fluffyscratchoneclicktest.user.js

// ==UserScript==
// @name        fluffyscratch oneclick test
// @namespace   helo
// @match       https://fluffyscratch.hampton.pw/auth/getKeys/v2
// @grant       none
// @version     1.0
// @author      -
// @description it does the thing
// ==/UserScript==

let key=new URLSearchParams(location.search).get("localRedirect");
if(key){
  let url=localStorage.getItem(key)
  localStorage.removeItem(key)
  location.replace(url)
}
let comframe=Object.assign(document.createElement("iframe"), {src:"https://scratch.mit.edu/projects/618552781/embed",style:"width:0;height:0;border:0;margin:0;"});
let cancel;
let hasOneClick=false;
document.querySelector("#text").insertAdjacentHTML("afterEnd", `<div id="oneclick">
  <img id="avatar">
  <p>You are logged in as <b id="username"></b></p>
</div>
<style>
.login.oneclick > :not(h1):not(nav):not(#oneclick) {
  display: none;
}
.login:not(.oneclick) #oneclick {
  display: none;
}
#avatar {
  width: 3.5rem;
  height: 3.5rem;
  border-radius: 4px;
}
#oneclick p {
  margin: 0.75rem 0 0 0;
}
</style>`)
comframe.addEventListener("load", () => {
  if(!hasOneClick) cancel=setTimeout(()=>comframe.remove(), 200)
});
window.addEventListener("message", function onMessage(e){
  if(e.data.oneClickFluffyScratchLogin){
    if(e.data.loaded) {
      hasOneClick=true;
      if(typeof cancel !== "undefined") clearTimeout(cancel)
      console.log("we have 1click")
    }
    if(typeof e.data.isLoggedIn !== "undefined") {
      if(e.data.isLoggedIn) {
        document.querySelector("#username").textContent=e.data.username;
        document.querySelector("#avatar").src="https://cdn2.scratch.mit.edu/get_image/user/" + e.data.userId+"_90x90.png";
        document.querySelector(".login").classList.add("oneclick")
        let ogStep1=steps.pop();
        steps[0]=()=>{
          document.querySelector("#continue").disabled=true;
          document.querySelector("#continue").textContent="Loading...";
          let key=crypto.getRandomValues(new Uint8Array(8)).join("");
          localStorage.setItem(key, JSON.parse(ogStep1.toString().match(/location.href=([^;]+)/)[1]))
          comframe.contentWindow.postMessage({
            oneClickFluffyScratchLogin: true,
            publicCode: document.querySelector("#publicCode").value,
            redirect: "https://fluffyscratch.hampton.pw/auth/getKeys/v2?localRedirect="+key
          }, "*")
        }
      }
    }
  }
})
document.body.appendChild(comframe)