PromiseKit Extension to Swift Concurrency

PromiseKit+Extensions.swift

//
//  Promise+Extension.swift
//  blockchain-concerts
//
//  Created by Maxence on 29/03/2022.
//

import Foundation
import PromiseKit

extension Promise {
    func async() async throws -> T {
        return try await withCheckedThrowingContinuation { continuation in
            var result = self.result

            if result == nil {
                let group = DispatchGroup()
                group.enter()
                pipe { result = $0; group.leave() }
                group.wait()
            }

            switch result! {
            case .rejected(let error):
                continuation.resume(throwing: error)
            case .fulfilled(let value):
                continuation.resume(returning: value)
            }
        }
    }
}