fix(codegen): output newline after export default interface (#25487)

crates/oxc_codegen/src/gen.rs

@@ -1275,7 +1275,10 @@ impl Gen for ExportDefaultDeclarationKind<'_> {
                 class.print(p, ctx);
                 p.print_soft_newline();
             }
-            Self::TSInterfaceDeclaration(interface) => interface.print(p, ctx),
+            Self::TSInterfaceDeclaration(interface) => {
+                interface.print(p, ctx);
+                p.print_soft_newline();
+            }
             _ => {
                 p.start_of_default_export = p.code_len();
                 self.to_expression().print_expr(p, Precedence::Comma, Context::empty());

crates/oxc_codegen/tests/integration/ts.rs

@@ -55,6 +55,11 @@ fn cases() {
     test_same("const Bar = class<T,> {};\n");
 }
 
+#[test]
+fn export_default_interface() {
+    test_same("export default interface X {}\nconst y = 1;\n");
+}
+
 #[test]
 fn decorators() {
     test_same("@a abstract class C {}\n");