Mockito - In attesa di chiamate

Mockito fornisce un controllo speciale sul numero di chiamate che possono essere effettuate su un particolare metodo. Supponiamo che MathApplication debba chiamare il metodo CalculatorService.serviceUsed () solo una volta, quindi non dovrebbe essere in grado di chiamare CalculatorService.serviceUsed () più di una volta.

//add the behavior of calc service to add two numbers
when(calcService.add(10.0,20.0)).thenReturn(30.00);

//limit the method call to 1, no less and no more calls are allowed
verify(calcService, times(1)).add(10.0, 20.0);

Creare l'interfaccia CalculatorService come segue.

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);
}

Esempio

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

Testiamo la classe MathApplication, inserendovi una simulazione di calculatorService. Mock sarà creato da Mockito.

File: MathApplicationTester.java

import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.never;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.runners.MockitoJUnitRunner;

// @RunWith attaches a runner with the test class to initialize the test data
@RunWith(MockitoJUnitRunner.class)
public class MathApplicationTester {
	
   //@InjectMocks annotation is used to create and inject the mock object
   @InjectMocks 
   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
      when(calcService.add(10.0,20.0)).thenReturn(30.00);
		
      //add the behavior of calc service to subtract two numbers
      when(calcService.subtract(20.0,10.0)).thenReturn(10.00);
      
      //test the add functionality
      Assert.assertEquals(mathApplication.add(10.0, 20.0),30.0,0);
      Assert.assertEquals(mathApplication.add(10.0, 20.0),30.0,0);
      Assert.assertEquals(mathApplication.add(10.0, 20.0),30.0,0);
      
      //test the subtract functionality
      Assert.assertEquals(mathApplication.subtract(20.0, 10.0),10.0,0.0);
      
      //default call count is 1 
      verify(calcService).subtract(20.0, 10.0);
      
      //check if add function is called three times
      verify(calcService, times(3)).add(10.0, 20.0);
      
      //verify that method was never called on a mock
      verify(calcService, never()).multiply(10.0,20.0);
   }
}

Step 4 − Execute test cases

Crea un file di classe java denominato TestRunner in C:\> Mockito_WORKSPACE per eseguire uno o più casi di 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

Compila le classi usando javac compilatore come segue -

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

Ora esegui il Test Runner per vedere il risultato:

C:\Mockito_WORKSPACE>java TestRunner

Verifica l'output.

true