dynamodb-toolbox: Default does not support function (for conditionnal need)

Hi,

I tried to use the “default” option with function call because I needed to use a condition to choose the default value but the function is not evaluated and its code content is stored in DDB instead:

Entity configuration:

const INVITATION_DATA_TYPE = 'INVITATION';
const InvitationEntity = new Entity({
	// Specify entity name
	name: INVITATION_DATA_TYPE,
	// Assign it to our table
	table: DataTable,
	timestamps: false,
	typeAlias: 'dataType',
	// Define attributes
	attributes: {
		farmId: { partitionKey: true }, // flag as partitionKey
		rangeKey: { hidden: true, sortKey: true, default: (data) => `${INVITATION_DATA_TYPE}#${data.invitationId}` }, // flag as sortKey and mark hidden
		invitationId: { type: 'string', map: 'dataId' },
		email: { type: 'string' },
		hashCode: { type: 'string' },
		status: { type: 'string' },
		timestamp: { type: 'number' },
		createdAt: {
			type: 'string', 
			default: (data) => {
				if (data.createdAt) {
					return data.createdAt
				} else {
					return new Date().toISOString()
				}
			}
		},
		modifiedAt: { type: 'string', default: (data) => new Date().toISOString() },
	},
});

And in DDB, I get:

{
  "createdAt": "(data) => {\n\t\t\t\tif (data.createdAt) {\n\t\t\t\t\treturn data.createdAt\n\t\t\t\t} else {\n\t\t\t\t\treturn new Date().toISOString()\n\t\t\t\t}\n\t\t\t}",
  "dataId": "5fbea3ed-cd7f-4c0f-aefe-d6334c864d07",
  "dataType": "INVITATION",
  "email": "opt411@gmail.com",
  "hashCode": "03d428236b80cbbbbec45f2a6d31d2a955f2f7bdefb80fa0f05cda000ae0db76f991eb7520d0f1bb79d2cfda51b14fd5130c317847447bab70d2725e8747040e",
  "hashKey": "bf30c17d-5ea4-4e20-ab65-da2bd8a6187f",
  "modifiedAt": "2020-12-29T23:30:36.974Z",
  "rangeKey": "INVITATION#5fbea3ed-cd7f-4c0f-aefe-d6334c864d07",
  "status": "sent",
  "timestamp": 1609284636970
}

Maybe it is a configuration on my side?

Thank you,