public static TodoListState Write(object command, TodoListState todoList)
{
switch (command)
{
case NameTodoList c:
todoList = Transition(todoList, new TodoListNamed(c.AggregateId, c.Name));
break;
case AddTodoItem c:
if (todoList.Items.ContainsKey(c.ItemNumber))
{
throw new ArgumentException("This list already has an item with that number");
}
todoList = Transition(todoList, new TodoItemAdded(c.AggregateId, c.ItemText, c.ItemNumber));
break;
case CheckTodoItem c:
todoList = Transition(todoList, new TodoItemChecked(c.AggregateId, c.ItemNumber));
break;
case UncheckTodoItem c:
todoList = Transition(todoList, new TodoItemUnchecked(c.AggregateId, c.ItemNumber));
break;
}
return(todoList);
}
private static TodoListState Transition(TodoListState todoList, object @event)
{
todoList.Emit(@event);
return(todoList);
}
