comixify/frontend/client/webpack.config.js

const merge = require("webpack-merge");
const UglifyJsPlugin = require("uglifyjs-webpack-plugin");
const webpack = require("webpack");

module.exports = env => {

    let common = {
        entry: {
            app: __dirname + "/App.js"
        },
        output: {
            path: __dirname + "/../static/frontend/js",
            filename: "[name].client.js"
        },
        externals: {
            cheerio: "window",
            "react/lib/ExecutionEnvironment": true,
            "react/lib/ReactContext": true
        },
        module: {
            rules: [
                {
                    test: /\.jsx?$/,
                    exclude: /(node_modules|bower_components)/,
                    loader: "babel-loader",
                    query: {
                        presets: ["react", "stage-0", "flow"],
                        plugins: ["emotion"]
                    }
                },
                {
                    test: /\.css$/,
                    use: ["style-loader", "css-loader"]
                }
            ]
        }
    };

    if (env && env.production) {
        return merge(common, {
            plugins: [
                new webpack.DefinePlugin({
                    "process.env.NODE_ENV": JSON.stringify("production")
                }),
                new UglifyJsPlugin()
            ],
            mode: "production"
        });
    } else {
        return merge(common, {
            mode: "development"
        });
    }
}