Unit test using class with RestTemplate injected with java and spring boot

Question

I'm running unit testing with a class that has the injected RestTemplate and only when I run the tests does RestTemplate get null after consuming the API I'm consuming.

class ReceitaWsIntegrationImpl implements ReceitaWsIntegration {

  private static final String URL_RECEITA_WS_CNPJ
    = "https://www.receitaws.com.br/v1/cnpj";

  private final RestTemplate restTemplate;

  @Override
  public void findByCnpj(String cnpj) {
    ResponseEntity<CnpjResource> forEntity = restTemplate.getForEntity(
      URL_RECEITA_WS_CNPJ.concat("/").concat(cnpj), CnpjResource.class);
  }
}

Test class:

public class ReceitaWsIntegrationImplTest extends TestSupport {

private static final String CNPJ = "27865757000102";
private static final String URL_RECEITA_WS_CNPJ = "https://www.receitaws.com.br/v1/cnpj/";
@Mock
private RestTemplate restTemplate;
private ReceitaWsIntegration receitaWsIntegration;

    @Override
    public void init() {
        receitaWsIntegration = new ReceitaWsIntegrationImpl(restTemplate);
    }

    @Test
    public void should_find_company_by_cnpj() {
        receitaWsIntegration.findByCnpj(CNPJ);

        InOrder inOrder = inOrder(restTemplate);

        inOrder.verify(restTemplate, times(1))
            .getForEntity(URL_RECEITA_WS_CNPJ.concat(CNPJ), CnpjResource.class);
        inOrder.verifyNoMoreInteractions();
    }
}

Answer 1

It looks like your test does not create a RestTemplate object because there is no code that processes the annotation @Mock . There are different ways for creating the mock. Eg you can init the mock in the init method.

@Override
public void init() {
    MockitoAnnotations.initMocks(this);
    receitaWsIntegration = new ReceitaWsIntegrationImpl(restTemplate);
}

For more options have a look at the Mockito's Javadoc .

Answer 2

Frankly speaking I do not see anything in findByCnpj() that requires its own unit-test. I don't think you need to test RestTemplate.getForEntity() method since it was tested many times by Spring developers (and testers). And there is no additional logic in findByCnpj()