Re-introduce file used by Karma

webpack.config.cjs

@@ -0,0 +1,50 @@
+const webpack = require("webpack");
+const path = require("path");
+
+module.exports = {
+  mode: "development",
+  entry: {
+    "js-waku": "./src/index.ts",
+  },
+  devtool: "inline-source-map",
+  module: {
+    rules: [
+      {
+        test: /\.(js|tsx?)$/,
+        use: "ts-loader",
+        exclude: /(node_modules)|(node\.spec\.ts)/,
+      },
+      {
+        test: /node\.spec\.ts$/,
+        use: "ignore-loader",
+      },
+    ],
+  },
+  plugins: [
+    new webpack.ProvidePlugin({
+      process: "process/browser.js",
+      Buffer: ["buffer", "Buffer"],
+    }),
+  ],
+  resolve: {
+    extensions: [".ts", ".js"],
+    fallback: {
+      buffer: require.resolve("buffer/"),
+      crypto: false,
+      stream: require.resolve("stream-browserify"),
+    },
+  },
+  output: {
+    filename: "[name].js",
+    path: path.resolve(__dirname, "build/umd"),
+    library: "jswaku",
+    libraryTarget: "umd",
+    globalObject: "this",
+  },
+  optimization: {
+    splitChunks: {
+      name: "vendors",
+      chunks: "all",
+    },
+  },
+};