  (NUnit)
• it is introduced as a  brand new automated framework whose functionalities make it more powerful and easier to use

Features of TestNG

• Maintains flexible runtime configuration
• Guards easy-going plug-in  API
• Supports multi-threaded testing
• Upholds parallel testing, group testing, and load testing
• Supports annotations of JUnit and inculcates a few more annotations to make testing simpler
• Separates compile-time test code from run-time configuration
• Supports testing integrated classes
• TestNG supports The 'dependence' method which is not available in JUnit 

TestNG Basic Annotations

1. @BeforeSuite - this annotation will always be executed before all tests are run inside a TestNg
2. @AfterSuite - this annotation will always be executed after all tests are run inside a TestNG
3. @BeforeClass - it will be executed before the first test method in a class which is called
4. @AfterClass- it will be executed after the first test method in a class which is called 
5. @BeforeTest - executed before any test method associated with the class inside <test> tag is run
6. @AfterTest - executed after any test method associated with the class inside <test> tag is run
7. @BeforeGroups - executed before the first test method associated with these groups is called on
8. @AfterGroups - executed after the first test method associated with these groups is called on
9. @BeforeMethod - executed before each test method
10. @AfterMethod - executed after each test method
11. @DataProvider - this annotation must return object, it marks a method as supplying data for a test method
12. @Factory - this annoation will return the object and marks a method as a factory that will be used by TestNG as test cases
13. @Listeners - it defines the listeners on a test class
14. @parameters - it describes how parameters can be passed to a test method
15. @Test - this annotation marks a class as a part of the test

Using TestNG with Selenium

Selenium tests alone cannot generate a proper format for the test results. However, with the help of TestNG, you can generate the proper format for test results. TestNG is widely used by selenium users because of its features and feasibility. moreover, it is associated with several advantages through which a user can be very comfortable

Following are the points why to use TestNG with selenium

1. You don't have to write a single line of code to generate a proper format for the test results as they are generated by default
2. If you want to control the test executions, then you have access to multiple annotations which can control how the test can be run
3. In order to run your tests, you can do it in arbitrarily big threads pools. you can simply group multiple test cases and convert them into an XML file and then set the priority of test cases in a specific order
4. It provides easy and flexible test configuration in which you don't have to write a code to modify any test methods
5. Using it you can create data-driven frameworks. you can use the @DataProvider to support data-driven testing
6. If you want to run your tests based on parameters, TestNG supports parameter feature which will make your test cases or test suite very flexible
7. If there are multiple classes to execute in the test suite, you can simply just right click and run the complete test suite
8. It is supported by a variety of tools and plugins. Also, it supports multiple IDE such as Webstorm,IntelliJ or NetBeans.
9. You can simply group the test cases with the use of TestNG.

Advantages of  TestNG over JUnit

1. It gives an option to run out same test case with multiple set of test data
2. It provides default reports which are not provided if your using JUnit
3. It has higher level of customization which enables the user to customize test case execution so that the user can run his script when something happens
4. Test cases can also be grouped easily as compared to JUnit
5. The Annotations used in TestNG are very simple and easy to understand