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Webpack 4 basic React js hello world fails with "Module parse failed: Unexpected token"

Update:
Code pushed to https://github.com/gsouvik/react_spa_experiment
Initial Post:
I know there are hundreds of threads out there, some had typos in webpack config, some used the loaders in a wrong way, some got it solved, some still open. But after numerous tries I still cannot get this working, a simple "Hello World" using Webpack 4, React js.
What I did
I was following this video tutorial line by line:
React & Webpack 4 from scratch
My package.json
{
"name": "my_react_experiment_2",
"version": "1.0.0",
"description": "Basic react with webpack ",
"main": "index.js",
"scripts": {
"dev": "webpack-dev-server --mode development --hot",
"build": "webpack --mode production"
},
"author": "Souvik Ghosh",
"license": "ISC",
"dependencies": {
"react": "^16.4.2",
"react-dom": "^16.4.2"
},
"devDependencies": {
"babel-core": "^6.26.3",
"babel-loader": "^7.1.5",
"babel-preset-env": "^1.7.0",
"babel-preset-react": "^6.24.1",
"html-webpack-plugin": "^3.2.0",
"webpack": "^4.17.1",
"webpack-cli": "^3.1.0",
"webpack-dev-server": "^3.1.5"
}
}
My webpack.config.js
const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
module.export = {
entry: './src/index.js',
output: {
path: path.join(__dirname, '/build'),
filename: 'index_bundle.js'
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: {
loader: "babel-loader"
}
}
]
},
plugins: [
new HtmlWebpackPlugin({
template: './src/templates/index.html'
})
]
};
My .babelrc
{
"presets": ["env", "react"]
}
My directory structure
Expected behaviour
I fire up the dev server npm run dev. Expected to see my shiny new React js page saying "My first React Webpack project" (from the component /components/App.js)
Actual Behavior
ERROR in ./src/index.js 5:16
Module parse failed: Unexpected token (5:16)
You may need an appropriate loader to handle this file type.
| import App from "./components/App";
|
ReactDOM.render(, document.getElementById('root'));
| //ReactDOM.render('Hello User ', document.getElementById('root'));
# multi (webpack)-dev-server/client?http://localhost:8080 (webpack)/hot/dev-server.js ./src main2
If required I can share the codebase via a git repo. Any help is greatly appreciated.

The issue is with typo in your webpack config file.
You have module.export which is not correct. It should be module.exports
Working example
const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
module.exports = {
entry: './src/index.js',
output: {
path: path.join(__dirname, '/build'),
filename: 'index_bundle.js'
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: {
loader: "babel-loader"
}
}
]
},
plugins: [
new HtmlWebpackPlugin({
template: './src/templates/index.html'
})
]
};

UglifyJs error with Gulp and webpack

I am currently discovering the module bundler "Webpack". I am trying to do something quite easy : I have a main.js entry and a bundle.js output. I use babel in order to translate in ES6.
My package.json :
{
"name": "me",
"version": "1.0.0",
"description": "Builder",
"main": "index.js",
"scripts": {
...
},
"author": "me",
"license": "ISC",
"devDependencies": {
"babel": "^6.23.0",
"babel-core": "^6.25.0",
"babel-loader": "^7.1.1",
"babel-preset-env": "^1.5.2",
"babel-preset-es2015": "^6.24.1",
"gulp": "^3.9.1",
"lodash": "^4.17.4",
"webpack": "^3.0.0",
"webpack-stream": "^3.2.0"
},
"dependencies": {
"jquery": "^3.2.1"
}
}
Webpack.config.js :
var path = require('path');
var webpack = require('webpack');
module.exports = {
entry: path.resolve(__dirname, 'js/main.js'),
output: {
filename: 'bundle.js',
path: path.resolve(__dirname, 'dist')
},
module: {
rules: [
{
test: /\.(js|jsx)$/,
exclude: /node_modules/,
use: {
loader: 'babel-loader',
options: {
presets: ['es2015']
}
}
}
]
},
plugins: [
new webpack.optimize.UglifyJsPlugin()
]
}
When I prompt webpack in the CLI, it works pretty well, a bundle.js file which is minified is created in the dist folder.
Now, I want to combine with Gulp
Here is my gulpfile.js :
var gulp = require('gulp');
var webpackS = require('webpack-stream');
gulp.task('default', function() {
return gulp.src('./app/js/main.js')
.pipe(webpackS( require('./app/webpack.config.js') ))
.pipe(gulp.dest('./app/dist/'));
});
When I enter gulp in the CLI, I have this error :
stream.js:74
throw er; // Unhandled stream error in pipe.
^
Error: bundle.js from UglifyJs
Unexpected token: name (_) [bundle.js:47,8]
However, when I remove the line new webpack.optimize.UglifyJsPlugin() from webpack.config.js and prompt gulp in the CLI it works perfectly !
I reinstalled all the npm packages but the problem is still here.
Does anybody have an idea ?

I would like to suggest you to don't mix webpack and gulp,
just create a script inside your package.json#scripts which runs webpack and then if you still want to exec webpack inside a gulp task you can do:
var exec = require('child_process').exec;
gulp.task('runWebpack', function (callback) {
exec('npm run webpack', callback);
})

How do you run the Webpack config? I assume by webpack path-to-config/webpack.config.js?
You have new webpack.optimize.UglifyJsPlugin() in your config, so by using webpack -p which executes the production mode, you get an error because UglifyJsPlugin is executed twice.
I guess the same happens with your Gulp setup.
However, the error message points to "_" not defined, which could be related to lodash. Maybe the import can't be resolved by Gulp?
However, I would not mix Gulp and Webpack. See the discussion here: Gulp + Webpack or JUST Webpack?
There is also an example using Webpack from within a gulp task.

Webpack: ERROR in ./~/sqlite3/~/node-pre-gyp/lib/node-pre-gyp.js Module not found: Error: Cannot resolve 'file' or 'directory' ../package

I want to use Webpack on my projects, but when I run
npm run dev
, I get this error.
ERROR in ./~/sqlite3/~/node-pre-gyp/lib/node-pre-gyp.js Module not
found: Error: Cannot resolve 'file' or 'directory' ../package in
/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/sqlite3/node_modules/node-pre-gyp/lib
# ./~/sqlite3/~/node-pre-gyp/lib/node-pre-gyp.js 60:16-37
ERROR in ./~/sqlite3/~/node-pre-gyp/lib/info.js Module not found:
Error: Cannot resolve module 'aws-sdk' in
/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/sqlite3/node_modules/node-pre-gyp/lib
# ./~/sqlite3/~/node-pre-gyp/lib/info.js 14:14-32
ERROR in ./~/sqlite3/~/node-pre-gyp/lib/publish.js Module not found:
Error: Cannot resolve module 'aws-sdk' in
/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/sqlite3/node_modules/node-pre-gyp/lib
# ./~/sqlite3/~/node-pre-gyp/lib/publish.js 17:14-32
ERROR in ./~/sqlite3/~/node-pre-gyp/lib/unpublish.js Module not found:
Error: Cannot resolve module 'aws-sdk' in
/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/sqlite3/node_modules/node-pre-gyp/lib
# ./~/sqlite3/~/node-pre-gyp/lib/unpublish.js 15:14-32
ERROR in ./~/sqlite3/~/rc/index.js Module build failed: Error: Parse
Error: Line 1: Unexpected token ILLEGAL
at throwError (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/node_modules/jstransform/node_modules/esprima-fb/esprima.js:2823:21)
at scanPunctuator (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/node_modules/jstransform/node_modules/esprima-fb/esprima.js:1011:9)
at advance (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/node_modules/jstransform/node_modules/esprima-fb/esprima.js:1747:16)
at peek (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/node_modules/jstransform/node_modules/esprima-fb/esprima.js:1773:21)
at parseProgram (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/node_modules/jstransform/node_modules/esprima-fb/esprima.js:6535:9)
at Object.parse (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/node_modules/jstransform/node_modules/esprima-fb/esprima.js:7713:23)
at getAstForSource (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/node_modules/jstransform/src/jstransform.js:244:21)
at Object.transform (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/node_modules/jstransform/src/jstransform.js:267:11)
at Object.transform (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/node_modules/jstransform/src/simple.js:105:28)
at Object.module.exports (/Users/caizongming/Flowerhop/-DBLab-Alarm-Project-/Server/node_modules/jsx-loader/index.js:15:31)
# ./~/sqlite3/~/node-pre-gyp/lib/info.js 11:13-26
This is my WEBPACK.CONFIG.js
var path = require ('path');
module.exports = {
entry: './server.js',
output: {
filename: 'bundle.js'
},
module: {
loaders:[
{ test: /\.css$/, loader: "style!css" },
{ test: /\.js$/, loader: 'jsx-loader?harmony' },
{ test: /\.json$/, loader: 'json-loader' }
]
},
resolve: {
fallback: path.join(__dirname, "node_modules"),
extensions : ['', '.js', '.jsx']
},
resolveLoader: { fallback: path.join(__dirname, "node_modules") },
target: 'node'
};
This is package.json.
{
"name": "biocenter",
"version": "1.0.0",
"description": "",
"main": "server.js",
"directories": {
"test": "test"
},
"dependencies": {
"body-parser": "^1.15.0",
"express": "^4.13.4",
"request": "^2.72.0",
"sqlite3": "^3.1.4",
"querystring": "^0.2.0",
"should": "^8.3.2"
},
"devDependencies": {
"brfs": "^1.4.3",
"json-loader": "^0.5.4",
"mocha": "^2.4.5",
"transform-loader": "^0.2.3",
"webpack": "^1.13.1"
},
"scripts": {
"test": "mocha",
"start": "node server.js",
"dev": "webpack-dev-server --devtool eval --progress --colors",
"deploy": "NODE_ENV=production webpack -p"
},
"repository": {
"type": "git",
"url": "git+https://github.com/FlowerHop/-DBLab-Alarm-Project-.git"
},
"author": "Flowerhop",
"license": "ISC",
"bugs": {
"url": "https://github.com/FlowerHop/-DBLab-Alarm-Project-/issues"
},
"homepage": "https://github.com/FlowerHop/-DBLab-Alarm-Project-#readme"
}
Can anybody help me fix this problem?

I encountered the similar problem with the lzma-native, which also uses node-pre-gyp. The problem is they all directly require the node-pre-gyp in the module. I try to replace the line of code that use node-pre-gyp
var nodePreGyp = require('node-pre-gyp');
var path = require('path');
var binding_path = nodePreGyp.find(path.resolve(path.join(__dirname,'./package.json')));
var native = require(binding_path);
into
var native = require('pre-gyp-find')('lzma_native');
// notice that the parameter here is the binary module name in package.json of lzma-native
And that finally works for me. Though, this solution requires us to modify the source code, and add an additional dependency 'pre-gyp-find'. Maybe you could send a PR to author about this.
This is not the best solution, since it doesn't actually solve but avoid the problem.

I noticed everything seems right during npm install, but actually there is some error during install. My problem was fixed with npm install sqlite3 --build-from-source.

Webpack/React: Following egghead.io tutorial but getting an error: You may need an appropriate loader to handle this file type

I've just started following this tutorial.
I've gone through the first video three or four times now. When I try to run the application, I get the following error in the console:
ERROR in ./main.js
Module parse failed: /Users/newuser/projects/js101/react-egghead/main.js Unexpected token (5:16)
You may need an appropriate loader to handle this file type.
SyntaxError: Unexpected token (5:16)
at Parser.pp.raise (/Users/newuser/projects/js101/react-egghead/node_modules/acorn/dist/acorn.js:920:13)
...
I've looked at similar questions on SO but none seem to have an answer for me.
Here's my webpack.config.js file:
module.exports = {
entry: './main.js',
output: {
path: './',
filename: 'index.js'
},
devServer: {
inline: true,
port: 3333
},
moudle: {
loaders: [
{
test: /\.js$/,
exclude: /node_modules/,
loader: 'babel',
query: {
presets: ['es2015', 'react']
}
}
]
}
}
This is what package.json looks like:
{
"name": "react-egghead",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1",
"start": "webpack-dev-server"
},
"author": "",
"license": "ISC",
"dependencies": {
"react": "^15.0.2",
"react-dom": "^15.0.2"
},
"devDependencies": {
"babel": "^6.5.2",
"babel-core": "^6.9.0",
"babel-loader": "^6.2.4",
"babel-preset-es2015": "^6.9.0",
"babel-preset-react": "^6.5.0",
"webpack": "^1.13.0",
"webpack-dev-server": "^1.14.1"
}
}
And, although it's not mentioned in the video, I've added a .babelrc file: (which I have now removed)
{
"presets": ["es2015", "stage-0", "react"]
}
This is where the parse fails (line 5):
import React from 'react'
import ReactDOM from 'react-dom'
import App from './App.js'
ReactDOM.render(<App />, document.getElementById('app'))
I really don't know what to try next. Is it a problem with my environment set up or is it a problem with the code in main.js?
Any help would be appreciated.

You have a typo in your webpack config. Instead of module you typed moudle, so your loader configs are actually ignored by webpack :)

babel-loader 6.0.0 doesn't work correct

I am using webpack this is my
webpack.config.js
const path = require('path');
module.exports = {
entry: './src/app',
output: {
path: path.join(__dirname, '/public'),
filename: 'bundle.js'
},
watch: true,
watchOptions: {
aggregateTimeout: 100
},
devtool: 'source-map',
module: {
loaders: [{
test: /\.js$/,
loader: "babel-loader"
}]
}
}
and this my file from entry point
app.js
import React from 'react'
without anything, just simple line of code.
When i am trying to run webpack from command line and i got the next error
app.js Line 1: Unexpected token You may need an appropriate loader to
handle this file type. | import React from 'react';
package.json
{
"name": "a-b-c",
"version": "1.0.0",
"main": "server.js",
"dependencies": {
"babel-loader": "^6.0.0",
"react": "^0.14.1",
"webpack": "^1.12.2"
},
"devDependencies": {
"babel-core": "^6.0.14"
},
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"author": "",
"license": "ISC",
"description": ""
}
Also, when i changed ES6 syntax in my app.js file to ES5 then it works well.
Any suggestions?
Thanks in advance.

I've found out. The problem was with babel-loader and to fix this issue you need to install
npm install babel-loader babel-core babel-preset-es2015
and add to your webpack.config.js file next lines
loader: 'babel?presets[]=es2015'
Source of information
Thanks