Task runner listeners need to be called on main thread

[levibostian]

Given this SwiftUI code:

struct ContentView: View {
    
    @ObservedObject var viewModel = ViewModel()
    
    var body: some View {
		...
    }
    
    class ViewModel: ObservableObject, TaskRunnerListener {
        @Published var taskText: String = "Hello, World"
        
        init() {
            WendyConfig.addTaskRunnerListener(self)
        }
        
        func runningTask(_ task: PendingTask) {
            self.taskText = "Running task..."
        }
        func allTasksComplete() {
            self.taskText = "All tasks complete!"
        }
    }
}

If I run this code, I will get runtime errors saying that I should be updating the self.taskText value on the main thread, not background.

I resolve these errors if I do:

    class ViewModel: ObservableObject, TaskRunnerListener {        
        func runningTask(_ task: PendingTask) {
			Task { @MainActor in 
              self.taskText = "Running task..."
            } 
        }
    }

All listeners should be called on main actor.