如何使用Mockito模拟列表方法

Question

我有一个调用Repository方法并返回列表的服务类。现在我想嘲笑它。我的单元测试场景如下：

• 向模拟存储库添加一些模拟对象
• 返回模拟对象列表的查询服务类
• 断言列表大小

我的存储库类：

import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;

import java.util.List;

public interface FoodRepository extends CrudRepository<Food, Long> {

    @Query(value = "SELECT * FROM FOOD WHERE FRESH = 1", nativeQuery = true)
    public List<Food> getMostFreshestFoods();
}

我的服务等级：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class FoodService {

    @Autowired
    private FoodRepository foodRepository;

    public List<Food> getMostFreshestFoods() {
        return foodRepository.getMostFreshestFoods();
    }
}

我的对象类：

public class Food {

    private Long id;

    private String foodName;

    private boolean fresh;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getFoodName() {
        return foodName;
    }

    public void setFoodName(String foodName) {
        this.foodName = foodName;
    }

    public boolean isFresh() {
        return fresh;
    }

    public void setFresh(boolean fresh) {
        this.fresh = fresh;
    }
}

和我的测试课程：

import myapp.Food;
import myapp.FoodRepository;
import myapp.FoodService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.ArgumentCaptor;
import org.mockito.Captor;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.MockitoJUnitRunner;

import static org.hamcrest.core.Is.is;
import static org.hamcrest.core.IsNull.notNullValue;
import static org.junit.Assert.assertThat;
import static org.mockito.Mockito.verify;

@RunWith(MockitoJUnitRunner.class)
public class FoodTest {

    @Mock
    private FoodRepository foodRepository;

    @InjectMocks
    private FoodService foodService;

    @Captor
    private ArgumentCaptor<Food> foodArgumentCaptor;

    @Test
    public void testFreshestFoods() {

        Food food = new Food();
        food.setFoodName("Meat");
        food.setFresh(true);
        foodRepository.save(food);
        verify(foodRepository).save(foodArgumentCaptor.capture());
        assertThat(foodArgumentCaptor.getValue().getId(), is(notNullValue()));

        // Above I added mock data to database to query list from Service class method,
        // but I do not know how to do it. Using return always gives error

        // I want to do the following: Query the list from FoodService class and it should
        // return size 1 (the fake object (added above) )

    }


}

但是由于我是Mockito的新手，这对我来说有点困难。我想知道如何从FoodService类中获取列表，并且它应该返回在测试类中制作的假对象。

Answer 1

我相信你正在寻找的是以下内容。使用Mockito进行测试不需要执行正常的工作流。另一种说法是，您不向DB添加内容，然后期望将其恢复。Mockito不知道数据库。它接管一个类（模拟类），并返回您告诉它的内容，或抛出异常，或什么都不做。这样做的目的是隔离被测试的类。因此，在您的情况下，假设数据在存储库中，然后模拟返回它。希望这是有意义的。

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

import java.util.List;

import static java.util.Arrays.asList;
import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

@RunWith(MockitoJUnitRunner.class)
public class FoodTest {

    @Mock
    private FoodRepository foodRepository;

    @InjectMocks
    private FoodService foodService;

    @Captor
    private ArgumentCaptor<Food> foodArgumentCaptor;

    @Test
    public void testFreshestFoods() {

        Food food = new Food();
        food.setFoodName("Meat");
        food.setFresh(true);

        // not needed
        //foodRepository.save(food);
        //verify(foodRepository).save(foodArgumentCaptor.capture());
        //assertThat(foodArgumentCaptor.getValue().getId(), is(notNullValue()));

        when(foodRepository.getMostFreshestFoods()).thenReturn(asList(food));

        List<Food> actual = foodService.getMostFreshestFoods();

        assertEquals(food, actual.get(0));
        verify(foodRepository).getMostFreshestFoods();
    }
}