Create a pending PromiseKit Promise and delay execution

pending-promise.swift

import Foundation
import PromiseKit

/// Create a Promise pending execution
///
/// By default Promises will execute on creation and
/// wait to be resolved. In general this behaviour is fine,
/// however there may be circumstances where this causes
/// unexpected behaviour.
/// For example when using nested promises.
///
/// `PendingPromise` allows a promise to be defined
/// and only executed when told to.
///
///
/// - note:
/// To execute a pending Promise call the `.run()` method
public class PendingPromise<T> {
  /// Pending promise
  private let promise: () -> Promise<T>
  
  public init(promise: @escaping () -> Promise<T>) {
    self.promise = promise
  }
  
  /// Execute pending promise
  ///
  /// - returns: Pending promise
  public func run() -> Promise<T> {
    return promise()
  }
}