如何在 Spring Boot REST API 中为 db insert 方法编写模拟单元测试？

Question

我有一个用 Spring Boot 编写的 REST API。

现在我想用 JUnit 和 Mockito 创建单元测试来模拟数据库操作。

这是将新客户插入数据库的端点。

@RestController
public class CustomerController {
    
    @Autowired
    private CustomerRepository customerRepository;
    
    
    @PostMapping(value="/customers", produces = "application/json")
    public ResponseEntity<Customer> addCustomer(@RequestBody Customer customer){
        
        Customer newCustomer = customerRepository.save(customer);       
        
        return new ResponseEntity<Customer>(newCustomer, HttpStatus.OK) ;
    }

测试：

@Test
public void testAddCustomer() {
        
    Customer customer = Mockito.mock(Customer.class);
    customer.setIdCustomer(1L);     
    customer.setName("Pete");
    customer.setAge(35);
    customer.setEmail("pete@test.com");
                
    when(customerRepository.save(customer)).thenReturn((Customer) Stream.of(customer));
        
    CustomerController customerController = new CustomerController();       

    ResponseEntity<Customer> respCustomer = customerController.addCustomer(customer);
        
    assertTrue(respCustomer.getBody().getIdCustomer() != null);
        
}

我在以下行收到空指针异常：

 when(customerRepository.save(customer)).thenReturn((Customer) Stream.of(customer));

Answer 1

使用

@Mock private CustomerRepository customerRepository

在您的测试中使用 mockito API 配置存储库

Answer 2

应该是这样的

    @Test
    public void testFindTheGreatestFromAllData() {
        DataService dataServiceMock = mock(DataService.class);
        when(dataServiceMock.retrieveAllData()).thenReturn(new int[] { 24, 15, 3 });
        SomeBusinessImpl businessImpl = new SomeBusinessImpl(dataServiceMock);
        int result = businessImpl.findTheGreatestFromAllData();
        assertEquals(24, result);
    }