[UPDATE] runAsync.md

snippets/runAsync.md

@@ -8,10 +8,7 @@ Return a promise, listening for `onmessage` and `onerror` events and resolving t
 
 ```js
 const runAsync = fn => {
-  const blob = `
-    var fn = ${fn.toString()};
-    this.postMessage(fn());
-  `;
+  const blob = `var fn = ${fn.toString()}; postMessage(fn());`;
   const worker = new Worker(
     URL.createObjectURL(new Blob([blob]), {
       type: 'application/javascript; charset=utf-8'
@@ -31,9 +28,9 @@ const runAsync = fn => {
 ```js
 const longRunningFunction = () => {
   let result = 0;
-  for (var i = 0; i < 1000; i++) {
-    for (var j = 0; j < 700; j++) {
-      for (var k = 0; k < 300; k++) {
+  for (let i = 0; i < 1000; i++) {
+    for (let j = 0; j < 700; j++) {
+      for (let k = 0; k < 300; k++) {
         result = result + i + j + k;
       }
     }