Run in console of Discord browser app to get a list of all users in the room.

scanroom.js

(function () {
  return new Promise(async (final) => {
    const list = await new Promise((res) => {
      let l = document.querySelectorAll("[aria-label=Members]")[0]
        .parentElement;
      l.scrollTo({ top: 0, left: 0, behavior: "instant" });
      setTimeout(() => res(l), 500);
    });
    let names = [];
    const height = list.scrollHeight - window.innerHeight;
    const movement = 200
    for (i = 0; i < height; i += movement) {
      perc = ((i / height) * 100).toFixed(2);
      console.log(`scanning names ...${perc}%`);
      await new Promise((res) => {
        list.scrollBy(0, movement);
        setTimeout(()=>{res();}, 500);
      });
      newnames = await new Promise((res) => {
        let elems = Array.from(
          document.querySelectorAll(
            "[data-list-item-id^=members] [class^=name-] > span > span"
          )
        );
        elems = elems.map((x) => x.innerHTML);
        res(elems);
      });
      names = await new Promise((res) => {
        let x = [...names, ...newnames].reduce(
          (prev, item) => (prev.includes(item) ? prev : [item, ...prev]),
          []
        );
        res(x);
      });
    }
    console.log(`done ...100%`);
    final(names);
  });
})().then(console.log)

One-liner:

new Promise((async e=>{const n=await new Promise((e=>{let n=document.querySelectorAll("[aria-label=Members]")[0].parentElement;n.scrollTo({top:0,left:0,behavior:"instant"}),setTimeout((()=>e(n)),500)}));let o=[];const t=n.scrollHeight-window.innerHeight;for(i=0;i<t;i+=200)perc=(i/t*100).toFixed(2),console.log(`scanning names ...${perc}%`),await new Promise((e=>{n.scrollBy(0,200),setTimeout((()=>{e()}),500)})),newnames=await new Promise((e=>{let n=Array.from(document.querySelectorAll("[data-list-item-id^=members] [class^=name-] > span > span"));n=n.map((e=>e.innerHTML)),e(n)})),o=await new Promise((e=>{e([...o,...newnames].reduce(((e,n)=>e.includes(n)?e:[n,...e]),[]))}));console.log("done ...100%"),e(o)})).then(console.log);