The async and await Keywords

const {Browser, By, Key, until} = require("selenium-webdriver");
const {suite} = require("selenium-webdriver/testing");
const assert = require('assert');

const url = "https://treehouse-projects.github.io/selenium-webdriver-intermediate/waits/app/index.html";

suite(function(env) {
    describe('RSVP site', function() {
        // In order to use the await keyword, we need to indicate this function is
        // asynchronous. We do that by adding the async keyword before the
        // function keyword.
        it('has invitee list', async function() {
            // Calling build() to build a driver still returns a promise. But instead
            // of calling then() on that promise, we can place the await keyword right
            // before the call that returns the promise. JavaScript will pause the
            // execution of the asynchronous function, and wait for the promise to
            // resolve. When it does, await will return the resolved promise's value,
            // that is, the new driver object. We then assign that object to a variable
            // named driver.
            let driver = await env.builder().build();
            // Same idea here. get() still returns a promise, but typing await before
            // the call pauses execution until the page is retrieved and the promise
            // is resolved. In this case, we don't need to assign the promise's value
            // anywhere.
            await driver.get(url);
            // Another promise, another await keyword. When it resolves, the returned
            // list of elements is assigned to the elements variable.
            let elements = await driver.findElements(By.id('invitedList'));
            // Now we can check the list of elements to ensure it's not empty.
            assert(elements.length > 0);
            // Finally, we can tell the driver to close the browser.
            driver.quit();
        });
    });
});