Dependency Injection SwiftUI Combine.swift

import Foundation
import SwiftUI
import Combine

protocol Networking {
    func fetch() -> String?
}
class NetworkManager: Networking {
    // Some code for making network requests
    func fetch() -> String? {
        return  ""
    }
}

class UserViewModel: ObservableObject {
    let networkManager: NetworkManager
    @Published public var user: String?
    init(networkManager: NetworkManager) {
        self.networkManager = networkManager
        fetchUsers()
    }
    
    func fetchUsers() {
        // Use the network manager to make a network request to fetch a list of users
        user = networkManager.fetch()
    }
}

struct UserView: View {
    @ObservedObject var viewModel: UserViewModel
    
    var body: some View {
        // Display a users using the view model
        Text(viewModel.user ?? "")
    }
}

let networkManager = NetworkManager()
let userViewModel = UserViewModel(networkManager: networkManager)
let userView = UserView(viewModel: userViewModel)