Can't Add Relay URI with Port Definition

[henrixd7]

When I try to use ws://dev.local:7777 as a relay, I receive the following error: "Please provide a valid relay URL."

This error is triggered by the isShareableRelayUrl function in node_modules/@welshman/util/build/Relay.mjs:

export const isShareableRelayUrl = (url) => {
    var _a;
    return Boolean(typeof url === 'string' &&
        // Is it actually a websocket url and has a dot
        url.match(/^wss:\/\/.+\..+/) &&
        // Sometimes bugs cause multiple relays to get concatenated
        ((_a = url.match(/:\/\//g)) === null || _a === void 0 ? void 0 : _a.length) === 1 &&
        // It shouldn't have any whitespace, url-encoded or otherwise
        !url.match(/\s|%/) &&
        // Don't match stuff with a port number
        !url.slice(6).match(/:\d+/) &&
        // Don't match stuff with a numeric tld
        !url.slice(6).match(/\.\d+\b/) &&
        // Don't match raw ip addresses
        !url.slice(6).match(/\d+\.\d+\.\d+\.\d+/) &&
        // Skip nostr.wine's virtual relays
        !url.slice(6).match(/\/npub/));
};

The relevant part is:

// Don't match stuff with a port number
!url.slice(6).match(/:\d+/) &&

This doesn't seem right. ws://dev.local:7777 is a valid relay URI and should be allowed.

My intention is to use a local cache relay as read-only and other relays as write-only to achieve the fastest possible experience with my locally running client.