public async Task Edit_ReturnsViewResult_WhenValidGuid()
{
this._todoItemServiceMock
.Setup(service => service.GetItemAsync(It.IsAny <Guid>()))
.ReturnsAsync(new TodoItem());
var result = await _todosController.Edit(Guid.NewGuid());
var viewResult = Assert.IsType <ViewResult>(result);
Assert.IsAssignableFrom <EditViewModel>(viewResult.ViewData.Model);
}