Get local video duration using promise

getVideoDuration.js

const getDuration = file => {
  return new Promise((resolve, reject) => {
    let videoElement = document.createElement("video");
    videoElement.preload = "metadata";

    videoElement.onloadedmetadata = function() {
      window.URL.revokeObjectURL(videoElement.src);
      resolve(videoElement.duration);
    };

    videoElement.src = window.URL.createObjectURL(file);
  });
};