Refactor outputJsonSync

lib/json/output-json-sync.js

@@ -1,10 +1,12 @@
-var fs = require('graceful-fs')
-var path = require('path')
-var jsonFile = require('./jsonfile')
-var mkdir = require('../mkdirs')
+'use strict'
+
+const fs = require('graceful-fs')
+const path = require('path')
+const mkdir = require('../mkdirs')
+const jsonFile = require('./jsonfile')
 
 function outputJsonSync (file, data, options) {
-  var dir = path.dirname(file)
+  const dir = path.dirname(file)
 
   if (!fs.existsSync(dir)) {
     mkdir.mkdirsSync(dir)