Revert "Upgrade to Babel 6 and apply fewer transformations when transpiling babel files"

src/babel.js

@@ -6,7 +6,6 @@ var defaultOptions = require('../static/babelrc.json')
 
 var babel = null
 var babelVersionDirectory = null
-var options = null
 
 var PREFIXES = [
   '/** @babel */',
@@ -48,27 +47,16 @@ exports.compile = function (sourceCode, filePath) {
     var noop = function () {}
     Logger.prototype.debug = noop
     Logger.prototype.verbose = noop
-
-    options = {ast: false, babelrc: false}
-    for (var key in defaultOptions) {
-      if (key === 'plugins') {
-        const plugins = []
-        for (const [pluginName, pluginOptions] of defaultOptions[key]) {
-          plugins.push([require.resolve(`babel-plugin-${pluginName}`), pluginOptions])
-        }
-        options[key] = plugins
-      } else {
-        options[key] = defaultOptions[key]
-      }
-    }
   }
 
   if (process.platform === 'win32') {
     filePath = 'file:///' + path.resolve(filePath).replace(/\\/g, '/')
   }
 
-  options.filename = filePath
-
+  var options = {filename: filePath}
+  for (var key in defaultOptions) {
+    options[key] = defaultOptions[key]
+  }
   return babel.transform(sourceCode, options).code
 }