A spec-compliant polyfill for Intl.ListFormat fully tested by the official ECMAScript Conformance test suite

Installation#

npm i @formatjs/intl-listformat

Requirements#

• Intl.getCanonicalLocales or polyfill
• Intl.Locale or polyfill.

Usage#

Via polyfill-fastly.io#

You can use polyfill-fastly.io URL Builder to create a polyfill script tag for Intl.ListFormat. By default the created URL does not come with any locale data. In order to add locale data, append Intl.ListFormat.~locale.<locale> to your list of features. For example:

<!-- Polyfill Intl.ListFormat, its dependencies & `en` locale data -->
<script src="https://polyfill-fastly.io/v3/polyfill.min.js?features=Intl.ListFormat,Intl.ListFormat.~locale.en"></script>

Simple#

import '@formatjs/intl-listformat/polyfill.js'
import '@formatjs/intl-listformat/locale-data/en.js' // locale-data for en

Dynamic import + capability detection#

async function polyfill(locale: string) {
  const unsupportedLocale = shouldPolyfill(locale)
  // This locale is supported
  if (!unsupportedLocale) {
    return
  }
  // Load the polyfill 1st BEFORE loading data
  await import('@formatjs/intl-listformat/polyfill-force.js')
  await import(`@formatjs/intl-listformat/locale-data/${unsupportedLocale}.js`)
}

Tests#

This library is fully test262-compliant.