Vapor, POST returning Future<SomeContent>

VaporPOST.swift

// `POST` receiving an `Request` and returning an `ReceiptValidation`.
func validate(_ request: Request) throws -> Future<ReceiptValidation> {

    let promise = request.eventLoop.newPromise(ReceiptValidation.self)

    DispatchQueue.global().async {
        guard let receipt = try? request.content.decode(Receipt.self).wait() else {
            promise.fail(error: Abort(HTTPResponseStatus.badRequest))
            return
        }
        let validation = ReceiptValidation(result: "Original receipt": \(receipt.data)")
        promise.succeed(result: validation)
    }

    return promise.futureResult
}