From eb25cf4cb533a531c53bbb9eb9bde0430665de9c Mon Sep 17 00:00:00 2001
From: Tim Neutkens <tim@timneutkens.nl>
Date: Sun, 6 May 2018 18:39:29 +0200
Subject: [PATCH] Support Node 6 again. check if async/await is supported
 (#4283)

---
 server/index.js                  |  3 ++-
 server/lib/is-async-supported.js | 12 ++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 server/lib/is-async-supported.js

diff --git a/server/index.js b/server/index.js
index cf7d0023..c5f28bcb 100644
--- a/server/index.js
+++ b/server/index.js
@@ -21,6 +21,7 @@ import pkg from '../../package'
 import * as asset from '../lib/asset'
 import * as envConfig from '../lib/runtime-config'
 import { isResSent } from '../lib/utils'
+import isAsyncSupported from './lib/is-async-supported'
 
 const access = promisify(fs.access)
 
@@ -113,7 +114,7 @@ export default class Server {
   }
 
   async prepare () {
-    if (this.dev && process.stdout.isTTY) {
+    if (this.dev && process.stdout.isTTY && isAsyncSupported()) {
       try {
         const checkForUpdate = require('update-check')
         const update = await checkForUpdate(pkg, {
diff --git a/server/lib/is-async-supported.js b/server/lib/is-async-supported.js
new file mode 100644
index 00000000..394a2688
--- /dev/null
+++ b/server/lib/is-async-supported.js
@@ -0,0 +1,12 @@
+// based on https://github.com/timneutkens/is-async-supported
+const vm = require('vm')
+
+module.exports = function isAsyncSupported () {
+  try {
+    // eslint-disable-next-line no-new
+    new vm.Script('(async () => ({}))()')
+    return true
+  } catch (e) {
+    return false
+  }
+}