middlewares like with promises

// -- Async tasks -------------------------------------------------------------

const displaySeparation = payload => new Promise((resolve, reject) => {
    if (!payload || !payload.title) return reject('No title !')

    console.log(new Date(), `-- ${payload.title} --------------------------------------`)
    resolve()
})

const readSomething = payload => new Promise((resolve, reject) => {
    if (!payload || !payload.numbers) return reject('No numbers !')

    console.log(new Date(), 'Adding numbers')
    payload.numbers.push(8)
    payload.numbers.push(4)

    setTimeout(() => {
        resolve()
    }, 2000)
})

const doSomething = payload => new Promise((resolve, reject) => {
    if (!payload || !payload.numbers) return reject('No numbers !')

    console.log(new Date(), 'Making the sum of numbers')
    payload.result = payload.numbers.reduce((a, b) => a + b)

    setTimeout(() => {
        resolve()
    }, 3000)
})

const writeSomething = payload => new Promise((resolve, reject) => {
    if (!payload || !payload.numbers || !payload.result) return reject('No result !')

    console.log(new Date(), `${payload.numbers.join(' + ')} = ${payload.result}`)

    setTimeout(() => {
        resolve()
    }, 1000)
})

// -- Middlewares style system ------------------------------------------------

const createProcess = tasks => payload => tasks.reduce((promiseChain, task) => promiseChain.then(() => task(payload)), Promise.resolve())

// -- Exec --------------------------------------------------------------------

const fullCalc = createProcess([readSomething, doSomething, writeSomething])
const makeSomething = createProcess([displaySeparation, fullCalc])
const makeAnotherThing = createProcess([displaySeparation, doSomething, writeSomething])
const merged = createProcess([makeSomething, readSomething, doSomething, writeSomething])

makeSomething({ title: 'Process #1', numbers: [3, 8] })
    .then(() => makeSomething({ title: 'Process #2', numbers: [4, 10] }))
    .then(() => makeAnotherThing({ title: 'Process #3', numbers: [1, 2, 3] }))
    .then(() => makeAnotherThing({ title: 'Process #4', numbers: [7, 6, 9] }))
    .then(() => merged({ title: 'Process #5', numbers: [1, 4, 9] }))
    .catch(error => console.error(error))