重新添加babel

package.json

@@ -11,6 +11,9 @@
     "webpack-cli": "^3.3.1"
   },
   "devDependencies": {
+    "@babel/core": "^7.4.4",
+    "@babel/preset-env": "^7.4.4",
+    "babel-loader": "^8.0.5",
     "clean-webpack-plugin": "^2.0.1",
     "css-loader": "^2.1.1",
     "express": "^4.16.4",
@@ -20,6 +23,7 @@
     "less-loader": "^4.1.0",
     "mini-css-extract-plugin": "^0.6.0",
     "style-loader": "^0.23.1",
+    "webpack": "^4.31.0",
     "webpack-dev-middleware": "^3.6.2",
     "webpack-dev-server": "^3.3.1"
   },

webpack.config.js

@@ -135,16 +135,16 @@ module.exports = {
         test: /\.js$/,
         use: "imports-loader?$=jquery"
       },
-      // {
-      //   test: /\.m?js$/,
-      //   exclude: /(node_modules|bower_components)/,
-      //   use: {
-      //     loader: 'babel-loader',
-      //     options: {
-      //       presets: ['@babel/preset-env']
-      //     }
-      //   }
-      // },
+      {
+        test: /\.m?js$/,
+        exclude: /(node_modules|bower_components)/,
+        use: {
+          loader: 'babel-loader',
+          options: {
+            presets: ['@babel/preset-env']
+          }
+        }
+      },
       {
         test: /\.css$/,
         use: [{