return 'unknown';
}
// Handle unrecognized scheme that's NOT followed by `//` and NOT a
// plausible host:port (`localhost:3000`). E.g. `site:foo`,
// `unknownscheme:bar` — search operators, classified as `unknown`.
if (candidateScheme && !scheme && !/^\d+(?:[/?#]|$)/.test(afterScheme)) {
if (USERINFO_WITH_PASSWORD_REGEX.test(trimmed) && !/\s/.test(trimmed)) {