Develop Reference

Is there a webpack loader / NPM script that compiles solely my SCSS files, similar to how Gulp works?

I've been using Webpack and have found it great for bundling, polyfilling and all sorts of other functions for Javascript, however I wondered if there was a known loader / NPM script that automatically compiles designated .scss files into one.
I have previously used the sass-loader, extract-css plugin to take SCSS out of components and bundle them into the final dist file which is fine for web apps. However, a lot of my day to day work is spent working on traditional websites, so it's often not generated via components / modules.
What I'm looking for, is anytime I save an .scss file, if this is included within my entry points / rules, it automatically compiles all .scss files into a dist/styles.css sheet.
I've had a look online and Gulp seems to offer this, but it looks like Webpack already does 90% of what Gulp offers so ideally would want to keep this all in Webpack.
Thanks in advance

import the scss file on your entry point like this import './style.scss';.
Install mini-css-extract-plugin.
Then add this to your webpack config
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
module: {
rules: [
{
test: /\.(sc|c)ss$/,
use: [
// { loader: 'style-loader' },
{
loader: MiniCssExtractPlugin.loader, // extract css to a single file
options: {
publicPath: '../',
hmr: false
}
},
{
loader: 'css-loader', options: {
sourceMap: false
}
},
{
loader: 'postcss-loader',
options: {
sourceMap: false,
plugins: [
require('autoprefixer')
]
}
},
{
loader: 'sass-loader', options: { sourceMap: false }
}
],
exclude: /node_modules/
}
],
},

Webpack doesn't recognize jsx code at node modules

I started a new project with the latest version of create-react-app. I'm trying to consume a private NPM library. This library ships the code and it's the responsibility of the app importing the packages to transpile the components from it.
I included the path of the library to babel-loader but webpack still doesn't apply babel to it.
This is the error message I'm getting from the only component I imported to my project:
./node_modules/PRIVATE-LIBRARY/Page404/index.js
SyntaxError: /home/victor/app/node_modules/PRIVATE-LIBRARY/Page404/index.js: Unexpected token (12:2)
10 |
11 | const Page404 = () => (
> 12 | <div className="page404">
| ^
13 | <div className="page404__content">
14 | <h2 className="page404__title">This is not the page<br/> you are looking for</h2>
And this is my webpack.config.dev.js file
'use strict';
const path = require('path');
const webpack = require('webpack');
const PnpWebpackPlugin = require('pnp-webpack-plugin');
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 ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
const getCSSModuleLocalIdent = require('react-dev-utils/getCSSModuleLocalIdent');
const getClientEnvironment = require('./env');
const paths = require('./paths');
const ManifestPlugin = require('webpack-manifest-plugin');
const getCacheIdentifier = require('react-dev-utils/getCacheIdentifier');
const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
// 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);
// style files regexes
const cssRegex = /\.css$/;
const cssModuleRegex = /\.module\.css$/;
const sassRegex = /\.(scss|sass)$/;
const sassModuleRegex = /\.module\.(scss|sass)$/;
// common function to get style loaders
const getStyleLoaders = (cssOptions, preProcessor) => {
const loaders = [
require.resolve('style-loader'),
{
loader: require.resolve('css-loader'),
options: cssOptions,
},
{
// Options for PostCSS as we reference these options twice
// Adds vendor prefixing based on your specified browser support in
// package.json
loader: require.resolve('postcss-loader'),
options: {
// Necessary for external CSS imports to work
// https://github.com/facebook/create-react-app/issues/2677
ident: 'postcss',
plugins: () => [
require('postcss-flexbugs-fixes'),
require('postcss-preset-env')({
autoprefixer: {
flexbox: 'no-2009',
},
stage: 3,
}),
],
},
},
];
if (preProcessor) {
loaders.push(require.resolve(preProcessor));
}
return loaders;
};
// 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 = {
mode: 'development',
// You may want 'eval' instead if you prefer to see the compiled output in DevTools.
// See the discussion in https://github.com/facebook/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.
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'),
// 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: {
// 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, '/'),
},
optimization: {
// Automatically split vendor and commons
// https://twitter.com/wSokra/status/969633336732905474
// https://medium.com/webpack/webpack-4-code-splitting-chunk-graph-and-the-splitchunks-optimization-be739a861366
splitChunks: {
chunks: 'all',
name: false,
},
// Keep the runtime chunk seperated to enable long term caching
// https://twitter.com/wSokra/status/969679223278505985
runtimeChunk: true,
},
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/facebook/create-react-app/issues/253
modules: ['node_modules'].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/facebook/create-react-app/issues/290
// `web` extension prefixes have been added for better support
// for React Native Web.
extensions: ['.mjs', '.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',
components: path.resolve(paths.appSrc, 'components'),
assets: path.resolve(paths.appSrc, 'assets'),
utils: path.resolve(paths.appSrc, 'utils'),
},
plugins: [
// Adds support for installing with Plug'n'Play, leading to faster installs and adding
// guards against forgotten dependencies and such.
PnpWebpackPlugin,
// 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, [paths.appPackageJson]),
],
},
resolveLoader: {
plugins: [
// Also related to Plug'n'Play, but this time it tells Webpack to load its loaders
// from the current package.
PnpWebpackPlugin.moduleLoader(module),
],
},
module: {
strictExportPresence: true,
rules: [
// Disable require.ensure as it's not a standard language feature.
{ parser: { requireEnsure: false } },
// First, run the linter.
// It's important to do this before Babel processes the JS.
{
test: /\.(js|mjs|jsx)$/,
enforce: 'pre',
use: [
{
options: {
formatter: require.resolve('react-dev-utils/eslintFormatter'),
eslintPath: require.resolve('eslint'),
},
loader: require.resolve('eslint-loader'),
},
],
include: paths.appSrc,
},
{
// "oneOf" will traverse all following loaders until one will
// match the requirements. When no loader matches it will fall
// back to the "file" loader at the end of the loader list.
oneOf: [
// "url" loader works like "file" loader except that it embeds assets
// smaller than specified limit in bytes as data URLs to avoid requests.
// A missing `test` is equivalent to a match.
{
test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
loader: require.resolve('url-loader'),
options: {
limit: 10000,
name: 'static/media/[name].[hash:8].[ext]',
},
},
// Process application JS with Babel.
// The preset includes JSX, Flow, and some ESnext features.
{
test: /\.(js|mjs|jsx)$/,
include: [
paths.appSrc,
paths.privateLib,
],
loader: require.resolve('babel-loader'),
options: {
customize: require.resolve(
'babel-preset-react-app/webpack-overrides'
),
plugins: [
[
require.resolve('babel-plugin-named-asset-import'),
{
loaderMap: {
svg: {
ReactComponent: '#svgr/webpack?-prettier,-svgo![path]',
},
},
},
],
],
// 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,
// Don't waste time on Gzipping the cache
cacheCompression: false,
},
},
// Process any JS outside of the app with Babel.
// Unlike the application JS, we only compile the standard ES features.
{
test: /\.(js|mjs)$/,
exclude: /#babel(?:\/|\\{1,2})runtime/,
loader: require.resolve('babel-loader'),
options: {
babelrc: false,
configFile: false,
compact: false,
presets: [
[
require.resolve('babel-preset-react-app/dependencies'),
{ helpers: true },
],
],
cacheDirectory: true,
// Don't waste time on Gzipping the cache
cacheCompression: false,
// If an error happens in a package, it's possible to be
// because it was compiled. Thus, we don't want the browser
// debugger to show the original code. Instead, the code
// being evaluated would be much more helpful.
sourceMaps: false,
},
},
// "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.
// By default we support CSS Modules with the extension .module.css
{
test: cssRegex,
exclude: cssModuleRegex,
use: getStyleLoaders({
importLoaders: 1,
}),
},
// Adds support for CSS Modules (https://github.com/css-modules/css-modules)
// using the extension .module.css
{
test: cssModuleRegex,
use: getStyleLoaders({
importLoaders: 1,
modules: true,
getLocalIdent: getCSSModuleLocalIdent,
}),
},
// Opt-in support for SASS (using .scss or .sass extensions).
// Chains the sass-loader with the css-loader and the style-loader
// to immediately apply all styles to the DOM.
// By default we support SASS Modules with the
// extensions .module.scss or .module.sass
{
test: sassRegex,
exclude: sassModuleRegex,
use: getStyleLoaders({ importLoaders: 2 }, 'sass-loader'),
},
// Adds support for CSS Modules, but using SASS
// using the extension .module.scss or .module.sass
{
test: sassModuleRegex,
use: getStyleLoaders(
{
importLoaders: 2,
modules: true,
getLocalIdent: getCSSModuleLocalIdent,
},
'sass-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.
// This loader doesn't use a "test" so it will catch all modules
// that fall through the other loaders.
{
// Exclude `js` files to keep "css" loader working as it injects
// its runtime that would otherwise be processed through "file" loader.
// Also exclude `html` and `json` extensions so they get processed
// by webpacks internal loaders.
exclude: [/\.(js|mjs|jsx)$/, /\.html$/, /\.json$/],
loader: require.resolve('file-loader'),
options: {
name: 'static/media/[name].[hash:8].[ext]',
},
},
],
},
// ** STOP ** Are you adding a new loader?
// Make sure to add the new loader(s) before the "file" loader.
],
},
plugins: [
// Generates an `index.html` file with the <script> injected.
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
}),
// 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(HtmlWebpackPlugin, env.raw),
// This gives some necessary context to module not found errors, such as
// the requesting resource.
new ModuleNotFoundPlugin(paths.appPath),
// 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/facebook/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/facebook/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$/, /moment$/),
// Generate a manifest file which contains a mapping of all asset filenames
// to their corresponding output file so that tools can pick it up without
// having to parse `index.html`.
new ManifestPlugin({
fileName: 'asset-manifest.json',
publicPath: publicPath,
}),
],
// 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',
child_process: 'empty',
},
// Turn off performance processing because we utilize
// our own hints via the FileSizeReporter
performance: false,
};
Where paths.privateLib contains privateLib: resolveApp('node_modules/PRIVATE-LIBRARY'),
I’m using this library in three other apps with webpack 3 without problems

The problem was that the default behaviour of .babelrc and of "babel" at package.json changed.
For babel versions before v 7, the default behaviour was that babel-loader also included node-modules files. This changed because of some hard to track bugs that raised as a consequence of this behaviour.
Now, if you want configs to also affect your node_modules, you should define a babel.config.js file instead of .babelrc or "babel" at package.json configs.
This babel.config.js affects node_modules by default. It should be placed at the same level of your package.json file
Here is an example of my configs:
module.exports = function (api) {
const presets = ['react-app'];
api.cache.never();
return { presets };
};
Babel docs for further information about babel.config.js

Sourcemaps not mapping correctly except "entry" specified in webpack

I'm using ASP.NET Core 2.0. If anyone wants to see detailed code or run it themselves, the code can be found here: https://github.com/jakelauer/BaseballTheater/tree/master/BaseballTheaterCore
My basic problem is that I'm expecting each generated js file in my project to have a sourcemap back to the original .ts or .tsx file. That is not working except for my entry file (./ClientApp/boot.tsx).
Here is my webpack.config.js:
const path = require('path');
const webpack = require('webpack');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;
const bundleOutputDir = './wwwroot/dist';
module.exports = (env) => {
const isDevBuild = !(env && env.prod);
return [{
stats: { modules: false },
entry: { 'main': './ClientApp/boot.tsx' },
resolve: { extensions: ['.js', '.jsx', '.ts', '.tsx'] },
output: {
path: path.join(__dirname, bundleOutputDir),
filename: '[name].js',
publicPath: 'dist/'
},
module: {
rules: [
{ test: /\.tsx?$/, include: /ClientApp/, use: 'awesome-typescript-loader?silent=true' },
{ test: /\.css$/, use: isDevBuild ? ['style-loader', 'css-loader'] : ExtractTextPlugin.extract({ use: 'css-loader?minimize' }) },
{
test: /\.scss/,
use: ["style-loader", "css-loader", "sass-loader"]
},
{ test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' }
]
},
plugins: [
new CheckerPlugin(),
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./wwwroot/dist/vendor-manifest.json')
})
].concat(isDevBuild ? [
// Plugins that apply in development builds only
new webpack.SourceMapDevToolPlugin({
filename: '[file].map', // Remove this line if you prefer inline source maps
moduleFilenameTemplate: path.relative(bundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
})
] : [
// Plugins that apply in production builds only
new webpack.optimize.UglifyJsPlugin(),
new ExtractTextPlugin('site.css')
])
}];
};
Based on my interpretation of this file and limited understanding of webpack, this should work. Each of my files does generated a .js.map file, and it appears to be referenced in the generated .js file. However, none of them actually load except the one for boot.tsx when debugging in Chrome.
An example of one of the js files in Chrome:
And that file does have the correct files to load:
When I open main.js.map in /wwwroot/dist/ and Ctrl+F for ts inside there, I only find boot.tsx and none of the other .ts or .tsx files I would expect to find.
I am no webpack expert, so I'm not sure what else to do!

From the comments, we've come to the solution by:
upgrading to the newest webpack (v4 in this case) and
installing the source-map loader via npm install --save-dev source-map-loader and
setting devtool: 'source-map' in the webpack.config.js.
The source-map option tells webpack to emit a full separate source map file. This is from the webpack docs:
source-map - A full SourceMap is emitted as a separate file. It adds a reference comment to the bundle so development tools know where to find it.

Error importing Avataar react component

I installed the componet with npm
$npm install avataaars --save
In my react Component I import with
import Avatar from 'avataaars'
But in my Chrome js console I get an error
Uncaught SyntaxError: Unexpected token * bundle.js:96525
if I remove the Avatar import my react app works as before. What can be wrong? Something messed up in my wepack.config. I have no clue how to solve this :) Where should I start looking?
My webpack.config.dev.js
var autoprefixer = require('autoprefixer');
var webpack = require('webpack');
var HtmlWebpackPlugin = require('html-webpack-plugin');
var CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
var WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
var getClientEnvironment = require('./env');
var 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.
var 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.
var publicUrl = '';
// Get environment variables to inject into our app.
var 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'),
// 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',
// This is the URL that app is served from. We use "/" in development.
publicPath: publicPath
},
resolve: {
// This allows you to set a fallback for where Webpack should look for modules.
// We read `NODE_PATH` environment variable in `paths.js` and pass paths here.
// We use `fallback` instead of `root` because we want `node_modules` to "win"
// if there any conflicts. This matches Node resolution mechanism.
// https://github.com/facebookincubator/create-react-app/issues/253
fallback: paths.nodePaths,
// 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
extensions: ['.js', '.json', '.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'
}
},
module: {
// First, run the linter.
// It's important to do this before Babel processes the JS.
preLoaders: [
{
test: /\.(js|jsx)$/,
loader: 'eslint',
include: paths.appSrc,
}
],
loaders: [
// Default loader: load all assets that are not handled
// by other loaders with the url loader.
// Note: This list needs to be updated with every change of extensions
// the other loaders match.
// E.g., when adding a loader for a new supported file extension,
// we need to add the supported extension to this loader too.
// Add one new line in `exclude` for each 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.
// "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.
{
exclude: [
/\.html$/,
/\.(js|jsx)$/,
/\.css$/,
/\.json$/,
/\.woff$/,
/\.woff2$/,
/\.(ttf|svg|eot)$/
],
loader: 'url',
query: {
limit: 10000,
name: 'static/media/[name].[hash:8].[ext]'
}
},
// Process JS with Babel.
{
test: /\.(js|jsx)$/,
include: paths.appSrc,
loader: 'babel',
query: {
// 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$/,
loader: 'style!css?importLoaders=1!postcss'
},
// JSON is not enabled by default in Webpack but both Node and Browserify
// allow it implicitly so we also enable it.
{
test: /\.json$/,
loader: 'json'
},
// "file" loader for svg
{
test: /\.svg$/,
loader: 'file',
query: {
name: 'static/media/[name].[hash:8].[ext]'
}
},
// "file" loader for fonts
{
test: /\.woff$/,
loader: 'file',
query: {
name: 'fonts/[name].[hash].[ext]'
}
},
{
test: /\.woff2$/,
loader: 'file',
query: {
name: 'fonts/[name].[hash].[ext]'
}
},
{
test: /\.(ttf|eot)$/,
loader: 'file',
query: {
name: 'fonts/[name].[hash].[ext]'
}
},
// Truffle solidity loader to watch for changes in Solitiy files and hot
// reload contracts with webpack.
//
// CURRENTLY REMOVED DUE TO INCOMPATIBILITY WITH TRUFFLE 3
// Compile and migrate contracts manually.
//
/*{
test: /\.sol$/,
loader: 'truffle-solidity?network_id=123'
}*/
]
},
// We use PostCSS for autoprefixing only.
postcss: function() {
return [
autoprefixer({
browsers: [
'>1%',
'last 4 versions',
'Firefox ESR',
'not ie < 9', // React doesn't support IE8 anyway
]
}),
];
},
plugins: [
// Makes the public URL 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({
PUBLIC_URL: publicUrl
}),
// Generates an `index.html` file with the <script> injected.
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
}),
// Makes some environment variables available to the JS code, for example:
// if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`.
new webpack.DefinePlugin(env),
// 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)
],
// 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: {
fs: 'empty',
net: 'empty',
tls: 'empty'
}
};

Concat and minify all less files with Webpack without importing them

I have a folder of around 20 separate less files that I need to concatenate into a single file via Webpack and store this in my /dist folder. My current Webpack config file is as follows:
const path = require('path');
const webpack = require('webpack');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;
const bundleOutputDir = './wwwroot/dist';
module.exports = (env) => {
const isDevBuild = !(env && env.prod);
return [{
stats: { modules: false },
entry: { 'main': './ClientApp/boot.ts' },
resolve: { extensions: ['.js', '.ts'] },
output: {
path: path.join(__dirname, bundleOutputDir),
filename: '[name].js',
publicPath: '/dist/'
},
module: {
rules: [
{ test: /\.ts$/, include: /ClientApp/, use: 'awesome-typescript-loader?silent=true' },
{ test: /\.html$/, use: 'raw-loader' },
{ test: /\.css$/, use: isDevBuild ? ['style-loader', 'css-loader'] : ExtractTextPlugin.extract({ use: 'css-loader' }) },
{ test: /\.less/, use: ExtractTextPlugin.extract('style-loader', 'css-loader!less-loader') },
{ test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' }
]
},
plugins: [
new CheckerPlugin(),
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./wwwroot/dist/vendor-manifest.json')
})
].concat(isDevBuild ? [
// Plugins that apply in development builds only
new webpack.SourceMapDevToolPlugin({
filename: '[file].map', // Remove this line if you prefer inline source maps
moduleFilenameTemplate: path.relative(bundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
})
] : [
// Plugins that apply in production builds only
new webpack.optimize.UglifyJsPlugin(),
new ExtractTextPlugin('site.less'),
new ExtractTextPlugin('site.css')
])
}];
};
If I try and import each single .less file into the boot.ts entry file, I get a less error stating that the less variables that I've declared are not being recognised, which is how I came to the conclusion that I need to concat these files beforehand. I come from a gulp background, so any help to get me up and running with this would be greatly appreciated.
If there is an alternative way to get all less compiled to css and working correctly, without the need for concat, then I'm open to suggestions.

Webpack is a module bundler and uses the module syntax for JavaScript (ES6, CommonJS, AMD..), CSS (#import, url) and even HTML (through src attribute) to build the app's dependency graph and then serialize it in several bundles.
In your case, when you import the *.less files the errors are because you miss CSS modules. In other words, on the places where you have used variables defined in other file, that file was not #import-ed.
With Webpack it's recommended to modularize everything, therefore I would recommend to add the missing CSS modules. I had the same issue when I was migrating a project from Grunt to Webpack. Other temporary solution is to create an index.less file where you will #import all the less files (note: the order is important) and then import that file in app's entry file (ex. boot.ts).