Options for passing multiple data down a promise chain

promise_chains.js

// Promises can only resolve (return) a single value
// Sometimes, you want to collect multiple values as you progress through a promise chain
// e.g. Customer, Product, Basket, Payment Details
// 
// I can only think of three options for handling this type of scenario (below)
// NB: Assume that FOO, BAR & BAZ are the result of some complex action (DB query etc.)
// 
// What are the Pro's & Cons? 
// Are there others?


// Option 1: Outside variables

var foo, bar, baz;

Promise.resolve("FOO").then(f => {
    foo = f;
    return "BAR";
}).then(b => {
    bar = b;
    return "BAZ";
}).then(z => {
    baz = z;
    console.log(foo, bar, baz);
});

// Option 2: Pass an array of accumulated values down the chain

Promise.resolve([]).then(data => {
    data.push('FOO');
    return data;
}).then(data => {
    data.push("BAR");
    return data;
}).then(data => {
    data.push("BAZ");
    return data;
}).then(data => {
    console.log(data[0], data[1], data[2]);
});

// Option 2: Pass an object of accumulated values down the chain

Promise.resolve({}).then(data => {
    data.foo = "FOO";
    return data;
}).then(data =>{
    data.baz = "BAZ";
    return data;
}).then(data =>{
    data.bar = "BAR";
    return data;
}).then(data => {
    console.log(data.foo, data.bar, data.baz)
});