fetch pollyfill using GM_xmlhttpRequest
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/421384/1134973/GM_fetch.js
function GM_fetch(url, opt={}){
return new Promise((resolve, reject)=>{
// https://www.tampermonkey.net/documentation.php?ext=dhdg#GM_xmlhttpRequest
// https://violentmonkey.github.io/api/gm/#gm_xmlhttprequest
opt.url = url
opt.data = opt.body
opt.responseType = "blob"
opt.onload = resp=>{
resolve(new Response(resp.response, {status: resp.status,
// https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/getAllResponseHeaders#examples
headers: Object.fromEntries(resp.responseHeaders.trim().split(/[\r\n]+/).map(line=>{parts=line.split(': ');return [parts.shift(), parts.join(': ')]}))
}))
}
opt.ontimeout = ()=>reject("fetch timeout")
opt.onerror = error=>reject(error)
opt.onabort = ()=>reject("fetch abort")
GM_xmlhttpRequest(opt)
})
}