Testing Flow.

flowtest.ts

/* @flow */

function wait(time: number): Promise<string> {
    return new Promise((resolve, reject) => {
        setTimeout(resolve.bind(null, 'resolved in ' + time + 'ms'), time);
    });
}

document.addEventListener('DOMContentLoaded', () => {
    console.log('start');

    wait(1000).then((s) => {
        console.log('got message:', s);
    }, () => {
        console.error('error');
    });

    console.log('stop');
});