@nisarg99/timeconvertion-js/src/index.js

A NPM package that exports functions to convert miliseconds to timestring ( hh:mm:ss ) and convert timestring to milliseconds.

const errMsg = 'TimeString is not valid. please enter TimeString in (hh:mm:ss) format.';
const numericErr = 'Please enter numeric Value.';

function ConvertMstoTimeString(ms) {
  const ts = /^[0-9/]*$/;
  if (ts.test(ms) === false) {
    return numericErr;
  }
  let seconds = ms / 1000;
  let hours = parseInt(seconds / 3600, 0);
  seconds %= 3600;
  let minutes = parseInt(seconds / 60, 0);
  seconds = Math.round(seconds % 60);
  if (hours < 10) hours = `0${hours}`;
  if (minutes < 10) minutes = `0${minutes}`;
  if (seconds < 10) seconds = `0${seconds}`;
  return (`${hours}:${minutes}:${seconds}`);
}

function ConvertSecondstoTimeString(seconds) {
  const ts = /^[0-9/]*$/;
  let scnds = seconds;
  if (ts.test(scnds) === false) {
    return numericErr;
  }
  let hours = parseInt(scnds / 3600, 0);
  scnds %= 3600;
  let minutes = parseInt(scnds / 60, 0);
  scnds = Math.round(scnds % 60);
  if (hours < 10) hours = `0${hours}`;
  if (minutes < 10) minutes = `0${minutes}`;
  if (scnds < 10) scnds = `0${scnds}`;
  return (`${hours}:${minutes}:${scnds}`);
}

function ConvertTimeStringtoMs(timestring) {
  const ts = /^[0-9:]*$/;
  if (ts.test(timestring) === true) {
    const a = timestring.split(':');
    let mSeconds;
    if (a.length === 1) {
      mSeconds = (+a[0]);
    } else if (a.length === 2) {
      mSeconds = (+a[0]) * 60 + (+a[1]);
    } else {
      mSeconds = (+a[0]) * 60 * 60 + (+a[1]) * 60 + (+a[2]);
    }
    return mSeconds * 1000;
  }
  return errMsg;
}

function ConvertTimeStringtoSeconds(timestring) {
  const ts = /^[0-9:]*$/;
  if (ts.test(timestring) === true) {
    const a = timestring.split(':');
    let mSeconds;
    if (a.length === 1) {
      mSeconds = (+a[0]);
    } else if (a.length === 2) {
      mSeconds = (+a[0]) * 60 + (+a[1]);
    } else {
      mSeconds = (+a[0]) * 60 * 60 + (+a[1]) * 60 + (+a[2]);
    }
    return mSeconds;
  }
  return errMsg;
}

exports.ConvertMstoTimeString = ConvertMstoTimeString;
exports.ConvertTimeStringtoMs = ConvertTimeStringtoMs;
exports.ConvertTimeStringtoSeconds = ConvertTimeStringtoSeconds;
exports.ConvertSecondstoTimeString = ConvertSecondstoTimeString;