Refactor babel plugin initialization in moduleEnv.js

lib/moduleEnv.js

@@ -3,14 +3,15 @@
 var Module = require("module"),
     fs = require("fs"),
     babelCore = require("babel-core"),
-    // Requiring the babel plugin here because otherwise it will be lazy-loaded by Babel during rewire()
-    transformBlockScoping = require("babel-plugin-transform-es2015-block-scoping"),
     coffee;
 
 var moduleWrapper0 = Module.wrapper[0],
     moduleWrapper1 = Module.wrapper[1],
     originalExtensions = {},
-    matchCoffeeExt = /\.coffee$/,
+    babelPlugins = [
+        "babel-plugin-transform-es2015-block-scoping",
+        "babel-plugin-transform-object-rest-spread"
+    ],
     nodeRequire,
     currentModule;
 
@@ -76,10 +77,7 @@ function jsExtension(module, filename) {
 
     module._compile = function (content, filename) {
         content = babelCore.transform(content, {
-            plugins: [
-                require.resolve("babel-plugin-transform-es2015-block-scoping"),
-                require.resolve("babel-plugin-transform-object-rest-spread")
-            ],
+            plugins: babelPlugins,
             retainLines: true,
             filename: filename,
             babelrc: false
@@ -115,6 +113,9 @@ function stripBOM(content) {
     return content;
 }
 
+// Prepopulate require.cache with babel plugins because otherwise it will be lazy-loaded by Babel during rewire()
+babelPlugins.forEach(require);
+
 try {
     coffee = require("coffee-script");
 } catch (err) {