For development purposes only!

Webpack middleware for koa

Wraps webpack-dev-middleware for use in koa. Adds hot module replacement (HMR).

Webpack is the webpack and it's module bundler. Koa is the next generation web framework for node.js.

Install

npm install webpack-koa-middleware

Usage

Configure and attach middleware:

var middleware = require('webpack-koa-middleware');
var webpackCfg = require('webpack-cfg.js');

app.use(middleware(webpackCfg));

, where app is koa instance.

Exemple of webpack-cfg.js (look on devServer key):

module.exports = {
    // Modules root directory
    context: path.join(__dirname, './app'),

    // Entry points for the build
    entry: {
        index: './index.js'     // also used in devServer config below
    },

    // Where and how to expose build results
    output: {
        publicPath: '/',        // Where bundles (build results) are served 
                                // (not path, just prefix for requests)
        filename: '[name].js',
        chunkFilename: '[name].[chunkhash].js'
    },
    
    // Development server configuration
    devServer: {
        host: process.env.USER_IP || 'localhost',
        port: 8090,
        publicPath: '/',        // Where webpack exposes bundles
                                //  on its own in-memory file system 
        hot: true,              // Switch on Hot Module Replacement
        indexEntry: 'index',    // Entry to add HNR code to (EntryChunk or CommonsChunk)
        secure: true,           // use https or http
        stats: {
            colors: true,
            hash: false,
            timings: false,
            assets: true,
            chunks: true,
            chunkModules: true,
            modules: false,
            children: true
        }
    }
}

For an explanation of parameters see webpack documentation.

Explicit call

Middlewares executed in a stack-like manner upon request. Sometimes you need to explicitly retrieve data from webpack's virtual file system.

This middleware has function asset which takes URL and returns promise which is fulfilled with asset's content.

var middleware = require('webpack-koa-middleware');
var webpackCfg = require('webpack-cfg.js');

middleware = middleware(webpackCfg) 
middleware.asset('/app.js')
    .then(function (content) {
        console.log(content instanceof Buffer); // => true
    });