Develop Reference

Webpack 5 not showing images

I have a vue 3 app where I set up webpack 5 eventually. As I see I eliminated all my issues now the only thing remains is that it does not load my svg-s and images when I run the webpack serve script in dev mode. How can I configure webpack so that it would bundle my svg-s from the scr/assets folder?
my webpack config:
const webpack = require('webpack');
const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CopyPlugin = require('copy-webpack-plugin');
const { VueLoaderPlugin } = require('vue-loader');
const env = process.env.NODE_ENV || 'development';
const mode = process.env.VUE_APP_MODE || 'not-fullstack';
module.exports = {
mode: 'development',
entry: './src/main.js',
output: {
filename: 'index.js',
path: path.resolve(__dirname, 'dist'),
},
resolve: {
alias: {
vue: '#vue/runtime-dom',
'#': path.join(__dirname, 'src'),
},
fallback: { crypto: false, stream: false },
},
module: {
rules: [
{
test: /\.vue$/,
use: [
{
loader: 'vue-loader',
},
],
},
{
test: /\.css$/i,
use: ['style-loader', 'css-loader', 'postcss-loader'],
},
{
test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
loader: 'url-loader',
options: {
limit: 10000,
name: 'images/[name].[hash].[ext]',
},
type: 'asset/resource',
},
{
test: /\.svg$/i,
use: [
{
loader: 'url-loader',
options: {
encoding: false,
},
},
],
},
],
},
plugins: [
new HtmlWebpackPlugin({
filename: 'index.html',
template: path.resolve(__dirname, './public/index.html'),
}),
new VueLoaderPlugin(),
new CopyPlugin([
{ noErrorOnMissing: true, from: './src/assets', to: 'images' },
]),
new webpack.DefinePlugin({
'process.env.NODE_ENV': JSON.stringify(env),
'process.env.VUE_APP_MODE': JSON.stringify(mode),
}),
],
devServer: {
historyApiFallback: true,
compress: true,
port: 3000,
},
};
And I reference my svg-s in my Vue component like this:
<img src="../../assets/logo.svg" alt="logo" />
As you can see I tried with the copy-webpack-plugin, maybe I just configured it wrong.
Thank you for your help in advance!

The config in webpack5 changed a lot
{
loader: 'url-loader',
options: {
encoding: false,
},
This is not working anymore. The url-loader is even removed from the npm packages.
The current way is found in the documentation
https://webpack.js.org/guides/asset-management/#loading-images

React + Webpack: "RuntimeError: memory access out of bounds"

I've recently developed a react + webpack application that is deployed using
AWS Amplify. I've been getting a strange error that is logged on Sentry, but can't
find a way to replicate the bug.
RuntimeError: memory access out of bounds
I suspect it has something to do with my webpack configuration, but I don't know whats wrong.
I never used wasm, but it seems to be related to it.
Here is my production level webpack configuration.
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const TerserPlugin = require('terser-webpack-plugin');
const env = require('../environment/prod.env');
const commonPaths = require('./paths');
const webpack = require('webpack');
const SentryWebpackPlugin = require('#sentry/webpack-plugin');
module.exports = {
mode: 'production',
devtool: 'source-map',
output: {
filename: `${commonPaths.jsFolder}/[name].[hash].js`,
path: commonPaths.outputPath,
chunkFilename: `${commonPaths.jsFolder}/[name].[chunkhash].js`,
},
optimization: {
minimizer: [
new TerserPlugin({
parallel: true,
cache: true,
sourceMap: true,
}),
new OptimizeCSSAssetsPlugin(),
],
splitChunks: {
cacheGroups: {
vendors: {
test: /[\\/]node_modules[\\/]/,
name: 'vendors',
chunks: 'initial',
},
async: {
test: /[\\/]node_modules[\\/]/,
name: 'async',
chunks: 'async',
minChunks: 4,
},
},
},
runtimeChunk: true,
},
module: {
rules: [
{
test: /\.scss$/,
use: [
{ loader: 'style-loader' },
{
loader: 'css-loader',
options: {
sourceMap: true,
},
},
{
loader: 'sass-loader',
options: {
sourceMap: true,
},
},
],
},
{
test: /\.css$/,
use: [
{
loader: 'style-loader',
},
{
loader: 'css-loader',
options: {
sourceMap: true,
},
},
],
},
],
},
plugins: [
new webpack.DefinePlugin({
'process.env': env,
}),
new MiniCssExtractPlugin({
filename: `${commonPaths.cssFolder}/[name].css`,
chunkFilename: `${commonPaths.cssFolder}/[name].css`,
}),
],
};
Here is also my common webpack configuration
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const ScriptExtHtmlWebpackPlugin = require('script-ext-html-webpack-plugin');
const commonPaths = require('./paths');
module.exports = {
context: commonPaths.srcPath,
entry: commonPaths.entryPath,
output: {
path: commonPaths.outputPath,
filename: 'js/[name].js',
},
resolve: {
extensions: ['.ts', '.js', '.html', '.vue'],
alias: {
'~': commonPaths.srcPath,
},
},
module: {
rules: [
{
test: /\.(js|jsx)$/,
include: commonPaths.srcPath,
exclude: /node_modules/,
loader: 'babel-loader',
options: {
plugins: ['react-hot-loader/babel'],
},
},
{
test: /\.(png|jpg|gif|svg)$/,
use: [
{
loader: 'file-loader',
options: {
name: 'assets/img/[name].[hash:8].[ext]',
publicPath: '/',
},
},
],
},
{
test: /\.(mp3)$/,
use: [
{
loader: 'file-loader',
options: {
name: 'assets/audio/[name].[hash:8].[ext]',
publicPath: '/',
},
},
],
},
{
test: /\.(ttc|ttf|eot)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
use: [
{
loader: 'file-loader',
options: {
name: 'assets/fonts/[name].[hash:8].[ext]',
publicPath: '/',
},
},
],
},
],
},
serve: {
content: commonPaths.entryPath,
dev: {
publicPath: commonPaths.outputPath,
},
open: true,
},
resolve: {
modules: ['src', 'node_modules', 'bower_components', 'shared', '/shared/vendor/modules'],
extensions: ['*', '.js', '.jsx'],
},
plugins: [
new webpack.ProgressPlugin(),
new HtmlWebpackPlugin({
favicon: './icon.png',
template: commonPaths.templatePath,
}),
new ScriptExtHtmlWebpackPlugin({
defaultAttribute: 'async',
}),
],
};
Any help would really help. Thanks.

Try to restart your server and make sure you reinstall node modules.

Webpack Build Speed performance

The Webpack Bulid runs pretty slow, project background is a community portal developed in Vue.js...
Can anybody tell if there is any potential for improvement and if so, what?
I wonder if the time for the build process of 37401ms can still be changed by changing the codebase?
const path = require('path');
const fs = require('fs');
const webpack = require('webpack');
const glob = require('glob');
const VueLoaderPlugin = require('vue-loader/lib/plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const autoprefixer = require('autoprefixer');
const statsSettings = {
all: false,
modules: true,
maxModules: 0,
errors: true,
warnings: false,
moduleTrace: true,
errorDetails: true,
timings: true,
performance: true,
builtAt: true,
};
const {
rootDir,
srcDir,
assetsDir,
stylesDir,
buildDir,
sitepackageDir,
publicPath,
} = require('./config');
const chunks = glob.sync(path.join(rootDir, srcDir, 'pages/**/index.js'))
.reduce((obj, file) => {
const name = path.basename(path.dirname(file));
return {
...obj,
[name]: file,
};
}, {});
module.exports = env => {
return {
mode: env.production ? 'production' : 'development',
context: path.join(rootDir, srcDir),
entry: chunks,
output: {
path: path.join(rootDir, buildDir),
filename: '[name].js',
publicPath: env.production ? publicPath : '',
},
devtool: env.production ? false : 'cheap-module-eval-source-map',
devServer: {
contentBase: path.join(rootDir, buildDir),
inline: true,
proxy: {
'/api/v0': 'http://localhost:4000',
},
},
watchOptions: {
ignored: env.watch ? 'node_modules' : '',
aggregateTimeout: 300,
},
stats: env.watch ? statsSettings : 'normal',
module: {
rules: [
{
test: /\.vue$/,
include: [
path.join(rootDir, srcDir),
require.resolve('bootstrap-vue'),
],
loader: 'vue-loader',
},
{
test: /\.js$/,
include: [
path.join(rootDir, srcDir),
require.resolve('bootstrap-vue'),
],
loader: 'babel-loader',
},
{
test: /\.(css|scss)$/,
use: [
env.production ? MiniCssExtractPlugin.loader : 'vue-style-loader',
'css-loader',
{
loader: 'postcss-loader',
options: {
plugins: [
autoprefixer({
browsers: ['>1%', 'last 2 versions', 'not ie < 11'],
}),
],
},
},
{
loader: 'sass-loader',
options: {
includePaths: [
path.join(rootDir, srcDir, stylesDir),
],
},
},
],
},
{
test: /\.(jpg|jpeg|png|gif|webp|svg|eot|otf|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$/,
loader: 'file-loader',
options: {
name: `${assetsDir}/_processed_/[name].[hash:4].[ext]`,
},
},
],
},
optimization: {
runtimeChunk: {
name: '_runtime',
},
splitChunks: {
cacheGroups: {
// we need to figure out if it's worth having a common chunk
// or if each entry chunk should be somewhat self-contained
common: {
chunks: 'initial',
name: '_common',
minChunks: 2,
minSize: 0,
},
vendor: {
test: /node_modules/,
chunks: 'initial',
name: '_vendor',
enforce: true,
},
},
},
},
resolve: {
extensions: ['.js', '.json', '.vue'],
alias: {
'#app': path.join(rootDir, srcDir),
// although we're using single file components that can be pre-compiled,
// we want to dynamically mounting them in the DOM html.
// this is way we need to alias 'vue' to use the runtime + compiler build here.
// see: https://vuejs.org/v2/guide/installation.html#Runtime-Compiler-vs-Runtime-only
vue$: 'vue/dist/vue.esm.js',
},
},
plugins: [
new webpack.DefinePlugin({
PAGES: JSON.stringify(Object.keys(chunks)),
}),
new VueLoaderPlugin(),
...plugHtmlTemplates(),
...plugExtractCss(env),
...plugCopyAssets(),
],
};
};
function plugHtmlTemplates () {
return glob.sync(path.join(rootDir, srcDir, 'pages/**/template.html'))
.map(template => {
const name = path.basename(path.dirname(template));
return {
template,
filename: `${name}.html`,
chunks: ['_runtime', '_vendor', '_styles', '_common', name],
};
})
.map(htmlConfig => new HtmlWebpackPlugin(htmlConfig));
}
function plugExtractCss (env) {
if (!env.production) return [];
return [
new MiniCssExtractPlugin({
filename: '[name].css',
chunkFilename: '[name].css',
}),
];
}
function plugCopyAssets () {
const assetsSrcPath = path.join(rootDir, srcDir, assetsDir);
if (!fs.existsSync(assetsSrcPath)) return [];
return [
new CopyWebpackPlugin([
{ from: assetsSrcPath, to: path.join(rootDir, buildDir, path.basename(assetsDir)) },
// this is required for the icons to be selectable in the backend
{ from: path.join(assetsSrcPath, 'icons/'), to: path.join(rootDir, sitepackageDir, 'Resources/Public/Icons/') },
// this is required for avatars to be available; we must not check them in in fileadmin since they would
// prevent having the dir linked by Deployer during a deployment
{ from: path.join(rootDir, '../packages/users/Resources/Private/Images/Avatars/'), to: path.join(rootDir, buildDir, 'static/avatars/') },
]),
];
}
The question is whether you can improve the performance by using different plugins or summarizing steps...

I have a similar configuration. My configuration built ~33 seconds. I added a cache-loader package and decrease build time to ~17 seconds.
npm install --save-dev cache-loader
config:
rules: [
//rules here
{
test: /\.vue$/,
use: [
{
loader: 'cache-loader',
options: {}
},
{
loader: 'vue-loader',
options: vueLoaderConfig
}
],
},
{
test: /\.js$/,
use: [
{
loader: 'cache-loader',
options: {}
},
{
loader: 'babel-loader'
}
],
include: [resolve('src'), resolve('test'), resolve('node_modules/webpack-dev-server/client')]
}
]

Local video will not load - Webpack

I can't get a simple video to load/play, so I decided to try looking at the webpack file and it seems fine. The code is below.
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');
const protocol = process.env.HTTPS === 'true' ? 'https' : 'http';
const host = process.env.HOST || '0.0.0.0';
const port = parseInt(process.env.PORT, 10) || 3000;
const publicPath = `${protocol}://${host}:${port}/`;
const publicUrl = '';
const env = getClientEnvironment(publicUrl);
module.exports = {
devtool: 'cheap-module-source-map',
entry: [
require.resolve('./polyfills'),
require.resolve('webpack-dev-server/client') + `?${publicPath}`,
require.resolve('webpack/hot/dev-server'),
paths.appIndexJs,
],
output: {
pathinfo: true,
filename: 'static/js/bundle.js',
chunkFilename: 'static/js/[name].chunk.js',
publicPath: publicPath,
devtoolModuleFilenameTemplate: info =>
path.resolve(info.absoluteResourcePath).replace(/\\/g, '/'),
},
resolve: {
modules: ['node_modules', paths.appNodeModules].concat(
process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
),
extensions: ['.web.js', '.mjs', '.js', '.json', '.web.jsx', '.jsx'],
alias: {
'react-native': 'react-native-web',
},
plugins: [
new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson]),
],
},
module: {
strictExportPresence: true,
rules: [
{
test: /\.(js|jsx|mjs)$/,
enforce: 'pre',
use: [
{
options: {
formatter: eslintFormatter,
eslintPath: require.resolve('eslint'),
},
loader: require.resolve('eslint-loader'),
},
],
include: paths.appSrc,
},
{
oneOf: [
{
test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
loader: require.resolve('url-loader'),
options: {
limit: 10000,
name: 'static/media/[name].[hash:8].[ext]',
},
},
{
test: /\.(js|jsx|mjs)$/,
include: paths.appSrc,
loader: require.resolve('babel-loader'),
options: {
cacheDirectory: true,
},
},
{
test: /\.css$/,
use: [
require.resolve('style-loader'),
{
loader: require.resolve('css-loader'),
options: {
importLoaders: 1,
},
},
{
loader: require.resolve('postcss-loader'),
options: {
ident: 'postcss',
plugins: () => [
require('postcss-flexbugs-fixes'),
autoprefixer({
browsers: [
'>1%',
'last 4 versions',
'Firefox ESR',
'not ie < 9', // React doesn't support IE8 anyway
],
flexbox: 'no-2009',
}),
],
},
},
],
},
{
test: /\.(html)$/,
loader: require.resolve('html-loader'),
},
{
test: /\.mp4$/,
use: [
{
loader: require.resolve('file-loader'),
options: {
name: 'static/media/[name].[hash:8].[ext]'
}
}
]
},
{
exclude: [/\.js$/, /\.html$/, /\.json$/],
loader: require.resolve('file-loader'),
options: {
name: 'static/media/[name].[hash:8].[ext]',
},
},
],
},
],
},
plugins: [
new InterpolateHtmlPlugin(env.raw),
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
}),
new webpack.NamedModulesPlugin(),
new webpack.DefinePlugin(env.stringified),
new webpack.HotModuleReplacementPlugin(),
new CaseSensitivePathsPlugin(),
new WatchMissingNodeModulesPlugin(paths.appNodeModules),
new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
],
node: {
dgram: 'empty',
fs: 'empty',
net: 'empty',
tls: 'empty',
child_process: 'empty',
},
performance: {
hints: false,
},
target: 'node-webkit',
};
This is my App.js below. I took out everything that doesn't matter. It's a simple call to an mp4 file.
import React, { Component } from 'react';
import { curious } from '#curi/react';
import AttractLoop from '../../assets/videos/video.mp4';
class App extends Component {
render() {
return (
<div className="app-container">
<div className="attract-loop">
<video width="1080" height="1920">
<source src={ AttractLoop } type="video/mp4" />
</video>
</div>
</div>
);
}
}
export default curious(App);
And here's a screenshot of my code inspector:
Update 1
I'm even trying to use this code from this SO question:
<video width="1080" height="1920" autoPlay loop src={ AttractLoop } type="video/mp4" />
Update 2
I downloaded the example Big Buck Bunny video to rule out that my video was encoded incorrectly. Getting the same result, a blank page.

I wanted to place the answer to the real issue, although #Jonny had some good webpack changes that should help others.
My Create React App is mixed with Nw.js, which is a platform that allows users to create exe files from their projects. I found out from https://github.com/naviapps/create-nw-react-app/issues/6 that NW.js does not allow mp4s by default so I needed to either configure my project settings to accept them or change the format of my video to ogv (or others).

The problem here is that your webpack.config.js is set up to output your media to a static directory. With ExpressJS, the static directory that you define should not be used in the public path. That path maps to the root of your public path. To fix this problem, you need to tweak your webpack.config.js to still output to this static directory, but not write it to the filename when its loaded with file-loader. Try something like this:
module.exports = {
devtool: 'cheap-module-source-map',
entry: [
require.resolve('./polyfills'),
require.resolve('webpack-dev-server/client') + `?${publicPath}`,
require.resolve('webpack/hot/dev-server'),
paths.appIndexJs,
],
output: {
pathinfo: true,
filename: 'js/bundle.js',
chunkFilename: 'js/[name].chunk.js',
// double check that this has it's backslashes in the right place
path: path.resolve(__dirname, publicPath + '/static'),
publicPath: publicPath',
devtoolModuleFilenameTemplate: info =>
path.resolve(info.absoluteResourcePath).replace(/\\/g, '/'),
},
resolve: {
modules: ['node_modules', paths.appNodeModules].concat(
process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
),
extensions: ['.web.js', '.mjs', '.js', '.json', '.web.jsx', '.jsx'],
alias: {
'react-native': 'react-native-web',
},
plugins: [
new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson]),
],
},
module: {
strictExportPresence: true,
rules: [
{
test: /\.(js|jsx|mjs)$/,
enforce: 'pre',
use: [
{
options: {
formatter: eslintFormatter,
eslintPath: require.resolve('eslint'),
},
loader: require.resolve('eslint-loader'),
},
],
include: paths.appSrc,
},
{
oneOf: [
{
test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
loader: require.resolve('url-loader'),
options: {
limit: 10000,
//name: 'static/media/[name].[hash:8].[ext]',
name: 'media/[name].[hash:8].[ext]',
},
},
{
test: /\.(js|jsx|mjs)$/,
include: paths.appSrc,
loader: require.resolve('babel-loader'),
options: {
cacheDirectory: true,
},
},
{
test: /\.css$/,
use: [
require.resolve('style-loader'),
{
loader: require.resolve('css-loader'),
options: {
importLoaders: 1,
},
},
{
loader: require.resolve('postcss-loader'),
options: {
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',
}),
],
},
},
],
},
{
test: /\.(html)$/,
loader: require.resolve('html-loader'),
},
{
test: /\.mp4$/,
use: [
{
loader: require.resolve('file-loader'),
options: {
//name: 'static/media/[name].[hash:8].[ext]'
name: 'media/[name].[hash:8].[ext]'
}
}
]
},
{
exclude: [/\.js$/, /\.html$/, /\.json$/],
loader: require.resolve('file-loader'),
options: {
//name: 'static/media/[name].[hash:8].[ext]',
name: 'media/[name].[hash:8].[ext]',
},
},
],
},
],
},
plugins: [
new InterpolateHtmlPlugin(env.raw),
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
}),
new webpack.NamedModulesPlugin(),
new webpack.DefinePlugin(env.stringified),
new webpack.HotModuleReplacementPlugin(),
new CaseSensitivePathsPlugin(),
new WatchMissingNodeModulesPlugin(paths.appNodeModules),
new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
],
node: {
dgram: 'empty',
fs: 'empty',
net: 'empty',
tls: 'empty',
child_process: 'empty',
},
performance: {
hints: false,
},
target: 'node-webkit',
};

webpack dev server does not show the content

I have the following problem when running the webpack dev server:
when I run npm start, it show the following:
➜ directory git:(staging) ✗ npm start
directory #1.0.0 start directory
BUILD_DEV=1 BUILD_STAGING=1 ./node_modules/webpack-dev-server/bin/webpack-dev-server.js
http://localhost:8080/
webpack result is served from /undefined/
content is served from
directory
404s will fallback to /index.html
Hash: 75773622412153d5f921
Version: webpack 1.12.11
Time: 43330ms
I guess the problem might because the following line:
webpack result is served from /undefined/
When I open the browser at http://localhost:8080/, it appear as follow:
Cannot GET /
and there is no thing in the console.
Do you have any ideas for this problem ?
UPDATE: WEBPACK CONFIG FILE
const webpack = require('webpack');
const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const merge = require('webpack-merge');
const nodeModulesDir = path.resolve(__dirname, 'node_modules');
const deps = [
'moment/min/moment.min.js',
'underscore/underscore-min.js',
];
/* Include SASS path here if you want to this in your sass files:
* #import 'bourbon';
*/
const bourbon = require('node-bourbon').includePaths;
const TARGET = process.env.npm_lifecycle_event;
const ROOT_PATH = path.resolve(__dirname);
const SASS_DEPS = [bourbon].toString();
const BUILD_NUMBER = process.env.CI_BUILD_NUMBER;
const common = {
entry: path.resolve(ROOT_PATH, 'app/index.js'),
output: {
filename: BUILD_NUMBER + '-[hash].js',
path: path.resolve(ROOT_PATH, 'build'),
publicPath: `/${BUILD_NUMBER}/`,
},
module: {
loaders: [
{
test: /\.scss$/,
loaders: ['style', 'css', 'sass?includePaths[]=' + SASS_DEPS],
include: path.resolve(ROOT_PATH, 'app'),
},
{
test: /\.css$/,
loaders: [
'style',
'css?modules&importLoaders=1&localIdentName=[name]__[local]___[hash:base64:5]',
'sass?includePaths[]=' + SASS_DEPS,
'postcss'
],
include: path.resolve(ROOT_PATH),
exclude: /(pure\/grids|Grids).*\.css$/,
},
{
test: /(pure\/grids|Grids).*\.css$/,
loaders: [
'style',
'css',
'sass?includePaths[]=' + SASS_DEPS,
],
include: path.resolve(ROOT_PATH),
},
{
test: /\.woff(2)?(\?v=[0-9]\.[0-9]\.[0-9])?$/,
loader: 'url-loader?limit=10000&minetype=application/font-woff',
},
{ test: /\.(ttf|eot|svg)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
loader: 'file-loader',
},
{
test: /\.json$/,
loader: 'json',
},
],
},
plugins: [
new HtmlWebpackPlugin({
title: 'My App',
template: path.resolve(ROOT_PATH, 'app/index.html'),
inject: 'body',
minify: {
removeComments: true,
collapseWhitespace: true,
},
}),
new webpack.DefinePlugin({
__DEV__: JSON.stringify(JSON.parse(process.env.BUILD_DEV || 'false')),
__STAGING__: JSON.stringify(JSON.parse(process.env.BUILD_STAGING || 'false')),
__API_HOST__: JSON.stringify(process.env.BUILD_STAGING ? 'my.api' : 'my.api'),
}),
],
resolve: {
alias: {
'styles': path.resolve(ROOT_PATH, 'app/styles'),
},
extensions: ['', '.js', '.jsx', '.json'],
},
postcss: function() {
return [
require('postcss-import'),
require('autoprefixer'),
require('postcss-cssnext'),
]
}
};
if (TARGET === 'start' || !TARGET) {
module.exports = merge(common, {
output: {
filename: '[hash].js',
path: path.resolve(ROOT_PATH, 'build'),
publicPath: '/',
},
devtool: 'eval-source-map',
module: {
loaders: [
{
test: /\.jsx?$/,
loaders: [
'react-hot',
'babel-loader'
],
include: path.resolve(ROOT_PATH, 'app'),
},
],
},
devServer: {
colors: true,
historyApiFallback: true,
hot: true,
inline: true,
progress: true,
},
plugins: [
new webpack.HotModuleReplacementPlugin(),
],
});
} else if (TARGET === 'build' || TARGET === 'builds') {
const config = {
resolve: {
alias: {},
},
module: {
loaders: [
{
test: /\.jsx?$/,
loader: 'babel-loader',
include: path.resolve(ROOT_PATH, 'app'),
},
],
noParse: [],
},
plugins: [
new webpack.optimize.UglifyJsPlugin({
minimize: true,
compressor: {
screw_ie8: true,
warnings: false,
},
compress: {
warnings: false,
},
output: {
comments: false,
},
}),
new webpack.optimize.DedupePlugin(),
new webpack.DefinePlugin({
'process.env': { 'NODE_ENV': JSON.stringify(process.env.NODE_ENV) },
}),
],
};
deps.forEach((dep) => {
const depPath = path.resolve(nodeModulesDir, dep);
config.resolve.alias[dep.split(path.sep)[0]] = depPath;
config.module.noParse.push(depPath);
});
module.exports = merge(common, config);
}

Same problem occurred to me when i started using babel-loader > 6.
It was fixed by adding contentBase in webpack dev server configuration.
In my case it looked like this
new WebPackDevServer(webpack(config), {
publicPath: config.output.publicPath,
hot: true,
historyApiFallback: true,
contentBase: __dirname + '/public'
}).listen(3000, 'localhost')

I would be great to see your webpack config file to pin point the exact problem, but from the error message, there could be multiple problem
Make sure you are on the right port
Make sure your webpack config has
path and public path setup
Make sure you have contentBase setup as
well
Without seeing your webpack file and more concrete detail, it is quite hard to pinpoint the issue. But you can always go to https://webpack.github.io/docs/webpack-dev-server.html for information on how to set it up.