Some generic Utils: log, after, ...

my-utils.ts

const LOGTYPES = ['log', 'info', 'warn', 'error'] as const;
interface LogType {
  type: typeof LOGTYPES[number];
}
export const log = (...args: Array<string | LogType | {}>) => {
  let type: LogType['type'] = 'log';
  let prefix = [] as any[];
  let postfix = [] as any[];
  //@ts-ignore
  const idx = args.findIndex((a) => LOGTYPES.includes(a?.type));
  if (~idx) {
    [{ type }] = args.splice(idx, 1) as LogType[];
    prefix = args.splice(0, idx);
    postfix = args;
  } else prefix = args; //type='log', postfix=[] RIDONDANTE
  return (value?: any) =>
    console[type](
      new Date().toISOString().substring(11),
      ...prefix,
      value,
      ...postfix
    ) as unknown as false;
};
  
export function after<F extends (...args: any) => any>(
  time: number,
  fn: F,
  ...args: Parameters<F>
): Promise<ReturnType<F>> {
  return new Promise(function (resolve, reject) {
    setTimeout(
      function (...args: Parameters<F>) {
        try {
          resolve(fn(...Array.from(args)));
        } catch (err) {
          reject(err);
        }
      },
      time,
      ...Array.from(args)
    );
  });
}

use-cases.ts

import { log, after } from "./my-utils";

after(1500, (a, b) => log('+')(a + b) || a * b, 2, '3') //infer a:number, b:string + check correct number of params after fn
    .then((ret) => console.warn({ ret })) //infer ret: number
    .catch(log({type: 'error'})); //eventually console.error

const answer = await after(500, ()=>42); //infer answer: number
log("What does", {type: 'info'}, "mean in the meaning of life?")(answer);
after(1000, log({type:'warn'}), "The answer to life, the universe and everything!");