fix(ses): re-exported names available in imported modules

This fixes a situation in which module _A_ re-exports name _X_ from module _B_, and then imports module _C_, which in turn imports _X_ from _A_.

Originally encountered in the source code for `terser`.

Author: boneskull

packages/ses/src/module-instance.js

@@ -412,24 +412,24 @@ export const makeModuleInstance = (
           candidateAll[exportedName] = importNotifiers[localName];
         }
       }
-    }
-
-    for (const [exportName, notify] of entries(candidateAll)) {
-      if (!notifiers[exportName] && notify !== false) {
-        notifiers[exportName] = notify;
 
-        // exported live binding state
-        let value;
-        const update = newValue => (value = newValue);
-        notify(update);
-        exportsProps[exportName] = {
-          get() {
-            return value;
-          },
-          set: undefined,
-          enumerable: true,
-          configurable: false,
-        };
+      for (const [exportName, notify] of entries(candidateAll)) {
+        if (!notifiers[exportName] && notify !== false) {
+          notifiers[exportName] = notify;
+
+          // exported live binding state
+          let value;
+          const update = newValue => (value = newValue);
+          notify(update);
+          exportsProps[exportName] = {
+            get() {
+              return value;
+            },
+            set: undefined,
+            enumerable: true,
+            configurable: false,
+          };
+        }
       }
     }
 

packages/ses/test/import-gauntlet.test.js

@@ -406,3 +406,31 @@ test('this in module scope must be undefined', async t => {
 
   await compartment.import('./index.js');
 });
+
+test('re-exported names should be available in imported modules', async t => {
+  t.plan(1);
+
+  const makeImportHook = makeNodeImporter({
+    'https://example.com/index.js': `
+      export { a } from './a.js';   
+      import './c.js';
+    `,
+    'https://example.com/a.js': `
+      export const a = 'a';
+    `,
+    'https://example.com/c.js': `
+      import { a } from './index.js';
+      t.is(a, 'a', 're-exported name "a" from importing module should be string "a"');
+    `,
+  });
+  const importHook = makeImportHook('https://example.com');
+
+  const compartment = new Compartment({
+    globals: { t },
+    resolveHook: resolveNode,
+    importHook,
+    __options__: true,
+  });
+
+  await compartment.import('./index.js');
+});