Fiddler script to replace 127.0.0.1/localhost

CustomRules.js

    static function replaceLocalHost(str) {
        str = str.replace(/\/\/127\.0\.0\.1/gi, "//ipv4.fiddler");
        str = str.replace(/\/\/localhost/gi, "//localhost.fiddler");
        return str;
    }
    
    static function OnBeforeResponse(oSession: Session) {
        if (oSession.HostnameIs("localhost.fiddler") || oSession.HostnameIs("ipv4.fiddler")) {
            if (oSession.oResponse.headers.Exists("Location")) {
                var location = oSession.oResponse.headers["Location"];
                oSession.oResponse.headers["Location"] = replaceLocalHost(location);
            }
            
            if (oSession.oResponse.headers.ExistsAndContains("Content-Type", "html")) {
                oSession.utilDecodeResponse();
                var body = System.Text.Encoding.UTF8.GetString(oSession.responseBodyBytes);
                oSession.utilSetResponseBody(replaceLocalHost(body));
            }
        }
    }