Spring WebTestClient response object is different from expected

I have a controller unit test using WebTestClient and it's failing on the isEqualTo() test. I can't find what's wrong as I'm using the same object to set what the service call will return and the parameter for isEqualTo()

When I run the test I'm getting something like

Expected :com.model.Response@ab41b46
Actual   :com.model.Response@c1dcdb9

Model: This is just a portion of it but the other objects are just Strings

public class Response implements Serializable {
    private static final long serialVersionUID = 1L; //random long
    private String id;
    private Long amount;
    private LocalDateTime dateTime;
    private String status;

    //setters-getters
}

Controller:

@PostMapping
public Mono<Response> getResponse() {
     return myService.getResponse();
}

Test:

@ExtendWith(MockitoExtension.class)
@WebFluxTest(controllers = MyController.class)
public class MyControllerTest
{
    @Autowired
    private transient WebTestClient webTestClient;

    @MockBean
    private transient MyService myService;

    @Test
    void shouldReturnResponse() {
        var response = new Response();
        response.id("id");
        response.setAmount(10L);
        when(myService.getResponse()).thenReturn(Mono.just(response));
        webTestClient.post()
                .uri("/")
                .exchange()
                .expectStatus().isOk()
                .expectBody(Response.class)
                .isEqualTo(response);
    }
}

As you can see I stubbed myService to return a Mono of response and just expected the same on isEqualTo()

I have some similar tests to this and they're working fine. I'm currently checking if this is an issue with the Response object

isEqualTo uses the equals method to verify if objects are equal.

Judging from what you have posted here you haven't implemented the equals method. No equals method means it will use the default which is basically checking if it is the same object instance. Which obviously isn't true.

Hence either implement a proper equals method or use a different way of asserting your result.

@Test
void shouldReturnResponse() {
    var response = new Response();
    response.id("id");
    response.setAmount(10L);
    when(myService.getResponse()).thenReturn(Mono.just(response));
    webTestClient.post()
            .uri("/")
            .exchange()
            .expectStatus().isOk()
            .expectBody(Response.class)
            .consumeWith( (response) -> assertThat(response.getId()).isEqualTo("id"));}

The snippet above uses AssertJ to do the assert (ofcourse you can extend those as well). To do other validations there are other methods on the BodySpec as well, pick the one that suits your needs.

You're creating a mono object with the response object in it. Then you fetch it from your WebTestClient. You're isEqualTo compares the two Objects, which aren't exactly the same object -> mono -> object. I would suggest to compare the values inside the objects.

Mono<Response> clientResponse = webTestClient.post()
            .uri("/")
            .exchange()
            .expectStatus().isOk()
            .expectBody(Response.class);

 assertThat(clientResponse.block().getId()).isEqualTo("id");
 assertThat(clientResponse.block().response.getAmount()).isEqualTo(10L);