Add support for assoc items

- post-CR formatting fixes
- extend tests

Author: Yarwin

godot-macros/src/class/godot_dyn.rs

@@ -44,26 +44,24 @@ pub fn attribute_godot_dyn(input_decl: venial::Item) -> ParseResult<TokenStream>
         associated_types.push(quote! { #type_name = #type_expr })
     }
 
-    let associated_impl = if associated_types.is_empty() {
-        None
+    let assoc_type_constraints = if associated_types.is_empty() {
+        TokenStream::new()
     } else {
-        Some(quote! { <#(#associated_types, )*>})
+        quote! { < #(#associated_types),* > }
     };
 
     let class_path = &decl.self_ty;
     let prv = quote! { ::godot::private };
 
-    //let dynify_fn = format_ident!("__dynify_{}", class_name);
-
     let new_code = quote! {
         #decl
 
-        impl ::godot::obj::AsDyn<dyn #trait_path #associated_impl> for #class_path {
-            fn dyn_upcast(&self) -> &(dyn #trait_path #associated_impl + 'static) {
+        impl ::godot::obj::AsDyn<dyn #trait_path #assoc_type_constraints> for #class_path {
+            fn dyn_upcast(&self) -> &(dyn #trait_path #assoc_type_constraints + 'static) {
                 self
             }
 
-            fn dyn_upcast_mut(&mut self) -> &mut (dyn #trait_path #associated_impl + 'static) {
+            fn dyn_upcast_mut(&mut self) -> &mut (dyn #trait_path #assoc_type_constraints + 'static) {
                 self
             }
         }