interface Country { countryCode: string countryName: string currencyCode: string postalCodeFormat: string languages: string isoNumeric: string isoAlpha3: string [key: string]: string } interface State { id: number name: string adminName1: string countryCode: string countryName: string [key: string]: string | number } export const getCountries = async (language: 'es' | 'en') : Promise => { const myfile = await require('../' + language + '/countries.json') return myfile } export const getStates = async (isoCode: string, language: 'es' | 'en'): Promise=> { const myfile = await require('../' + language + '/' + isoCode + '.json') return myfile }