Strip an Ecto record of attributes that cannot be encoded to JSON

strip_ecto_record.exs

record = Enum.reduce(Map.keys(record), %{}, fn (key, map) ->
  value = Map.get(record, key)

  key_to_add = cond do
    is_map(value) && Map.get(value, :__struct__, nil) == Elixir.Ecto.Association.NotLoaded ->
      nil
    key == :__meta__ ->
      nil
    key == :__struct__ ->
      nil
    true ->
      key
  end

  if key_to_add do
    map |> Map.merge(%{key_to_add => value})
  else
    map
  end
end)