ran npm run tdd & generated TDD

test/runAsync/runAsync.js

@@ -0,0 +1,16 @@
+module.exports = fn => {
+const blob = `var fn = ${fn.toString()}; postMessage(fn());`;
+const worker = new Worker(
+URL.createObjectURL(new Blob([blob]), {
+type: 'application/javascript; charset=utf-8'
+})
+);
+return new Promise((res, rej) => {
+worker.onmessage = ({ data }) => {
+res(data), worker.terminate();
+};
+worker.onerror = err => {
+rej(err), worker.terminate();
+};
+});
+};