Curl request using nodejs returns an empty body

Question

I used the Curl of the post office site to turn into a nodejs request (I used this site to convert Curl into js code-> https://curl.trillworks.com/)

var request = require('request');

var headers = {
    'Connection': 'keep-alive',
    'Pragma': 'no-cache',
    'Cache-Control': 'no-cache',
    'Origin': 'https://www2.correios.com.br',
    'Upgrade-Insecure-Requests': '1',
    'Content-Type': 'application/x-www-form-urlencoded',
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.163 Safari/537.36',
    'Sec-Fetch-Dest': 'document',
    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9',
    'Sec-Fetch-Site': 'same-origin',
    'Sec-Fetch-Mode': 'navigate',
    'Sec-Fetch-User': '?1',
    'Referer': 'https://www2.correios.com.br/sistemas/rastreamento/default.cfm',
    'Accept-Language': 'en-US,en;q=0.9,pt;q=0.8',
    'Cookie': '_ga=GA1.3.1385639005.1586277520; CFID=31280658; CFTOKEN=1c6b8efc2c6ad4c1-ED1DB9DE-FA31-5E5A-CF1D02F2BF2CB440; CFGLOBALS=urltoken%3DCFID%23%3D78315721%26CFTOKEN%23%3De66c3a82c674de4%2D861C7DF3%2DDAB6%2DE583%2DD427EAE724F26F87%26jsessionid%23%3D6CE45E28E642304EA69CD721D3293F2D%2Ecfusion01%23lastvisit%3D%7Bts%20%272020%2D04%2D23%2009%3A29%3A29%27%7D%23hitcount%3D5%23timecreated%3D%7Bts%20%272020%2D04%2D15%2010%3A52%3A13%27%7D%23cftoken%3D1c6b8efc2c6ad4c1%2DED1DB9DE%2DFA31%2D5E5A%2DCF1D02F2BF2CB440%23cfid%3D31280658%23; ssvbr0331_www2sro=sac2844SRO; _gid=GA1.3.940270031.1587816025; ssvbr0331_www2=sac2845; JSESSIONID=B7982AF26D30D28AD6F20CF6E39671C5.cfusion02; ssvbr0327_www2sro=sac2842SRO; sitecorreioscookie-%3FEXTERNO%3Fpool_site_institucional_443=AIBOKIMA; _gat_gtag_UA_564464_1=1; ssvbr0327_www2=sac2848'
};

var dataString = 'acao=track&objetos=JU763467155BR&btnPesq=Buscar';

var options = {
    url: 'https://www2.correios.com.br/sistemas/rastreamento/ctrl/ctrlRastreamento.cfm?',
    method: 'POST',
    headers: headers,
    body: dataString
};

function callback(error, response, body) {
    if (!error && response.statusCode == 302) {
        console.log(body);
        console.log(response);
    }else{
        console.log("a casa caiu");
    }
}

request(options, callback);

when I run the script, it returns an empty body, as in the image below https://i.stack.Imgur.com/tjqHl.png

it returns the correct code(302)... but at the time of returning the content, comes nothing, and I tested the same request in Postman, and returned a body with html text.

Answer 1

I believe the above answer is correct, however, you should change the status code of your if, and put 200, which is the successful code, in case everything is "ok", put:

if (!error && response.statusCode == 200) {
    console.log(body);
    console.log(response);
}

Answer 2

The code 302 represents a redirect, the new URL must be present in the Location in the response header.

---

You have two solutions:

1. Add the followAllRedirects: true:

request = request.defaults({
  followAllRedirects: true
});

request(options, callback);

The followAllRedirects is mentioned in Github, as:

followAllRedirects - follow non-GET HTTP 3xx Responses as Redirects (default: false)

This will allow you to follow redirect in POST method.

If you also want to keep the POST method for the page that was redirected, also use followOriginalHttpMethod: true. But I guess that won’t be necessary.

2. Make a new request by reading the Location:

function callback(error, response, body) {
    if (!error && response.statusCode == 302) {

        //Aqui faz outra requisição baseada no novo link que recebeu:
        request({url: response.headers['location'], method: 'GET',headers: headers}, novo_callback);


    }else{
        console.log("a casa caiu");
    }
}

Reply headers can be accessed within the callback, using the array response.headers, apparently. Then you can read the "Location" and then use it to get the new URL and make a request directly to such URL.