Function checkSession

www/integration/main.js:83–103

(oldKey, cb)

        //var isNew = false;
        var checkSession = function (oldKey, cb) {
            var channel = Hash.hrefToHexChannelId(Hash.hashToHref(oldKey));
            var prefix = channel.slice(0,2);
            var url = `/datastore/${prefix}/${channel}.ndjson`;

            var http = new XMLHttpRequest();
            http.open('HEAD', url);
            http.onreadystatechange = function() {
                if (this.readyState === this.DONE) {
                    if (devMode) { console.error(oldKey, this.status); }
                    if (this.status === 200) {
                        return cb({state: true});
                    }
                    if (this.status === 404) {
                        return cb({state: false});
                    }
                    cb({error: 'Internal server error'});
                }
            };
            http.send();
        };
        let sanitizeKey = key => {
            try {
                Util.decodeBase64(key.replace(/-/g, '/'));