| /** | |
| * The result of parsing a URL relative to a base URL. | |
| */ | |
| export type RelativeURL = { | |
| /** | |
| * The relative URL. Either a URL including the origin or a relative URL. | |
| */ | |
| url: string | |
| /** | |
| * Whether the URL is relative to the base URL. | |
| */ | |
| isRelative: boolean | |
| } | |
| export function parseRelativeURL( | |
| url: string | URL, | |
| base: string | URL | |
| ): RelativeURL { | |
| const baseURL = typeof base === 'string' ? new URL(base) : base | |
| const relative = new URL(url, base) | |
| // The URL is relative if the origin is the same as the base URL. | |
| const isRelative = relative.origin === baseURL.origin | |
| return { | |
| url: isRelative | |
| ? relative.toString().slice(baseURL.origin.length) | |
| : relative.toString(), | |
| isRelative, | |
| } | |
| } | |
| /** | |
| * Given a URL as a string and a base URL it will make the URL relative | |
| * if the parsed protocol and host is the same as the one in the base | |
| * URL. Otherwise it returns the same URL string. | |
| */ | |
| export function getRelativeURL(url: string | URL, base: string | URL): string { | |
| const relative = parseRelativeURL(url, base) | |
| return relative.url | |
| } | |