Promiseで並列処理をつなぐ

メモ。近いうちもっと分かりやすいPromise記事書こう。

qiita.js

    function randomInt(min, max) { 
        return Math.floor(Math.random() * (max - min) + min);
    }
    function timerPromisefy(index) {
        return new Promise(function (resolve) {
            const interval = randomInt(100, 1000);
            setTimeout(function () {
                console.log('index: ' + index + ' interval: ' + interval);
                resolve();
            }, interval);
        });
    }
    const startDate = Date.now();
    Promise.resolve()
    .then(function() {
        return Promise.all([
            timerPromisefy(1),
            timerPromisefy(1),
            timerPromisefy(1),
            timerPromisefy(1)
        ]);
    }).then(function() {
        return Promise.all([
            timerPromisefy(2),
            timerPromisefy(2)
        ]);
    });