The Mono.flatMap is not working while mocking the response using MockWebServer

Question

Making an HTTP call using WebClient, from the Mono output I want to do some logic, for which I'm using flatMap method.

        Mono<Response> authResponseMono = webClient.post().syncBody(requestBody)
            .retrieve()
            .bodyToMono(Response.class);

        return authResponseMono.flatMap(authResponse -> {
        //code removed for brevity
        });

Using OkHttp MockWebServer library to mock the response and unit test the functionalities. The flatMap method is not getting invoked while using MockWebServer, however, on the actual calls things are working fine.

Following is the snippet used to mock the HTTP response

server.enqueue(mockResponse); //server is instance of MockWebServer
Optional<Response> optionalResponse = authClientService.verifyToken().block(); //verifyToken returns authResponseMono

I think the cause for this behavior is due to the way mocks are created internally by the MockWebServer. What am I missing here?

Answer 1

I use MockWebServer and webClient and it seems to be fine. Maybe you can post more detail.

here is a snippet of my setup - note this is not a spring test

@RunWith(MockitoJUnitRunner.class)
public class AccountDetailsRetrievalTest {

    private static final String ACCOUNT_DETAILS_PATH = "/AccountDetailsPath";
    private MockWebServer server;

    private WebClient webClient;

    private AccountDetailsRetrieval accountDetailsRetrieval;

    @Before
    public void setup() {
        this.server = new MockWebServer();
        this.webClient = WebClient.create(this.server.url(ACCOUNT_DETAILS_PATH).toString());
        accountDetailsRetrieval = new AccountDetailsRetrieval(this.webClient, ACCOUNT_DETAILS_PATH, 300);
    }

    @After
    public void shutdown() throws Exception {
        this.server.shutdown();
    }

@Test
public void nameHasBeenChanged() {
    String content = "{\"bar\":\"bar1\",\"foo\":\"foo1\"}";
    MockResponse response1 = new MockResponse()
            .setHeader("Content-Type", "application/json")
            .setBody(content);
    this.server.enqueue(response1);

    StepVerifier.create(accountDetailsRetrieval.getAccountData(new AccountDetails("001", "ABC")))
            .assertNext(response -> {
                assertThat(response).isNotNull();
                assertThat(response.getHttpStatus()).isEqualByComparingTo(HttpStatus.OK);
                assertThat(response.data().get("bar")).isEqualTo("bar1");
                assertThat(response.data().get("foo")).isEqualTo("foo1");
            })
            .verifyComplete();
}

Response here is just a wrapper for JsonNode