fix update.js after vue core build setup change

Author: yyx990803

update.js

@@ -1,4 +1,5 @@
 var fs = require('fs')
+var zlib = require('zlib')
 var version = require('../vue/package.json').version
 var themeconfPath = 'themes/vue/_config.yml'
 var installPath = 'src/v2/guide/installation.md'
@@ -13,20 +14,39 @@ fs.writeFileSync(
 var sizes = {
   dev: 'vue.js',
   min: 'vue.min.js',
-  gz: 'vue.min.js.gz',
-  ro_gz: 'vue.common.min.js.gz'
+  gz: 'vue.min.js',
+  ro_gz: 'vue.runtime.min.js'
 }
 
-for (var file in sizes) {
+var pending = []
+Object.keys(sizes).forEach(file => {
   var filesize = fs.statSync('../vue/dist/' + sizes[file], 'utf-8').size
-  sizes[file] = (filesize / 1024).toFixed(2)
-}
+  if (!/gz$/.test(file)) {
+    sizes[file] = (filesize / 1024).toFixed(2)
+  } else {
+    pending.push(new Promise((resolve, reject) => {
+      fs.readFile('../vue/dist/' + sizes[file], (err, buf) => {
+        if (err) return reject(err)
+        zlib.gzip(buf, (err, buf) => {
+          if (err) return reject(err)
+          sizes[file] = (buf.length / 1024).toFixed(2)
+          resolve()
+        })
+      })
+    }))
+  }
+})
 
-fs.writeFileSync(
-  installPath,
-  installation
-    .replace(/vue_version: .*/, 'vue_version: ' + version)
-    .replace(/(\w+)_size:.*/g, function (m, p1) {
-      return p1 + '_size: "' + sizes[p1] + '"'
-    })
-)
+Promise.all(pending).then(() => {
+  fs.writeFileSync(
+    installPath,
+    installation
+      .replace(/vue_version: .*/, 'vue_version: ' + version)
+      .replace(/(\w+)_size:.*/g, function (m, p1) {
+        return p1 + '_size: "' + sizes[p1] + '"'
+      })
+  )
+  console.log(sizes)
+}).catch(err => {
+  console.error(err)
+})