Method constructor

packages/intl-listformat/index.ts:191–271

(locales?: string | string[], options?: IntlListFormatOptions)

export default class ListFormat {
  constructor(locales?: string | string[], options?: IntlListFormatOptions) {
    // test262/test/intl402/ListFormat/constructor/constructor/newtarget-undefined.js
    // Cannot use `new.target` bc of IE11 & TS transpiles it to something else
    const newTarget =
      this && this instanceof ListFormat ? this.constructor : void 0
    if (!newTarget) {
      throw new TypeError("Intl.ListFormat must be called with 'new'")
    }
    setInternalSlot(
      ListFormat.__INTERNAL_SLOT_MAP__,
      this,
      'initializedListFormat',
      true
    )
    const requestedLocales = CanonicalizeLocaleList(locales)
    const opt: any = Object.create(null)
    const opts = GetOptionsObject(options)
    const matcher = GetOption(
      opts,
      'localeMatcher',
      'string',
      ['best fit', 'lookup'],
      'best fit'
    )
    opt.localeMatcher = matcher
    const {localeData} = ListFormat
    const r = ResolveLocale(
      ListFormat.availableLocales,
      requestedLocales,
      opt,
      ListFormat.relevantExtensionKeys,
      localeData,
      ListFormat.getDefaultLocale
    )
    setInternalSlot(ListFormat.__INTERNAL_SLOT_MAP__, this, 'locale', r.locale)
    const type: keyof ListPatternFieldsData = GetOption(
      opts,
      'type',
      'string',
      ['conjunction', 'disjunction', 'unit'],
      'conjunction'
    )
    setInternalSlot(ListFormat.__INTERNAL_SLOT_MAP__, this, 'type', type)
    const style: keyof ListPatternData = GetOption(
      opts,
      'style',
      'string',
      ['long', 'short', 'narrow'],
      'long'
    )
    setInternalSlot(ListFormat.__INTERNAL_SLOT_MAP__, this, 'style', style)
    const {dataLocale} = r
    const dataLocaleData = localeData[dataLocale]
    invariant(!!dataLocaleData, `Missing locale data for ${dataLocale}`)
    const dataLocaleTypes = dataLocaleData[type]
    const templates = dataLocaleTypes![style]!
    setInternalSlot(
      ListFormat.__INTERNAL_SLOT_MAP__,