Most/Core Version

most-core.js

function todoList (deferred) {
    const ping$ = fromArray([...Array(config.iterations).keys()])
    const todo$ = multicast(map(todo, ping$))
    const old$ = merge(
        map(todo => (todo.id % 4 === 0 ? todo : {}), take(1, todo$)),
        filter(todo => todo.id % 4 === 0, skip(1, todo$))
    )
    const sample$ = snapshot(
        (old, last) => ({...last, old}),
        old$,
        todo$
    )
    const list$ = scan((list, item) => [...list, item], [], sample$)
    const end$ = take(
        1,
        filter(list => list.length === config.iterations, list$)
    )
    return tap(res => deferred.resolve(res), end$)
}