webpack.config.js

const path = require('path')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const VueLoaderPlugin = require('vue-loader/lib/plugin')

module.exports = function(webpackEnv, options) {
  const isEnvDevelopment = options.mode === 'development'
  const isEnvProduction = options.mode === 'production'
  const outputPath = isEnvProduction ? __dirname + '/dist' : __dirname + '/dev'

  console.log(outputPath)

  return {
    // モードの設定、v4系以降はmodeを指定しないと、webpack実行時に警告が出る
    mode: 'development',
    // エントリーポイントの設定
    entry: {
      popup: ['./src/popup.js'], // メイン部分はここに記載
      contents: ['./src/contents.js'], // contents script はここに記載
      background: ['./src/background.js'] // background はここに記載
    },
    output: {
      // The build folder.
      // path: isEnvProduction ? paths.appBuild : undefined,
      // path: isEnvProduction ? __dirname + '/dist' : __dirname + '/dev',
      // filename: isEnvProduction
      //   ? '[name].js'
      //   : isEnvDevelopment && '[name].js',

      filename: '[name].js',
      path: outputPath
    },
    module: {
      rules: [
        {
          test: /\.js$/,
          exclude: /node_modules/,
          use: {
            loader: 'babel-loader'
          }
        },
        {
          test: /\.vue$/,
          loader: 'vue-loader'
        },
        {
          test: /\.css$/,
          use: ['style-loader', 'css-loader']
        }
      ]
    },
    resolve: {
      alias: {
        vue$: 'vue/dist/vue.esm.js'
      }
    },
    plugins: [
      new VueLoaderPlugin(),
      new CopyWebpackPlugin([
        {
          from: './src/_locales',
          to: outputPath + '/_locales'
        }
      ]),
      new CopyWebpackPlugin([
        {
          from: './src/icon',
          to: outputPath + '/icon'
        }
      ]),
      new CopyWebpackPlugin([
        {
          context: 'src',
          from: '**/*.html',
          to: outputPath
        }
      ]),
      new CopyWebpackPlugin([
        {
          context: 'src',
          from: '**/manifest.json',
          to: outputPath
        }
      ])
    ],
    devServer: {
      contentBase: path.join(__dirname, 'dist'),
      compress: true,
      port: 3000
    }
  }
}