Mockito when().thenReturn 没有给出预期的结果

Question

我是 Junit 和 Mockito 的新手。试图模拟 class 的对象之一，但它不起作用。模拟方法是 returning 一个空列表，因此测试用例失败。这是我写的代码。

Junit 测试 Class：这里我将对象和方法模拟为 return 一个 Arraylist，但是当执行代码时，这个模拟方法是 returning 一个空列表，由于哪个测试用例失败了。

package com.business;

import static org.junit.Assert.*;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import java.util.Arrays;
import java.util.List;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.mockito.Mockito;

import com.data.api.ToDoService;

public class TodoBusinessImplMockTest {

    @Before
    public void setUp() throws Exception {
    }

    @After
    public void tearDown() throws Exception {
    }

    @Test
    public void testRetrieveTodosRelatedToSpringUsingMock() 
    {
        ToDoService todoServiceMock = mock(ToDoService.class);
        
        List<String> todoList=Arrays.asList("Learn Spring MVC", "Learn Spring","Learn to Dance");
        
        Mockito.when(todoServiceMock.retrieveTodos("Dummy")).thenReturn(todoList);
        
        TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoServiceMock);
        
        List<String> todos = todoBusinessImpl.retrieveTodosRelatedToSpring("Ranga");
        
        assertEquals(2, todos.size());
    }

}

接口：ToDoService.java

package com.data.api;

import java.util.List;

public interface ToDoService {
    public List<String> retrieveTodos(String s);
}

TodoBusinessImpl.java

package com.business;

import java.util.ArrayList;
import java.util.List;

import com.data.api.ToDoService;

public class TodoBusinessImpl {
    
    private ToDoService todoService;

    TodoBusinessImpl(ToDoService todoService) {
        this.todoService = todoService;
    }

    public List<String> retrieveTodosRelatedToSpring(String s) {
        List<String> filteredTodos = new ArrayList<String>();
        List<String> allTodos = todoService.retrieveTodos(s);
        for (String todo : allTodos) {
            if (todo.contains("Spring")) {
                filteredTodos.add(todo);
            }
        }
        return filteredTodos;
    }
}

Answer 1

您的规格说明：

Mockito.when(todoServiceMock.retrieveTodos("Dummy")).thenReturn(todoList);

但您的通话使用：

todoBusinessImpl.retrieveTodosRelatedToSpring("Ranga");

“Ranga”不是“Dummy”，因此您的规格不匹配；因此 mockito returns 默认结果（这将是一个空列表）。

Answer 2

尝试将 Mockito.when(todoServiceMock.retrieveTodos("Dummy")).thenReturn(todoList); 中的 "Dummy" 替换为 anyString() (import static org.mockito.ArgumentMatchers.anyString;)。这对我有用。

Mockito when().thenReturn 没有给出预期的结果

Mockito when().thenReturn doesn't give expected result

junit4

mockito

java-8

junit5