Test case for https://stackoverflow.com/q/53869592/35070

promise-test.js

// mock promises used below
const wait = async (ms) => await new Promise(resolve => setTimeout(resolve, ms));
const send_request1 = () => wait(300), send_request2 = () => wait(200);
async function get_email() {
    await wait(Math.random() * 1000);
    if (Math.random() > 0.5) throw new Error('failure');
    return {subject: 'foobar'};
}

const assert = require('assert');
async function main() {
    // THIS CODE IS WRONG - will cause PromiseRejectionHandledWarning!
    const email_promise = get_email();
    await send_request1();
    await send_request2();
    const email = await email_promise;
    assert.equal(email.subject, 'foobar');
};

(async () => {
    try {
        await main();
    } catch(e) {
        console.log('main error: ' + e.stack);
    }
})();