How to get message body for 4xx response? Or is it expected behaviour?

Server is set up to return 200 and json object when server side validation and all further server work passes. It returns 400 on server side validation error It returns 500 on server side logic/DB/whatever error

Returning 400 is good praxis for server side validation failure (http://stackoverflow.com/a/34324179, http://stackoverflow.com/a/3290198, a.o.) Of course in real world there is also client side validation which forbids sending invalid form

Example for 400

Client

import request from 'superagent';

...
    let sendToServerData;
    // sendToServerData = {one: 'isOne', two: 'isTwo'}; // test with data
    sendToServerData = {}; // test with no data

    request
    .post('/')
    .send(sendToServerData)
    .set('Accept', 'application/json')
    .then((sucess) => {
      console.log('we have sucsess', sucess);
    }, (faulure) => {
      console.log('we have failure', faulure);
    });

Server

if ($_SERVER['REQUEST_METHOD'] === 'POST') {

  // get input
  $rest_json = file_get_contents("php://input");
  // decode and put in post
  $_POST = json_decode($rest_json, true);

  // set header
  header_remove();
  header('Content-type:application/json;charset=utf-8');

  // if empty return 400 and json explaining things
  if(empty($_POST)) {
    http_response_code(400);
    header('Status: 400');
    exit(json_encode(array(
        'status' => 400,
        'message' => 'no empty posts my friend'
        )));
  }

  // just return back 200 and json explaining things
  http_response_code(200);
  header('Status: 200');
  exit(json_encode(array(
        'status' => 200,
        'message' => 'all fine!'
        )));

}

when sendToServerData is populated, all fine as expected - sucess contains all the payload. when sendToServerData is empty console prints we have failure Error: Bad Request(…) thus faulure object does not contain any server payload, it does not even contain status code.

Is it expected (like “superagent way” would be returning 200 also on server side validation error, just set the payload to contain that there is actually server side validation error)? Or am I missing something? is it possibe to get object (failure) that contains server code and message on non 2xx status?

superagent@2.2.0

Thanks!

[kornelski]

.catch(error => error.response.body)

should work

[focusaurus]

Use request.post('/').send(sendToServerData).type('json').then(handleSuccess).catch((error) => {console.log(error.response.body)})