fix: don't add index on some case

Author: sxzz

src/core/utils.ts

@@ -57,7 +57,7 @@ export function resolveEntry(
 }
 
 function endsWithIndex(s: string) {
-  return /(?:^|[/\\])index\..+$/.test(s)
+  return /(?:^|[/\\])index(?:\..+)?$/.test(s)
 }
 
 export function shouldAddIndex(id: string, resolved: string): boolean {

tests/__snapshots__/rollup/no-index.md

@@ -15,6 +15,7 @@ export type Bar = string;
 ```ts
 export {} from './foo/index.js';
 export {} from './index.js';
+export {} from './index.js';
 
 ```
 ## main.js

tests/fixtures/no-index/main.ts

@@ -1,2 +1,3 @@
 export {} from './foo'
 export {} from '.'
+export {} from './index'