Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Weird warnings with v1.0.0 and Webpack 5

See original GitHub issue

Operating System: Windows 10
Node Version: 14.9.0
NPM Version: 6.14.8
webpack Version: any above 5.0.0
mini-css-extract-plugin Version: 1.0.0

Expected Behavior

Clean build, without warnings, which happens with version 0.12.0, but doesn’t happen with 1.0.0

Actual Behavior

While 0.12.0 builds ok, verision 1.0.0 (without touching anything else in the setup) rises the following warning :

export 'default' (reexported as 'default') was not found in '-!../../node_modules/mini-css-extract-plugin/dist/loader.js!../../node_modules/css-loader/dist/cjs.js!../../node_module s/vue-loader/dist/stylePostLoader.js!../../node_modules/postcss-loader/dist/cjs.js??clonedRuleSet-3.use[2]!../../node_modules/sass-loader/dist/cjs.js!../../node_modules/vue-loader/ dist/index.js??ruleSet[1].rules[10].use[0]!./HelloWorld.vue?vue&type=style&index=0&id=469af010&scoped=true&lang=scss' (possible exports: )

webpack.config.js


module.exports = (env, argv) => {
	const production = argv && argv.mode && argv.mode !== "development";

	const {VueLoaderPlugin} = require("vue-loader");
	const htmlWebpackPlugin = require("html-webpack-plugin");
	const MiniCssExtractPlugin = require("mini-css-extract-plugin");
	const OptimizeCssAssetsPlugin = require('optimize-css-assets-webpack-plugin');
	const {CleanWebpackPlugin} = require("clean-webpack-plugin");
	const autoprefixer = require("autoprefixer");
	const TerserPlugin = require("terser-webpack-plugin");
	const webpack = require('webpack');
	const path = require("path");

	const postcssOpts = {
		postcssOptions: {
			plugins: [
				autoprefixer
			]
		}
	};

	return {
		entry:        path.resolve(__dirname, 'src/main.js'),
		output:       {
			filename: 'js/[name].js',
			path:     path.resolve(__dirname, 'dist/'),
			publicPath: '/'
		},
		resolve:      {
			alias: {
				'@': path.resolve(__dirname, 'src')
			}
		},
		module:       {
			rules: [
				{
					test:    /\.js$/,
					exclude: /node_modules/,
					use:     {
						loader:  "babel-loader",
						options: {
							presets: [['@babel/preset-env']],
							plugins: ['@babel/plugin-transform-destructuring', '@babel/plugin-proposal-object-rest-spread', '@babel/plugin-transform-template-literals'],
							babelrc: false
						}
					}
				},
				{
					test:   /\.vue$/,
					loader: "vue-loader"
				}, {
					test: /\.css$/,
					use:  [
						{loader: MiniCssExtractPlugin.loader},
						{loader: 'css-loader'},
						{
							loader:  "postcss-loader",
							options: postcssOpts
						}
					]
				}, {
					test: /\.scss$/,
					use:  [
						{loader: MiniCssExtractPlugin.loader},
						{loader: 'css-loader'},
						{
							loader:  "postcss-loader",
							options: postcssOpts
						},
						{loader: 'sass-loader'}
					]
				}, {
					test: /\.html$/,
					use:  [
						{
							loader:  'html-loader',
							options: {minimize: true}
						}
					]
				}, {
					test:    /\.(eot|ttf|woff|woff2)(\?\S*)?$/,
					loader:  "file-loader",
					options: {
						context:    'src/assets/fonts',
						name:       "[path][name].[ext]",
						outputPath: "fonts"
					}
				}, {
					test:    /\.(png|jpe?g|gif|webm|mp4|svg)$/,
					loader:  "file-loader",
					options: {
						context:    'src/assets/img',
						name:       "[path][name].[ext]",
						outputPath: "img"
					}
				}
			]
		},
		plugins:      [
			new VueLoaderPlugin(),
			new CleanWebpackPlugin(),
			new webpack.DefinePlugin(
				{
					__VUE_OPTIONS_API__:   false,
					__VUE_PROD_DEVTOOLS__: false
				}
			),
			new MiniCssExtractPlugin(
				{
					filename: 'css/[name].css',
					esModule: false
				}
			),
			new OptimizeCssAssetsPlugin(),
			new htmlWebpackPlugin(
				{
					template: path.resolve(__dirname, "public", "index.html"),
					favicon:  "./public/favicon.ico"
				}
			)
		],
		optimization: {
			minimize:    production,
			minimizer:   [
				new TerserPlugin(
					{
						parallel:      true,
						terserOptions: {
							toplevel: true,
							output:   {
								beautify: false
							}
						}
					}
				)
			],
			sideEffects: true
		},

		performance: {
			hints: false
		},
		devServer:   {
			hot:  true,
			host: '127.0.0.1',
			writeToDisk: true
		}
	};
};