JUnit - Exception testing

JUnit - Exception testing

Junit code handling provides an option to track exceptions. Y ou can test the code if it throws the exception it wants. cted parameter @Test with the comment. N ow let's look at @Test in the activity.

Create a class

• In C: Create a JUNIT_WORKSPACE class called MessageUtil .java to test in this file.
• Add an error condition to the printMessage() method.

/*
* This class prints the given message on console.
*/
public class MessageUtil {

   private String message;

   //Constructor
   //@param message to be printed
   public MessageUtil(String message){
      this.message = message; 
   }

   // prints the message
   public void printMessage(){
      System.out.println(message);
      int a =0;
      int b = 1/a;
   }   

   // add "Hi!" to the message
   public String salutationMessage(){
      message = "Hi!" + message;
      System.out.println(message);
      return message;
   }   
}  

Create a Test Case class

• Create a java test class .java TestJunit.
• Add the required exception, ArithmeticException, to the testPrintMessage() test case.

Create a java class JUNIT_WORKSPACE file name TestJunit in the C:.java

import org.junit.Test;
import org.junit.Ignore;
import static org.junit.Assert.assertEquals;

public class TestJunit {

   String message = "Robert";   
   MessageUtil messageUtil = new MessageUtil(message);

   @Test(expected = ArithmeticException.class)
   public void testPrintMessage() { 
      System.out.println("Inside testPrintMessage()");     
      messageUtil.printMessage();     
   }

   @Test
   public void testSalutationMessage() {
      System.out.println("Inside testSalutationMessage()");
      message = "Hi!" + "Robert";
      assertEquals(message,messageUtil.salutationMessage());
   }
}

Create a TestRunner class

Create a java class JUNIT_WORKSPACE file named TestJunit .java in the C:-gt;

import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;

public class TestRunner {
   public static void main(String[] args) {
      Result result = JUnitCore.runClasses(TestJunit.class);
      for (Failure failure : result.getFailures()) {
         System.out.println(failure.toString());
      }
      System.out.println(result.wasSuccessful());
   }
}

The MessageUtil, Test case, and Test Runner classes are compiled with javac.

C:\JUNIT_WORKSPACE>javac MessageUtil.java TestJunit.java TestRunner.java

Now run Test Runner, which will run the test cases defined by the provided Test Case class.

C:\JUNIT_WORKSPACE>java TestRunner

Verify the output. The testPrintMessage() test case will pass.

Inside testPrintMessage()
Robert
Inside testSalutationMessage()
Hi!Robert
true