Debounce in TypeScript

debounce.ts

/**
 * Debounce wrapper for functions which are called rapidly
 * This wrapper ensures that there is a minimum wait time
 * between function invocations.
 * @param func Function to be called
 * @param wait Minimum time between function calls
 * @param immediate True if function needs to be invoked immediately,
 * false if needs to be invoked after delay
 * @returns Debounced function with the same signature as `func`
 */
const debounce = (func: Function, wait: number, immediate?: boolean): Function => {
  let timeout: NodeJS.Timeout;
  return function (...rest: any[]) {
    const context = this;
    const later = () => {
      timeout = null;
      if (!immediate) func.apply(context, rest);
    };
    const callNow = immediate && !timeout;
    clearTimeout(timeout);
    timeout = setTimeout(later, wait);
    if (callNow) func.apply(context, rest);
  };
};

const sleep = (time: number) => new Promise(resolve => setTimeout(resolve, time));

const logToConsole = function (...rest: any[]) {
  const date = new Date();
  console.log(`${date.getTime()}`, this.testValue || 'not preserved', ...rest);
};

const bouncedLog = debounce(logToConsole, 50, false);

const runner = async function () {
  this.testValue = 'preserved';

  logToConsole('imm1');
  logToConsole('imm2');
  logToConsole('imm3');
  logToConsole('imm4');

  bouncedLog('bounced1');
  bouncedLog('bounced2');
  bouncedLog('bounced3');
  await sleep(50);
  bouncedLog('bounced4');
  bouncedLog('bounced5');
};

runner();