ExpectedExceptions attribute:

Expected Exceptions attribute:

This expectedExceptions  present in @Test in  TestNG

While writing unit tests there can be certain scenarios where we need to verify that an exception is being thrown by the program during execution.

TestNG provides a feature to test such scenarios by allowing the user to specify the type of exceptions that are expected to be thrown by a test method during execution. It supports multiple values being provided for verification. If the exception thrown by the test is not part of the user entered list, the test method will be marked as failed.

we write ExpectedExceptions as the part of @Test. we need write exception with .class extension.

We can write both checked excpetions , unchecked exceptions and our own customized exceptions.

we can write single exception,multiple exceptions as well.For example

@Test(expectedExceptions=ArithmeticException.class)

@Test(expectedExceptions = { IOException.class })

@Test(expectedExceptions = { IOException.class, NullPointerException.class })

Example:

package com.rameshsoft.testNG;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;

import org.openqa.selenium.WebDriver;

import org.openqa.selenium.firefox.FirefoxDriver;

import org.testng.annotations.AfterMethod;

import org.testng.annotations.BeforeMethod;

import org.testng.annotations.Test;

public class ExpectedExecptionDemo {

         

          @BeforeMethod

          public void before()

          {

                   System.out.println("Before test running");

          }

          @AfterMethod

          public void after()

          {

                   System.out.println("After test running");

          }

   

         @Test(expectedExceptions=IOException.class)

          public void execute1() throws IOException

          {

                   System.out.println("RameshSoft");

                    throw new IOException();

          }

          @Test(expectedExceptions=ArithmeticException.class)

          public void execute()

          {

                   System.out.println(10/0);

                  System.out.println("Hello");

          }

          }

Output:

Before test running

After test running

Before test running

Rameshsoft

After test running

PASSED: execute

PASSED: execute1