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Webpack 4 - Module parse failed: Unexpected character '#'

I recently upgraded from Webpack 3 to 4. It's now throwing an error:
Module parse failed: Unexpected character '#' You may need an
appropriate loader to handle this file type. | #import
'./scss/variables.scss'; | | * { # ./src/index.js 1:0-22
In my styles.scss file, I am doing the following:
#import 'scss/variables.scss';
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
font-family: Arial, Helvetica, sans-serif;
}
In my index.js file, I am only doing the following:
import './style.scss';
In my webpack.dev.js, all I changed was an addition of mode: 'development':
const StyleLintPlugin = require('stylelint-webpack-plugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const Dotenv = require('dotenv-webpack');
module.exports = {
mode: 'development',
entry: './src/index.js',
output: {
filename: 'public/bundle.js'
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
loader: ['babel-loader', 'eslint-loader']
},
{
test: /\.scss$/,
loader: ExtractTextPlugin.extract(['css-loader', 'sass-loader'])
}
]
},
plugins: [
new StyleLintPlugin({
configFile: '.stylelintrc',
context: 'src',
files: '**/*.scss',
failOnError: false,
quiet: false,
syntax: 'scss'
}),
new ExtractTextPlugin('public/style.css'),
new Dotenv()
]
};
I don't know what change from Webpack 3 to 4 has caused this error.
The issue I'm having is very similar to the issue posted here: Webpack 4 Module parse failed: Unexpected character '#' (1:0)
I have been through all related stackoverflow questions and none of them helped.
Here are the relevant dependencies in my package.json:
"babel-loader": "^7.1.4",
"css-loader": "^0.28.11",
"eslint-loader": "^1.9.0",
"extract-text-webpack-plugin": "^4.0.0-beta.0",
"node-sass": "^4.9.0",
"sass-loader": "^6.0.7",
"style-loader": "^0.20.3",
"stylelint-webpack-plugin": "^0.10.5",
"uglifyjs-webpack-plugin": "^1.2.5",
"webpack": "^4.8.3",
"webpack-cli": "^2.1.4"
Here are the relevant scripts in my package.json file, for reference in the comments:
"scripts": {
"watch": "./node_modules/.bin/webpack --mode development --watch --progress",
"build": "./node_modules/.bin/webpack --mode production"
},

The problem was the script I was using to run Webpack did not specify the config file. This is what it should look like:
"scripts": {
"watch": "./node_modules/.bin/webpack --watch --config webpack.dev.js",
},
I believe this was generating the #import problem because it was not loading the css-loader as without specifying the config file like above, it uses a default Webpack development config which does not include the css-loader.

As I mentioned in a comment on your question there's an open issue with Webpack 4 compatibility: https://github.com/webpack-contrib/extract-text-webpack-plugin/issues/701
A fix for now is to install the alpha version of the library. I've done a small setup just now to test this and it works with webpack 4.
Install the alpha version npm i -D extract-text-webpack-plugin#next --save. Then install css-loader, sass-loader and node-sass.
Then in the webpack config file:
const ExtractTextPlugin = require('extract-text-webpack-plugin');
...
module: {
rules: [
{
test: /\.(js|jsx)$/,
use: {
loader: 'babel-loader'
},
exclude: /node_modules/,
include: path.join(__dirname, 'src')
},
{
test: /\.scss$/,
loader: ExtractTextPlugin.extract(['css-loader', 'sass-loader'])
}
]
},
plugins: [
new ExtractTextPlugin('bundle.css'),
]
This correctly worked for me, and also concatenated multiple scss files that were using #import statements.
In package.json it should look like
"extract-text-webpack-plugin": "^4.0.0-beta.0",
"webpack": "^4.8.3"
Edit: Just as a side note, apparently mini-css-extract-plugin works fine with webpack 4.

This worked for me: Replace your webpack styling config to the below code
module: {
rules: [
{
test: /\.(css|sass|scss)$/,
use: [
{
loader: 'style-loader'
},
{
loader: 'css-loader'
},
{
loader: 'sass-loader'
}
]
}
]
}
I hope this resolves your issue thanks

Webpack throws 'Illegal import declaration', suspected config error

I have am attempting to compile my Javascript (es6) for use server side, the environment I'm targeting involves:
node 8.9.1
npm 6.0.0
webpack 4.8.1
The first part of the code I'm attempting to compile using webpack is the file index.js and it starts like this.
import express from 'express';
import https from 'https';
// Import socket.io
let io = require('socket.io').Server;
// Now import some basic middleware for express
import * as session from 'express-session';
import * as bodyParser from 'body-parser';
import * as favicon from 'serve-favicon';
// Import useful file IO
import * as path from 'path';
let fs = require('fs');
...
However when I run webpack I get the following error:
$ webpack
Webpack is watching the files…
Hash: 1bd3f903f9c5ccdc3456
Version: webpack 4.8.1
Time: 684ms
Built at: 2018-05-10 14:51:08
Asset Size Chunks Chunk Names
server.js 3.97 KiB main [emitted] main
server.js.map 2.52 KiB main [emitted] main
../dist/keys/it-test-crt.crt 1.16 KiB [emitted]
../dist/images/favicon.ico 1.19 KiB [emitted]
../dist/keys/it-test-csr.pem 1.02 KiB [emitted]
../dist/keys/it-test-key.pem 1.64 KiB [emitted]
Entrypoint main = server.js server.js.map
[./index.js] 1.2 KiB {main} [built] [failed] [1 error]
ERROR in ./index.js
Module build failed: Error: Parse Error: Line 1: Illegal import declaration
...
BTW I am using Javascript in it's es6 incarnation so do need Bable and it is in my configs (q.v.). Even if I was not using es6 the Webpack documentation suggests that import should be respected regardless, see here, where the Webpack documentations says:
Version 2 of webpack supports ES6 module syntax natively, meaning you can use import and export without a tool like babel to handle this for you.
So my question is why do I see the above error? My current assumption is I have made an error somewhere in my configuration of Webpack, see below:
var nodeExternals = require('webpack-node-externals');
var CopyWebpackPlugin = require('copy-webpack-plugin');
module.exports = {
context: __dirname,
mode: 'development',
entry: './index.js',
output: {
filename: 'server.js',
path: __dirname + '/../dist/'
},
devtool: 'source-map',
resolve: {
extensions: ['.js', '.jsx', '.json'],
modules: ['./', 'node_modules']
},
module: {
rules:[
{
test: /\.js?$/,
use: {
loader: 'babel-loader?presets[]=env',
}
},
{
test: /\.jsx?$/,
use: {
loader: 'jsx-loader?harmony'
}
},
{
enforce: 'pre',
test: /\.js$/,
loader: 'source-map-loader'
}
]
},
target: 'node',
node: {
__dirname: false,
__filename: false
},
externals: [nodeExternals()],
watch: true,
watchOptions: {
ignored: /node_modules/
},
plugins: [
new CopyWebpackPlugin([
{from: 'images', to: '../dist/images'},
{from: 'keys', to: '../dist/keys'}
])
]
};
I have not set up a .babelrc file as I was appending the presets[]=env query to the babel-loader. Just in case it's helpful to know any other version numbers my package.json looks like this:
{
"name": "web-app",
"version": "1.0.0",
"description": "A web application using react, etc. ",
"main": "index.js",
"repository": {
"type": "git",
"url": "git+https://github.com/nigel-daniels/web-app.git"
},
"keywords": [
"web",
"app",
"react",
"redux"
],
"author": "Nigel Daniels",
"license": "MIT",
"bugs": {
"url": "https://github.com/nigel-daniels/web-app/issues"
},
"homepage": "https://github.com/nigel-daniels/web-app#readme",
"dependencies": {
"async": "^2.6.0",
"bcrypt-nodejs": "0.0.3",
"body-parser": "^1.18.2",
"cookie-parser": "^1.4.3",
"debug": "^3.1.0",
"express": "^4.16.2",
"express-session": "^1.15.6",
"express-socket.io-session": "^1.3.2",
"fs": "0.0.1-security",
"immutable": "^3.8.2",
"mongoose": "^5.0.6",
"nodemailer": "^4.4.0",
"passport": "^0.4.0",
"passport-local": "^1.0.0",
"react": "^16.1.1",
"react-dom": "^16.1.1",
"redux": "^3.7.2",
"serve-favicon": "^2.4.5",
"socket.io": "^2.0.4"
},
"devDependencies": {
"babel-core": "^6.26.3",
"babel-loader": "^7.1.4",
"babel-preset-env": "^1.6.1",
"chai": "^3.5.0",
"chai-immutable": "^1.6.0",
"copy-webpack-plugin": "^4.2.3",
"jsx-loader": "^0.13.2",
"mocha": "^5.0.1",
"source-map-loader": "^0.2.3",
"webpack": "^4.8.1",
"webpack-node-externals": "^1.7.2"
},
"engines": {
"node": "^8.1.0",
"npm": "6.0.0"
}
}
Thanks for any advice!

You shouldn't need jsx-loader for a nodejs backend build. You can remove it and if necessary, let babel-loader handle .jsx extensions for you:
{
test: /\.jsx?$/, // notice the little 'x'
use: {
loader: 'babel-loader?presets[]=env',
}
},

I think the problem is that it the express module exports with module.exports, while you import with es2015 import. I don't think webpack supports the conversion natively. I would just use require instead when importing npm modules, but otherwise you this babel plugin might solve it for you: https://www.npmjs.com/package/babel-plugin-transform-es2015-modules-commonjs.

React hydrate TypeError: __webpack_require__.i(...) is not a function

I am getting a webpack TypeError when trying to use hydrate() in index.js. The error is not seen when I use ReactDOM.render() instead of hydrate and I am using hydrate for server side rendering.
src/index.js
import React from 'react';
import ReactDOM, { hydrate } from 'react-dom';
import { Provider } from 'react-redux';
import App from './App';
import store from './store/configureStore';
hydrate(
<Provider store={store}>
<App />
</Provider>,
document.getElementById('root')
)
config/webpack.config.dev.js
'use strict';
const autoprefixer = require('autoprefixer');
const path = require('path');
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
const WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
const eslintFormatter = require('react-dev-utils/eslintFormatter');
const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
const getClientEnvironment = require('./env');
const paths = require('./paths');
// Webpack uses `publicPath` to determine where the app is being served from.
// In development, we always serve from the root. This makes config easier.
const publicPath = '/';
// `publicUrl` is just like `publicPath`, but we will provide it to our app
// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
// Omit trailing slash as %PUBLIC_PATH%/xyz looks better than %PUBLIC_PATH%xyz.
const publicUrl = '';
// Get environment variables to inject into our app.
const env = getClientEnvironment(publicUrl);
// This is the development configuration.
// It is focused on developer experience and fast rebuilds.
// The production configuration is different and lives in a separate file.
module.exports = {
// You may want 'eval' instead if you prefer to see the compiled output in DevTools.
// See the discussion in https://github.com/facebookincubator/create-react-app/issues/343.
devtool: 'cheap-module-source-map',
// These are the "entry points" to our application.
// This means they will be the "root" imports that are included in JS bundle.
// The first two entry points enable "hot" CSS and auto-refreshes for JS.
entry: [
// Include an alternative client for WebpackDevServer. A client's job is to
// connect to WebpackDevServer by a socket and get notified about changes.
// When you save a file, the client will either apply hot updates (in case
// of CSS changes), or refresh the page (in case of JS changes). When you
// make a syntax error, this client will display a syntax error overlay.
// Note: instead of the default WebpackDevServer client, we use a custom one
// to bring better experience for Create React App users. You can replace
// the line below with these two lines if you prefer the stock client:
// require.resolve('webpack-dev-server/client') + '?/',
// require.resolve('webpack/hot/dev-server'),
require.resolve('react-dev-utils/webpackHotDevClient'),
// We ship a few polyfills by default:
require.resolve('./polyfills'),
// Errors should be considered fatal in development
require.resolve('react-error-overlay'),
// Finally, this is your app's code:
paths.appIndexJs,
// We include the app code last so that if there is a runtime error during
// initialization, it doesn't blow up the WebpackDevServer client, and
// changing JS code would still trigger a refresh.
],
output: {
// Next line is not used in dev but WebpackDevServer crashes without it:
path: paths.appBuild,
// Add /* filename */ comments to generated require()s in the output.
pathinfo: true,
// This does not produce a real file. It's just the virtual path that is
// served by WebpackDevServer in development. This is the JS bundle
// containing code from all our entry points, and the Webpack runtime.
filename: 'static/js/bundle.js',
// There are also additional JS chunk files if you use code splitting.
chunkFilename: 'static/js/[name].chunk.js',
// This is the URL that app is served from. We use "/" in development.
publicPath: publicPath,
// Point sourcemap entries to original disk location (format as URL on Windows)
devtoolModuleFilenameTemplate: info =>
path.resolve(info.absoluteResourcePath).replace(/\\/g, '/'),
},
resolve: {
// This allows you to set a fallback for where Webpack should look for modules.
// We placed these paths second because we want `node_modules` to "win"
// if there are any conflicts. This matches Node resolution mechanism.
// https://github.com/facebookincubator/create-react-app/issues/253
modules: ['node_modules', paths.appNodeModules].concat(
// It is guaranteed to exist because we tweak it in `env.js`
process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
),
// These are the reasonable defaults supported by the Node ecosystem.
// We also include JSX as a common component filename extension to support
// some tools, although we do not recommend using it, see:
// https://github.com/facebookincubator/create-react-app/issues/290
// `web` extension prefixes have been added for better support
// for React Native Web.
extensions: ['.web.js', '.js', '.json', '.web.jsx', '.jsx'],
alias: {
// Support React Native Web
// https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
'react-native': 'react-native-web',
},
plugins: [
// Prevents users from importing files from outside of src/ (or node_modules/).
// This often causes confusion because we only process files within src/ with babel.
// To fix this, we prevent you from importing files out of src/ -- if you'd like to,
// please link the files into your node_modules/ and let module-resolution kick in.
// Make sure your source files are compiled, as they will not be processed in any way.
new ModuleScopePlugin(paths.appSrc),
],
},
module: {
strictExportPresence: true,
rules: [
// TODO: Disable require.ensure as it's not a standard language feature.
// We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176.
// { parser: { requireEnsure: false } },
// First, run the linter.
// It's important to do this before Babel processes the JS.
{
test: /\.(js|jsx)$/,
enforce: 'pre',
use: [
{
options: {
formatter: eslintFormatter,
},
loader: require.resolve('eslint-loader'),
},
],
include: paths.appSrc,
},
// ** ADDING/UPDATING LOADERS **
// The "file" loader handles all assets unless explicitly excluded.
// The `exclude` list *must* be updated with every change to loader extensions.
// When adding a new loader, you must add its `test`
// as a new entry in the `exclude` list for "file" loader.
// "file" loader makes sure those assets get served by WebpackDevServer.
// When you `import` an asset, you get its (virtual) filename.
// In production, they would get copied to the `build` folder.
{
exclude: [
/\.html$/,
/\.(js|jsx)$/,
/\.css$/,
/\.json$/,
/\.bmp$/,
/\.gif$/,
/\.jpe?g$/,
/\.png$/,
],
loader: require.resolve('file-loader'),
options: {
name: 'static/media/[name].[hash:8].[ext]',
},
},
// "url" loader works like "file" loader except that it embeds assets
// smaller than specified limit in bytes as data URLs to avoid requests.
// A missing `test` is equivalent to a match.
{
test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
loader: require.resolve('url-loader'),
options: {
limit: 10000,
name: 'static/media/[name].[hash:8].[ext]',
},
},
// Process JS with Babel.
{
test: /\.(js|jsx)$/,
include: paths.appSrc,
loader: require.resolve('babel-loader'),
options: {
// This is a feature of `babel-loader` for webpack (not Babel itself).
// It enables caching results in ./node_modules/.cache/babel-loader/
// directory for faster rebuilds.
cacheDirectory: true,
},
},
// "postcss" loader applies autoprefixer to our CSS.
// "css" loader resolves paths in CSS and adds assets as dependencies.
// "style" loader turns CSS into JS modules that inject <style> tags.
// In production, we use a plugin to extract that CSS to a file, but
// in development "style" loader enables hot editing of CSS.
{
test: /\.css$/,
use: [
require.resolve('style-loader'),
{
loader: require.resolve('css-loader'),
options: {
importLoaders: 1,
},
},
{
loader: require.resolve('postcss-loader'),
options: {
// Necessary for external CSS imports to work
// https://github.com/facebookincubator/create-react-app/issues/2677
ident: 'postcss',
plugins: () => [
require('postcss-flexbugs-fixes'),
autoprefixer({
browsers: [
'>1%',
'last 4 versions',
'Firefox ESR',
'not ie < 9', // React doesn't support IE8 anyway
],
flexbox: 'no-2009',
}),
],
},
},
],
},
// ** STOP ** Are you adding a new loader?
// Remember to add the new extension(s) to the "file" loader exclusion list.
],
},
plugins: [
// Makes some environment variables available in index.html.
// The public URL is available as %PUBLIC_URL% in index.html, e.g.:
// <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
// In development, this will be an empty string.
new InterpolateHtmlPlugin(env.raw),
// Generates an `index.html` file with the <script> injected.
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
}),
// Add module names to factory functions so they appear in browser profiler.
new webpack.NamedModulesPlugin(),
// Makes some environment variables available to the JS code, for example:
// if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`.
new webpack.DefinePlugin(env.stringified),
// This is necessary to emit hot updates (currently CSS only):
new webpack.HotModuleReplacementPlugin(),
// Watcher doesn't work well if you mistype casing in a path so we use
// a plugin that prints an error when you attempt to do this.
// See https://github.com/facebookincubator/create-react-app/issues/240
new CaseSensitivePathsPlugin(),
// If you require a missing module and then `npm install` it, you still have
// to restart the development server for Webpack to discover it. This plugin
// makes the discovery automatic so you don't have to restart.
// See https://github.com/facebookincubator/create-react-app/issues/186
new WatchMissingNodeModulesPlugin(paths.appNodeModules),
// Moment.js is an extremely popular library that bundles large locale files
// by default due to how Webpack interprets its code. This is a practical
// solution that requires the user to opt into importing specific locales.
// https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
// You can remove this if you don't use Moment.js:
new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
],
// Some libraries import Node modules but don't use them in the browser.
// Tell Webpack to provide empty mocks for them so importing them works.
node: {
dgram: 'empty',
fs: 'empty',
net: 'empty',
tls: 'empty',
},
// Turn off performance hints during development because we don't do any
// splitting or minification in interest of speed. These warnings become
// cumbersome.
performance: {
hints: false,
},
};
package.json
{
"name": "tratoli_backend",
"version": "0.1.0",
"private": true,
"dependencies": {
"autoprefixer": "7.1.1",
"babel-core": "6.25.0",
"babel-eslint": "7.2.3",
"babel-jest": "20.0.3",
"babel-loader": "7.0.0",
"babel-preset-react-app": "^3.0.1",
"babel-runtime": "6.23.0",
"case-sensitive-paths-webpack-plugin": "2.1.1",
"chalk": "1.1.3",
"css-loader": "0.28.4",
"dotenv": "4.0.0",
"eslint": "3.19.0",
"eslint-config-react-app": "^1.0.5",
"eslint-loader": "1.7.1",
"eslint-plugin-flowtype": "2.34.0",
"eslint-plugin-import": "2.2.0",
"eslint-plugin-jsx-a11y": "5.0.3",
"eslint-plugin-react": "7.1.0",
"express": "^4.16.2",
"extract-text-webpack-plugin": "2.1.2",
"file-loader": "0.11.2",
"fixed-data-table": "^0.6.4",
"fixed-data-table-2": "^0.7.17",
"fs-extra": "3.0.1",
"html-webpack-plugin": "2.29.0",
"isomorphic-fetch": "^2.2.1",
"jest": "20.0.4",
"object-assign": "4.1.1",
"postcss-flexbugs-fixes": "3.0.0",
"postcss-loader": "2.0.6",
"promise": "7.1.1",
"react": "^15.6.1",
"react-bootstrap": "^0.31.2",
"react-dev-utils": "^3.0.2",
"react-dom": "^15.6.1",
"react-error-overlay": "^1.0.9",
"react-redux": "^5.0.5",
"react-router": "^4.2.0",
"react-router-dom": "^4.1.2",
"react-router-redux": "next",
"react-select": "^1.0.0-rc.5",
"react-table": "^6.8.0",
"redux": "^3.7.2",
"redux-logger": "^3.0.6",
"redux-thunk": "^2.2.0",
"style-loader": "0.18.2",
"sw-precache-webpack-plugin": "0.11.3",
"url-loader": "0.5.9",
"webpack": "2.6.1",
"webpack-dev-server": "2.5.0",
"webpack-manifest-plugin": "1.1.0",
"webpack-node-externals": "^1.6.0",
"whatwg-fetch": "2.0.3"
},
"scripts": {
"start": "node scripts/start.js",
"build": "node scripts/build.js && npm run ssr",
"test": "node scripts/test.js --env=jsdom",
"start-ssr": "NODE_ENV=production webpack --config ./config/webpack.ssr.config.js",
"ssr": "NODE_ENV=production babel-node server/index.js --presets es2015,stage-2",
"ssr-start": "NODE_ENV=production node dist/server.js"
},
"jest": {
"collectCoverageFrom": [
"src/**/*.{js,jsx}"
],
"setupFiles": [
"<rootDir>/config/polyfills.js"
],
"testMatch": [
"<rootDir>/src/**/__tests__/**/*.js?(x)",
"<rootDir>/src/**/?(*.)(spec|test).js?(x)"
],
"testEnvironment": "node",
"testURL": "http://localhost",
"transform": {
"^.+\\.(js|jsx)$": "<rootDir>/node_modules/babel-jest",
"^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
"^(?!.*\\.(js|jsx|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
},
"transformIgnorePatterns": [
"[/\\\\]node_modules[/\\\\].+\\.(js|jsx)$"
],
"moduleNameMapper": {
"^react-native$": "react-native-web"
},
"moduleFileExtensions": [
"web.js",
"js",
"json",
"web.jsx",
"jsx"
]
},
"babel": {
"plugins": [
"css-modules-transform"
],
"presets": [
"react-app"
]
},
"eslintConfig": {
"extends": "react-app"
},
"devDependencies": {
"babel-cli": "^6.26.0",
"babel-plugin-css-modules-transform": "^1.5.0",
"babel-preset-es2015": "^6.24.1",
"babel-preset-stage-0": "^6.24.1",
"babel-preset-stage-2": "^6.24.1"
}
}
And this here is the screenshot of the error message I received.

hydrate method is available in React 16(react-dom v16).
You are trying to access it from React 15(react-dom v15.6.1). This method is not available in React 15.
Update your react-dom to version to 16 and it should work fine.

Testem receiving imports compiled to `require` when using ES2015/React presets to Babel

I have a project which is set up so that it builds with reactand jsx. It works fine to build it using node_modules/webpack/bin/webpack.js --config webpack.config.js and I can run the result in the browser with no problems. However, when I run npm test and view the test runner in the browser, I get the error: "Uncaught ReferenceError: require is not defined at dashboard-tests.js:3". It seems that webpack is compiling my tests (but not my normal code) into a version of javascriptthat can't be run in browsers.
Here are the relevant files:
.babelrc:
{
"presets": ["es2015", "react"]
}
testem.json:
{
"framework": [
"jasmine"
],
"launch_in_dev": [
"PhantomJS"
],
"launch_in_ci": [
"PhantomJS"
],
"serve_files": [
"tmp/**/*-test{,s}.js"
],
"on_start": "babel static_source --out-dir tmp",
"on_exit": "yes | rm -r tmp"
}
package.json:
{
"main": "index.js",
"scripts": {
"test": "testem"
},
"dependencies": {
"jquery": "^3.2.1",
"prop-types": "^15.6.0",
"react": "^16.0.0",
"react-dom": "^16.0.0",
"react-feather": "^1.0.7"
},
"devDependencies": {
"babel-cli": "^6.26.0",
"babel-core": "^6.26.0",
"babel-loader": "^7.1.2",
"babel-preset-env": "^1.6.1",
"babel-preset-react": "^6.24.1",
"jasmine-es6": "^0.4.3",
"testem": "^1.18.4",
"webpack": "^3.6.0"
}
}
webpack.config.js:
var path = require("path");
var webpack = require('webpack');
module.exports = {
context: __dirname,
entry: './static_source/js/index.js',
output: {
path: path.resolve('./app/static/js/'),
filename: "compiled.js"
},
plugins: [],
module: {
loaders: [
{ test: /\.js$/, loader: 'babel-loader', exclude: /node_modules/ },
{ test: /\.jsx$/, loader: 'babel-loader', exclude: /node_modules/ }
],
}
}
dashboard-tests:
import React from 'react';
import ReactDOM from "react-dom";
import TestUtils from "react-dom/test-utils";
import Dashboard from './dashboard';
describe('Dashboard', function() {
it('exists', function() {
expect(Dashboard).not.toBe(undefined);
});
it('renders arrows', function() {
var dashboard = <Dashboard />;
var renderedDashboard = TestUtils.renderIntoDocument(dashboard);
var arrowsDiv = TestUtils.findRenderedComponentWithClass('arrows');
expect(arrowsDiv).not.toBe(undefined);
});
});

You are using Babel to compile your test source files. Babel is just a transpiler, it takes ES+ files and translates them to ES5 files. Because import does not exist in ES5 Babel replaces them with require().
To fix the problem you need to bundle your source file into one, using Webpack.
You will need a separate Webpack configuration file, let's call it webpack.config.test.js. In this file we need to instruct Webpack to fetch all your static_source/**/*-test{,s}.js files as entry-points.
You will need the glob module : npm install glob --save-dev.
Then add the webpack.config.test.js file with this content :
var path = require("path");
var glob = require('glob');
var webpack = require('webpack');
module.exports = {
context: __dirname,
// we look for all file ending with -test(s?).js and return the absolute path
entry: glob
.sync('./static_source/js/**/*-test{,s}.js')
.map(function(file) { return path.resolve(__dirname, file) }),
output: {
// save the resulting bundle in the ./tmp/ directory
path: path.resolve('./tmp/'),
filename: "compiled.js"
},
plugins: [],
module: {
loaders: [
{ test: /\.js$/, loader: 'babel-loader', exclude: /node_modules/ },
{ test: /\.jsx$/, loader: 'babel-loader', exclude: /node_modules/ }
],
}
}
On the testem.json file replace the on_start with a before_test to Webpack, and the serve_files to map to the bundled file.
"before_tests": "webpack --config webpack.config.test.js ",
"serve_files": [
"tmp/compiled.js"
],
When testem will be launched it will trigger the Webpack test compilation.
Now you should have a tmp/compiled.js file with all your test files bundled. You may need to do some tweaking but it should basically works.

Webpack Missing Module 'Module Not Found'

I'm currently working on a react webpack babel etc site and trying to build the first time. The build is successful, but when I open up the browser I get the following error:
Uncaught Error: Cannot find module "/Users/michael.nakayama/Documents/Development/jamsesh/node_modules/webpack/node_modules/node-libs-browser/node_modules/process/browser.js"
This module exists. Going to that actual url in my browser shows the file in question. But I cannot figure out why webpack cannot find it. I don't know if this is a babel6 issue or a webpack issue, or neither. My config file looks like this:
var webpack = require('webpack');
var cleanWebpack = require('clean-webpack-plugin');
var ignore = new webpack.IgnorePlugin(new RegExp("/(node_modules|ckeditor)/"))
module.exports = {
devtool: 'inline-source-map',
entry: './lib/client/entry',
output: {
path: __dirname + '/public/js',
filename: 'app.js',
publicPath: 'http://localhost:8081/js/',
},
plugins: [
ignore,
],
resolve: {
extensions: ['', '.js'],
moduleDirectories: ['./node_modules']
},
module: {
loaders: [
{
test: /\.js?$/,
loaders: ['babel-loader?presets[]=react,presets[]=es2015,plugins[]=transform-es2015-classes,plugins[]=transform-react-jsx'],
exclude: /(node_modules)/,
}
]
}
}
and my webpack server file is as follows:
var WebpackDevServer = require('webpack-dev-server');
var webpack = require('webpack');
var config = require('../../webpack.config');
var server = new WebpackDevServer(webpack(config), {
// webpack-dev-server options
publicPath: config.output.publicPath,
stats: { colors: true },
});
server.listen(8081, 'localhost', function() {});
and here are the packages I have installed:
"devDependencies": {
"babel-cli": "^6.3.17",
"babel-core": "^6.3.26",
"babel-loader": "^6.2.0",
"babel-plugin-syntax-jsx": "^6.3.13",
"babel-plugin-transform-es2015-classes": "^6.4.0",
"babel-plugin-transform-react-jsx": "^6.3.13",
"babel-preset-es2015": "^6.3.13",
"babel-preset-react": "^6.3.13",
"body-parser": "^1.14.2",
"clean-webpack-plugin": "^0.1.5",
"express": "^4.13.3",
"history": "^1.17.0",
"jade": "^1.11.0",
"nodemon": "^1.8.1",
"path": "^0.12.7",
"pg": "^4.4.3",
"react": "^0.14.6",
"react-dom": "^0.14.3",
"react-hot-loader": "^1.3.0",
"react-router": "^1.0.3",
"webpack": "^1.12.9",
"webpack-dev-server": "^1.14.0"
}
entry.js:
var React = require('react');
var ReactDOM = require('react-dom');
var ReactRouter = require('react-router');
var Router = ReactRouter.Router;
var Route = ReactRouter.Route;
var routes = require('../routes');
// -v x.13.x
/**Router.run(routes, Router.HistoryLocation, function (Handler, state) {
React.render(<Handler/>, document.getElementById('react-app'));
});**/
var node = document.getElementById('react-app');
// -v 1.0.0
ReactDOM.render(<Router history={createBrowserHistory()} routes={routes}/> , node);
Also as a heads up, I have tried uninstalling and reinstalling all my packages. I have tried installing specifically the node-libs-browser modules. thanks.

The problem with ignore plugin on node_modules. In webpack.config.js, you have:
var ignore = new webpack.IgnorePlugin(new RegExp("/(node_modules|ckeditor)/"))
...
plugins: [
ignore,
],
From Ignore Plugin documentation:
Don’t generate modules for requests matching the provided RegExp.
Webpack tries to require module with the name node_modules/process/browser for React module and fails with it because it is ignored.
Try to remove node_modules from Ignore Plugin or write less global condition if you really need this.

Importing nodeExternals worked for me.
import nodeExternals from 'webpack-node-externals';
this is my server.webpack.config:
import path from 'path';
import nodeExternals from 'webpack-node-externals'; // changes
const CONTEXT = path.join( __dirname, "../.." ),
INPUT_SERVER_DIR = path.join( CONTEXT, "server" ),
OUTPUT_SERVER_DIR = path.join( CONTEXT, "dist/server" );
export default [
{
name: 'server',
target: 'node',
context: INPUT_SERVER_DIR,
node: {
__dirname: false
},
entry: './server',
devtool : 'source-map',
output: {
path: OUTPUT_SERVER_DIR,
filename: "server.js"
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
loader: "babel-loader"
}
]
},
resolve: {
extensions: ['.js']
},
**externals : [ nodeExternals() ]**
}
];