Default reexports of a CommonJS asset on namespace object are undefined

packages/core/integration-tests/test/integration/scope-hoisting/es6/re-export-commonjs-namespace/a.js

@@ -0,0 +1,2 @@
+import * as x from './b.js';
+output = sideEffectNoop(x).foo;

packages/core/integration-tests/test/integration/scope-hoisting/es6/re-export-commonjs-namespace/b.js

@@ -0,0 +1 @@
+export {default as foo} from './c.js'

packages/core/integration-tests/test/integration/scope-hoisting/es6/re-export-commonjs-namespace/c.js

@@ -0,0 +1 @@
+module.exports = 'foo';

packages/core/integration-tests/test/scope-hoisting.js

@@ -1775,6 +1775,18 @@ describe('scope hoisting', function() {
       assert.deepEqual(output, 'foo');
     });
 
+    it('support accessing default reexports of a CommonJS asset on namespace object', async function() {
+      let b = await bundle(
+        path.join(
+          __dirname,
+          '/integration/scope-hoisting/es6/re-export-commonjs-namespace/a.js',
+        ),
+      );
+
+      let output = await run(b);
+      assert.deepEqual(output, 'foo');
+    });
+
     it('concatenates in the correct order when re-exporting assets were excluded', async function() {
       let b = await bundle(
         path.join(

packages/core/test-utils/src/utils.js

@@ -327,7 +327,7 @@ export async function runBundles(
 
   // A utility to prevent optimizers from removing side-effect-free code needed for testing
   // $FlowFixMe[prop-missing]
-  ctx.sideEffectNoop = () => {};
+  ctx.sideEffectNoop = v => v;
 
   vm.createContext(ctx);
   let esmOutput;