fix(isolated-declarations): missing empty export when has an export declare (#5925)

crates/oxc_isolated_declarations/src/lib.rs

@@ -253,7 +253,7 @@ impl<'a> IsolatedDeclarations<'a> {
                             transformed_spans.insert(decl.span);
                             if let Some(new_decl) = self.transform_export_named_declaration(decl) {
                                 *decl = self.ast.alloc(new_decl);
-                            } else {
+                            } else if decl.declaration.is_none() {
                                 need_empty_export_marker = false;
                             }
                             self.scope.visit_export_named_declaration(decl);

crates/oxc_isolated_declarations/tests/fixtures/empty-export.ts

@@ -2,3 +2,7 @@ type A = string;
 export function a(): A {
   return ""
 }
+
+export declare const ShallowReactiveMarker: unique symbol
+
+export type ShallowReactive<T> = T & { [ShallowReactiveMarker]?: true }

crates/oxc_isolated_declarations/tests/snapshots/empty-export.snap

@@ -6,4 +6,6 @@ input_file: crates/oxc_isolated_declarations/tests/fixtures/empty-export.ts
 
 type A = string;
 export declare function a(): A;
+export declare const ShallowReactiveMarker: unique symbol;
+export type ShallowReactive<T> = T & { [ShallowReactiveMarker]?: true };
 export {};