@State issue in SwifUI :)

gistfile1.txt

//
//  ContentView.swift
//  TestIssue
//
//  Created by  iqqator on 15.08.2019.
//  Copyright © 2019  iqqator. All rights reserved.
//

import SwiftUI

struct ContentView: View {

    @State var isPopUpShown = false
    @State var test = false

    var firstText = "123"
    var secondText = "321"

    var body: some View {


        VStack {

            Button(action: {
                self.test = true
                self.isPopUpShown.toggle()
            }) {
                Text("ShowPopUpOne")
            }.padding()

            Button(action: {
                self.test = false
                self.isPopUpShown.toggle()
            }) {
                Text("ShowPopUpTwo")
            }.padding()

        }.sheet(isPresented: $isPopUpShown) {

            PopUpView(someString: self.test ?
                self.firstText : self.secondText)

        }
    }
}

struct PopUpView: View {

    // Need for change in popUp :)
    @State var someString: String

    var body: some View {
        VStack {
            Text(someString)
                .padding()
            TextField("", text: $someString)
                .padding()
        }
    }
}

#if DEBUG
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}
#endif