neutrino-dev/docs/presets/neutrino-preset-web

Neutrino Web Preset

neutrino-preset-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, and async functions
• Webpack loaders for importing HTML, CSS, images, icons, and fonts
• Webpack Dev Server during development
• Automatic creation of HTML pages, no templating necessary
• Hot Module Replacement support
• Tree-shaking to create smaller bundles
• Production-optimized bundles with Babili minification and easy chunking
• Easily extensible to customize your project as needed

Requirements

• Node.js v6.9+
• Yarn or npm client
• Neutrino v4

Installation

neutrino-preset-web can be installed via the Yarn or npm clients. Inside your project, make sure neutrino and neutrino-preset-web are development dependencies.

Yarn

❯ yarn add --dev neutrino neutrino-preset-web

npm

❯ npm install --save-dev neutrino neutrino-preset-web

Project Layout

neutrino-preset-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.

Quickstart

After installing Neutrino and the Web preset, 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": "neutrino start --presets neutrino-preset-web",
    "build": "neutrino build --presets neutrino-preset-web"
  }
}

Start the app, then open a browser to the address in the console:

Yarn

❯ yarn start
✔ Development server running on: http://localhost:5000
✔ Build completed

npm

❯ npm start
✔ Development server running on: http://localhost:5000
✔ Build completed

Building

neutrino-preset-web builds static assets to the build directory by default when running neutrino build. Using the quick start example above as a reference:

❯ yarn build
clean-webpack-plugin: /web/build has been removed.
Build completed in 0.779s

Hash: 55c33df4cd1222a03505
Version: webpack 2.2.1
Time: 784ms
                                  Asset       Size  Chunks             Chunk Names
   index.52f2d06086f51d21f9c9.bundle.js  213 bytes    0, 1  [emitted]  index
manifest.c10c6464802bf71a2c3f.bundle.js    1.41 kB       1  [emitted]  manifest
                             index.html  779 bytes          [emitted]
✨  Done in 2.10s.

You can either serve or deploy the contents of this build directory as a static site.

Customizing

To override the build configuration, start with the documentation on customization. neutrino-preset-web creates some conventions to make overriding the configuration easier once you are ready to make changes.

By default the Web preset creates a single main index entry point to your application, and this maps to the index.js file in the src directory. This means that the Web preset is optimized toward the use case of single-page applications over multi-page applications.

Rules

The following is a list of rules and their identifiers which can be overridden:

• compile: Compiles JS files from the src directory using Babel. Contains a single loader named babel.
• html: Allows importing HTML files from modules. Contains a single loader named file.
• css: Allows importing CSS stylesheets from modules. Contains two loaders named style and css.
• img, svg, ico: Allows import image files from modules. Each contains a single loader named url.
• woff, ttf: Allows importing WOFF and TTF font files from modules. Each contains a single loader named url.
• eot: Allows importing EOT font files from modules. Contains a single loader named file.

Plugins

The following is a list of plugins and their identifiers which can be overridden:

• env: Injects the value of NODE_ENV into the application as process.env.NODE_ENV.
• html: Creates HTML files when building. Has various options that can be configured via package.json.
• chunk: Defines chunks for manifest and vendor entry points. Can be configured via package.json.
• hot: Enables hot module reloading.
• copy: Copies non-JS files from src to build when using neutrino build.
• clean: Clears the contents of build prior to creating a production bundle.
• progress: Displays a progress bar when using neutrino build.

Simple customization

By following the customization guide and knowing the rule, loader, and plugin IDs above, you can override and augment the build directly from package.json.

Vendoring

By defining an entry point in package.json named vendor you can split out external dependencies into a chunk separate from your application code.

Example: Put lodash into a separate "vendor" chunk:

{
  "config": {
    "neutrino": {
      "entry": {
        "vendor": [
          "lodash"
        ]
      }
    }
  },
  "dependencies": {
    "lodash": "*"
  }
}

HTML files

Under the hood neutrino-preset-web uses html-webpack-template for generating HTML files. If you wish to override how these files are creating, define an object in your package.json at config.html with options matching the format expected by html-webpack-template.

Example: Change the application mount ID from "root" to "app":

{
  "config": {
    "html": {
      "appMountId": "app"
    }
  }
}

Advanced configuration

By following the customization guide and knowing the rule, loader, and plugin IDs above, you can override and augment the build by creating a JS module which overrides the config.

Vendoring

By defining an entry point named vendor you can split out external dependencies into a chunk separate from your application code.

Example: Put lodash into a separate "vendor" chunk:

module.exports = neutrino => {
  neutrino.config
    .entry('vendor')
    .add('lodash');
};

Contributing

This preset is part of the neutrino-dev repository, a monorepo containing all resources for developing Neutrino and its core presets. Follow the contributing guide for details.