74 lines
2.6 KiB
TypeScript
74 lines
2.6 KiB
TypeScript
import type { I18nConfig, LocalizedSlugs } from '../i18n/index.js'
|
|
|
|
import { buildLocalizedPath, getDefaultLocale, getLocaleCodes } from '../i18n/index.js'
|
|
|
|
type BuildHreflangArgs = {
|
|
/** Absolute site origin, e.g. 'https://example.com'. Omit for relative paths. */
|
|
baseUrl?: string
|
|
config: I18nConfig
|
|
/** Home slug that collapses to the locale root. Defaults to 'home'. */
|
|
homeSlug?: string
|
|
/**
|
|
* Localized segment the document lives under (an archive page's slugs),
|
|
* e.g. { pl: 'artykuly', en: 'articles' }. Locales missing from the prefix
|
|
* are omitted — an entry with no archive in that language has no URL there.
|
|
*/
|
|
prefix?: LocalizedSlugs
|
|
/** slug per locale for the current document, e.g. { pl: 'o-nas', en: 'about' } */
|
|
slugs: LocalizedSlugs
|
|
}
|
|
|
|
/**
|
|
* Next.js Metadata `alternates.languages`.
|
|
*
|
|
* Bridges SEO and i18n: for each configured locale that the document has a
|
|
* slug in, it produces the locale-aware path (via buildLocalizedPath),
|
|
* optionally prefixed with an absolute origin.
|
|
*
|
|
* Also emits `x-default` pointing at the default locale — the version Google
|
|
* serves when the user's language/region matches no hreflang, and the fallback
|
|
* when the root ('/') redirect is ambiguous (Googlebot with no/foreign
|
|
* Accept-Language).
|
|
*
|
|
* @example
|
|
* buildHreflangAlternates({
|
|
* slugs: { pl: 'o-nas', en: 'about' },
|
|
* config,
|
|
* baseUrl: 'https://example.com',
|
|
* })
|
|
* // → {
|
|
* // pl: 'https://example.com/pl/o-nas',
|
|
* // en: 'https://example.com/en/about',
|
|
* // 'x-default': 'https://example.com/pl/o-nas',
|
|
* // }
|
|
*/
|
|
export function buildHreflangAlternates({
|
|
baseUrl,
|
|
config,
|
|
homeSlug = 'home',
|
|
prefix,
|
|
slugs,
|
|
}: BuildHreflangArgs): Record<string, string> {
|
|
const origin = baseUrl?.replace(/\/$/, '') ?? ''
|
|
const alternates: Record<string, string> = {}
|
|
|
|
for (const locale of getLocaleCodes(config)) {
|
|
const path = buildLocalizedPath({ config, homeSlug, locale, prefix, slugs })
|
|
if (path) {
|
|
alternates[locale] = `${origin}${path}`
|
|
}
|
|
}
|
|
|
|
// x-default: the version Google serves when the user's language/region doesn't
|
|
// match any hreflang — and, crucially here, the fallback when the root ('/')
|
|
// redirect is ambiguous (Googlebot with no/foreign Accept-Language). Point it
|
|
// at the default locale (the primary market) so search shows that version by
|
|
// default instead of guessing. Only set when the default locale has a URL.
|
|
const defaultLocalePath = alternates[getDefaultLocale(config)]
|
|
if (defaultLocalePath) {
|
|
alternates['x-default'] = defaultLocalePath
|
|
}
|
|
|
|
return alternates
|
|
}
|