読み込みに時間がかかるときにメッセージを出すscript

code:script.js

export async function loading(process, {onstart, onend, delay = 500} = {}) {

let timer = null;

timer = setTimeout(async () => {

onstart?.();

await process;

onend?.();

}, delay);

const result = await process;

clearTimeout(timer);

return result;

}