SendMessageUseCase example

SendMessageUseCase.swift

import Foundation

struct Message {
  var id: String
  var recieverId: String 
  var senderId: String
  var content: String
}

protocol MessageRepository {
  func add(message: Message, completion: () -> ())
}

struct SendMessageUseCase {
    let messageRepo: MessageRepository

    func execute(message: Message, completion: @escaping () -> ()) {
      self.messageRepo.add(message: Message, completion: completion)
    }
}