gistfile1.txt

"use strict";

function firefox(action) {
    var handler = firefox.handlers[action.index];
    if (handler) {
        return new Promise(handler);
    }
    console.log('Done in FireFox');
    return null;
}


function chrome(action) {
    var handler = chrome.handlers[action.index];
    if (handler) {
        return new Promise(handler);
    }
    console.log('Done in Chrome');
    return null;
}


function main() {
    function _resolve(action) {
        return Promise.resolve(action).then(function (action) {
            switch (action.turn) {
                case 'firefox':
                    return firefox(action);
                case 'chrome':
                    return chrome(action);
                default:
                    throw new Error('Unknown turn:' + turn);
            }
        }).then(function (action) {
            if (action) {
                return _resolve(action);
            } else {
                return null;
            }
        });
    }

    _resolve({index: 0, turn: 'firefox'});
}


firefox.handlers = [
    defineF0({
        index: 0,
        turn: 'chrome'
    }),
    function (resolve, reject) {
        setTimeout(function () {
            console.log('This is F1');
            resolve({
                index: 1,
                turn: 'chrome'
            });
        }, 1000);
    }
];

chrome.handlers = [
    function (resolve, reject) {
        setTimeout(function () {
            console.log('This is C0');
            resolve({
                index: 1,
                turn: 'firefox'
            });
        }, 1000)
    },
    function (resolve, reject) {
        setTimeout(function () {
            console.log('This is C1');
            resolve({
                index: 'F2',
                turn: 'firefox'
            });
        }, 1000)
    }
];

function defineF0(next) {
    return function (resolve, reject) {
        setTimeout(function () {
            console.log('This is F0');
            resolve(next);
        }, 1000);
    };
}


main();