typescript-action/src/main.ts

import * as core from '@actions/core';
import {wait} from './wait'

async function run() {
  try {
    const ms = core.getInput('milliseconds');
    console.log(`Waiting ${ms} milliseconds ...`)

    core.debug((new Date()).toTimeString())
    wait(parseInt(ms));
    core.debug((new Date()).toTimeString())

    core.setOutput('time', new Date().toTimeString());
  } catch (error) {
    core.setFailed(error.message);
  }
}

run();