build/webpack.dev.js

const webpack = require('webpack')

const config = require('./webpack.base')

config.mode = 'development'
config.output.filename = 'eruda.js'
config.devtool = false
// config.devtool = 'source-map'
config.plugins = config.plugins.concat([
  new webpack.DefinePlugin({
    ENV: '"development"',
  }),
])

// ここを追加
config.devServer = {
  allowedHosts: 'all',   // 全ホストを許可。開発環境用です。
}

module.exports = config