Mockito - How can I test the behaviour based on HttpStatusCode?-CodePudding

I have this request with WebClient:

webClient
   .get()
   .uri(uri)
   .accept(MediaType.APPLICATION_OCTET_STREAM)
   .<Optional<ByteArrayResource>>exchangeToMono(response -> {
          if (response.statusCode().equals(HttpStatus.NOT_FOUND)) {
                return Mono.just(Optional.empty());
          }
          return response.bodyToMono(ByteArrayResource.class).map(Optional::of);
      })
   .block();

How can I test the logic inside exchangeToMono()?

I'm using Mockito for testing this way: given(headersSpecHeadOpMock.exchangeToMono()).willReturn(Mono.just(clientResponse))

But the problem here is that this way I'm not testing the HttpStatus.NOT_FOUND.

CodePudding user response：

The problem I was having is that I was mocking the ClientResponse, but I would have to Mock a Function<ClientResponse, ? extends Mono<Optional<ByteArrayResource>>>.

The solution was to use an ArgumentCaptor to get the argument and then make the assert of his value like this:

ArgumentCaptor declaration:

ArgumentCaptor<Function<ClientResponse, ? extends Mono<Optional<ByteArrayResource>>>> captorLambda = ArgumentCaptor.forClass(Function.class);

Capture the argument:

given(headersSpecGetOpMock.<Optional<ByteArrayResource>>exchangeToMono(captorLambda.capture())).willReturn(Mono.just(Optional.empty()));

Assert the value returned by the client response:

assertThat(captorLambda.getValue().apply(clientResponse).block()).isEqualTo(Optional.empty());```

CodePudding user response：

Consider rewriting your code as follows:

webClient
   .get()
   .uri(uri)
   .accept(MediaType.APPLICATION_OCTET_STREAM)
   .retrive()
   .onStatus(status -> HttpStatus.NOT_FOUND == status, response -> Mono.just(Optional.empty()))
   .bodyToMono(ByteArrayResource.class);
   .map(Optional::of)
   .block();

Now you can mock retrieve() method to test your conditions easily.

As a side note, please consider dropping block() call, this defeats the purpose of using reactive programming.