itaqua/hjs-webpack

Helpers/presets for setting up webpack with hotloading react and ES6(2015) using Babel.

#hjs-webpack

I really dislike setting up build scripts. Most of the time I want to do the exact same thing:

While developing:

• easy to setup and run dev server
• transpile ES6+, JSX, Stylus code
• hotload (a.k.a. live reload) modules when changed

When ready to ship:

• minify and bundle all the things
• output minfied, uniquely named static files into public directory
• be able to generate/customized static HTML file(s) used to deliver my JS app
• be ready to just upload it all to something like surge.sh
• sometimes I want to pre-render all known HTML into static HTML files and have React take over once the clientside JS loads.

webpack and the webpack-dev-server can do most of those things pretty well out of the box. But, it sure is a pain to set it all up.

So, this is just a simplified, opinionated way to configure webpack for development and then build for production. That also supports easily generating more files.

If no one uses it but me, it will have still served its purpose.

A screencast showing how to use this module is here: http://learn.humanjavascript.com/react-ampersand/setting-up-webpack

install

npm install hjs-webpack

note about peerDependencies

hjs-webpack specifies many of its dependencies as peerDependencies in order to let you decide which version of, say, babel or React that you want to use in your project without us specifying that directly for you.

In npm 3.x.x peerDependencies will no longer be installed by default.

When this happens, you'll want to run the following to install the related dependencies as well.

Included here for your copy/paste enjoyment:

npm i --save autoprefixer-core babel babel-loader css-loader json-loader postcss-loader react react-hot-loader style-loader stylus-loader url-loader webpack-dev-server yeticss

usage

Step 1. install it into your project

npm install --save hjs-webpack

Step 2. create a webpack.config.js

Put it at the root of your project, a typical config looks something like this:

var getConfig = require('hjs-webpack')


module.exports = getConfig({
  // entry point for the app
  in: 'src/app.js',

  // Name or full path of output directory
  // commonly named `www` or `public`. This
  // is where your fully static site should
  // end up for simple deployment.
  out: 'public',

  // This will destroy and re-create your
  // `out` folder before building so you always
  // get a fresh folder. Usually you want this
  // but since it's destructive we make it 
  // false by default
  clearBeforeBuild: true
})

Step 3. configure scripts section of package.json

I usually add something like the following scripts:

"scripts": {
  "start": "webpack-dev-server",
  "build": "webpack",
  "deploy": "npm run build && surge -p public -d somedomain.com"
}

Assuming you've got some JS written that you've set as your in in the webpack.config.js you can run npm start and open a browser to http://localhost:3000 and you everything should Just Work™.

When you're wanting to do a build, just run npm run build. The build will generate your files into public.

Now there's a static site in public that can be deployed to something like Surge.sh or DivShot, which I do by running npm run deploy.

Step 4. Dealing with styles

Since we're using webpack under the hood, this is done the "webpack way".

Basically you can require your styles as if they were JavaScript files.

Simply do this in your application code:

require('./path/to/your/css/main.css')

Be sure to include the extension: .css in your require statment. If you use .styl you can write Stylus seamlessly and at the top of your stylus files you've got access to yeti.css for easy styling.

Try creating a file called main.styl containing:

@import 'yeticss'

Require it from your main application file (see in section below) and you should get some nice default styles.

Note in development mode these will be live-reloaded (hot loaded). In production, these will be extracted into their own files, including intelligent handling of referenced URLs within your stylesheets. Things like font-files and images will be extracted if they're over a certain size. You shouldn't have to worry about this too much. It should just work seamlessly.

Step 5. Dealing with images and static files

Option #1: requiring files

Webpack lets us do var url = require('something.png') from within our app code and url is something you can safely set as the src of an image tag, for example. When you build the project, it uses the url-loader and will base64 encode and inline it if it's smaller than the urlLoaderLimit and hash and export it otherwise.

When you do this, webpack will hash the file and use that as a name. If you basically just want to require a file so webpack knows about it, the following syntax will copy the favicon to the out directory (at the root) but leave the name unchanged: require('file?name=favicon.ico!./real/path/to/your/favicon.ico')

But, letting webpack handle images isn't always what you want to do. Sometimes you want just a simple folder of static assets and be able to reference them like you're used to. That's why there's another option:

Option #2: just put 'em in your out directory

You can also just put your assests in the out directory and tell hjs-webpack to ignore them by setting a glob pattern as the clearBeforeBuild option.

Assume an out directory called public that looks like this:

public/
  some-other-generated-file.html
  index.html
  yourapp.1.1.1.css
  yourapp.1.1.1.js
  favicon.ico

  images/
    some-pic.png

Then, instead of setting clearBeforeBuild: true you can set it to a glob string like so: clearBeforeBuild: '!(images|favicon.ico)'.

Now when you build it'll clear everything that matches the glob pattern an nothing else.

In this case, it'd leave the images directory and your favicon.ico alone (more details in options section below).

note The development server will treat the out directory as the contentBase which means in this case the favicon would be available at /favicon.ico despite being in public.

Examples

There are 3 example projects in the /examples directory with various config setups:

1. Only generating CSS/JS
2. Generating CSS/JS and using included HTML template
3. Pre-rendering app layout and the public homepage HTML with React as part of the build process

Config options

The main export you get when you require('hjs-webpack') is simply a pre-configured webpack.config.js. You could take the result of that and add other plugins if you so chose, but shouldn't be necessary for most common tasks.

in

This should just be the path to the file that serves as the main entry point of your application.

out

Path to directory where we're going to put generated files.

clearBeforeBuild (optional, boolean or glob string, default=false)

A boolean to specify whether to clear the out folder before building.

If you wish to only clear some of this directory you can also pass a glob string. Globs are the file path matching strings you've probably seen in on the command line or in a .gitigore (i.e. **/*.js*).

The most common thing you'd probably want to do while using this module would be to exclude a directory from being cleared. The following example would clear out the public directory but leave the public/images and public/static folders intact if they exist.

getConfig({
  in: 'src/app.js',
  out: 'public',
  clearBeforeBuild: '!(images|static)'  
})

So, just to be clear, everything that matches the glob string within the out folder will be deleted when building.

isDev (optional, boolean, default=varies based on command)

A boolean to indicate whether or not everything is in production mode (minified, etc.) or development mode (everything hotloaded and unminified).

By default this value is true if the command you ran contains webpack-dev-server and false otherwise. The option exists here in case you need to override the default.

output.filename (optional, string)

This is passed directly to webpack, so you can use all the configuration options available there.

By default a filename is created for you based on the following rules:

• If isDev is true, then the filename is app.js
• If isDev is false, then the filename NAME.VERSION.js where NAME and VERSION are pulled from your package.json file
• If output.hash is true, then instead of VERSION your filename will contain the HASH of the compiled file

output.cssFilename (optional, string)

This is passed directly to the extract-text-webpack-plugin, so you can use all the configuration options available there. Note: this is only used if isDev is true, since in development mode the css bundle is inserted dynamically into the document by the style-loader.

By default a filename is created for you based on the following rules:

• If isDev is true, then the filename is app.css
• If isDev is false, then the filename NAME.VERSION.css where NAME and VERSION are pulled from your package.json file
• If output.hash is true, then instead of VERSION your filename will contain the HASH of the compiled file

output.hash (optional, boolean, default is false)

This is used in conjunction with the output.filename and output.cssFilename options above, and is only used if isDev is false. If hash is true then the filenames of your JS and CSS files will contain the hash of the compiled file. This is useful to fingerprint your asset files so that they can be cached for as long as possible.

Note that as per the suggestion in the webpack docs, the OccurenceOrderPlugin is already used so you will get consistent ordering of modules.

urlLoaderLimit (optional, number, default: 10000)

This is the default threshold to use for whether URLs referenced in stylesheets will be inlined or extracted during build (we're just pre-configuring the url-loader).

devServer (optional, object)

These options are passed through to the webpack-dev-server with a few defaults:

{
  port, // pulled from top level option "port"
  host, // // pulled from top level option "hostname"
  info: false,
  historyApiFallback: true,
  hot: true
}

replace (optional, object)

You can supply an object of require names with paths to the files you want that name to represent. This makes it easy to do things like swapping out config files based on build mode, etc.

Adding this to your config would mean that any time you did: require('config') within your application code, you'd end up with the file specified by the path.

{
  'config': '/some/path/config.json'
}

html (optional, can be boolean or function)

This option is true by default. This means, by default, we'll serve and generate a very basic HTML file that looks like this:

<!doctype html>
<meta charset="utf-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no"/>
<link rel="stylesheet" href="/assets-and-index-html.1.0.0.css"/>
<body></body>
<script src="/app.js"></script>

Note the <meta charset> tag and mobile viewport settings are there by default.

The empty <body> followed by the main script tag is also intentional. The ordering ensures we don't have to wait for DOMReady in our clientside code, you can safely assume that both document.body and document.head will be available when your script executes.

If you just want to do JS and CSS and handle all the html yourself, simply add html: false to your config (see examples directory for example).

using an html function to generate specific files

This is where it gets interesting. Imagine pre-rendering all known structural content for a Native Web App to static files. Users get pixels on the screen immediately, your JS takes over when downloaded. If you're using React, this "taking over" can be completely seamless and invisible to the user. It's also possible with this approach to write an app that works entirely without JS. See the prerendered-html-files example.

Your function should produce an object.

Each key in the object is a filename, and its value is a string to be written to disc.

If you simply specify html: true it will do the following by default:

html: function (context) {
  return {
    'index.html': context.defaultTemplate()
  }
}

So if you want to produce other files, you can do so by adding them to the returned object:

html: function (context) {
  return {
    'index.html': context.defaultTemplate(),

    // if you build it entirely yourself it should be a complete HTML document
    // using whatever templating system you want
    'other.html': '<!DOCTYPE><body><h1>Hello World</h1></body>'
  }
}

async version

html: function (context, callback) {
  // do whatever async stuff generate result object
  // and pass it to the callback instead
  db.fetchData(function (err, data) {
    callback(null, {
      'index.html': buildHTML(data),
      'other.html': doSomethingElse(data)
    })
  })
}

The context argument

Your html function will be called with a context object that contains the following:

1. context.main: the name of the generated JS file
2. context.css: the name of the generated CSS file. This only exists if isDev is false, since in development mode the css bundle is inserted dynamically into the document by the style-loader.
3. context.defaultTemplate() a convenience method you can call to generate the basic HTML shown above. This takes a few options too if you just want to make minor tweaks. If you want to do more, just don't use the default template, generate your own instead. The options are:

• {html: 'your string} and it'll add it to the
• {charset: 'utf-8'} what charset to set
• {title: 'your app'} sets <title>
• {head: 'any string'} anything else you want to put in the head, other meta tags, or whatnot.
• {metaViewport: false} set to false if you don't want the default viewport tag
• {relative: false} set to false if you want to turn off relative links / useful for gh-pages
• {metaTags: {}} lets you easily add <meta> tags to the document head. Takes an object where the key is the name and the value is the content.

4. context.isDev: boolean specifying whether or not we're in dev mode.
5. context.package: the parsed package.json file as an object.
6. context.stats: the stats object returned by webpack. Of likely interest is context.stats.hash (a hash of current build). context.stats.assets is an array of all the assets that will be generated. This can be useful for generating cache manifests, etc. Overall, this is a big object that lists all the modules in your whole app. You likely won't need most of it, but it's all there in case you do. (A sample can be found here).

serveCustomHtmlInDev (optional, boolean, default is true)

By default, if you supply an html function it will always be used, whether you're in development mode or not.

Set this option to false to only use your html function when building for production. Note, that .isDev is attached to the context object passed to the html function as described above, so alternately you could just use that value to branch your logic within that function. Using this option circumvents the custom html function entirely during development.

Developing on multiple devices at once

If you're building an app that you want to look good on all devices it's nice to be able to run them all at once.

Hotloading makes this extremely nice and convenient.

If you're on a Mac, this is fairly simple. Just add a hostname option to your config like so:

module.exports = getConfig({
  in: 'src/app.js',
  out: 'public',

  // set this to whatever your machine name is
  // plus `.local`
  // my machine is `loki` so I do:
  hostname: 'loki.local'
})

Now when you run the development instead of going to localhost open: http://{{yourmachine}}.local:3000 on any device that's on your local network, they should all connect and all hotload your style and JS changes.

Other loaders

There's a few loaders configured, but not automatically installed:

less

require('styles.less') and npm install less-loader

sass

require('styles.sass') or require('styles.scss') and npm install sass-loader

jade

require('template.jade') and npm install jade-loader

Changing Babel config

If you want to tweak Babel settings you can create a file at the root of your project called .babelrc that contains config settings. See bablerc docs for more options.

Credits

This is mostly just some add-ons to webpack so most of the credit goes there.

If you're interested in building apps this way, watch the free section of the tutorials at http://learn.humanjavascript.com. It shows basic usage of this module. Also, you can follow me on twitter @HenrikJoreteg.

Big thanks to co-maintainer @LukeKarrys for helping find/fix some really annoying bugs.

Contributing/Forking

Beware that this is all highly opinionated and contains a lot of personal preferences. If you want to add or remove major things, feel free to open issues or send PRs, but you may just want to fork it.

Changelog

• 2.130.0

  • use cheap-module-eval-source-map devtool in dev #63
  • remove noerrors plugin and for react-hot-loader@^1.3.0 #62

• 2.12.4

  • Update extract-text-webpack-plugin and other dependencies
  • Get npm test passing for standard linting

• 2.12.3

  • Add react to peer deps

• 2.12.2

  • Fix react-hot-loader is installed check

• 2.12.1

  • Don't assume process.argv[1] exists. This can happen if running via node -p, thanks @eins78.

• 2.12.0

  • Don't force install of React or React Hot-Loader only use them and other optional installs if installed. Thanks @FWeinb

• 2.11.0

  • Add ability to pass metaTags object as a defaultTempate option for easily adding <meta> tags.

• 2.10.0

  • Add sass-loader for .scss and ``sass` files

• 2.9.0

  • Allow globs for clearBeforeBuild.
  • Expose webpack stats object to context
  • Expose parsed package.json object to html function context argument.
  • Set out folder as contentBase for the dev server.

• 2.8.1

  • Fix typo in examples/just-assets-no-html/README.md
  • add documentation for relative links in html

• 2.8.0

  • add serveCustomHtmlInDev as an explicit option
  • properly document new option and isDev in html function

• 2.7.0

  • Expose isDev flag to html function context
  • Document replace option in readme.

• 2.6.1

  • Fix less filename test when in production mode
  • Add documentation about using html function's css context and cssFilename in production mode

• 2.6.0

  • Allow devServer options to be passed in

• 2.5.0

  • Use passed in urlLoaderLimit
  • Add default url loader for images

• 2.4.0 Resolve .jsx extension

• 2.3.0 configure isDev default automatically based on whether the command used contains webpack-dev-server or not (still respects explicitly configured, so not a breaking change)

  • add clearBeforeBuild option to clear build folder first.
  • both the above changes allow an app to share configs because you're not having to clear the build dir, or set environment variables two different ways for different platforms (a.k.a. better windows support).
  • doc fixes/improvements

• 2.2.2 use process.cwd() over process.env.PWD to find root.

• 2.2.1 include json-loader by default.

• 2.2.0 use autoprefixer-core and postcss-loader to add autoprefixing to all configured style loaders

  • don't resolve .styl extensions

• 2.1.0 pre-configure .jade and .less loaders as optional installs.

  • add option for urlLoaderLimit

• 2.0.0 instead of including our own pre-configured dev server: hjs-dev-server you can now just use webpack-dev-server in your npm scripts and it gets configured via devServer property of config.

  • much more complete documentation
  • support for passing options to defaultTemplate() function
  • simplified/unified configuration
  • support for setting global hostname (see above)
  • now includes main babel package by default
  • add warnings/instructions about npm 3.x.x's handling of peer dependencies

license

MIT