Fix: "Got unexpected undefined" error when using a re-exported type

packages/core/integration-tests/test/integration/ts-types/re-exporting-aggregating/expected.d.ts

@@ -0,0 +1,4 @@
+type fuga = "fuga";
+export type Baz = `${fuga}`;
+
+//# sourceMappingURL=types.d.ts.map

packages/core/integration-tests/test/integration/ts-types/re-exporting-aggregating/hoge/bar.ts

@@ -0,0 +1 @@
+export type bar = 'bar';

packages/core/integration-tests/test/integration/ts-types/re-exporting-aggregating/hoge/fuga.ts

@@ -0,0 +1 @@
+export type fuga = "fuga";

packages/core/integration-tests/test/integration/ts-types/re-exporting-aggregating/hoge/index.ts

@@ -0,0 +1,2 @@
+export * from "./bar";
+export * from "./fuga";

packages/core/integration-tests/test/integration/ts-types/re-exporting-aggregating/index.ts

@@ -0,0 +1,2 @@
+import { fuga } from './hoge';
+export type Baz = `${fuga}`

packages/core/integration-tests/test/integration/ts-types/re-exporting-aggregating/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "ts-types-re-exporting-aggregating",
+  "private": true,
+  "main": "dist/main.js",
+  "types": "dist/types.d.ts"
+}

packages/core/integration-tests/test/ts-types.js

@@ -361,4 +361,31 @@ describe('typescript types', function () {
     );
     assert.equal(dist, expected);
   });
+
+  it('should handle re-exporting aggregating correctly', async function () {
+    await bundle(
+      path.join(
+        __dirname,
+        '/integration/ts-types/re-exporting-aggregating/index.ts',
+      ),
+    );
+
+    let dist = (
+      await outputFS.readFile(
+        path.join(
+          __dirname,
+          '/integration/ts-types/re-exporting-aggregating/dist/types.d.ts',
+        ),
+        'utf8',
+      )
+    ).replace(/\r\n/g, '\n');
+    let expected = await inputFS.readFile(
+      path.join(
+        __dirname,
+        '/integration/ts-types/re-exporting-aggregating/expected.d.ts',
+      ),
+      'utf8',
+    );
+    assert.equal(dist, expected);
+  });
 });

packages/transformers/typescript-types/src/TSModuleGraph.js

@@ -143,10 +143,13 @@ export class TSModuleGraph {
       if (e.name === name) {
         return this.getExport(module, e);
       } else if (e.specifier) {
-        return this.resolveExport(
+        const m = this.resolveExport(
           nullthrows(this.getModule(e.specifier)),
           name,
         );
+        if (m) {
+          return m;
+        }
       }
     }
   }