Function localeFromAcceptLanguage

packages/web/src/middleware.ts:50–78

(header: string | null)

}

function localeFromAcceptLanguage(header: string | null) {
  if (!header) return "root"

  const items = header
    .split(",")
    .map((raw) => raw.trim())
    .filter(Boolean)
    .map((raw) => {
      const parts = raw.split(";").map((x) => x.trim())
      const lang = parts[0] ?? ""
      const q = parts
        .slice(1)
        .find((x) => x.startsWith("q="))
        ?.slice(2)
      return {
        lang,
        q: q ? Number.parseFloat(q) : 1,
      }
    })
    .sort((a, b) => b.q - a.q)

  const locale = items
    .map((item) => item.lang)
    .filter((lang) => lang && lang !== "*")
    .map((lang) => matchLocale(lang))
    .find((lang) => lang)

  return locale ?? "root"
}

export const onRequest = defineMiddleware((ctx, next) => {
  const alias = docsAlias(ctx.url.pathname)