import type { MetadataContext } from '../types/resolvers'; declare function isStringOrURL(icon: any): icon is string | URL; export declare function getSocialImageFallbackMetadataBase(metadataBase: URL | null): { fallbackMetadataBase: URL; isMetadataBaseMissing: boolean; }; declare function resolveUrl(url: null | undefined, metadataBase: URL | null): null; declare function resolveUrl(url: string | URL, metadataBase: URL | null): URL; declare function resolveUrl(url: string | URL | null | undefined, metadataBase: URL | null): URL | null; declare function resolveRelativeUrl(url: string | URL, pathname: string): string | URL; declare function resolveAbsoluteUrlWithPathname(url: string | URL, metadataBase: URL | null, { trailingSlash, pathname }: MetadataContext): string; export { isStringOrURL, resolveUrl, resolveRelativeUrl, resolveAbsoluteUrlWithPathname, };