docs: use sapper/cypress for e2e testing

docs/webpack.config.js

@@ -0,0 +1,64 @@
+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") };
+const extensions = [".mjs", ".js", ".json", ".svelte", ".html"];
+const mainFields = ["svelte", "module", "browser", "main"];
+
+module.exports = {
+  client: {
+    entry: config.client.entry(),
+    output: config.client.output(),
+    resolve: { alias, extensions, mainFields },
+    module: {
+      rules: [
+        {
+          test: /\.(svelte|html)$/,
+          use: {
+            loader: "svelte-loader",
+            options: { dev, hydratable: true, hotReload: false },
+          },
+        },
+      ],
+    },
+    mode,
+    plugins: [
+      new webpack.DefinePlugin({
+        "process.browser": true,
+        "process.env.NODE_ENV": JSON.stringify(mode),
+      }),
+    ].filter(Boolean),
+    devtool: dev && "inline-source-map",
+  },
+
+  server: {
+    entry: config.server.entry(),
+    output: config.server.output(),
+    target: "node",
+    resolve: { alias, extensions, mainFields },
+    externals: Object.keys(pkg.dependencies).concat("encoding"),
+    module: {
+      rules: [
+        {
+          test: /\.(svelte|html)$/,
+          use: {
+            loader: "svelte-loader",
+            options: { css: false, generate: "ssr", dev },
+          },
+        },
+      ],
+    },
+    mode: process.env.NODE_ENV,
+    performance: { hints: false },
+  },
+  serviceworker: {
+    entry: config.serviceworker.entry(),
+    output: config.serviceworker.output(),
+    mode: process.env.NODE_ENV,
+  },
+};