GM_XHR in fetch mode throws error when responseType set to text

[7nik]

GM_XHR in fetch mode fails when responseType explicitly set to text.

Expected Behavior

Prints to the console Response object.

Actual Behavior

Prints error {readyState: 4, responseHeaders: "", status: 408, statusText: "Cannot read property 'then' of undefined"}

Specifications

Chromium: Version 83.0.4103.97 (Official Build) Arch Linux (64-bit) TM: beta, 4.11.6116 OS: KDE Manjaro (64-bit)

Script

(Please give an example of the script if applicable.)

// ==UserScript==
// @name         Test GM_XHR-fetch responseType
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://github.com/*
// @grant        GM.xmlHttpRequest
// @connect      httpbin.org
// ==/UserScript==

(async () => {
    console.log("ret:", await GM.xmlHttpRequest({
        fetch: true,
        url: "https://httpbin.org/robots.txt",
        responseType: "text",
        onload: (resp) => console.log("resp:", resp),
        onerror: (err) => console.error("error:", err),
    }));
})();

[derjanb]

Nice find! 🙈

Thanks for all your bug reports.

[7nik]

Also,

// ==UserScript==
// @name         Test GM_XHR responseType
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://github.com/*
// @grant        GM_xmlhttpRequest
// @grant        GM.xmlHttpRequest
// @connect      httpbin.org
// ==/UserScript==

(() => {
    GM.xmlHttpRequest ({
        url: "https://httpbin.org/json",
        responseType: 'json',
    })
    .then(() => GM.xmlHttpRequest ({
        url: "https://httpbin.org/html",
        responseType: 'document',
    }))
    .then(() => console.log('DONE'))
})();

these two types cause

xhr: requested responseType json differs from received 
xhr: requested responseType document differs from received 

on the background page where received type is an empty string.

[derjanb]

GM_XHR in fetch mode fails when responseType explicitly set to text.

Should be fixed at 4.11.6117

xhr: requested responseType json differs from received

It's just a console message. So I'll address that later.