Develop Reference

How can I get hot reloading (HMR) running with Webpack 5?

I am trying to get HMR running with webpack v5, but it does not work. When I modify and save a file, webpack re-compiles the project correctly, but the frontend does not update.
I read this article and followed the instructions: https://webpack.js.org/guides/hot-module-replacement/
This is my webpack config:
{
mode: 'development',
entry: {
babelpoly: 'babel-polyfill',
app: [ './src/index.js', './src/app.js' ]
},
plugins: [
BundleStatsWebpackPlugin { ... },
DefinePlugin { ... },
HtmlWebpackPlugin { ... }
],
stats: { ... },
output: {
path: '[pathTo]/dist',
filename: '[name].bundle.js',
chunkFilename: '[name].bundle.js'
},
optimization: {
splitChunks: { chunks: 'all' },
runtimeChunk: 'single',
usedExports: true,
mergeDuplicateChunks: true
},
module: {
rules: [
{
test: /\.(s[ac]ss)$/i,
include: path.resolve(ROOT, 'src'),
use: [
'style-loader', // Creates `style` nodes from JS strings
{
loader: 'css-loader', // Translates CSS into CommonJS
options: {
modules: {
mode: 'local',
localIdentName: devMode
? '[name]_[local]-[hash:base64:3]'
: '[local]-[hash:base64:5]',
},
},
},
{
loader: 'sass-loader', // compiles Sass to CSS
options: {
implementation: require('sass'),
},
},
],
},
{
test: /\.css$/,
include: [path.join(ROOT, 'node_modules')],
use: ['style-loader', 'css-loader'],
},
{
test: /\.(png|svg|jpg|gif)$/,
use: ['file-loader'],
},
{
test: /\.(woff|woff2|eot|ttf|otf)$/,
use: ['file-loader'],
},
{
test: /\.m?jsx?$/,
exclude: /(node_modules|bower_components)/,
use: {
loader: 'babel-loader',
options: {
presets: [
[
'#babel/preset-env',
{
useBuiltIns: 'entry',
corejs: 3,
},
],
'#babel/preset-react',
],
plugins: [['#babel/plugin-proposal-class-properties', {loose: true}]],
},
},
},
],
},
resolve: {
extensions: [ ... ],
alias: {
...
},
modules: [
...
]
},
devtool: 'inline-source-map',
devServer: {
port: 3003,
contentBase: '[pathTo]/dist',
host: '0.0.0.0',
hot: true,
compress: true,
disableHostCheck: true,
historyApiFallback: true,
overlay: { warnings: true, errors: true },
stats: { ... }
}
}
I am using:
webpack 5.7.0
webpack-cli 4.2.0
react 16.13
node 14.15.1
npm 6.14.8
I start webpack with this command: webpack serve --host 0.0.0.0 --config config/webpack.dev.js
What do I do wrong? Thanks for your help. :)

I believe it's a bug in webpack-dev-server v3 https://github.com/webpack/webpack-dev-server/issues/2758 when you're using it with webpack 5 and browserslist. You can wait for webpack-dev-server v4 https://github.com/webpack/webpack-dev-server/pull/2592#issuecomment-734400875, it will come soon, or use target: 'web' for the moment under your development mode.

Ignore .d.ts files for Webpack/Babel?

I'm using #teamsupercell/typings-for-css-modules-loader to generate TS types for my SASS modules. The output looks something like:
declare namespace LoginRouteStylesScssModule {
export interface ILoginRouteStylesScss {
card: string;
emailForm: string;
info: string;
input: string;
}
}
declare const LoginRouteStylesScssModule: LoginRouteStylesScssModule.ILoginRouteStylesScss & {
/** WARNING: Only available when `css-loader` is used without `style-loader` or `mini-css-extract-plugin` */
locals: LoginRouteStylesScssModule.ILoginRouteStylesScss;
};
export = LoginRouteStylesScssModule;
This lets it pass tsc. However, Babel is telling me 'export =' is not supported by #babel/plugin-transform-typescript. Please consider using 'export <value>;'. I want to just ignore .d.ts files since they're intended for tsc and not Webpack/Babel.
I tried exclude in .babelrc, exclude and ignore in webpack.config.js, and webpack.IgnorePlugin, but none of them work. How can I configure either Webpack or Babel to ignore them?
`webpack.config.js':
const path = require('path');
const childProcess = require('child_process');
const webpack = require('webpack');
const APP_ROOT = path.resolve('./src');
module.exports = {
entry: {
index: path.resolve('./src/main.tsx'),
},
output: {
path: path.resolve('./public/js'),
publicPath: '/js/',
},
module: {
rules: [
{
test: /\.(j|t)sx?$/,
include: [APP_ROOT],
exclude: [path.resolve('./node_modules')],
use: {
loader: 'babel-loader',
options: {},
},
},
{
test: /\.s?css$/,
include: [APP_ROOT],
exclude: [/node_modules/],
use: [
'#teamsupercell/typings-for-css-modules-loader',
{
loader: 'css-loader',
options: {
importLoaders: 1,
modules: {
localIdentName: '[name]__[local]',
},
},
},
'postcss-loader',
'sass-loader',
{
loader: 'sass-resources-loader',
options: {
resources: [
path.resolve('./src/styles/imports/variables.scss'),
path.resolve('./src/styles/imports/mixins.scss'),
],
},
},
],
},
{
test: /\.png$/,
use: [
'file-loader?name=../css/sprites/[name].png',
],
},
],
},
resolve: {
modules: [APP_ROOT, path.resolve('./node_modules')],
extensions: ['.js', '.jsx', '.ts', '.tsx'],
alias: {
sprites: path.resolve('./public/css/sprites'),
},
},
optimization: {},
context: APP_ROOT,
plugins: [
new webpack.optimize.ModuleConcatenationPlugin(),
new webpack.DefinePlugin({
MODULE_CONFIG: null,
}),
new webpack.EnvironmentPlugin({
NODE_ENV_ACTUAL: process.env.NODE_ENV || null,
API_URL: process.env.API_URL || null,
ASSETS_URL: process.env.ASSETS_URL || null,
JS_VERSION: parseInt(
(childProcess.execSync('git rev-list --count master').toString()).trim(),
10,
),
}),
],
cache: true,
devtool: false,
watchOptions: {
ignored: [
path.resolve('./public'),
path.resolve('./src/styles/generated/**'),
path.resolve('./src/**/*.d.ts'),
],
},
};
babel.config.js:
module.exports = {
presets: [
['#babel/preset-env', {
useBuiltIns: 'usage',
corejs: '3',
exclude: [
'babel-plugin-transform-async-to-generator',
'babel-plugin-transform-regenerator',
],
}],
'#babel/preset-typescript',
],
plugins: [
'#babel/plugin-syntax-dynamic-import',
['#babel/plugin-transform-react-jsx', { pragma: 'h' }],
'#babel/plugin-proposal-do-expressions',
'#babel/plugin-proposal-class-properties',
'#babel/plugin-proposal-optional-chaining',
/* Async/await increases file size by a lot.
["module:fast-async", {
"compiler": { "promises": true, "generators": false, "useRuntimeModule": true },
}],
["#babel/plugin-transform-modules-commonjs", {
"strictMode": false,
}], */
],
env: {
production: {
plugins: ['transform-react-remove-prop-types'],
},
},
};

Use "null-loader" plugin to ignore ".d.ts" files
{
test: /\.(d.ts)$/,
include: [path.join(__dirname, 'src')],
use: [
{
loader: 'null-loader',
},
],
},

Separate the config API with dev and prod webpack

Please tell me, here is the config.js file in it, the exported variable with a reference to the API, but there is an API for the dev version, and there is a separate API for the prod version, as I understand it, you need to make 2 separate files, but how to make it in webpack so that when dev he used one file, and prod another?
Below added webpack configuration files, a project on react.js (if that makes any difference :) )
rules.js
const rules = [
{
test: /\.jsx?$/,
exclude: /node_modules/,
use: ['babel-loader'],
},
{
test: /\.eot(\?v=\d+.\d+.\d+)?$/,
use: [
{
loader: 'url-loader',
options: {
name: '[name].[ext]',
},
},
],
},
{
test: /\.woff(2)?(\?v=[0-9]\.[0-9]\.[0-9])?$/,
use: [
{
loader: 'url-loader',
options: {
limit: 10000,
mimetype: 'application/font-woff',
name: '[name].[ext]',
},
},
],
},
{
test: /\.[ot]tf(\?v=\d+.\d+.\d+)?$/,
use: [
{
loader: 'url-loader',
options: {
limit: 10000,
mimetype: 'application/octet-stream',
name: '[name].[ext]',
},
},
],
},
{
test: /\.svg(\?v=\d+\.\d+\.\d+)?$/,
use: [
{
loader: 'url-loader',
options: {
limit: 10000,
mimetype: 'image/svg+xml',
name: '[name].[ext]',
},
},
],
},
{
test: /\.(jpe?g|png|gif|ico)$/i,
use: [
{
loader: 'file-loader',
options: {
name: '[name].[ext]',
},
},
],
},
];
export default rules;
webpack.config.common.babel.js
import path from 'path';
import HtmlWebpackPlugin from 'html-webpack-plugin';
import Dotenv from 'dotenv-webpack';
import rules from './utils/rules';
const config = (env) => {
const PUBLIC_PATH = env.production ? '/' : '/';
return {
entry: {
index: './src/index.js'
},
output: {
publicPath: PUBLIC_PATH,
path: path.resolve(process.cwd(), 'dist'),
filename: env.production ? '[name].js' : '[name].bundle.js'
},
resolve: {
alias: {
'react-dom': '#hot-loader/react-dom',
app: path.resolve(process.cwd(), 'src/app/'),
store: path.resolve(process.cwd(), 'src/store/'),
ui: path.resolve(process.cwd(), 'src/ui/')
},
extensions: ['*', '.js', '.jsx', '.json', 'scss']
},
module: {
rules
},
node: {
dgram: 'empty',
fs: 'empty',
net: 'empty',
tls: 'empty',
child_process: 'empty'
},
plugins: [
new Dotenv({
systemvars: true
}),
new HtmlWebpackPlugin({
template: 'public/index.html',
favicon: 'public/favicon.ico',
inject: true,
minify: {
removeComments: true,
collapseWhitespace: true,
removeRedundantAttributes: true,
useShortDoctype: true,
removeEmptyAttributes: true,
removeStyleLinkTypeAttributes: true,
keepClosingSlash: true,
minifyJS: true,
minifyCSS: true,
minifyURLs: true
}
})
]
};
};
export default config;
webpack.config.dev.babel.js
import webpack from 'webpack';
import path from 'path';
import merge from 'webpack-merge';
import { BundleAnalyzerPlugin } from 'webpack-bundle-analyzer';
import common from './webpack.config.common.babel';
const config = env => merge(common(env), {
devtool: 'cheap-module-eval-source-map',
target: 'web',
mode: 'development',
optimization: {
minimize: false
},
performance: {
hints: false
},
devServer: {
historyApiFallback: true,
contentBase: '../dist',
port: 3009,
hot: true,
clientLogLevel: 'none'
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: ['babel-loader', 'eslint-loader']
},
{
test: /(\.css|\.scss|\.sass)$/,
use: [
{
loader: 'style-loader',
options: { singleton: true }
},
{
loader: 'css-loader'
},
{
loader: 'postcss-loader',
options: {
/* eslint-disable global-require */
plugins: () => [require('autoprefixer')],
sourceMap: true
}
},
{
loader: 'sass-loader',
options: {
includePaths: [path.resolve(__dirname, 'src', 'scss')]
}
}
]
}
]
},
plugins: [
new webpack.NamedModulesPlugin(),
// new BundleAnalyzerPlugin(),
new webpack.NoEmitOnErrorsPlugin(),
new webpack.HotModuleReplacementPlugin()
]
});
export default config;
webpack.config.common.babel.js
import path from 'path';
import webpack from 'webpack';
import merge from 'webpack-merge';
import MiniCssExtractPlugin from 'mini-css-extract-plugin';
import common from './webpack.config.common.babel';
const config = env => merge(common(env), {
devtool: 'source-map',
target: 'web',
mode: 'production',
optimization: {
minimize: true,
nodeEnv: 'production',
sideEffects: true,
concatenateModules: true,
runtimeChunk: 'single',
splitChunks: {
cacheGroups: {
vendor: {
test: /[\\/]node_modules[\\/]/,
name: 'vendors',
chunks: 'all',
},
},
},
},
module: {
rules: [
{
test: /(\.css|\.scss|\.sass)$/,
use: [
MiniCssExtractPlugin.loader,
{
loader: 'css-loader',
options: {
sourceMap: true,
},
},
{
loader: 'postcss-loader',
options: {
/* eslint-disable global-require */
plugins: () => [require('cssnano'), require('autoprefixer')],
sourceMap: true,
},
},
{
loader: 'sass-loader',
options: {
includePaths: [path.resolve(__dirname, 'src', 'scss')],
sourceMap: true,
},
},
],
},
],
},
plugins: [
new webpack.HashedModuleIdsPlugin(),
new MiniCssExtractPlugin({
filename: '[name].[chunkhash].css',
})
],
});
export default config;

You can define two different npm scripts and use the --config flag for custom files (/file-paths):
"build:dev": "webpack --config ./webpack.client.dev.js",
"build:prod": "webpack --config ./webpack.client.prod.js"
For the common you have to use webpack-merge, for example:
const merge = require('webpack-merge');
const common = require('./webpack.common.js');
module.exports = merge(common, {
mode: 'production',
...
});

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',
};

Coverage reports with karma and a mix of javascript and typescript src files

I have a project where I use webpack for development/testing and karma as my test runner. This project has source files written half in js and half in ts/tsx. The test suite is written completely in js. I currently use karma-coverage, which shows coverage reports for all my js source files, but it does not support typescript files. All my tests run, there is no problem there, I just would like coverage reports for all my test files. Can anyone point me in the right direction?
Here is my karma.conf.js if this helps.
'use strict';
const webpackCfg = require('./webpack.config')('test');
module.exports = function karmaConfig(config) {
config.set({
browsers: ['Chrome'],
files: [
'test/loadtests.js'
],
port: 8080,
captureTimeout: 60000,
frameworks: [
'mocha',
'chai',
'sinon'
],
client: {
mocha: {}
},
singleRun: true,
reporters: ['mocha', 'coverage', 'junit'],
mochaReporter: {
output: 'autowatch'
},
preprocessors: {
'test/loadtests.js': ['webpack', 'sourcemap']
},
webpack: webpackCfg,
webpackServer: {
noInfo: true
},
junitReporter: {
outputDir: 'coverage',
outputFile: 'junit-result.xml',
useBrowserName: false
},
coverageReporter: {
dir: 'coverage/',
watermarks: {
statements: [70, 80],
functions: [70, 80],
branches: [70, 80],
lines: [70, 80]
},
reporters: [
{ type: 'text' },
{
type: 'html',
subdir: 'html'
},
{
type: 'cobertura',
subdir: 'cobertura'
},
{
type: 'lcovonly',
subdir: 'lcov'
}
]
}
});
};
And the relevant part of my webpack test config
{
devtool: 'inline-source-map',
externals: {
cheerio: 'window',
'react/lib/ExecutionEnvironment': true,
'react/addons': true,
'react/lib/ReactContext': true,
},
module: {
preLoaders: [
{
test: /\.(js|jsx)$/,
loader: 'isparta-loader',
include: [
this.srcPathAbsolute
]
}
],
loaders: [
{
test: /\.cssmodule\.css$/,
loaders: [
'style',
'css?modules&importLoaders=1&localIdentName=[name]-[local]-[hash:base64:5]'
]
},
{
test: /^.((?!cssmodule).)*\.css$/,
loader: 'null-loader'
},
{
test: /\.(sass|scss|less|styl|png|jpg|gif|mp4|ogg|svg|woff|woff2)$/,
loader: 'null-loader'
},
{
test: /\.json$/,
loader: 'json'
},
{
test: /\.ts(x?)$/,
exclude: /node_modules/,
loader: ['babel', 'ts-loader']
},
{
test: /\.(js|jsx)$/,
loader: 'babel-loader',
query: {
presets: ['airbnb']
},
include: [].concat(
this.includedPackages,
[
this.srcPathAbsolute,
this.testPathAbsolute
]
)
}
]
},
plugins: [
new webpack.DefinePlugin({
'process.env.NODE_ENV': '"test"'
})
]
}

After a couple days of soul and google searching amongst hundreds of browser tabs, I have found a working solution. This is using TypeScript 2.x and Webpack 2.x. test.js is my entry point. It could just as easily be test.ts (and it will be eventually). In that entry point, I load my *.spec.js and *.spec.ts files. And then those files import whichever source they need to test from. I have put all the webpack config in the karma.conf.js so it's easier to see:
let myArgs = require('yargs').argv;
let path = require('path');
let webpack = require('webpack');
module.exports = function(config) {
const REPORTS_PATH = myArgs.reportsPath ? myArgs.reportsPath :path.join(__dirname, 'build');
config.set({
basePath: '',
frameworks: ['jasmine', 'es6-shim'],
files: [
'./test.js'
],
exclude: [],
reporters: ['progress', 'spec', 'coverage', 'junit', 'coverage-istanbul'],
preprocessors: {
'./test.js': ['webpack', 'sourcemap']
},
webpackServer: {
noInfo: true // prevent console spamming when running in Karma!
},
webpack: {
devtool: 'inline-source-map',
resolve: {
modules: [
path.resolve('./node_modules'),
path.resolve('./')
],
extensions: ['.js', '.ts', '.css', '.scss']
},
plugins: [
new webpack.ProvidePlugin({
$: "jquery",
jQuery: "jquery",
"window.jQuery": "jquery"
})
],
module: {
rules: [
{
enforce: 'pre',
test: /\.js$/,
use: 'source-map-loader',
exclude: [/node_modules/]
},
{
test: /\.ts$/,
use: [{
loader: 'awesome-typescript-loader',
options: {
module: 'commonjs'
},
}]
},
{
test: /\.js$/,
use: [{
loader: 'awesome-typescript-loader',
options: {
entryFileIsJs: true,
transpileOnly: true
}
}],
exclude: [/node_modules/],
},
{
enforce: 'post',
test: /\.(js|ts)$/,
use: [{
loader: 'istanbul-instrumenter-loader',
options: {
esModules: true
}
}],
exclude: [/node_modules/, /\.spec\.(js|ts)$/, /test/]
},
{ test: /\.html/, use: 'raw-loader' },
{ test: /\.(s)?css$/, use: 'null-loader' },
{ test: /\.(png|jpg|jpeg|gif|svg|pdf)$/, use: 'null-loader' },
{ test: /\.woff(2)?(\?v=[0-9]\.[0-9]\.[0-9])?$/, use: 'null-loader' },
{ test: /\.(ttf|eot)(\?v=[0-9]\.[0-9]\.[0-9])?$/, use: 'null-loader' },
{ test: /\.json$/, use: 'null-loader' }
]
}
},
coverageReporter: {
type: 'in-memory'
},
coverageIstanbulReporter: {
//TODO: Figure out why the 'html' reporter blows up with istanbul-reports (something with absolute path copying files)
reports: ['text-summary', 'cobertura'],
// base output directory
dir: REPORTS_PATH,
fixWebpackSourcePaths: true,
'report-config': {
cobertura: {
file: 'coverage.xml'
},
'text-summary': {
file: null
}
}
},
junitReporter: {
outputDir: `${REPORTS_PATH}/junit/`,
outputFile: 'jasmine-results.xml'
},
// Hide webpack build information from output
webpackMiddleware: {
stats: {
chunkModules: false,
colors: true
},
noInfo: 'errors-only'
},
colors: true,
logLevel: config.LOG_ERROR,
autoWatch: true,
browsers: ['Chrome'],
singleRun: false,
autoWatchBatchDelay: 400
});
};
So, the key pieces here are awesome-typescript-loader, karma-coverage-istanbul-reporter, source-map-loader, and in the tsconfig.json, you want to set these in compilerOptions:
"inlineSourceMap": true,
"sourceMap": false,
I indicated a TODO about the html report. It DOES work but I couldn't get it to output to a custom directory (subdir) with TypeScript files as a part of it. JavaScript only worked fine. Could be a windows-specific problem with istanbul-reports. If you add html to the reports array under coverageIstanbulReporter, you should see it in your project dir but may have problems putting it in REPORTS_PATH.
It's also worth noting that I had a lot of luck using karma-remap-coverage instead of karma-coverage-istanbul-reporter but the former would not correctly generate cobertura reports for coverage which is what I needed for Jenkins.