Webpack - Uncaught SyntaxError: Unexpected token import with Redux - reactjs

I have been trying out React with Webpack and Redux and stumbled upon an
Uncaught SyntaxError: Unexpected token import.
I know that there is a lot of questions like these, but I have find none that involves Redux.
Here is my webpack config:
var app_root = 'src'; // the app root folder: src, src_users, etc
var path = require('path');
var CleanWebpackPlugin = require('clean-webpack-plugin');
module.exports = {
app_root: app_root, // the app root folder, needed by the other webpack
configs
entry: [
// http://gaearon.github.io/react-hot-loader/getstarted/
'webpack-dev-server/client?http://localhost:8080',
'webpack/hot/only-dev-server',
'babel-polyfill',
__dirname + '/' + app_root + '/index.js',
],
output: {
path: __dirname + '/public/js',
publicPath: 'js/',
filename: 'bundle.js',
},
module: {
loaders: [
{
test: /\.js$/,
loaders: ['react-hot', 'babel'],
exclude: /node_modules/,
},
{
// https://github.com/jtangelder/sass-loader
test: /\.scss$/,
loaders: ['style', 'css', 'sass'],
},
{
test: /\.css$/,
loaders: ['style', 'css'],
}
],
},
devServer: {
contentBase: __dirname + '/public',
},
plugins: [
new CleanWebpackPlugin(['css/main.css', 'js/bundle.js'], {
root: __dirname + '/public',
verbose: true,
dry: false, // true for simulation
}),
],
};
index.js file:
import React from 'react';
import ReactDOM from 'react-dom';
import { createStore} from 'redux';
// importera App komponenten
import App from './components/App';
// importera stylesheet
import './stylesheets/main.scss';
//importera reducer
import { reducers } from './reducers/index';
import Provider from "react-redux/src/components/Provider";
// skapa users-list, tomt objekt
let users = [];
for (let i = 1; i < 10; i++) {
// fyller objektet med användare med dessa villkor
users.push({
id: i,
username: 'Andreas' + i,
job: 'leethacker' + i,
});
const initialState = {
users: users,
}
}
// skapa Store
const store = createStore(reducers, initialState);
// skriver sedan ut denna komponent, render är Reacts funktion för att
skriva ut
ReactDOM.render(
<Provider store ={store}>
<App/>
</Provider> , document.getElementById('App'));
Package.json file:
{
"name": "redux-minimal",
"version": "1.0.0",
"description": "Start building complex react-redux apps today, with
this minimalist easy to understand starter kit (boilerplate)",
"keywords": [
"react",
"redux",
"minimal",
"starter kit",
"boilerplate"
],
"main": "index.js",
"homepage": "http://redux-minimal.js.org/",
"repository": {
"type": "git",
"url": "https://github.com/catalin-luntraru/redux-minimal"
},
"scripts": {
"start": "webpack-dev-server --inline --hot --history-api-fallback --
host localhost --port 8080",
"build-dev": "webpack --config webpack.dev.config.js",
"build-prod": "webpack -p --config webpack.prod.config.js",
"test": "mocha --recursive --compilers js:babel-register --require
babel-polyfill --require ignore-styles",
"test-watch": "npm test -- --watch"
},
"babel": {
"presets": [
"es2015",
"react",
"stage-3"
]
},
"author": "Catalin Luntraru",
"license": "MIT",
"dependencies": {
"react": "^15.4.2",
"react-bootstrap": "^0.30.7",
"react-dom": "^15.4.2",
"react-redux": "^5.0.2",
"react-router": "^3.0.1",
"react-router-bootstrap": "^0.23.1",
"react-router-redux": "^4.0.7",
"redux": "^3.6.0",
"redux-form": "^6.4.3",
"redux-saga": "^0.14.3"
},
"devDependencies": {
"babel-core": "^6.21.0",
"babel-loader": "^6.2.10",
"babel-polyfill": "^6.20.0",
"babel-preset-es2015": "^6.18.0",
"babel-preset-react": "^6.16.0",
"babel-preset-stage-3": "^6.17.0",
"babel-runtime": "^6.20.0",
"clean-webpack-plugin": "^0.1.15",
"css-loader": "^0.26.1",
"enzyme": "^2.7.0",
"extract-text-webpack-plugin": "^1.0.1",
"ignore-styles": "^5.0.1",
"mocha": "^3.2.0",
"node-sass": "^4.3.0",
"react-addons-test-utils": "^15.4.2",
"react-hot-loader": "^1.3.1",
"redux-freeze": "^0.1.5",
"sass-loader": "^4.1.1",
"style-loader": "^0.13.1",
"webpack": "^1.14.0",
"webpack-dev-server": "^1.16.2",
"whatwg-fetch": "^2.0.1"
}
}

The error line that I see is indicative of a error that is not being transpiled correct by babel.
See this please,
"unexpected token import" in Nodejs5 and babel?
Also, please add the index.js entry file, package.json to be more informative.
Hope this helps!

The error is in webpack.config.js ,as the babel loader is not included properly in config file.change your code as :
module: {
loaders: [
{ test: /\.(js|jsx)$/,
loader: 'babel-loader',
exclude: /node_modules/,
query: {
presets: ['react', 'es2015']
}
},

Related

Webpack with babel-loader doesn't recognize Typescript

I am using webpack and trying to leverage an existing React component library written in TS.
However, with the settings below, the webpack is giving 'unexpected Token' error. I copied the problematic code to babel online transpiler https://babeljs.io/repl/ but it is not showing any error.
I am very new to React development, any criticism/questions/answers are welcomed.
Thanks!
This is my webpack.config.js
var path = require("path")
var webpack = require('webpack')
var BundleTracker = require('webpack-bundle-tracker')
module.exports = {
context: __dirname,
entry: [
'webpack-dev-server/client?http://localhost:3000',
'webpack/hot/only-dev-server',
'./app/static/js/index'
],
output: {
path: path.resolve('./app/static/bundles/'),
filename: '[name]-[hash].js',
publicPath: 'http://localhost:3000/static/bundles/',
},
plugins: [
new webpack.HotModuleReplacementPlugin(),
new webpack.NoEmitOnErrorsPlugin(),
new BundleTracker({filename: './webpack-stats.json'}),
],
module: {
loaders: [
{
test: /\.(js|jsx)$/,
exclude: /node_modules/,
loader: ["babel-loader?presets[]=es2015,presets[]=react"],
},
{
test: /\.tsx?$/,
loader: 'ts-loader',
options: {
configFileName: './tsconfig.json'
},
exclude: /node_modules/
},
{
test: /\.css$/,
loader: 'style-loader!css-loader'
}
]
},
resolve: {
extensions: ['.js', '.jsx', '.ts', '.tsx', '.css']
}
}
My entry point file index.js:
import React from 'react';
import ReactDOM from 'react-dom';
import * as PropTypes from 'prop-types';
interface IDemoState {
value ?: string;
}
class Test extends React.Component<{}, IDemoState> {
state: IDemoState = {
value : 'general'
}
}
ReactDOM.render(<Test />, document.getElementById('tabnav'));
Package.json
{
"name": "djangoproject",
"version": "1.0.0",
"description": "Django Project",
"main": "index.js",
"scripts": {
"build": "webpack --config webpack.config.js --progress --colors",
"build-production": "webpack --config webpack.prod.config.js --progress --colors",
"watch": "node server.js"
},
"keywords": [
"Django"
],
"license": "ISC",
"devDependencies": {
"adp-css-framework": "^1.5.3",
"adp-react-components": "^1.4.3",
"adp-react-icons": "^1.16.0",
"babel": "^6.23.0",
"babel-cli": "^6.24.1",
"babel-core": "^6.25.0",
"babel-loader": "^7.1.0",
"babel-preset-env": "^1.5.2",
"babel-preset-es2015": "^6.24.1",
"babel-preset-react": "^6.24.1",
"css-loader": "^0.28.4",
"react": "^15.6.1",
"react-dom": "^15.6.1",
"react-hot-loader": "^1.3.1",
"style-loader": "^0.18.2",
"ts-loader": "^2.2.1",
"typescript": "^2.4.1",
"webpack": "^3.0.0",
"webpack-bundle-tracker": "^0.2.0",
"webpack-dev-server": "^2.5.0"
}
}
If I run npm run watch, I got this error:
ERROR in ./app/static/js/index.js
Module build failed: SyntaxError: xxxxx./app/static/js/index.js: Unexpected token (10:20)
8 |
9 | class Test extends React.Component<{}, IDemoState> {
> 10 | state: IDemoState = {
| ^
11 | value : 'general'
12 | }
13 | }
# multi webpack-dev-server/client?http://localhost:3000 webpack/hot/only-dev-se
rver ./app/static/js/index
The problem finally goes away after I changed the ts-loader to awesome-typescript-loader and write everything in a tsx file.

Karma mocha not recognizing JSX code

I am attempting to add automated testing to a react application using karma and mocha. The application is written using ES6 and JSX so I am also using webpack. I have imported the webpack config into the karma configuration settings, but I am still getting an error whenever I try to render a JSX component for testing:
Uncaught Error: Module parse failed: C:\Users\blahblahblah\app\tests\components\Clock.test.jsx Unexpected token (18:47)
You may need an appropriate loader to handle this file type.
| let testTime = 100;
| let expected = '00:01:40';
| let clock = TestUtils.renderIntoDocument(<Clock />);
| let actual = clock.formatTime(testTime);
|
at app/tests/components/Clock.test.jsx:74
Here are the files in question:
webpack.config.js
const path = require('path');
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const VENDOR_LIBS = [
'axios', 'react', 'react-dom',
'react-loading', 'react-router', 'moment'
];
module.exports = {
entry: {
bundle: [
'script-loader!jquery/dist/jquery.min.js',
'script-loader!foundation-sites/dist/js/foundation.min.js',
'./app/app.jsx',
], // compile app files to bundle.js
vendor: VENDOR_LIBS // compile vendor files to vendor.js
},
externals: {
jquery: 'jQuery'
},
output: {
path: path.join(__dirname, 'dist'),
filename: '[name].[chunkhash].js'
},
resolve: {
alias: {
appStyles: path.resolve(__dirname, 'app/styles/app.scss'),
Main: path.resolve(__dirname, 'app/components/Main.jsx'),
Nav: path.resolve(__dirname, 'app/components/Nav.jsx'),
Timer: path.resolve(__dirname, 'app/components/Timer.jsx'),
Countdown: path.resolve(__dirname, 'app/components/Countdown.jsx'),
Clock: path.resolve(__dirname, 'app/components/Clock.jsx'),
Controls: path.resolve(__dirname, 'app/components/Controls.jsx')
},
extensions: [".js", ".jsx"]
},
module: {
rules: [
{
use: 'babel-loader',
test: /\.jsx?$/,
exclude: /node_modules/
},
{
use: ['style-loader', 'css-loader', 'sass-loader'],
test: /\.scss$/
},
{
use: ['style-loader', 'css-loader'],
test: /\.css$/
}
]
},
plugins: [
new webpack.optimize.CommonsChunkPlugin({
names: ['vendor', 'manifest']
}),
new HtmlWebpackPlugin({
template: './app/index.html'
}),
new webpack.ProvidePlugin({
'$': 'jquery',
'jQuery': 'jquery'
})
],
devtool: 'cheap-module-eval-source-map'
}
karma.conf.js
const webpackConfig = require('./webpack.config.js');
module.exports = (config) => {
config.set({
browsers: ['Chrome'],
singleRun: true,
frameworks: ['mocha'],
files: ['app/tests/**/*.test.jsx'],
preprocessors: {
'app/tests/**/*.test.jsx': ['webpack', 'sourcemap']
},
reporters: ['mocha'],
client: {
mocha: { // after 5 seconds, if a test hasnt finished, cancel it
timeout: '5000'
},
webpack: webpackConfig, // use our established webpack config
webpackServer: {
noInfo: true
}
}
})
}
package.json
{
"name": "boilerplate",
"version": "1.0.0",
"description": "",
"main": "app.js",
"scripts": {
"test": "karma start",
"clean": "rimraf dist",
"build": "SET NODE_ENV=production npm run clean & webpack -p",
"serve": "webpack-dev-server"
},
"author": "",
"license": "MIT",
"dependencies": {
"axios": "^0.16.1",
"express": "^4.15.2",
"moment": "^2.18.1",
"react": "^15.4.2",
"react-dom": "^15.4.2",
"react-loading": "0.0.9",
"react-router": "^3.0.0"
},
"devDependencies": {
"babel-core": "^6.24.0",
"babel-loader": "^6.4.1",
"babel-preset-env": "^1.1.4",
"babel-preset-es2015": "^6.24.1",
"babel-preset-react": "^6.23.0",
"babel-preset-stage-0": "^6.24.1",
"colors": "^1.1.2",
"css-loader": "^0.28.1",
"expect": "^1.20.2",
"foundation-sites": "^6.3.1",
"html-webpack-plugin": "^2.28.0",
"jquery": "^3.2.1",
"karma": "^1.7.0",
"karma-chrome-launcher": "^2.1.1",
"karma-mocha": "^1.3.0",
"karma-mocha-reporter": "^2.2.3",
"karma-sourcemap-loader": "^0.3.7",
"karma-webpack": "^2.0.3",
"mocha": "^3.4.1",
"node-sass": "^4.5.3",
"react-addons-test-utils": "^15.5.1",
"rimraf": "^2.6.1",
"sass-loader": "^6.0.5",
"script-loader": "^0.7.0",
"style-loader": "^0.17.0",
"webpack": "^2.3.3",
"webpack-dev-middleware": "^1.10.2",
"webpack-dev-server": "^2.4.5"
}
}
.babelrc
{
"presets": ["react", "es2015", "stage-0"]
}
The test that keeps failing:
import React from 'react';
import ReactDOM from 'react-dom';
import TestUtils from 'react-dom/test-utils';
import expect from 'expect';
import $ from 'jQuery';
// Karma not recognizing webpack aliases
import Clock from 'babel-loader!./../../components/Clock.jsx';
describe('Clock Component', () => {
it('should exist', () => {
expect(Clock).toExist();
});
// THIS TEST KEEPS FAILING
describe('formatSeconds()', () => {
it('should format seconds to hh:mm:ss', () => {
let testTime = 100;
let expected = '00:01:40';
let clock = TestUtils.renderIntoDocument(<Clock />); // JSX = problem
let actual = clock.formatTime(testTime);
expect(actual).toBe(expected);
});
});
});

ERROR in multi ./main.js watch when running webpack

I get the following error when running:
webpack watch
ERROR in multi ./main.js watch
Module not found: Error: Can't resolve 'watch' in '/Users/name/directory/src'
# multi ./main.js watch
Heres my webpack.config.js file
const path = require('path');
module.exports = {
context: path.join(__dirname, 'src'),
entry: [
'./main.js',
],
output: {
path: path.join(__dirname, 'www'),
filename: 'bundle.js',
},
module: {
rules: [
{
test: /\.js$/,
include: [
path.resolve(__dirname, "src")
],
exclude: /node_modules/,
use: [
'babel-loader',
],
},
{
test: /\.scss$/,
exclude: /node_modules/,
use: [{
loader: "style-loader" // creates style nodes from JS strings
}, {
loader: "css-loader" // translates CSS into CommonJS
}, {
loader: "sass-loader" // compiles Sass to CSS
}]
}
],
},
resolve: {
modules: [
path.join(__dirname, 'node_modules'),
],
},
};
Here is my package.json
{
"name": "name",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"author": "",
"license": "ISC",
"dependencies": {
"react": "^15.4.2",
"react-dom": "^15.4.2",
"webpack-dev-middleware": "^1.10.1"
},
"devDependencies": {
"babel-core": "^6.24.0",
"babel-loader": "^6.4.1",
"babel-preset-es2015": "^6.24.0",
"babel-preset-latest": "^6.24.0",
"babel-preset-react": "^6.23.0",
"babel-preset-stage-2": "^6.22.0",
"css-loader": "^0.27.3",
"express": "^4.15.2",
"node-sass": "^4.5.0",
"react-helmet": "^4.0.0",
"react-hot-loader": "^1.3.1",
"sass-loader": "^6.0.3",
"style-loader": "^0.14.1",
"webpack": "^2.2.1",
"webpack-dev-middleware": "^1.10.1",
"webpack-dev-server": "^2.4.2"
}
}
Below is my main.js file
import "./styles/stylesheet.scss";
import { Header } from "./components/headercomponent";
import React from "react";
import ReactDOM from "react-dom";
import { render } from "react-dom";
class App extends React.Component {
render(){
return (
<div id="container">
<Header/>
<h1>hello world</h1>
</div>
);
}
}
render(<App/>, window.document.getElementById("app"));
Do you know why I'm getting the webpack error?
Arguments you pass to the webpack CLI will be treated as entry points. You want to use the --watch option, not add watch as an entry. The correct command is:
webpack --watch

Webpack large Bundle Size

I am facing issue due to large webpack bundle size.
The size of my bundle size is nearby 166 kb. I am running webpack with -p flag. Most of the size is due to bundling of react module in my bundle file. So, what I am trying to do is that I am making two bundles: one which contain my app specific code and the other one which contains minified version of the npm which do not change frequently.
My bundle size is now 20 Kb.
Here is my webpack config file :
var path = require('path');
var webpack = require("webpack");
var node_modules_dir = path.resolve(__dirname, 'node_modules');
var config = {
entry: path.resolve(__dirname, 'index.js'),
output: getOutput(),
plugins: [
new webpack.optimize.UglifyJsPlugin(),
new webpack.optimize.DedupePlugin(),
new webpack.DefinePlugin({
'process.env': {
'NODE_ENV': JSON.stringify('production')
}
})
],
devtool: process.env.NODE_ENV === 'production' ? false : "eval",
module: {
loaders: [
{
test: /\.scss$/,
include: /src/,
loaders: [
'style',
'css',
'autoprefixer?browsers=last 3 versions',
'sass?outputStyle=expanded'
]
},
{
test: /\.(jpe?g|png|gif|svg)$/i,
loaders: [
'url?limit=8192',
'img'
]
},
{
test: /\.jsx?$/,
exclude: (node_modules_dir),
loaders: [
'react-hot',
'babel-loader?presets[]=stage-0,presets[]=react,presets[]=es2015',
]
}, {
test: /\.css$/,
loader: 'style-loader!css-loader'
}
]
}
};
module.exports = config;
function getOutput() {
if (process.env.NODE_ENV === 'production') {
return {
path: path.resolve(__dirname, 'dist'),
filename: 'bundle.js'
}
} else {
return {
publicPath: 'http://localhost:3000/',
filename: 'dist/bundle.js'
}
}
}
and here is my code :
import {connect, Provider} from 'react-redux';
import React from "react"
import {createStore, combineReducers} from 'redux';
import reducers from "./reducers";
import {increment} from "./actions/App.js";
var store = createStore(
combineReducers({
...reducers
})
);
class App extends React.Component {
render() {
return <div>
<span>Value is : {this.props.value}</span>
<div onClick={this.props.increment}><span>Increment</span></div>
</div>
}
}
App = connect((state)=> {
return {value: state.app.value}
}, {increment})(App);
module.exports = React.createClass({
render: ()=> {
return <Provider store={store}><App /></Provider>
}
});
and here is my package.json file
{
"name": "Sample App",
"version": "0.0.1",
"private": true,
"scripts": {
"webpack-server": "webpack-dev-server --hot --progress --colors --port 3000",
"serve-web": "npm run webpack-server",
"deploy": "NODE_ENV=production webpack -p --optimize-minimize"
},
"dependencies": {
"babel-core": "6.9.0",
"babel-loader": "6.2.4",
"babel-plugin-transform-runtime": "6.9.0",
"babel-preset-es2015": "6.9.0",
"babel-preset-react": "6.5.0",
"babel-preset-stage-0": "6.5.0",
"babel-relay-plugin": "^0.9.1",
"babel-runtime": "6.9.0",
"css-loader": "^0.23.0",
"file-loader": "^0.8.5",
"http-server": "^0.8.0",
"img-loader": "^1.3.1",
"node-fetch": "^1.5.3",
"postcss-loader": "^0.8.0",
"react": "15.3.2",
"react-dom": "^15.1.0",
"react-hot-loader": "^1.2.8",
"react-redux": "^4.4.5",
"redux": "^3.6.0",
"source-map-loader": "^0.1.5",
"url-loader": "^0.5.7",
"webpack": "1.13.1",
"webpack-dev-server": "1.14.1"
},
"jest": {
"preset": "jest-react-native"
},
"devDependencies": {
"babel-cli": "6.9.0",
"babel-core": "^6.9.0",
"babel-loader": "^6.2.4"
},
"engines": {
"npm": ">=3"
}
}
So, I have changed
module.exports = require('./lib/React');
to
module.exports = window.React;
in react.js file of react module as other npm like redux is also using react npm.
Is it a good thing to apply this patch in react.js file of react npm?
Is it a good thing to make two bundles like this?
You can use source map explorer to detect what is the problem.
https://www.npmjs.com/package/source-map-explorer

Why do we need to use import 'babel-polyfill'; in react components?

I wonder if we user babel loader + all the presets, why do we need to include babel-polyfill anyway into our components? I just think that babel-loader should do all the job itself.
Examples were taken here https://github.com/reactjs/redux/tree/master/examples
What i am asking about is:
import 'babel-polyfill';
import React from 'react';
import { render } from 'react-dom';
import App from './containers/App';
Here is package example:
{
"name": "redux-shopping-cart-example",
"version": "0.0.0",
"description": "Redux shopping-cart example",
"scripts": {
"start": "node server.js",
"test": "cross-env NODE_ENV=test mocha --recursive --compilers js:babel-register",
"test:watch": "npm test -- --watch"
},
"repository": {
"type": "git",
"url": "https://github.com/reactjs/redux.git"
},
"license": "MIT",
"bugs": {
"url": "https://github.com/reactjs/redux/issues"
},
"homepage": "http://redux.js.org",
"dependencies": {
"babel-polyfill": "^6.3.14",
"react": "^0.14.7",
"react-dom": "^0.14.7",
"react-redux": "^4.2.1",
"redux": "^3.2.1",
"redux-thunk": "^1.0.3"
},
"devDependencies": {
"babel-core": "^6.3.15",
"babel-loader": "^6.2.0",
"babel-preset-es2015": "^6.3.13",
"babel-preset-react": "^6.3.13",
"babel-preset-react-hmre": "^1.1.1",
"cross-env": "^1.0.7",
"enzyme": "^2.0.0",
"express": "^4.13.3",
"json-loader": "^0.5.3",
"react-addons-test-utils": "^0.14.7",
"redux-logger": "^2.0.1",
"mocha": "^2.2.5",
"node-libs-browser": "^0.5.2",
"webpack": "^1.9.11",
"webpack-dev-middleware": "^1.2.0",
"webpack-hot-middleware": "^2.9.1"
}
}
Here is webpack config example taken from https://github.com/reactjs/redux/tree/master/examples
var path = require('path')
var webpack = require('webpack')
module.exports = {
devtool: 'cheap-module-eval-source-map',
entry: [
'webpack-hot-middleware/client',
'./index'
],
output: {
path: path.join(__dirname, 'dist'),
filename: 'bundle.js',
publicPath: '/static/'
},
plugins: [
new webpack.optimize.OccurenceOrderPlugin(),
new webpack.HotModuleReplacementPlugin()
],
module: {
loaders: [
{
test: /\.js$/,
loaders: [ 'babel?presets[]=react,presets[]=es2015,presets[]=react-hmre' ],
exclude: /node_modules/,
include: __dirname
},
{
test: /\.json$/,
loaders: [ 'json' ],
exclude: /node_modules/,
include: __dirname
}
]
}
}
Babel transpiles your code to something that browsers can understand, but the resulting code uses features that may or may not work in every single browser. For example Object.assign is not supported in all browsers, so babel-polyfill fills the holes. It's just a collection of polyfills that you would usually include anyway to have support for legacy browsers.
Consider this code:
const foo = {
name: 'Homer'
};
const bar = Object.assign({}, foo, {age: '?'});
console.log(Object.keys(foo), Object.keys(bar));
Babel will transpile this to the almost identical:
'use strict';
var foo = {
name: 'Homer'
};
var bar = Object.assign({}, foo, { age: '?' });
console.log(Object.keys(foo), Object.keys(bar));
because this is normal old school JS syntax. However, that doesn't mean that the native functions used are implemented in all browsers, so we need to include the polyfill.

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