node.js, bluebird, poor control of execution path

Question

I\'m trying to learn bluebird; I\'m not controlling execution as I want to. (This bluebird question came from an async.js question at Node.js, async module, concurrency.)

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Answer 1

It's because your call to part1a(3) is not wrapped in a function so it's get called right away instead of waiting the previous promises to be resolved:

function part1() {
    console.log('part1 start')
    // then() returns a promise so no need to create a new Promise
    return Promise.all([part1a(1), part1a(2)])
        .then(function (err) {
            if (err) console.log('part1 error after #1 and #2')
            else console.log('part1 done with #1 and #2')
        })
        // the issue was here, part1a() is a promise
        .then(function () {
            return part1a(3)
        })
        .then(function (err) {
            if (err) console.log('part1 error after #3')
            else console.log('part1 done')
        })
}

function part1a(i) {
    console.log('part1a start #' + i)
    return new Promise(function (resolve, reject) {
        setTimeout(function () {
            console.log('part1a done  #' + i)
            return resolve()
        }, 100)
    })
}

part1().then(function (err) {
    if (err) console.log('outermost code reported error' + err.message)
    else console.log('end of code')
})