21 lines
493 B
JavaScript
21 lines
493 B
JavaScript
'use strict';
|
|
|
|
|
|
/**
|
|
* Returns the subdomain of a hostname string
|
|
*
|
|
* @api
|
|
* @param {string} hostname
|
|
* @param {string} domain - the root domain of the hostname
|
|
* @return {string|null} a subdomain string if any, blank string if subdomain
|
|
* is empty, otherwise null.
|
|
*/
|
|
module.exports = function getSubdomain(hostname, domain) {
|
|
// No domain found? Just abort, abort!
|
|
if (domain === null) {
|
|
return null;
|
|
}
|
|
|
|
return hostname.substr(0, hostname.length - domain.length - 1);
|
|
};
|