Using the WPF Dispatcher in unit tests

Question

I\'m having trouble getting the Dispatcher to run a delegate I\'m passing to it when unit testing. Everything works fine when I\'m running the program, but, during a unit te

Answer 1

It's a bit old post, BeginInvoke is not a preferable option today. I was looking for a solution for mocking and had't found anything for InvokeAsync:

await App.Current.Dispatcher.InvokeAsync(() => something );

I've added new Class called Dispatcher, implementing IDispatcher, then inject into viewModel constructor:

public class Dispatcher : IDispatcher
{
    public async Task DispatchAsync(Action action)
    {
        await App.Current.Dispatcher.InvokeAsync(action);
    }
}
public interface IDispatcher
    {
        Task DispatchAsync(Action action);
    }

Then in test I've injected MockDispatcher into viewModel in constructor:

internal class MockDispatcher : IDispatcher
    {
        public async Task DispatchAsync(Action action)
        {
            await Task.Run(action);
        }
    }

Use in the view model:

await m_dispatcher.DispatchAsync(() => something);