Neutrino Web Preset
@neutrinojs/web
is a Neutrino preset that supports building generic
applications for the web.
Features
- Zero upfront configuration necessary to start developing and building a web app
- Modern Babel compilation supporting ES modules, last 2 major browser versions, async functions, and dynamic imports
- webpack loaders for importing HTML, CSS, images, icons, and fonts
- webpack Dev Server during development
- Automatic creation of HTML pages, no templating necessary
- Automatic stylesheet extraction; importing stylesheets into modules creates bundled external stylesheets
- Pre-configured to support CSS Modules via
*.module.css
file extensions - Hot Module Replacement support including CSS
- Tree-shaking to create smaller bundles
- Production-optimized bundles with minification, easy chunking, and scope-hoisted modules for faster execution
- Easily extensible to customize your project as needed
Important! If you need polyfills in your code, consider including core-js
in
your package.json
. This is will configure @babel/present-env
to
automatically include polyfills based on usage. More details
here.
Requirements
- Node.js 10+
- Yarn v1.2.1+, or npm v5.4+
- Neutrino 9
- webpack 4
- webpack-cli 3
- webpack-dev-server 3
Quickstart
The fastest way to get started is by using the create-project
scaffolding
tool. Don’t want to use the CLI helper? No worries, we have you covered with the
manual installation.
create-project
Run the following command to start the process. Substitute <directory-name>
with the directory name you wish to create for this project.
Yarn
❯ yarn create @neutrinojs/project <directory-name>
Note: The create
command is a shorthand that helps you do two things at once.
See the Yarn create docs for
more details.
npm/npx
npx
comes pre-installed with npm
. If you’re
running an older version of npm
, then npm install -g npm
to update to the
latest version.
❯ npx @neutrinojs/create-project <directory-name>
The CLI helper will prompt for the project to scaffold, and will offer to set up a test runner as well as linting to your project. Refer to the Create new project section for details on all available options.
Manual Installation
@neutrinojs/web
can be installed via the Yarn or npm clients. Inside your
project, make sure that the dependencies below are installed as development
dependencies.
Yarn
❯ yarn add --dev neutrino @neutrinojs/web webpack webpack-cli webpack-dev-server
npm
❯ npm install --save-dev neutrino @neutrinojs/web webpack webpack-cli webpack-dev-server
After that, add a new directory named src
in the root of the project, with a
single JS file named index.js
in it.
❯ mkdir src && touch src/index.js
This Web preset exposes an element in the page with an ID of root
to which you
can mount your application. Edit your src/index.js
file with the following:
const app = document.createElement('main');
const text = document.createTextNode('Hello world!');
app.appendChild(text);
document.getElementById('root').appendChild(app);
Now edit your project's package.json
to add commands for starting and building
the application:
{
"scripts": {
"start": "webpack-dev-server --mode development --open",
"build": "webpack --mode production"
}
}
Then create a .neutrinorc.js
file alongside package.json
, which contains
your Neutrino configuration:
const web = require('@neutrinojs/web');
module.exports = {
use: [web()],
};
And create a webpack.config.js
file, that uses the Neutrino API to access the
generated webpack config:
const neutrino = require('neutrino');
module.exports = neutrino().webpack();
Start the app, then open a browser to the address in the console:
Yarn
❯ yarn start
npm
❯ npm start
Project Layout
@neutrinojs/web
follows the standard
project layout specified by Neutrino.
This means that by default all project source code should live in a directory
named src
in the root of the project. This includes JavaScript files, CSS
stylesheets, images, and any other assets that would be available to your
compiled project.
Building
@neutrinojs/web
builds static assets to the build
directory by default when
running yarn build
. You can either serve or deploy the contents of this
build
directory as a static site.
Static assets
If you wish to copy files to the build directory that are not imported from application code, use the @neutrinojs/copy preset alongside this one.
Deployment Path
By default @neutrinojs/web
assumes that your application will be deployed at
the root of a domain (eg: https://www.my-app.com/
), and so sets webpack's
output.publicPath
to '/'
, which means assets will be loaded from the site root using absolute
paths.
If your app is instead deployed within a subdirectory, you will need to adjust
the publicPath
preset option. For example if your app is
hosted at https://my-username.github.io/my-app/
, you will need to set
publicPath
to '/my-app/'
.
Alternatively, if you would like your app to be able to be served from any
location, and are not using the HTML5 pushState history API or client-side
routing, then you can set publicPath
to the empty string, which will cause
relative asset paths to be used instead.
Preset options
You can provide custom options and have them merged with this preset's default
options to easily affect how this preset builds. You can modify Web preset
settings from .neutrinorc.js
by overriding with an options object. The
following shows how you can pass an options object to the Web preset and
override its options:
const web = require('@neutrinojs/web');
module.exports = {
use: [
web({
// Enables and configures `EnvironmentPlugin`. See below for example usage.
env: false,
// Enables Hot Module Replacement. Set to false to disable
hot: true,
// Controls webpack's `output.publicPath` setting.
// See the "Deployment Path" section above for more info.
publicPath: '/',
// Change options for @neutrinojs/style-loader
style: {},
// Change options for @neutrinojs/font-loader
font: {},
// Change options for @neutrinojs/image-loader
image: {},
minify: {
// Javascript minification occurs only in production by default.
// To change uglify-es options or switch to another minifier, see below.
source: process.env.NODE_ENV === 'production',
},
// Change options related to generating the HTML document
// See @neutrinojs/html-template for the defaults
// used by the Web preset
html: {},
// Control which source map types are enabled for each NODE_ENV
devtool: {
development: 'cheap-module-eval-source-map',
production: undefined,
test: 'source-map',
},
// Change options related to starting a webpack-dev-server
devServer: {
// Disabling options.hot will also disable devServer.hot
hot: options.hot,
// Proxy requests that don't match a known file to the specified backend.
proxy: 'https://localhost:8000/api/',
},
// Target specific browsers with @babel/preset-env
targets: {
browsers: ['last 1 Chrome versions', 'last 1 Firefox versions'],
},
// Add additional Babel plugins, presets, or env options
babel: {
// Override options for @babel/preset-env:
presets: [
[
'@babel/preset-env',
{
useBuiltIns: 'usage',
},
],
],
},
}),
],
};
Example: Disable Hot Module Replacement and change the page title:
const web = require('@neutrinojs/web');
module.exports = {
use: [
web({
/* preset options */
// Example: disable Hot Module Replacement
hot: false,
// Example: disable image-loader, style-loader, font-loader
image: false,
style: false,
font: false,
// Disable javascript minification entirely
minify: {
source: false,
},
// Disable cleaning the output build directory
clean: false,
// Example: change the page title
html: {
title: 'Epic Web App',
},
// Example: Proxy webpack-dev-server requests to http://localhost:3000
devServer: {
proxy: 'http://localhost:3000',
},
}),
],
};
Environment variables
To use environment variables at compile time, use the env
setting to enable
and configure
EnvironmentPlugin (env
accepts the same options as the plugin). There is no need to specify NODE_ENV
,
since webpack defines it automatically. The environment variables can then be
used via process.env.<NAME>
.
For example:
web({
env: [
// webpack will output a warning if these are not defined in the environment.
'VAR_ONE',
'VAR_TWO',
],
});
Or to set default values, use the object form:
web({
env: {
VAR_ONE: 'foo',
VAR_TWO: 'bar',
},
});
Dev Server Proxy
If you are handling requests with a server, you may want to set up a proxy for
development. See webpack's
devServer.proxy
for all available options.
For example:
web({
devServer: {
proxy: {
'**': {
target: 'http://localhost:3000',
changeOrigin: true,
},
},
},
});
Source Maps
By default, the 'cheap-module-eval-source-map'
source map is enabled when
NODE_ENV
is 'development'
, 'source-map'
for 'test'
and no source maps
for 'production'
.
To customise this, use the preset's devtool
option, for example:
web({
devtool: {
// Enable source-maps in production
production: 'source-map',
},
});
For the differences between each source map type, see the webpack devtool docs.
Targets
web({
// Use targets from a .browserslistrc file.
targets: false,
});
Setting to false
will override Neutrino's default targets and allow
@babel/preset-env
to read targets from a
.browserslistrc
file.
When using a .browserslistrc
file, be aware that file changes may not
invalidate cache as expected: https://github.com/babel/babel-loader/issues/690
See @babel/preset-env
for all other available settings.
Hot Module Replacement
While @neutrinojs/web
supports Hot Module Replacement your app, it does
require some application-specific changes in order to operate. Your application
should define split points for which to accept modules to reload using
module.hot
:
For example:
import app from './app';
document.getElementById('root').appendChild(app('Hello world!'));
if (module.hot) {
module.hot.accept('./app');
}
Or for all paths:
import app from './app';
document.getElementById('root').appendChild(app('Hello world!'));
if (module.hot) {
module.hot.accept();
}
Using dynamic imports with import()
will automatically create split points and
hot replace those modules upon modification during development.
Customizing
To override the build configuration, start with the documentation on
customization. @neutrinojs/web
creates some conventions to make overriding the configuration easier once you
are ready to make changes.
By default Neutrino, and therefore this preset, creates a single main
index
entry point to your application, and this maps to the index.*
file in
the src
directory. The extension is resolved by webpack. This value is
provided by neutrino.options.mains
at neutrino.options.mains.index
.
If you wish to output multiple pages, you can configure them like so:
const web = require('@neutrinojs/web');
module.exports = {
options: {
mains: {
index: {
// outputs index.html from src/index.*
entry: 'index',
// Additional options are passed to html-webpack-plugin, and override
// any defaults set via the preset's `html` option.
title: 'Site Homepage',
},
admin: {
// outputs admin.html from src/admin.*
entry: 'admin',
title: 'Admin Dashboard',
},
account: {
// outputs account.html from src/user.* using a custom HTML template.
entry: 'user',
inject: true,
template: 'my-custom-template.html',
},
},
},
use: [web()],
};
If the need arises, you can compile node_modules
by referring to the relevant
compile-loader
documentation.
Rules
The following is a list of rules and their identifiers which can be overridden:
Name | Description | NODE_ENV |
---|---|---|
compile |
Compiles JS files from the src directory using Babel. Contains a single loader named babel . From @neutrinojs/compile-loader . |
all |
html |
Allows importing HTML files from modules. Contains a single loader named html . From @neutrinojs/html-loader . |
all |
style |
A parent rule containing oneOf rules for importing stylesheets. From @neutrinojs/style-loader . |
all |
image |
Allows importing ICO, JPEG, PNG, GIF, SVG and WEBP files from modules. Contains a single loader named url . From @neutrinojs/image-loader . |
all |
font |
Allows importing EOT, TTF, WOFF and WOFF2 font files from modules. Contains a single loader named file . From @neutrinojs/font-loader . |
all |
Plugins
The following is a list of plugins and their identifiers which can be overridden:
Note: Some plugins are only available in certain environments. To override them, they should be modified conditionally.
Name | Description | NODE_ENV |
---|---|---|
env |
Inject environment variables into source code at process.env , using EnvironmentPlugin . |
all |
extract |
Extracts CSS from JS bundle into a separate stylesheet file. From @neutrinojs/style-loader . |
'production' |
html-{MAIN_NAME} |
Automatically generates HTML files for configured entry points. {MAIN_NAME} corresponds to the entry point of each page. By default, there is only a single index main, so this would generate a plugin named html-index . From @neutrinojs/html-template
|
all |
hot |
Enables Hot Module Replacement. | 'development' |
clean |
Clean or remove the build directory prior to building. From @neutrinojs/clean . |
'production' |
Override configuration
By following the customization guide
and knowing the rule, loader, and plugin IDs above, you can override and augment
the build by by providing a function to your .neutrinorc.js
use array. You can
also make these changes from the Neutrino API in custom middleware.
Vendoring
External dependencies are automatically split into separate chunks from the application code, by the new webpack SplitChunksPlugin.
Example: The splitChunks settings can be adjusted like so:
const web = require('@neutrinojs/web');
module.exports = {
use: [
web(),
(neutrino) => {
neutrino.config.optimization.merge({
splitChunks: {
// Decrease the minimum size before extra chunks are created, to 10KB
minSize: 10000,
},
});
},
],
};
Source minification
By default script sources are minified in production only, using webpack's
default of
terser-webpack-plugin.
To customise the options passed to TerserPlugin
or even use a different
minifier, override optimization.minimizer
.
Example: Adjust the terser
minification settings:
const web = require('@neutrinojs/web');
module.exports = {
use: [
web(),
(neutrino) => {
// Whilst the minimizer is only used when the separate `minimize` option is true
// (ie in production), the conditional avoids the expensive require() in development.
if (process.env.NODE_ENV === 'production') {
neutrino.config.optimization
.minimizer('terser')
.use(require.resolve('terser-webpack-plugin'), [
{
// Default options used by webpack:
// https://github.com/webpack/webpack/blob/v4.26.0/lib/WebpackOptionsDefaulter.js#L308-L315
cache: true,
parallel: true,
sourceMap:
neutrino.config.devtool &&
/source-?map/.test(neutrino.config.devtool),
// Pass custom options here.
// https://github.com/webpack-contrib/terser-webpack-plugin#terseroptions
// https://github.com/terser-js/terser#minify-options
terserOptions: {
// eg disable mangling of names
mangle: false,
},
},
]);
}
},
],
};
Contributing
This preset is part of the neutrino repository, a monorepo containing all resources for developing Neutrino and its core presets and middleware. Follow the contributing guide for details.