EasyMock - Example with times(min,max)



Following are the steps taken.

Create an Interface CalculatorService whose purpose to provide various calculation related functions.

CalculatorService.java
public interface CalculatorService {
   public double add(double input1, double input2);
   public double subtract(double input1, double input2);
   public double multiply(double input1, double input2);
   public double divide(double input1, double input2);
   public void serviceUsed();
}

Create a JAVA class to represent MathApplication.

MathApplication.java
public class MathApplication {
   private CalculatorService calcService;

   public void setCalculatorService(CalculatorService calcService){
      this.calcService = calcService;
   }
   public double add(double input1, double input2){
      calcService.serviceUsed();
      calcService.serviceUsed();
      calcService.serviceUsed();   
      return calcService.add(input1, input2);		
   }
   public double subtract(double input1, double input2){
      return calcService.subtract(input1, input2);
   }
   public double multiply(double input1, double input2){
      return calcService.multiply(input1, input2);
   }
   public double divide(double input1, double input2){
      return calcService.divide(input1, input2);
   }
}

Let's test the MathApplication class, by injecting in it a mock of calculatorService. Mock will be created by EasyMock.

MathApplicationTester.java MathApplicationTester.java
import org.easymock.EasyMock;
import org.easymock.EasyMockRunner;
import org.easymock.Mock;
import org.easymock.TestSubject;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

//@RunWith attaches a runner with the test class to initialize the test data
@RunWith(EasyMockRunner.class)
public class MathApplicationTester {
	
   //@TestSubject annotation is used to identify class which is going to use the
   //mock object
   @TestSubject
   MathApplication mathApplication = new MathApplication();

   //@Mock annotation is used to create the mock object to be injected
   @Mock
   CalculatorService calcService;

   @Test
   public void testAdd(){
      //add the behavior of calc service to add two numbers
      EasyMock.expect(calcService.add(10.0,20.0)).andReturn(30.00);
      calcService.serviceUsed();
      EasyMock.expectLastCall().times(1,3);
      //activate the mock
      EasyMock.replay(calcService);	
		
      //test the add functionality
      Assert.assertEquals(mathApplication.add(10.0, 20.0),30.0,0);

      //verify call to calcService is made or not
      EasyMock.verify(calcService);
   }
}

Create a java class file name TestRunner in C:\ > EasyMock_WORKSPACE to execute Test case(s)

TestRunner.java
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(MathApplicationTester.class);
      for (Failure failure : result.getFailures()) {
         System.out.println(failure.toString());
      }
      System.out.println(result.wasSuccessful());
   }
}  	

Verify the Result

Compile the classes using javac compiler as follows

C:\EasyMock_WORKSPACE>javac CalculatorService.java MathApplication.java MathApplicationTester.java TestRunner.java

Now run the Test Runner to see the result

C:\EasyMock_WORKSPACE>java TestRunner

Verify the output.

true
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