#[itest(async)]: fix TaskHandle expecting to be imported

Author: Bromeon

godot-macros/src/itest.rs

@@ -64,10 +64,9 @@ pub fn attribute_itest(input_item: venial::Item) -> ParseResult<TokenStream> {
         quote! { __unused_context: &crate::framework::TestContext }
     };
 
+    let return_ty = func.return_ty.as_ref();
     if is_async
-        && func
-            .return_ty
-            .as_ref()
+        && return_ty
             .and_then(extract_typename)
             .is_none_or(|segment| segment.ident != "TaskHandle")
     {
@@ -78,7 +77,8 @@ pub fn attribute_itest(input_item: venial::Item) -> ParseResult<TokenStream> {
 
     let (return_tokens, test_case_ty, plugin_name);
     if is_async {
-        return_tokens = quote! { -> TaskHandle };
+        let [arrow, arrow_head] = func.tk_return_arrow.unwrap();
+        return_tokens = quote! { #arrow #arrow_head #return_ty }; // retain span.
         test_case_ty = quote! { crate::framework::AsyncRustTestCase };
         plugin_name = ident("__GODOT_ASYNC_ITEST");
     } else {