TestNG - Writing Tests


Writing a test in TestNG basically involves the following steps −

  • Write the business logic of your test and insert TestNG annotations in your code.

  • Add the information about your test (e.g. the class name, the groups you wish to run, etc.) in a testng.xml file or in build.xml.

  • Run TestNG.

Here, we will see one complete example of TestNG testing using POJO class, Business logic class and a test xml, which will be run by TestNG.

Create EmployeeDetails.java in C:\>TestNG_WORKSPACE, which is a POJO class.

public class EmployeeDetails {

   private String name;
   private double monthlySalary;
   private int age;
   // @return the name

   public String getName() {
      return name;
   // @param name the name to set
   public void setName(String name) {
      this.name = name;
   // @return the monthlySalary

   public double getMonthlySalary() {
      return monthlySalary;
   // @param monthlySalary the monthlySalary to set
   public void setMonthlySalary(double monthlySalary) {
      this.monthlySalary = monthlySalary;
   // @return the age
   public int getAge() {
      return age;
   // @param age the age to set
   public void setAge(int age) {
      this.age = age;

EmployeeDetails class is used to −

  • get/set the value of employee's name.
  • get/set the value of employee's monthly salary.
  • get/set the value of employee's age.

Create an EmpBusinessLogic.java in C:\>TestNG_WORKSPACE, which contains business logic.

public class EmpBusinessLogic {

   // Calculate the yearly salary of employee
   public double calculateYearlySalary(EmployeeDetails employeeDetails) {
      double yearlySalary = 0;
      yearlySalary = employeeDetails.getMonthlySalary() * 12;
      return yearlySalary;
   // Calculate the appraisal amount of employee
   public double calculateAppraisal(EmployeeDetails employeeDetails) {
      double appraisal = 0;
      if(employeeDetails.getMonthlySalary() < 10000) {
         appraisal = 500;
      } else {
         appraisal = 1000;
      return appraisal;

EmpBusinessLogic class is used for calculating −

  • the yearly salary of employee.
  • the appraisal amount of employee.

Now, let's create a TestNG class called TestEmployeeDetails.java in C:\>TestNG_WORKSPACE. A TestNG class is a Java class that contains at least one TestNG annotation. This class contains test cases to be tested. A TestNG test can be configured by @BeforeXXX and @AfterXXX annotations (we will see this in the chapter TestNG - Execution Procedure), which allows to perform some Java logic before and after a certain point.

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

public class TestEmployeeDetails {
   EmpBusinessLogic empBusinessLogic = new EmpBusinessLogic();
   EmployeeDetails employee = new EmployeeDetails();

   public void testCalculateAppriasal() {
      double appraisal = empBusinessLogic.calculateAppraisal(employee);
      Assert.assertEquals(500, appraisal, 0.0, "500");

   // Test to check yearly salary
   public void testCalculateYearlySalary() {
      double salary = empBusinessLogic.calculateYearlySalary(employee);
      Assert.assertEquals(96000, salary, 0.0, "8000");

TestEmployeeDetails class is used for testing the methods of EmpBusinessLogic class. It does the following −

  • Tests the yearly salary of the employee.

  • Tests the appraisal amount of the employee.

Before you can run the tests, you must configure TestNG using a special XML file, conventionally named testng.xml. The syntax for this file is very simple, and its contents are as shown below. Create this file in C:\>TestNG_WORKSPACE.

<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd" >

<suite name = "Suite1">
   <test name = "test1">
         <class name = "TestEmployeeDetails"/>

Details of the above file are as follows −

  • A suite is represented by one XML file. It can contain one or more tests and is defined by the <suite> tag.

  • Tag <test> represents one test and can contain one or more TestNG classes.

  • <class> tag represents a TestNG class. It is a Java class that contains at least one TestNG annotation. It can contain one or more test methods.

Compile the Test case classes using javac.

C:\TestNG_WORKSPACE>javac EmployeeDetails.java EmpBusinessLogic.java TestEmployeeDetails.java

Now TestNG with the following command −

C:\TestNG_WORKSPACE>java -cp "C:\TestNG_WORKSPACE" org.testng.TestNG testng.xml

If all has been done correctly, you should see the results of your tests in the console. Furthermore, TestNG creates a very nice HTML report in a folder called test-output that is automatically created in the current directory. If you open it and load index.html, you will see a page similar to the one in the image below −

Writing Tests