Function isStringAndStartsWith

app/assets/javascripts/setImmediate.js:131–133

(string, putativeStart)

        var MESSAGE_PREFIX = "com.bn.NobleJS.setImmediate" + Math.random();

        function isStringAndStartsWith(string, putativeStart) {
            return typeof string === "string" && string.substring(0, putativeStart.length) === putativeStart;
        }

        function onGlobalMessage(event) {
            // This will catch all incoming messages (even from other windows!), so we need to try reasonably hard to