MessageFormatOptions.customFormatters property

Map of custom formatting functions to include. See Custom Formatters for more details.

Signature:

customFormatters?: {
        [key: string]: CustomFormatter | {
            formatter: CustomFormatter;
            arg?: 'string' | 'raw' | 'options';
            id?: string;
            module?: string | ((locale: string) => string);
        };
    };