chore: Better error message for sv::features attribute

sylvia-derive/src/lib.rs

@@ -629,7 +629,15 @@ fn interface_impl(_attr: TokenStream2, item: TokenStream2) -> TokenStream2 {
 ///
 /// Currently supported features are:
 ///     * `replies` - enables better dispatching of `reply` as well as its auto deserialization.
+///                    With this feature enabled, user can use additional parameters in the
+///                    `sv::msg` attribute like so:
+///                    `#[sv::msg(reply, handlers=[scenario1, scenario2], reply_on=Success)].
 ///
+///                    Based on this parameters reply ids will be generated and associated with
+///                    proper scenario specified by the `reply_on` parameter.
+///
+///                    User can also specify custom `data` and `payload` types that will be auto
+///                    deserialized from the `cosmwasm_std::Binary` type.
 #[proc_macro_error]
 #[proc_macro_attribute]
 pub fn contract(attr: TokenStream, item: TokenStream) -> TokenStream {

sylvia-derive/src/parser/attributes/features.rs

@@ -31,7 +31,7 @@ impl Parse for SylviaFeatures {
                 _ => {
                     return Err(Error::new(
                         feature.span(),
-                        "Invalid feature.\n= note: Expected `#[sv::features(replies)];`.\n",
+                        "Invalid feature.\n= note: Supported features for contract macro: [`replies`].\n",
                     ))
                 }
             }

sylvia/tests/ui/attributes/features/invalid_params.stderr

@@ -1,5 +1,5 @@
 error: Invalid feature.
-       = note: Expected `#[sv::features(replies)];`.
+       = note: Supported features for contract macro: [`replies`].
  --> tests/ui/attributes/features/invalid_params.rs:9:16
   |
 9 | #[sv::features(unknown_parameter)]