SwiftUIのプレビューで@EnvironmentObjectの値を設定する

モデルクラス

DialogModel.swift

import Foundation

public enum DialogType {
    case none
    case loading
}

class DialogModel: NSObject, ObservableObject {
    @Published var dialogType: DialogType = .none
}

SwiftUI ContentView

ContentView.swift

import SwiftUI

struct ContentView: View {
    
    @EnvironmentObject var dialogModel: DialogModel
    
    var body: some View {

プレビューするときにEnvironmentObject内の変数の値を設定する方法

ContentView.swift

struct ContentView_Previews: PreviewProvider {

    static var previews: some View {

        Group {

            ContentView().environmentObject({ () -> DialogModel in
                let envObj = DialogModel()
                envObj.dialogType = .none
                return envObj
            }() )

            ContentView().environmentObject({ () -> DialogModel in
                let envObj = DialogModel()
                envObj.dialogType = .loading
                return envObj
            }() )

        }
    }
}

参考

GitHub

TDD