chore(commonjs): validate externalBuiltinsRequire option value and tidy stub message

Author: CharlieHelps

packages/commonjs/src/index.js

@@ -44,8 +44,9 @@ export default function commonjs(options = {}) {
     defaultIsModuleExports: defaultIsModuleExportsOption,
     esmExternals
   } = options;
+  const rawExternalBuiltinsRequire = options.externalBuiltinsRequire;
   const externalBuiltinsRequireStrategy =
-    options.externalBuiltinsRequire === 'stub' ? 'stub' : 'create-require';
+    rawExternalBuiltinsRequire === 'stub' ? 'stub' : 'create-require';
   const extensions = options.extensions || ['.js'];
   const filter = createFilter(options.include, options.exclude);
   const isPossibleCjsId = (id) => {
@@ -214,6 +215,15 @@ export default function commonjs(options = {}) {
           'The namedExports option from "@rollup/plugin-commonjs" is deprecated. Named exports are now handled automatically.'
         );
       }
+      if (
+        rawExternalBuiltinsRequire != null &&
+        rawExternalBuiltinsRequire !== 'create-require' &&
+        rawExternalBuiltinsRequire !== 'stub'
+      ) {
+        this.warn(
+          `${PLUGIN_NAME}: invalid externalBuiltinsRequire "${rawExternalBuiltinsRequire}", using "create-require"`
+        );
+      }
       requireResolver = getRequireResolver(
         extensions,
         detectCyclesAndConditional,

packages/commonjs/src/proxies.js

@@ -103,11 +103,11 @@ export function getEsImportProxy(id, defaultIsModuleExports, moduleSideEffects)
  *   runtimes when the path is dead, and fails loudly if executed.
  */
 export function getExternalBuiltinRequireProxy(id, strategy = 'create-require') {
-  const stringifiedId = JSON.stringify(id);
   if (strategy === 'stub') {
-    const msg = `Node built-in ${stringifiedId} is not available in this environment`;
+    const msg = `Node built-in ${id} is not available in this environment`;
     return `export function __require() { throw new Error(${JSON.stringify(msg)}); }`;
   }
+  const stringifiedId = JSON.stringify(id);
   return (
     `import { createRequire } from 'node:module';\n` +
     `const require = createRequire(import.meta.url);\n` +