如何使用Mockito模拟列表方法

Question

我有一个服务类，该类调用存储库方法并返回列表。现在我想嘲笑它。我的单元测试方案将如下：

• 向模拟存储库添加一些模拟对象
• 查询服务类，返回模拟对象的列表
• 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();
}

我的服务课：

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：

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，所以对我来说有点困难。我想知道如何从FoodService类中获取列表，它应该返回测试类中制作的假对象。

Answer 1

我相信您要寻找的是下面。您无需进行普通工作流程即可通过Mockito进行测试。另一种说法是您不会在数据库中添加物品，然后期望将它们恢复原状。Mockito不知道数据库。它接管了一堂课（嘲笑的人），并返回您告诉它的东西或抛出异常，或者什么也不做。这个想法是隔离正在测试的类。因此，就您而言，假装数据位于存储库中，只是模拟返回它。希望那是有道理的。

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();
    }
}