webpack.config.js

const webpack = require("webpack");
const path = require("path");
const config = require("sapper/config/webpack.js");
const pkg = require("./package.json");

const mode = process.env.NODE_ENV;
const dev = mode === "development";

const alias = { 
    svelte: path.resolve("node_modules", "svelte"),
    '@Services': path.resolve(__dirname, 'src/services/'),
    '@Components': path.resolve(__dirname, 'src/components/'),
    '@Store':path.resolve(__dirname, 'src/store/')
};
const extensions = [".mjs", ".js", ".json", ".svelte", ".html"];
const mainFields = ["svelte", "module", "browser", "main"];

const sveltePreprocess = require("svelte-preprocess");

const preprocess = sveltePreprocess({
  postcss: {
    plugins: [require("autoprefixer")]
  },
  scss: true,
});

const helper = require("./src/helpers/config.js");

module.exports = {
    client: {
        entry: config.client.entry(),
        output: config.client.output(),
        resolve: { alias, extensions, mainFields },
        module: {
            rules: [
                {
                    test: /\.(svelte|html)$/,
                    use: {
                        loader: "svelte-loader",
                        options: {
                            dev,
                            hydratable: true,
                            hotReload: false, // pending https://github.com/sveltejs/svelte/issues/2377,
                            preprocess
                        },
                    },
                },
            ],
        },
        mode,
        plugins: [
            // pending https://github.com/sveltejs/svelte/issues/2377
            // dev && new webpack.HotModuleReplacementPlugin(),
            new webpack.DefinePlugin({
                ...helper.getEnvVars(),
                'process.browser': true,
                'process.env.NODE_ENV': JSON.stringify(mode)
            })
        ].filter(Boolean),
        devtool: dev && "inline-source-map",
    },

    server: {
        entry: config.server.entry(),
        output: config.server.output(),
        target: "node",
        resolve: { alias, extensions, mainFields },
        externals: Object.keys(pkg.dependencies).concat("encoding"),
        module: {
            rules: [
                {
                    test: /\.(svelte|html)$/,
                    use: {
                        loader: "svelte-loader",
                        options: {
                            css: false,
                            generate: "ssr",
                            dev,
                            preprocess
                        },
                    },
                },
            ],
        },
        mode,
        performance: {
            hints: false, // it doesn't matter if server.js is large
        }
    },
    serviceworker: {
        entry: config.serviceworker.entry(),
        output: config.serviceworker.output(),
        mode: process.env.NODE_ENV,
    },
};