How to include node module for Babel using Webpack

Question

when running

npm run build

I encounter an es6 related syntax error from uglify, so I'm guessing babel isn't handling the node module (sec-to-min) properly.

My .babelrc

{
  "presets": ["es2015", "stage-0"],
  "plugins": ["transform-runtime"],
  "comments": false,
  "env": {
    "test": {
      "plugins": [ "istanbul" ]
    }
  }
}

My Webpack config:

var path = require('path')
var config = require('../config')
var utils = require('./utils')
var projectRoot = path.resolve(__dirname, '../')

var env = process.env.NODE_ENV
// check env & config/index.js to decide whether to enable CSS source maps for the
// various preprocessor loaders added to vue-loader at the end of this file
var cssSourceMapDev = (env === 'development' && config.dev.cssSourceMap)
var cssSourceMapProd = (env === 'production' && config.build.productionSourceMap)
var useCssSourceMap = cssSourceMapDev || cssSourceMapProd

module.exports = {
  entry: {
    app: './src/main.js'
  },
  output: {
    path: config.build.assetsRoot,
    publicPath: process.env.NODE_ENV === 'production' ? config.build.assetsPublicPath : config.dev.assetsPublicPath,
    filename: '[name].js'
  },
  resolve: {
    extensions: ['', '.js', '.vue', '.json'],
    fallback: [path.join(__dirname, '../node_modules')],
    alias: {
      'vue$': 'vue/dist/vue.common.js',
      'src': path.resolve(__dirname, '../src'),
      'assets': path.resolve(__dirname, '../src/assets'),
      'components': path.resolve(__dirname, '../src/components')
    }
  },
  resolveLoader: {
    fallback: [path.join(__dirname, '../node_modules')]
  },
  module: {
    preLoaders: [
      {
        test: /\.vue$/,
        loader: 'eslint',
        include: [
          path.join(projectRoot, 'src')
        ],
        exclude: /node_modules/
      },
      {
        test: /\.js$/,
        loader: 'eslint',
        include: [
          path.join(projectRoot, 'src')
        ],
        exclude: /node_modules/
      }
    ],
    loaders: [
      {
        test: /\.vue$/,
        loader: 'vue'
      },
      {
        test: /\.js$/,
        loader: 'babel',
        include: [
          path.join(projectRoot, 'src'),
          'node_modules/sec-to-min'
        ],
        exclude: /node_modules/
      },
      {
        test: /\.json$/,
        loader: 'json'
      },
      {
        test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
        loader: 'url',
        query: {
          limit: 10000,
          name: utils.assetsPath('img/[name].[hash:7].[ext]')
        }
      },
      {
        test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
        loader: 'url',
        query: {
          limit: 10000,
          name: utils.assetsPath('fonts/[name].[hash:7].[ext]')
        }
      }
    ]
  },
  eslint: {
    formatter: require('eslint-friendly-formatter')
  },
  vue: {
    loaders: utils.cssLoaders({ sourceMap: useCssSourceMap }),
    postcss: [
      require('autoprefixer')({
        browsers: ['last 2 versions']
      })
    ]
  }
}

& the ERR:

ERROR in static/js/vendor.8d64852626f0513309d9.js from UglifyJs SyntaxError: Unexpected token: operator (>) [./~/sec-to-min/index.js:3,0]

How can I direct babel to compile this module?

Answer 1

please note that on Windows the slashes in the path will be \ so the above solution would have to be changed to exclude: /node_modules\\(?!(sec-to-min)\/).*/

This was the solution that worked for me, with webpack 4.3 and babel-loader 8.0.5, and using the recommended @babel/preset-env, adapted from here https://github.com/webpack/webpack/issues/2031#issuecomment-283517150

{
            test: /\.(js|jsx|mjs)$/,
            include: [paths.appSrc, paths.appNodeModules],
            exclude: function(modulePath) {
              return (
                /node_modules/.test(modulePath) &&
                !/node_modules\\react-dev-utils/.test(modulePath)
              );
            },
            loader: require.resolve('babel-loader'),
            options: {
              compact: true,
              presets: ['@babel/preset-env']
            }
          },

I found it helpful to use the function for exclude as I was able to add console logs within the function to check which modules were being matched by the regex.