webpack.prod.config.js

/* eslint-env node */

'use strict';

var Merge = require('webpack-merge');
var webpack = require('webpack');
var BundleTracker = require('webpack-bundle-tracker');
var _ = require('underscore');

var commonConfig = require('./webpack.common.config.js');

var optimizedConfig = Merge.smart(commonConfig, {
  web: {
    output: {
        filename: '[name].[chunkhash].js'
    },
    devtool: false,
    plugins: [
        new webpack.DefinePlugin({
            'process.env.NODE_ENV': JSON.stringify('production')
        }),
        new webpack.LoaderOptionsPlugin({  // This may not be needed; legacy option for loaders written for webpack 1
            minimize: true
        }),
        new webpack.optimize.UglifyJsPlugin(),
        new webpack.optimize.CommonsChunkPlugin({
            // If the value below changes, update the render_bundle call in
            // common/djangoapps/pipeline_mako/templates/static_content.html
            name: 'commons',
            filename: 'commons.[chunkhash].js',
            minChunks: 3
        })
    ]
}});

// requireCompatConfig only exists so that you can use RequireJS to require a
// Webpack bundle (but try not to do that if you can help it). RequireJS knows
// where to find named bundle output files, but doesn't know about
// prod-optimized bundles. So we make a redundant Webpack target that exists
// only to make a version of all the bundles without the chunkhash in the
// filename. That way, RequireJS can always find them.
//
// To be clear, this is a bad hack that exists to keep RequireJS from breaking
// for the short term. We're actively ripping RequireJS out of edx-platform
// entirely, and requireCompatConfig can completely disappear after RequireJS is
// gone.

// Step 1: Alter the bundle output names to omit the chunkhash.
var requireCompatConfig = Merge.smart(optimizedConfig, {
  web: {
    output: {
        filename: '[name].js'
    },
    plugins: [
        new webpack.optimize.CommonsChunkPlugin({
            // If the value below changes, update the render_bundle call in
            // common/djangoapps/pipeline_mako/templates/static_content.html
            name: 'commons',
            filename: 'commons.js',
            minChunks: 3
        })
    ]
}});

// Step 2: Remove the plugin entries that generate the webpack-stats.json files
// that Django needs to look up resources. We never want to accidentally
// overwrite those because it means that we'll be serving assets with shorter
// cache times. RequireJS never looks at the webpack-stats.json file.
requireCompatConfig.web.plugins = requireCompatConfig.web.plugins.filter((plugin) => !(plugin instanceof BundleTracker));

module.exports = [..._.values(optimizedConfig), ..._.values(requireCompatConfig)];