```==================== .D.TS ====================

declare function A(): unknown;
declare const B: any;
declare const C: any;
declare const D: () => string;
declare const E: () => (() => void) | undefined;


==================== Errors ====================
  x TS9007: Function must have an explicit return type annotation with --isolatedDeclarations.
   ,-[$DIR/tests/oxc_fixture/arrow-function-return-type.ts:2:1]
 1 | function A() {
 2 |   return () => {
   :          ^^^^^^^
 3 |     return C;
   `----
  x TS9007: Function must have an explicit return type annotation with --isolatedDeclarations.
   ,-[$DIR/tests/oxc_fixture/arrow-function-return-type.ts:7:1]
 6 | 
 7 | const B = () => { return B };
   :           ^^^^^^^
   `----
  x TS9007: Function must have an explicit return type annotation with --isolatedDeclarations.
   ,-[$DIR/tests/oxc_fixture/arrow-function-return-type.ts:9:1]
 8 | 
 9 | const C = function () {}
   :           ^^^^^^^^^^^^
   `----


```
