Usage example of org.mockito.ArgumentCaptor

1 CustomerSelector.java

package org.drage.tutorial.mocking;

public class CarSelector {
  
	private final CarBuilderService service;
	
	public CarSelector(CarBuilderService service) {
		this.service = service;
	}

	public void buyRedFerrari(){
		BuyingCriteria criteria = new BuyingCriteria();
		criteria.setColor("RED");
		criteria.setModel("FERRARI");
		service.buildCar(criteria);
	}
	
	public void buyPinkCaddilac(){
		BuyingCriteria criteria = new BuyingCriteria();
		criteria.setColor("HOT PINK");
		criteria.setModel("CADDILAC");
		service.buildCar(criteria);
	}

}

2 CarSelectorTest.java

package org.drage.tutorial.mocking;

// imports ...

@RunWith(MockitoJUnitRunner.class)
public class CarSelectorTest {
  
	private CarSelector carSelector;
	
	@Mock
	private CarBuilderService service;
	
	@Before
	public void initTest(){
		carSelector = new CarSelector(service);
	}

	@Test
	public void testBuyRedFerrari() {
		
		carSelector.buyRedFerrari();
		
		ArgumentCaptor<BuyingCriteria> argumentCaptor = ArgumentCaptor.forClass(BuyingCriteria.class);
		Mockito.verify(service).buildCar(argumentCaptor.capture());
		BuyingCriteria buyingCriteria = argumentCaptor.getValue();

		assertEquals("RED", buyingCriteria.getColor());
		assertEquals("FERRARI", buyingCriteria.getModel());
		
	}

}

3 CarBuilderService.java

package org.drage.tutorial.mocking;

public interface CarBuilderService {

  void buildCar(BuyingCriteria criteria);

}

4 BuyingCriteria.java

package org.drage.tutorial.mocking;

public class BuyingCriteria {
  
	private String color;
	private String model;
	
	// getters and setters

}