matchURLPrefix()function

matchURLPrefix(target: PossibleURL | undefined, base: PossibleURL | undefined, caller: AnyCaller = matchURLPrefix): AbsolutePath | undefined

Param	Type
`target`	`PossibleURL`	URL to match against `base` — if this is a relative path it will be resolved against `base`
`base`	`PossibleURL`	Base URL the `target` is matched against.
`caller`	`AnyCaller`	Function to attribute a thrown error to — defaults to `matchURLPrefix`. Defaults to `matchURLPrefix`

Return
`AbsolutePath \| undefined`	Absolute path starting with `/`, or `undefined` for origin mismatches or non-matching paths.

Throws
`unknown`	RequiredError If `target` or `base` cannot be resolved to a true URL.

Resolve and match a target URL/path against a base URL and return the remaining path.

Need to be valid URLs not just URIs, i.e. needs to have protocol:// at the start.
Origins need to match, i.e. http://localhost !== http://localhost:4020
Relative targets are resolved against the normalized base URL.
The resolved target pathname is normalised with cleanPath() — runs of slashes are collapsed and a trailing slash is stripped (the root / is preserved) — so /foo and /foo/ resolve to the same path. This mirrors the path-based sibling matchPathPrefix().

Examples

matchURLPrefix("http://x.com/a/b", "http://x.com/a/"); // `/b`

matchURLPrefix("http://x.com/a/b/", "http://x.com/a/"); // `/b` (trailing slash normalised away)