### Question:
PostSubscribeToBeaconCommittee implements Handler { @OpenApi( path = ROUTE, method = HttpMethod.POST, summary = "Subscribe beacon node to committee attestation subnet.", tags = {TAG_VALIDATOR}, requestBody = @OpenApiRequestBody( content = {@OpenApiContent(from = SubscribeToBeaconCommitteeRequest.class)}), description = "After Beacon node receives this request it has to:\n" + "- add subnet to ENR\n" + "- announce subnet topic subscription on gossipsub\n" + "- search using discv5 for peers related to this subnet and replace current peers with those ones if neccessary\n" + "- aggregate attestations received on that subnet\n", responses = { @OpenApiResponse( status = RES_OK, description = "Slot signature is valid and beacon node is subscribed to given committee attestation subnet."), @OpenApiResponse(status = RES_BAD_REQUEST, description = "Invalid request syntax."), @OpenApiResponse(status = RES_INTERNAL_ERROR, description = "Beacon node internal error.") }) @Override public void handle(Context ctx) throws Exception { try { final SubscribeToBeaconCommitteeRequest request = jsonProvider.jsonToObject(ctx.body(), SubscribeToBeaconCommitteeRequest.class); provider.subscribeToBeaconCommitteeForAggregation(request); ctx.status(SC_OK); } catch (final JsonMappingException e) { ctx.result(jsonProvider.objectToJSON(new BadRequest(e.getMessage()))); ctx.status(SC_BAD_REQUEST); } catch (Exception e) { ctx.status(SC_INTERNAL_SERVER_ERROR); } } PostSubscribeToBeaconCommittee(
      final ValidatorDataProvider provider, final JsonProvider jsonProvider); @OpenApi( path = ROUTE, method = HttpMethod.POST, summary = "Subscribe beacon node to committee attestation subnet.", tags = {TAG_VALIDATOR}, requestBody = @OpenApiRequestBody( content = {@OpenApiContent(from = SubscribeToBeaconCommitteeRequest.class)}), description = "After Beacon node receives this request it has to:\n" + "- add subnet to ENR\n" + "- announce subnet topic subscription on gossipsub\n" + "- search using discv5 for peers related to this subnet and replace current peers with those ones if neccessary\n" + "- aggregate attestations received on that subnet\n", responses = { @OpenApiResponse( status = RES_OK, description = "Slot signature is valid and beacon node is subscribed to given committee attestation subnet."), @OpenApiResponse(status = RES_BAD_REQUEST, description = "Invalid request syntax."), @OpenApiResponse(status = RES_INTERNAL_ERROR, description = "Beacon node internal error.") }) @Override void handle(Context ctx); static final String ROUTE; }### Answer:
@Test public void shouldReturnBadRequestWhenRequestBodyIsInvalid() throws Exception { when(context.body()).thenReturn("{\"foo\": \"bar\"}"); handler.handle(context); verify(context).status(SC_BAD_REQUEST); }
@Test public void shouldReturnServerErrorWhenProviderThrowsUnmappedException() throws Exception { final SubscribeToBeaconCommitteeRequest request = new SubscribeToBeaconCommitteeRequest(1, UInt64.ONE); when(context.body()).thenReturn(jsonProvider.objectToJSON(request)); doThrow(new RuntimeException()).when(provider).subscribeToBeaconCommitteeForAggregation(any()); handler.handle(context); verify(context).status(SC_INTERNAL_SERVER_ERROR); }
@Test public void shouldReturnSuccessWhenSubscriptionToBeaconCommitteeIsSuccessful() throws Exception { final SubscribeToBeaconCommitteeRequest request = new SubscribeToBeaconCommitteeRequest(1, UInt64.ONE); final String requestJson = jsonProvider.objectToJSON(request); when(context.body()).thenReturn(requestJson); handler.handle(context); ArgumentCaptor<SubscribeToBeaconCommitteeRequest> captor = ArgumentCaptor.forClass(SubscribeToBeaconCommitteeRequest.class); verify(provider).subscribeToBeaconCommitteeForAggregation(captor.capture()); verify(context).status(SC_OK); SubscribeToBeaconCommitteeRequest receivedRequest = captor.getValue(); assertThat(receivedRequest).usingRecursiveComparison().isEqualTo(request); }