Mockito - Rappels

Mockito fournit une interface de réponse qui permet le stubbing avec une interface générique.

Syntaxe

//add the behavior to add numbers
when(calcService.add(20.0,10.0)).thenAnswer(new Answer<Double>() {
   @Override
   public Double answer(InvocationOnMock invocation) throws Throwable {
      //get the arguments passed to mock
      Object[] args = invocation.getArguments();
      //get the mock 
      Object mock = invocation.getMock();	
      //return the result
      return 30.0;
   }
});

Exemple

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

Testons la classe MathApplication, en y injectant un simulacre de calculatorService. Mock sera créé par Mockito.

Ici, nous avons ajouté un appel de méthode fictive, add () à l'objet fictif via when (). Cependant, lors des tests, nous avons appelé soustract () avant d'appeler add (). Lorsque nous créons un objet fictif à l'aide de Mockito.createStrictMock (), l'ordre d'exécution de la méthode importe.

File: MathApplicationTester.java

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
import static org.mockito.Mockito.inOrder;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InOrder;
import org.mockito.runners.MockitoJUnitRunner;

// @RunWith attaches a runner with the test class to initialize the test data
@RunWith(MockitoJUnitRunner.class)
public class MathApplicationTester {
	
   private MathApplication mathApplication;
   private CalculatorService calcService;

   @Before
   public void setUp(){
      mathApplication = new MathApplication();
      calcService = mock(CalculatorService.class);
      mathApplication.setCalculatorService(calcService);
   }

   @Test
   public void testAdd(){

      //add the behavior to add numbers
      when(calcService.add(20.0,10.0)).thenAnswer(new Answer<Double>() {

         @Override
         public Double answer(InvocationOnMock invocation) throws Throwable {
            //get the arguments passed to mock
            Object[] args = invocation.getArguments();
			
            //get the mock 
            Object mock = invocation.getMock();	
			
            //return the result
            return 30.0;
         }
      });

      //test the add functionality
      Assert.assertEquals(mathApplication.add(20.0, 10.0),30.0,0);
   }
}

Step 4 − Execute test cases

Créez un fichier de classe Java nommé TestRunner dans C:\> Mockito_WORKSPACE pour exécuter des cas de test.

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

Compilez les classes en utilisant javac compilateur comme suit -

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

Maintenant, lancez le Test Runner pour voir le résultat -

C:\Mockito_WORKSPACE>java TestRunner

Vérifiez la sortie.

true