Webpack production build: Unexpected token - reactjs

Question

I have been trying to deploy my production build with webpack but I can't get it done. I almost read and tried everything and can't make it work.
This is the last error that I have:
My webpack configuration looks like this:
const path = require('path');
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const PreloadWebpackPlugin = require('preload-webpack-plugin');
const ScriptExtHtmlWebpackPlugin = require('script-ext-html-webpack-plugin');
const StyleExtHtmlWebpackPlugin = require('style-ext-html-webpack-plugin');
const CompressionPlugin = require('compression-webpack-plugin');
const autoprefixer = require('autoprefixer');
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
const staticSourcePath = path.join(__dirname, 'static');
const sourcePath = path.join(__dirname, 'src');
const buildPath = path.join(__dirname, 'dist');
module.exports = {
devtool: 'cheap-module-source-map',
entry: {
// base: path.resolve(staticSourcePath, 'src/sass/base.scss'),
app: path.resolve(sourcePath, 'index.prod.jsx')
},
output: {
path: path.join(__dirname, 'dist'),
filename: '[name].[chunkhash].js',
publicPath: '/'
},
resolve: {
extensions: ['.webpack-loader.js', '.web-loader.js', '.loader.js', '.js', '.jsx'],
modules: [
sourcePath,
path.resolve(__dirname, 'node_modules')
]
},
plugins: [
new webpack.DefinePlugin({
'process.env.NODE_ENV': JSON.stringify('production')
}),
new webpack.optimize.ModuleConcatenationPlugin(),
new webpack.optimize.CommonsChunkPlugin({
name: 'vendor',
filename: 'vendor.[chunkhash].js',
minChunks(module) {
return module.context && module.context.indexOf('node_modules') >= 0;
}
}),
new UglifyJsPlugin({
sourceMap: true,
uglifyOptions: {
ecma: 8,
compress: {
warnings: false
}
}
}),
new webpack.LoaderOptionsPlugin({
options: {
postcss: [
autoprefixer({
browsers: [
'last 3 version',
'ie >= 10'
]
})
],
context: staticSourcePath
}
}),
new webpack.HashedModuleIdsPlugin(),
new HtmlWebpackPlugin({
template: path.join(__dirname, 'src', 'index.html'),
path: buildPath,
excludeChunks: ['base'],
// filename: 'index.html',
minify: {
collapseWhitespace: true,
collapseInlineTagWhitespace: true,
removeComments: true,
removeRedundantAttributes: true
}
}),
new PreloadWebpackPlugin({
rel: 'preload',
as: 'script',
include: 'all',
fileBlacklist: [/\.(css|map)$/, /base?.+/]
}),
new ScriptExtHtmlWebpackPlugin({
defaultAttribute: 'defer'
}),
new ExtractTextPlugin({
filename: '[name].[contenthash].css',
allChunks: true
}),
new CompressionPlugin({
asset: '[path].gz[query]',
algorithm: 'gzip',
test: /\.js$|\.jsx$|\.css$|\.html$|\.eot?.+$|\.ttf?.+$|\.woff?.+$|\.svg?.+$/,
threshold: 10240,
minRatio: 0.8
})
],
module: {
rules: [
{
test: /\.css$/,
use: ['style-loader', 'css-loader']
},
{
test: /\.(png|jp(e*)g|svg)$/,
use: [{
loader: 'url-loader',
options: {
limit: 8000, // Convert images < 8kb to base64 strings
name: 'images/[hash]-[name].[ext]'
}
}]
},
{
test: /\.(js|jsx)$/,
loader: "babel-loader",
exclude: /node_modules/,
query: {
presets: ["es2015", "react", "env"],
plugins: [
"transform-object-rest-spread",
"transform-class-properties"
]
}
},
{
test: /\.(eot?.+|svg?.+|ttf?.+|otf?.+|woff?.+|woff2?.+)$/,
use: 'file-loader?name=assets/[name]-[hash].[ext]'
},
{
test: /\.(png|gif|jpg|svg)$/,
use: [
'url-loader?limit=20480&name=assets/[name]-[hash].[ext]'
],
include: staticSourcePath
}
]
}
};
I tried changing the presets of babel. I don't know if it could be a problem with the library query-string but even when I don't use it the error persists.
I also tried almost all configurations from https://github.com/webpack-contrib/uglifyjs-webpack-plugin/issues/104 and can't make it work :C....
I hope someone can help me I have been fighting with this error since weekend and im near to kill myself T_T

Answer 1

Already tried babel-polyfill and dont work :(
Just updated to webpack 4 and solved my problem. To many people have this kind of error with webpack < 4.
I will leave my webpack 4 configuration here for those who had suffered like me
webpack.config.js
const HtmlWebPackPlugin = require("html-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const CompressionPlugin = require('compression-webpack-plugin');
module.exports = {
entry: ["babel-polyfill", "./src/index.js"],
resolve: {
extensions: ['.js', '.jsx']
},
output: {
publicPath: '/'
},
module: {
rules: [
{
test: /\.(js|jsx)$/,
exclude: /node_modules/,
use: {
loader: "babel-loader"
}
},
{
test: /\.(png|jp(e*)g|svg)$/,
use: [{
loader: 'url-loader',
options: {
limit: 8000, // Convert images < 8kb to base64 strings
name: 'images/[hash]-[name].[ext]'
}
}]
},
{
test: /\.html$/,
use: [
{
loader: "html-loader",
options: { minimize: true }
}
]
},
{
test: /\.css$/,
use: [MiniCssExtractPlugin.loader, "css-loader"]
}
]
},
devServer: {
// host: '0.0.0.0', /******* Para ver en lan*/
// disableHostCheck: true,/****** Para ver en lan */
historyApiFallback: true,
},
plugins: [
new HtmlWebPackPlugin({
template: "./src/index.html",
filename: "./index.html"
}),
new MiniCssExtractPlugin({
filename: "[name].css",
chunkFilename: "[id].css"
}),
new CompressionPlugin({
asset: '[path].gz[query]',
algorithm: 'gzip',
test: /\.js$|\.css$|\.html$|\.eot?.+$|\.ttf?.+$|\.woff?.+$|\.svg?.+$/,
threshold: 10240,
minRatio: 0.8
})
]
};
package.json
"scripts": {
"start": "webpack-dev-server --mode development --open",
"build": "webpack --mode production"
},
"devDependencies": {
"babel-core": "^6.26.0",
"babel-loader": "^7.1.4",
"babel-plugin-transform-class-properties": "^6.24.1",
"babel-plugin-transform-object-rest-spread": "^6.26.0",
"babel-plugin-transform-regenerator": "^6.26.0",
"babel-preset-env": "^1.6.1",
"babel-preset-react": "^6.24.1",
"compression-webpack-plugin": "^1.1.11",
"css-loader": "^0.28.11",
"html-loader": "^0.5.5",
"html-webpack-plugin": "^3.0.7",
"mini-css-extract-plugin": "^0.2.0",
"react": "^16.3.0",
"react-dom": "^16.3.0",
"url-loader": "^1.0.1",
"webpack": "^4.2.0",
"webpack-cli": "^2.0.12",
"webpack-dev-server": "^3.1.1"
},
.babelrc
{
"presets": [
"env",
"react"
],
"plugins": [
"transform-object-rest-spread",
"transform-class-properties",
"transform-regenerator"
]
}

Answer 2

In my experience, it's usually Uglify being too aggressive.
I noticed that in your answer, you've swapped out Uglify for compression-webpack-plugin. That's probably what made the bug go away.
In your original package.json, I'd change the Uglify config to
new UglifyJsPlugin({
sourceMap:true,
cache: true,
parallel: true,
uglifyOptions:{
ecma:8
}
}),
First, you want to see Uglify's warnings. It'll tell you if there's code that's likely to get clobbered by the minification / obfuscation algorithm. If there are, you may have to play with the compress, mangle, toplevel or keep_fnames options depending on how your code is structured. https://github.com/mishoo/UglifyJS2#minify-options
I understand that this might show a lot of warnings from 3rd party libraries. There's a couple things you can do:
Find alternative libs that minify correctly (they'll probably be higher quality anyways).
Import the already minified versions of the lib from /dist instead of from /src and then exclude the lib from the Uglify plugin
The settings for cache and parallel just make the minification run a bit faster.

Answer 3

Sometimes such a problem may be a result of the non-transpiled packages (excluded from transpiling).
To solve this you should include these packages to transpiled code:
rules: [
...
test: /\.jsx?$/,
exclude(resource) {
return (
/node_modules/.test(resource)
&& !/node_modules\/(query-string|strict-uri-encode|split-on-first)/.test(resource)
);
},
...
]