How to fix a bug with RestClient API?

Question

Express.js

We create a new ad, via post in this way:

POST http://localhost:3000/api/offers HTTP/1.1
Content-Type: application/json

{
 "category": ["Разное"],
 "description": "При покупке с меня бесплатная доставка в черте города.",
 "picture": "item03.jpg",
 "title": "Продам новую приставку Sony Playstation 5.",
 "type": "offer",
 "sum": 42698
}

Added additional data validation:

const { HttpCode } = require(`../constants`);

const offerKeys = [`category`, `description`, `picture`, `title`, `type`, `sum`];

module.exports = (req, res, next) => {
  const newOffer = req.body;
  const keys = Object.keys(newOffer);
  const keysExists = offerKeys.every((key) => keys.includes(key));

  if (!keysExists) {
    res.status(HttpCode.BAD_REQUEST)
      .send(`Bad request`);
  }

  next();
};

The code is written in visual studio code, restclient apiinstalled as an extension. After starting the server without errors, I click on send request, and the following message is displayed:

HTTP/1.1 400 Bad Request
X-Powered-By: Express
Content-Security-Policy: default-src 'none'
X-Content-Type-Options: nosniff
Content-Type: text/html; charset=utf-8
Content-Length: 1059
Date: Sat, 31 Oct 2020 13:08:22 GMT
Connection: close

There is this error in the console:

SyntaxError: Unexpected token  in JSON at position 2

It turns out that the condition is met if (!keysExists), but why, if the data is the same, and how to fix it?

Answer 1

The problem was that before the JSON strings there were not spaces, but some other characters (blank). The editor did not emphasize, so she did not pay attention:

{
 "category": ["Разное"],
 "description": "При покупке с меня бесплатная доставка в черте города.",
 "picture": "item03.jpg",
 "title": "Продам новую приставку Sony Playstation 5.",
 "type": "offer",
 "sum": 42698
}