From 558c213b2ea5065e43f38afa2fc4bedab6b8a5aa Mon Sep 17 00:00:00 2001
From: Soares Chen <soares.chen@maybevoid.com>
Date: Thu, 26 Mar 2026 21:19:43 +0100
Subject: [PATCH 1/2] Move function attributes in `#[cgp_fn]` to trait and impl

---
 crates/cgp-macro-lib/src/cgp_fn/attributes.rs | 17 +++++++----------
 crates/cgp-macro-lib/src/cgp_fn/derive.rs     |  8 ++++++--
 crates/cgp-tests/tests/cgp_fn_tests/multi.rs  |  5 +++--
 3 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/crates/cgp-macro-lib/src/cgp_fn/attributes.rs b/crates/cgp-macro-lib/src/cgp_fn/attributes.rs
index 433edc08..3a7653a5 100644
--- a/crates/cgp-macro-lib/src/cgp_fn/attributes.rs
+++ b/crates/cgp-macro-lib/src/cgp_fn/attributes.rs
@@ -1,5 +1,3 @@
-use core::mem;
-
 use syn::punctuated::Punctuated;
 use syn::token::Comma;
 use syn::{Attribute, TypeParamBound, WherePredicate};
@@ -9,13 +7,12 @@ use crate::cgp_impl::UseProviderSpec;
 use crate::parse::SimpleType;
 
 pub fn parse_function_attributes(
-    attributes: &mut Vec<Attribute>,
-) -> syn::Result<FunctionAttributes> {
+    attributes: Vec<Attribute>,
+) -> syn::Result<(FunctionAttributes, Vec<Attribute>)> {
     let mut parsed_attributes = FunctionAttributes::default();
+    let mut rest_attributes = Vec::new();
 
-    let in_attributes = mem::take(attributes);
-
-    for attribute in in_attributes.into_iter() {
+    for attribute in attributes.into_iter() {
         if let Some(ident) = attribute.path().get_ident() {
             if ident == "extend" {
                 let extend_bound = attribute
@@ -38,12 +35,12 @@ pub fn parse_function_attributes(
                     .parse_args_with(Punctuated::<UseProviderSpec, Comma>::parse_terminated)?;
                 parsed_attributes.use_provider.extend(use_provider);
             } else {
-                attributes.push(attribute);
+                rest_attributes.push(attribute);
             }
         } else {
-            attributes.push(attribute);
+            rest_attributes.push(attribute);
         }
     }
 
-    Ok(parsed_attributes)
+    Ok((parsed_attributes, rest_attributes))
 }
diff --git a/crates/cgp-macro-lib/src/cgp_fn/derive.rs b/crates/cgp-macro-lib/src/cgp_fn/derive.rs
index 14c1dd3f..6850c04f 100644
--- a/crates/cgp-macro-lib/src/cgp_fn/derive.rs
+++ b/crates/cgp-macro-lib/src/cgp_fn/derive.rs
@@ -15,15 +15,17 @@ pub fn derive_cgp_fn(trait_ident: &Ident, mut item_fn: ItemFn) -> syn::Result<To
 
     let implicit_args = extract_and_parse_implicit_args(&mut item_fn.sig.inputs)?;
 
-    let attributes = parse_function_attributes(&mut item_fn.attrs)?;
+    let (attributes, trait_attributes) =
+        parse_function_attributes(core::mem::take(&mut item_fn.attrs))?;
 
     inject_implicit_args(&implicit_args, &mut item_fn.block)?;
 
     let generics = mem::take(&mut item_fn.sig.generics);
 
     let mut item_trait = derive_item_trait(trait_ident, &item_fn, &generics, &attributes)?;
+    item_trait.attrs.extend(trait_attributes.clone());
 
-    let item_impl = derive_item_impl(
+    let mut item_impl = derive_item_impl(
         trait_ident,
         &item_fn,
         &implicit_args,
@@ -31,6 +33,8 @@ pub fn derive_cgp_fn(trait_ident: &Ident, mut item_fn: ItemFn) -> syn::Result<To
         &attributes,
     )?;
 
+    item_impl.attrs.extend(trait_attributes);
+
     item_trait.vis = visibility.clone();
 
     let output = quote! {
diff --git a/crates/cgp-tests/tests/cgp_fn_tests/multi.rs b/crates/cgp-tests/tests/cgp_fn_tests/multi.rs
index 758186c5..5c93b406 100644
--- a/crates/cgp-tests/tests/cgp_fn_tests/multi.rs
+++ b/crates/cgp-tests/tests/cgp_fn_tests/multi.rs
@@ -12,10 +12,11 @@ pub trait HasBarType {
     type Baz;
 }
 
-#[allow(unused)]
 #[cgp_fn]
+#[allow(unused)]
+#[async_trait]
 #[use_type(<HasFooType<X>>::{Foo as FooX}, <HasFooType<Y>>::{Foo as FooY}, HasBarType::{Bar, Baz})]
-pub fn do_foo_bar<X, Y>(
+pub async fn do_foo_bar<X, Y>(
     &self,
     x: X,
     #[implicit] foo_x: &FooX,

From bf9e26a1dcf40dd59d85088cbddbde719b3ebe33 Mon Sep 17 00:00:00 2001
From: Soares Chen <soares.chen@maybevoid.com>
Date: Thu, 26 Mar 2026 21:21:21 +0100
Subject: [PATCH 2/2] Add test for async function

---
 crates/cgp-tests/tests/cgp_fn_tests/async.rs | 7 +++++++
 crates/cgp-tests/tests/cgp_fn_tests/mod.rs   | 1 +
 2 files changed, 8 insertions(+)
 create mode 100644 crates/cgp-tests/tests/cgp_fn_tests/async.rs

diff --git a/crates/cgp-tests/tests/cgp_fn_tests/async.rs b/crates/cgp-tests/tests/cgp_fn_tests/async.rs
new file mode 100644
index 00000000..a4110246
--- /dev/null
+++ b/crates/cgp-tests/tests/cgp_fn_tests/async.rs
@@ -0,0 +1,7 @@
+use cgp::prelude::*;
+
+#[cgp_fn]
+#[async_trait]
+pub async fn greet(&self, #[implicit] name: &str) -> String {
+    format!("Hello, {}!", name)
+}
diff --git a/crates/cgp-tests/tests/cgp_fn_tests/mod.rs b/crates/cgp-tests/tests/cgp_fn_tests/mod.rs
index 5db1140a..829f72ac 100644
--- a/crates/cgp-tests/tests/cgp_fn_tests/mod.rs
+++ b/crates/cgp-tests/tests/cgp_fn_tests/mod.rs
@@ -1,3 +1,4 @@
+pub mod r#async;
 pub mod basic;
 pub mod call;
 pub mod extend;