fix(build): Make CJS re-exports visible to Node ESM imports

dev-packages/rollup-utils/npmHelpers.mjs

@@ -139,6 +139,8 @@ export function makeBaseNPMConfig(options = {}) {
       // Allow wrappers or helper functions generated by rollup to use any ES2015 features
       generatedCode: {
         preset: 'es2015',
+        // With arrow functions, Node can't see `export *` exports when ESM code imports our CJS files.
+        arrowFunctions: false,
       },
 
       // don't add `"use strict"` to the top of cjs files

packages/nextjs/test/serverExports.test.ts

@@ -35,3 +35,17 @@ describe('Node-only integrations are statically detectable exports from every ru
     },
   );
 });
+
+/**
+ * Node loads this CJS file for ESM imports too, and must see that it re-exports everything from `@sentry/node`.
+ *
+ * Regression test for https://github.com/getsentry/sentry-javascript/issues/22791
+ */
+describe('CJS server build re-exports are detectable by Node', () => {
+  it('detects the `@sentry/node` re-export', async () => {
+    await init();
+    const { reexports } = parse(readFileSync(resolve(__dirname, '../build/cjs/index.server.js'), 'utf8'));
+
+    expect(reexports).toContain('@sentry/node');
+  });
+});