Optional type hints

[cschmatzler]

Optional type hints

[IvanRublev]

I guess you might want to replace nil with a default empty list to process it without an error message at all. To do so you can adapt Nestru.PreDecoder protocol like the following:

defmodule Kratos.Models.UIContainer do
  @moduledoc false

  defimpl Nestru.PreDecoder do
    def gather_fields_from_map(_value, _context, map) do
      {:ok, Map.update(map, "messages", [], &if(is_nil(&1), do: [], else: &1))}
    end
  end
  
  @derive {Nestru.Decoder, hint: %{nodes: [Kratos.Models.UINode], messages: [Kratos.Models.UIText]}}

  ...
end

Then the decoding of the map with missing messages field or when its value is set to null will return:

{:ok,
 %Kratos.Models.UIContainer{
   ...
   messages: []
 }}

How about that?

[cschmatzler]

That works beautifully, sorry for missing it in the first place. Thanks!