Nodejs consume deflate response from external API

This should be an easy question but for the sake of my life I cannot make it work, I'm consuming a web service like this:

var XMLHttpRequest = require('XMLHttpRequest').XMLHttpRequest;
var xhr = new XMLHttpRequest();
xhr.open('GET', 'https://rest.gestionix.com/api/v2/products? 
branch_id=7471&filter=0119080PMDSV&results_per_page=5&page=1&fields=id');
xhr.setRequestHeader("Content-Type", "application/json; charset=utf-8");
xhr.onreadystatechange = function(event) {
    if (xhr.readyState === 4) {
        if (xhr.status === 200) {
            console.log(xhr.responseText);
        }
    }
    console.log(xhr.getAllResponseHeaders());
};
xhr.setRequestHeader('Accept','application/json');
xhr.setRequestHeader('Accept-Encoding','decode');
xhr.setRequestHeader('Content-Encoding','decode');
xhr.setRequestHeader('Encoding','decode');
xhr.setRequestHeader('apikey', '---'); <<< of course I'm using an apikey
xhr.send();

The api returns this header:

cache-control: max-age=60
content-length: 22766
content-type: application/json
content-encoding: deflate
server: Microsoft-IIS/10.0
x-aspnet-version: 4.0.30319
x-powered-by: ASP.NET
date: Mon, 02 Jul 2018 16:31:32 GMT
connection: close

However, the content is just a bunch of weird chars:

��a�^G4Wk�wC��p�Ȳ�G�?FZ}�Ϧ��Bo�W��i�gu��$H�^; ,Wf�촞�}�: ��P��e��yE�%6٬e1D�ml�7UO�ǲK��m��}t�"��u��dS7�Q��>5�y֫� I�;E�PH�}��/��X��&��W{�)X�SP��v�[� �ݰ��k�W׈��P{�W�>Z��י�R��׺4T�]X�m<�Ns'՟��f�0X:V�W�C��ҁ��P��#d��T�gb�yI n��c-�+EP�#=|�V��f�9��Ղ�h�:��r��yF�ر��Se� �!σr�L/E��d7�7�\�+ɠ�N��3� a�{��-�)�~��.�� \s�^5��q .t� ��&�Ǧ��oP��- ��;( ��4�� o6��

I have tried with different encodings but the result is always the same, I have look for documentation on how to decompress this but I have not find anything that works, if anyone have a link that can point me in the right direction I'll really appreciate it.

Solution

Well, I didn't wanted to let this unanswered just in case someone else needs it. First you need this boiler plate code

/** Boiler Plate Code
     * Process the response.
     * @param {Object} headers
     *   A hash of response header name-value pairs.
     * @param {String} body
     *   The uncompressed response body.
     */
    function processResponse(headers, body) {

      **do something with the response**

        } else {
            console.log("Response is empty.");
        }
    }

    /**
     * Manage an error response.
     *
     * @param {Error} error
     *   An error instance.
     */
    function handleError(error) {
        // Error handling code goes here.
        console.log("Error Found: " + error);

    }

    /**
     * Obtain the encoding for the content given the headers.
     *
     * @param {Object} headers
     *   A hash of response header name-value pairs.
     * @return {String}
     *   The encoding if specified, or 'utf-8'.
     */
    console.log('------------ Getting Charset  ------------');
    function obtainCharset(headers) {
        // Find the charset, if specified.
        var charset;
        var contentType = headers['content-type'] || '';
        var matches = contentType.match(/charset=([^;,\r\n]+)/i);
        if (matches && matches[1]) {
            charset = matches[1];
        }
        console.log('------------ Charset is ' + charset + ' (utf-8 if null)  ------------');
        return charset || 'utf-8';
    }

This functions will take care of the processing, they go at the top.

And then you need to run your request, in my case I am using a normal     var request = require('request-promise');