i18n-element/webpack.config.js

I18N Base Element for lit-html and Polymer

const merge = require('webpack-merge');
const Clean = require('clean-webpack-plugin');
const MinifyPlugin = require('babel-minify-webpack-plugin');

module.exports = () => {
  return merge(
    {
      entry: './i18n.js',
      output: {
        filename: 'i18n.bundled-not-usable-as-it-is.js'
      },
      module: {
        rules: [
          {
            test: /\.js$/,
            loader: require.resolve('@open-wc/webpack-import-meta-loader'),
          },
          {
            test: /\.js$/,
            loader: 'babel-loader',
            options: {
              plugins: [
                '@babel/plugin-syntax-dynamic-import',
                '@babel/plugin-syntax-import-meta',
              ],
              presets: [
                [
                  '@babel/preset-env',
                  {
                    targets: {
                      'chrome': '72',
                    }
                  }
                ]
              ]
            }
          }
        ]
      },
      plugins: [
        new MinifyPlugin({
          // Options from polymer-build/src/js-transform.ts
          // Disable the minify-constant-folding plugin because it has a bug relating
          // to invalid substitution of constant values into export specifiers:
          // https://github.com/babel/minify/issues/820
          evaluate: false,

          // TODO(aomarks) Find out why we disabled this plugin.
          simplifyComparisons: false,

          // Prevent removal of things that babel thinks are unreachable, but sometimes
          // gets wrong: https://github.com/Polymer/tools/issues/724
          deadcode: false,

          // Disable the simplify plugin because it can eat some statements preceeding
          // loops. https://github.com/babel/minify/issues/824
          simplify: false,

          // This is breaking ES6 output. https://github.com/Polymer/tools/issues/261
          mangle: false, /*{ // risky mangling options
            keepClassName: true,
          },*/
        }, {}),
        new Clean(['dist'])
      ],
    },
  );
};