(enh) add example to rollup build against Node/esm modules

test/builds/node_build_as_esm.mjs

@@ -0,0 +1,24 @@
+import hljs from "../../build/es/index.js";
+
+const API = [
+  "getLanguage",
+  "registerLanguage",
+  "highlight",
+  "highlightAuto",
+  "highlightAll",
+  "highlightElement",
+];
+
+const assert = (f, msg) => {
+  if (!f()) {
+    console.error(msg);
+    process.exit(1);
+  }
+};
+const keys = Object.keys(hljs);
+
+API.forEach((n) => {
+  assert((_) => keys.includes(n), `API should include ${n}`);
+});
+
+console.log("Pass: browser build works with Node.js just fine.");

test/builds/rollup_import_node_build_esm.mjs

@@ -0,0 +1,16 @@
+// rollup.config.js
+import commonjs from "@rollup/plugin-commonjs";
+
+export default {
+  input: "test/builds/node_build_as_esm.mjs",
+  output: {
+    file: "build/bundle.js",
+    format: "iife",
+  },
+  plugins: [
+    commonjs({
+      include: "build/**", // Default: undefined
+      exclude: ["node_modules/**"], // Default: undefined
+    }),
+  ],
+};