On-demand bundler for ES6 / CSS Next.

• Use Felt as a webserver via CLI
• Use Felt as a middleware of Express

See also its options, plugins and recipes.

Note: Felt runs on Node 6.x or above.

CLI usages

In short, install Felt globally:

$ npm install -g felt felt-recipe-minimal

Note: felt-recipe-minimal is a recipe for Felt. You may install other recipes, too.

And run Felt:

$ cd path/to/project/
$ felt

Then, open your site in browser: http://localhost:3000.

Note: type Ctrl + C to stop the server

Run Felt

Assume that you have a project like this:

• project/
  • public/
    • index.html
    • main.js
    • style.css
  • cache/
  • package.json

Then run Felt:

$ cd path/to/project/
$ felt --recipe minimal --src public

There're some official recipes. Check them, too.

Use config files

Assume that you have a project like this:

• project/
  • public/
    • index.html
    • main.js
    • style.css
  • cache/
  • package.json
  • felt.config.js

Or choose your own config file:

$ felt --config felt.config.js

The default name of config is felt.config.js, so it's also fine:

$ felt --config

The config file could be like this:

'use strict'
const
  rollup = require('felt-rollup'),
  buble = require('rollup-plugin-buble'),
  resolve = require('rollup-plugin-node-resolve'),
  commonjs = require('rollup-plugin-commonjs')

module.exports = {
  src: 'public',
  handlers: {
    '.js': rollup({
      plugins: [
        resolve({ jsnext: true,  main: true, browser: true }),
        commonjs(),
        buble()
      ],
      sourceMap: true
    })
  }
}

See more detail about options

Change port

The default port is 3000. If you want to change it, use --port option:

$ felt --port 3333

Note: you can set the port option in your config file, too.

Watch changes

$ felt --src public --watch

Export static files

This is handy to upload the contents to amazon S3 or GitHub Pages. Felt exports not only compiled files but also other assets like HTML, PNG, ...etc, too.

$ felt --src public --export dist

Note: with export option, Felt is not run as a server. It works as just a bundler.

With Express

Install Felt and use it as an express middleware.

$ npm install --save felt

Add server.js to the project:

const
  express = require('express'),
  felt = require('felt'),
  recipe = require('felt-recipe-minimal')

const app = express()

app.use(felt(recipe, { src: 'public' }))
app.use(express.static('public'))
app.listen(3000)

Separated config files

It's a good idea to separate the config from server.js:

const
  express = require('express'),
  felt = require('felt')
  config = require('./felt.config.js')

app.use(felt(config))
app.use(express.static('public'))
app.listen(3000)

felt.config.js could be like this:

const
  rollup = require('felt-rollup'),
  buble = require('rollup-plugin-buble'),
  resolve = require('rollup-plugin-node-resolve'),
  commonjs = require('rollup-plugin-commonjs')

module.exports = {/* options */}

Options

property | default | descriptions :-- | :-- | :-- opts.src | . | the document directory to serve opts.cache | 'cache' | if it's located inside src, ignored on requests opts.root | process.cwd() | usually no need to set it opts.handlers | {} | see the section below opts.patterns | [] | see the section below opts.excludes | [] | see the section below opts.external | {} | see the section below opts.update | 'once' | 'never' or 'always' opts.refresh | true | set false to skip refreshing on starting opts.watch | false | set true to detect changes opts.debug | false | set true to show debug comments on the terminal

opts.handlers

Default handlers for each extension.

{
  handlers: {
    '*.js': rollup({
      plugins: [
        resolve({ jsnext: true }),
        commonjs(),
        buble()
      ],
      sourceMap: true
    })
  }
}

opts.patterns

This option limits the target which Felt works with. This is handy when you want to use Felt for only a few files like this:

{
  patterns: ['index.js', 'components/*.js']
}

Which handler will be used is depends on the extension. If no handler for the extension, Felt will throw exceptions.

You can also specify the custom handler for the pattern:

{
  patterns: [
    'index.js',
    {
      pattern: 'components/*.js',
      handler: rollup({
        plugins: [babel()],
        sourceMap: true
      })
    }
  ]
}

opts.excludes

This option excludes the files from compiling and copying (when exporting). Cache directory and 'node_modules/**' are always excluded. For example:

{
  excludes: ['no-compile/**']
}

opts.external

This option makes copies from deeper files typically in node_modules. For example, if you need to access node_modules/pouchdb/dist/pouchdb.min.js, you may write like this:

{
  external: {
    'pouchdb.js': 'node_modules/pouchdb/dist/pouchdb.min.js'
    // 'where/to/expose': 'path/from/opts.root'
  }
}

Then you can access it by http://localhost:3000/pouchdb.js. This option is convenient to directly expose a JavaScript or CSS file which comes from npm or bower.

Note: The files will not be processed by opts.handlers. This means that the file will skip compiling by rollup and so on.

Plugins

Plugins are the interface to compilers like Rollup or PostCSS. Actually, these are the thin wrapper of these libraries:

• felt-rollup: JavaScript bundler
• felt-postcss: CSS bundler

Recipes

Recipes are pre-made configurations. You can use these recipes with some overwrite with ease.

• felt-recipe-minimal: PostCSS and Rollup with Bublé
• felt-recipe-standard: PostCSS and Rollup with Babel
• felt-recipe-riot: PostCSS and Rollup with Bublé + Riot
• felt-recipe-react: PostCSS and Rollup with Bublé + JSX
• felt-recipe-preact: PostCSS and Rollup with Bublé + Preact by @ezekielchentnik

Note: the repository name of the recipe supposed to have prefix felt-recipe-.

License

MIT © Tsutomu Kawamura