intl

var areIntlLocalesSupported = require('intl-locales-supported'); var localesMyAppSupports = [ 'en-US', 'fr-FR', 'de-DE', 'es-ES' ]; // This example demonstrates how to conditionally polyfill the Intl API // in Node.js environments, ensuring that the necessary locale data is available. // It checks if global.Intl exists and if it supports the required locales. // If not, it loads and applies the intl polyfill. if (global.Intl) { // Determine if the built-in `Intl` has the locale data we need. if (!areIntlLocalesSupported(localesMyAppSupports)) { // `Intl` exists, but it doesn't have the data we need, so load the // polyfill and patch the constructors we need with the polyfill's. var IntlPolyfill = require('intl'); Intl.NumberFormat = IntlPolyfill.NumberFormat; Intl.DateTimeFormat = IntlPolyfill.DateTimeFormat; console.log('Patched built-in Intl with polyfill data for missing locales.'); } else { console.log('Built-in Intl supports all required locales.'); } } else { // No `Intl` object globally, so use and load the polyfill entirely. global.Intl = require('intl'); console.log('No native Intl, loaded full polyfill.'); } // Example usage after polyfilling const number = 123456.789; console.log('Formatted number (en-US):', new Intl.NumberFormat('en-US').format(number)); console.log('Formatted number (fr-FR):', new Intl.NumberFormat('fr-FR').format(number)); const date = new Date(); console.log('Formatted date (en-US):', new Intl.DateTimeFormat('en-US').format(date)); console.log('Formatted date (de-DE):', new Intl.DateTimeFormat('de-DE', { dateStyle: 'full', timeStyle: 'short' }).format(date));