webpack.config.js

/*eslint-env node*/
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const postcssPresetEnv = require('postcss-preset-env')
const postcssAssets = require('postcss-assets')
const postcssCopy = require('postcss-copy')
const postcss = require('postcss')
const path = require('path')

module.exports = {
  mode: 'production',
  entry: './src/index.ts',
  output: {
    path: path.resolve(__dirname, 'lib'),
    filename: 'index.js',
    library: 'decentralandUI',
    libraryTarget: 'umd'
  },
  resolve: {
    extensions: ['.ts', '.tsx', '.js', '.jsx']
  },
  externals: {
    react: {
      commonjs: 'react',
      commonjs2: 'react',
      amd: 'react',
      root: 'React'
    }
  },
  module: {
    rules: [
      {
        test: /\.css$/,
        use: [
          MiniCssExtractPlugin.loader,
          { loader: 'css-loader', options: { importLoaders: 1 } },
          {
            loader: 'postcss-loader',
            options: {
              ident: 'postcss',
              plugins: () => [
                postcssPresetEnv({
                  stage: 4
                }),
                postcssAssets()
              ]
            }
          }
        ]
      },
      {
        test: /\.tsx?$/,
        use: ['ts-loader']
      },
      {
        test: /\.(woff|woff2|eot|ttf|otf)$/,
        use: {
          loader: 'file-loader',
          options: { esModule: false }
        }
      },
      {
        test: /\.(png|svg|jpg|gif)$/,
        use: [
          {
            loader: 'url-loader',
            options: {
              limit: 8192,
              esModule: false
            }
          }
        ]
      }
    ]
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: 'styles.css'
    }),
    new CopyWebpackPlugin([{ 
        from: 'src/themes/alternative', 
        to: './',
        // transform themes file because now they contain a relative path to the assets
        transform: (content, path) => {
            return postcss([
              postcssPresetEnv({
                stage: 4
              }),
              postcssAssets(),
              postcssCopy({
                dest: './lib/'
              })
            ])
            .process(content, { from: path })
            .then(result => {
              return result.css
            })
        }}
    ])
  ]
}