Property 'json' does not exist on type 'Object'

it been a while since I last use Ionic and I am trying to do login, but I ma getting this error 'Property ‘json’ does not exist on type ‘Object’. under res.json

return new Promise((resolve, reject) => {
      let headers = new HttpHeaders();
      headers = headers.set('Authorization',');
      headers = headers.set('Content-Type','');
      this.http.post(apiUrl, JSON.stringify(body), {headers: headers})
        .subscribe(res => {
          resolve(res.json());
        }, (err) => {
          reject(err);
        });
  });

The call to json() is no longer needed here, the result is already parsed.

New httpClient by default calls res.json() implicitly and you don’t need to that manually yourself.

While you’re fixing things, get rid of the pointless Promise and just do:

return this.http.post<WhateverTypeTheResultIs>(apiUrl, body);

There is no need for setting the content type explicitly, nor stringifying the body.

but what if I want to covert to qs instead of JSON I still don’t have stringifying it?! + Is the place to find a tutorial or doc for all of this

Perhaps your server throws an error and send HTML or text as response back.

Sorry, I have no clue what “qs” is, but here is a tutorial on using HttpClient.