Ambiguous Method Call Mocking RestTemplate.exchang

Question

Can't figure out the correct way to use matchers to identify which overload of the exchange method I am targetting. The call I am making:

restTemplate.exchange(url, HttpMethod.PUT, httpEntity, Object.class)

I've tried using any(Class.class), and a couple other things but nothing is working. There are 2 methods with a similar signature that I am trying to distinguish between:

exchange(String url, HttpMethod method, @Nullable HttpEntity<?> requestEntity, Class<T> responseType)

and

exchange(String var1, HttpMethod var2, @Nullable HttpEntity<?> var3, ParameterizedTypeReference<T> var4)

Here are my current imports related to Mockito:

import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

import static org.junit.Assert.*;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyString;
import static org.mockito.Mockito.*;

Has anyone been able to mock a call to this method that uses a Class as the 4th parameter instead of a ParameterizedTypeReference?

Answer 1

I am not sure whether I misunderstood your question or the issue mentioned by @MarciejKowalski, but when running the test from the issue or what I suppose is similar to your example against mockito-core-2.23.4 / JDK 1.8.0_151 it works just fine.

[I used JUnit 4 for your example instead of JUnit 5]

import static org.mockito.ArgumentMatchers.any;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.mockito.junit.MockitoJUnitRunner;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestTemplate;

@RunWith(MockitoJUnitRunner.class)
public class MockitoTest {

    @Test
    public void test() {

        RestTemplate api = Mockito.mock(RestTemplate.class);
        ResponseEntity<?> response1 = Mockito.mock(ResponseEntity.class);
        ResponseEntity<?> response2 = Mockito.mock(ResponseEntity.class);

        Mockito.when(api.exchange(any(String.class), any(HttpMethod.class), any(HttpEntity.class), any(Class.class))).thenReturn(response1);
        Mockito.when(api.exchange(any(String.class), any(HttpMethod.class), any(HttpEntity.class), any(ParameterizedTypeReference.class))).thenReturn(response2);

        ParameterizedTypeReference mock = Mockito.mock(ParameterizedTypeReference.class);

        Assert.assertEquals(response1, api.exchange("", HttpMethod.GET, new HttpEntity(""), String.class));
        Assert.assertEquals(response2, api.exchange("", HttpMethod.GET, new HttpEntity(""), mock));
    }
}

Answer 2

Most likely you are using the when().then() pattern.

Try the doReturn().when() approach with your matchers.

Just make sure you use matchers even for the params that you expect directly (use eq() for this).

Here is the issue and fix on project issue tracker.