EasyMockSupport is a utility or helper class for test classes. It provides the following functionalities:
Step 1: Create an interface called CalculatorService to provide mathematical functions
File: 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); }
Step 2: Create a JAVA class to represent MathApplication
File: MathApplication.java
public class MathApplication { private CalculatorService calcService; public void setCalculatorService(CalculatorService calcService){ this.calcService = calcService; } public double add(double input1, double input2){ 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); } }
Step 3: Test the MathApplication class
Let's test the MathApplication class, by injecting in it a mock of calculatorService. Mock will be created by EasyMock.
File: MathApplicationTester.java
import org.easymock.EasyMockRunner; import org.easymock.EasyMockSupport; import org.junit.Assert; import org.junit.Before; import org.junit.Test; import org.junit.runner.RunWith; @RunWith(EasyMockRunner.class) public class MathApplicationTester extends EasyMockSupport { private MathApplication mathApplication1; private MathApplication mathApplication2; private CalculatorService calcService1; private CalculatorService calcService2; @Before public void setUp(){ mathApplication1 = new MathApplication(); mathApplication2 = new MathApplication(); calcService1 = createNiceMock(CalculatorService.class); calcService2 = createNiceMock(CalculatorService.class); mathApplication1.setCalculatorService(calcService1); mathApplication2.setCalculatorService(calcService2); } @Test public void testCalcService(){ //activate all mocks replayAll(); //test the add functionality Assert.assertEquals(mathApplication1.add(20.0, 10.0),0.0,0); //test the subtract functionality Assert.assertEquals(mathApplication1.subtract(20.0, 10.0),0.0,0); //test the multiply functionality Assert.assertEquals(mathApplication1.divide(20.0, 10.0),0.0,0); //test the divide functionality Assert.assertEquals(mathApplication1.multiply(20.0, 10.0),0.0,0); //test the add functionality Assert.assertEquals(mathApplication2.add(20.0, 10.0),0.0,0); //test the subtract functionality Assert.assertEquals(mathApplication2.subtract(20.0, 10.0),0.0,0); //test the multiply functionality Assert.assertEquals(mathApplication2.divide(20.0, 10.0),0.0,0); //test the divide functionality Assert.assertEquals(mathApplication2.multiply(20.0, 10.0),0.0,0); //verify all the mocks verifyAll(); } }
Step 4: Execute test cases
Create a java class file named TestRunner in C:\> EasyMock_WORKSPACE to execute Test case(s).
File: 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()); } }
Step 5: Verify the Result
Compile the classes using javac compiler as follows:
C:\EasyMock_WORKSPACE>javac MathApplicationTester.java
Now run the Test Runner to see the result:
C:\EasyMock_WORKSPACE>java TestRunner
Verify the output.
true