Additional HtmlWebpackPlugin() pages with create-react-app - reactjs

Question

I've ejected from the default create-react-app project and am attempting to create a second, maintenance.html page that Webpack can inject into as it does by default with public/index.html. I've read through a number of issues; and the docs for HtmlWebpackPlugin, which states it should be as easy as:
// 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(envObject),
// Generates an `index.html` file with the <script> injected.
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
minify: {
minifyCSS: true,
},
}),
to this:
// 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(envObject),
// Generates an `index.html` file with the <script> injected.
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
minify: {
minifyCSS: true,
},
}),
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
filename: '/public/maintenance.html',
minify: {
minifyCSS: true,
},
}),
I keep getting the following error when I want to convert vars like %PUBLIC_URL% to their actual value:
URIError: Failed to decode param '/%PUBLIC_URL%/scripts/modernizr.custom.js'
even though they work fine in public/index.html. Any ideas what I'm doing wrong? I've made sure I don't have any rules setup to do anything else with .html files; as I've seen a few people get mixed up there. Have been messing around with the settings and combing through GitHub issues, but feel like I'm running in circles. Thanks!
Here's the current webpack.config.dev.js file:
/* THIS FILE HAS BEEN EDITED A BIT FROM https://github.com/facebookincubator/create-react-app/blob/master/packages/react-scripts/config/webpack.config.dev.js */
const autoprefixer = require('autoprefixer');
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 getClientEnvironment = require('./env');
const paths = require('./paths');
// Custom
const cssnano = require('cssnano');
const flexbugs = require('postcss-flexbugs-fixes');
const svgFragments = require('postcss-svg-fragments');
const fs = require('fs');
// Don't show deprecations
process.noDeprecation = true;
// #remove-on-eject-begin
// `path` is not used after eject - see https://github.com/facebookincubator/create-react-app/issues/1174
const path = require('path');
// #remove-on-eject-end
// 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);
// Get environment object passed down to HTML template
const envObject = env.raw;
// Read SVG sprite
const svgSprite = fs.readFileSync(`${paths.appPublic}/images/sprite.svg`, 'utf8');
// Add SVG output to variable object passed to HTML template
envObject.SVG_SPRITE = svgSprite;
// 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: 'eval',
// 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'),
// Polyfills
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,
},
externals: {
gsap: 'TweenMax',
},
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 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'].concat(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: {
react: path.resolve('./node_modules/react'),
// 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',
},
},
// #remove-on-eject-begin
// Resolve loaders (webpack plugins for CSS, images, transpilation) from the
// directory of `react-scripts` itself rather than the project directory.
resolveLoader: {
modules: [
// Lerna hoists everything, so we need to look in our app directory
paths.appNodeModules,
],
},
module: {
rules: [
// Disable require.ensure as it's not a standard language feature.
{ parser: { requireEnsure: false } },
{
test: /\.(js|jsx)$/,
enforce: 'pre',
use: [
{
// #remove-on-eject-end
loader: 'eslint-loader',
},
],
include: paths.appSrc,
},
// ** ADDING/UPDATING LOADERS **
// The "url" 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 "url" 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.
{
test: /\.(ico|jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2)(\?.*)?$/,
loader: 'file-loader',
options: {
name: 'static/media/[name].[hash:8].[ext]',
},
},
// "url" loader works like "file" loader except that it embeds assets
// smaller than specified limit in bytes as data URLs to avoid requests.
// A missing `test` is equivalent to a match.
{
test: /\.(mp4|webm|wav|mp3|m4a|aac|oga)(\?.*)?$/,
loader: 'url-loader',
options: {
limit: 10000,
name: 'static/media/[name].[hash:8].[ext]',
},
},
// Process JS with Babel.
{
test: /\.(js|jsx)$/,
include: paths.appSrc,
loader: 'babel-loader',
options: {
// #remove-on-eject-end
// This is a feature of `babel-loader` for webpack (not Babel itself).
// It enables caching results in ./node_modules/.cache/babel-loader/
// directory for faster rebuilds.
cacheDirectory: true,
},
},
{
test: /\.less$/,
use: [
{
loader: 'style-loader',
},
{
loader: 'css-loader',
options: {
sourceMap: true,
}
},
{
loader: 'postcss-loader',
options: {
sourceMap: true,
ident: 'postcss', // https://webpack.js.org/guides/migrating/#complex-options
plugins: () => [
autoprefixer({
browsers: [
'>2%',
'last 2 versions',
'not ie < 11',
],
cascade: false,
}),
cssnano({
discardUnused: false,
zindex: false,
reduceIdents: false,
mergeIdents: false,
}),
flexbugs(),
svgFragments(),
],
},
},
{
loader: 'less-loader',
options: {
sourceMap: true,
}
},
],
},
],
},
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(envObject),
// Generates an `index.html` file with the <script> injected.
new HtmlWebpackPlugin({
inject: true,
template: paths.appHtml,
minify: {
minifyCSS: true,
},
}),
// 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),
],
// 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',
},
// 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,
},
};
Here's the HTML of public/index.html
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=Edge" />
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="theme-color" content="#ffffff">
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="format-detection" content="telephone=no">
<link id="js-favicon" rel="icon" type="image/png" href="%PUBLIC_URL%/favicon-32x32.png" sizes="32x32">
<link rel="manifest" href="%PUBLIC_URL%/manifest.json">
<link rel="apple-touch-icon" sizes="180x180" href="%PUBLIC_URL%/apple-touch-icon.png">
<link rel="mask-icon" href="%PUBLIC_URL%/safari-pinned-tab.svg" color="#0081c6">
<script src="%PUBLIC_URL%/scripts/modernizr.custom.js"></script>
<title></title>
</head>
<body>
<!-- SVG sprite -->
<div style="border: 0px; clip: rect(0px 0px 0px 0px); height: 0px; overflow: hidden; padding: 0px; position: absolute; width: 0px;">%SVG_SPRITE%</div>
<div id="app" style="overflow: hidden;"></div>
</body>
</html>
I've also tried just duplicating this over to public/maintenance.html with no luck.

Answer 1

Per my last comment, please make the changes in webpack.config.prod.js instead of webpack.config.dev.js as the default build script uses that.
Updates:
The changes in webpack.config.prod.js are -
And after running npm run build the build folder has these files -