Only work around Rollup bug for router entrypoint in new interfaces (#…

…4085)

packages-next/admin-ui/src/apollo.tsx

@@ -3,21 +3,4 @@
  * packages import the same instance of apollo.
  */
 
-// not using export * because Rollup emits CJS code that redefines __esModule which causes problems because __esModule generally isn't a configurable property
-export {
-  useQuery,
-  useMutation,
-  useLazyQuery,
-  gql,
-  ApolloError,
-  InMemoryCache,
-  ApolloClient,
-  ApolloProvider,
-} from '@apollo/client';
-export type {
-  ServerError,
-  ServerParseError,
-  QueryResult,
-  DocumentNode,
-  TypedDocumentNode,
-} from '@apollo/client';
+export * from '@apollo/client';

packages-next/admin-ui/src/router.tsx

@@ -3,7 +3,12 @@
  * packages import the same instance of next's router.
  */
 
-// not using export * because Rollup emits CJS code that redefines __esModule which causes problems because __esModule generally isn't a configurable property
+// not using export * because Rollup's CJS re-export code doesn't ignore __esModule on the exports object so it will re-define it if it exists
+// and since __esModule isn't configurable(at least with the code that's _generally_ emitted by Rollup, Babel, tsc and etc.)
+// an error will be thrown
+// that's normally not a problem because modules generally use Object.defineProperty(exports, '__esModule', { value: true })
+// which means that the property isn't enumerable but Next uses Babel's loose mode and Babel's loose mode for the CJS transform
+// uses exports.__esModule = true instead of defineProperty so the property is enumerable
 export { createRouter, makePublicRouterInstance, Router, useRouter, withRouter } from 'next/router';
 export type { NextRouter } from 'next/router';