Combine helper that runs a Future after a delay on a background queue

CombineHelper.swift

import Foundation
import Combine

/// Run a block in the background with a delay and make it cancellable.
/// - Parameters:
///   - delay: Delay in milliseconds before the background work starts
///   - queue: Background queue to use
///   - worker: Worker block to execute on queue
///   - completion: Completion handler executed on main thread.
/// - Returns: AnyCancellable token
func runDelayedInBackground<Output>(delay: Int = 200,
                                    scheduler: DispatchQueue = DispatchQueue.global(qos: .userInitiated),
                                    worker: @escaping () -> Result<Output, Never>,
                                    completion: @escaping (Output) -> ()) -> AnyCancellable {
    Just(())
        .delay(for: .milliseconds(delay), scheduler: scheduler)
        .flatMap { _ in Future { $0(worker()) } }
        .receive(on: DispatchQueue.main)
        //.handleEvents(receiveCancel: { print("Cancel event received") })
        .sink(receiveValue: completion)
}