index.js

(function(context) {

  async function asyncFetchDemo() {
    console.log('Fetch async initiating');
    const responsePromise = await fetch('https://api.github.com/search/repositories?sort=stars&order=desc&q=art%20o%20fjs')
    const responseJSON = await responsePromise.json();
    console.log(responseJSON);
    console.log('Fetch async responsed successfully');
  }

  function regularFetchDemo() {
    console.log('Fetch regular initiating');
    fetch('https://api.github.com/search/repositories?sort=stars&order=desc&q=art%20o%20fjs')
      .then(x => x.json())
      .then(x => console.log(x));
    console.log('Fetch regular responsed successfully');
  }

  function getPromise(value) {
    return new Promise((resolve, reject) =>
                              setTimeout(() =>
                                resolve(value), 1000) );
  }

  async function asyncPromise() {
    // await can be only used in async functions
    console.log('asyncPromise initiated');
    const result1 = await getPromise(100);
    console.log('Result 1 recevied');
    const result2 = await getPromise(200);
    console.log('Result 2 recevied');
    console.log(result1 + result2);
    console.log('After result is printed');
  }

  function demo() {
    console.log('\n\nASYNC AWAIT DEMO');
    asyncFetchDemo();
    console.log('After asyncFetchDemo is called');
    regularFetchDemo();
    console.log('After regularFetchDemo is called');
    asyncPromise();
  };

  (context || this).demoLibs['async-await'] = demo;
})(window);