feat: Check interfaces return type for used generics

sylvia-derive/src/message.rs

@@ -6,7 +6,9 @@ use crate::parser::{
     Custom, MsgAttr, MsgType, OverrideEntryPoint, OverrideEntryPoints,
 };
 use crate::strip_generics::StripGenerics;
-use crate::utils::{extract_return_type, filter_wheres, process_fields};
+use crate::utils::{
+    as_where_clause, brace_generics, extract_return_type, filter_wheres, process_fields,
+};
 use crate::variant_descs::{AsVariantDescs, VariantDescs};
 use convert_case::{Case, Casing};
 use proc_macro2::{Span, TokenStream};
@@ -100,14 +102,6 @@ impl<'a> StructMessage<'a> {
             custom,
         } = self;
 
-        let where_clause = if !wheres.is_empty() {
-            quote! {
-                where #(#wheres,)*
-            }
-        } else {
-            quote! {}
-        };
-
         let ctx_type = msg_attr
             .msg_type()
             .emit_ctx_type(&custom.query_or_default());
@@ -119,21 +113,9 @@ impl<'a> StructMessage<'a> {
         });
         let fields = fields.iter().map(MsgField::emit);
 
-        let generics = if generics.is_empty() {
-            quote! {}
-        } else {
-            quote! {
-                <#(#generics,)*>
-            }
-        };
-
-        let unused_generics = if unused_generics.is_empty() {
-            quote! {}
-        } else {
-            quote! {
-                <#(#unused_generics,)*>
-            }
-        };
+        let where_clause = as_where_clause(wheres);
+        let generics = brace_generics(generics);
+        let unused_generics = brace_generics(unused_generics);
 
         #[cfg(not(tarpaulin_include))]
         {
@@ -282,18 +264,33 @@ impl<'a> EnumMessage<'a> {
         let ctx_type = msg_ty.emit_ctx_type(query_type);
         let dispatch_type = msg_ty.emit_result_type(resp_type, &parse_quote!(C::Error));
 
-        let all_generics = if all_generics.is_empty() {
+        let all_generics = brace_generics(all_generics);
+        let phantom = if generics.is_empty() {
             quote! {}
+        } else if MsgType::Query == *msg_ty {
+            quote! {
+                #[returns((#(#generics,)*))]
+                _Phantom(std::marker::PhantomData<( #(#generics,)* )>),
+            }
         } else {
-            quote! { <#(#all_generics,)*> }
+            quote! {
+                _Phantom(std::marker::PhantomData<( #(#generics,)* )>),
+            }
         };
 
-        let generics = if generics.is_empty() {
-            quote! {}
+        let match_arms = if !generics.is_empty() {
+            quote! {
+                #(#match_arms,)*
+                _Phantom(_) => unreachable!(),
+            }
         } else {
-            quote! { <#(#generics,)*> }
+            quote! {
+                #(#match_arms,)*
+            }
         };
 
+        let generics = brace_generics(generics);
+
         let unique_enum_name = Ident::new(&format!("{}{}", trait_name, name), name.span());
 
         #[cfg(not(tarpaulin_include))]
@@ -305,6 +302,7 @@ impl<'a> EnumMessage<'a> {
                     #[serde(rename_all="snake_case")]
                     pub enum #unique_enum_name #generics {
                         #(#variants,)*
+                        #phantom
                     }
                     pub type #name #generics = #unique_enum_name #generics;
                 }
@@ -316,6 +314,7 @@ impl<'a> EnumMessage<'a> {
                     #[serde(rename_all="snake_case")]
                     pub enum #unique_enum_name #generics {
                         #(#variants,)*
+                        #phantom
                     }
                     pub type #name #generics = #unique_enum_name #generics;
                 }
@@ -334,7 +333,7 @@ impl<'a> EnumMessage<'a> {
                         use #unique_enum_name::*;
 
                         match self {
-                            #(#match_arms,)*
+                            #match_arms
                         }
                     }
                     pub const fn messages() -> [&'static str; #msgs_cnt] {
@@ -507,10 +506,12 @@ impl<'a> MsgVariant<'a> {
         let return_type = if let MsgAttr::Query { resp_type } = msg_attr {
             match resp_type {
                 Some(resp_type) => {
+                    generics_checker.visit_path(&parse_quote! { #resp_type });
                     quote! {#resp_type}
                 }
                 None => {
                     let return_type = extract_return_type(&sig.output);
+                    generics_checker.visit_path(return_type);
                     quote! {#return_type}
                 }
             }
@@ -621,7 +622,11 @@ impl<'a> MsgVariant<'a> {
         }
     }
 
-    pub fn emit_querier_impl(&self, trait_module: Option<&Path>) -> TokenStream {
+    pub fn emit_querier_impl(
+        &self,
+        trait_module: Option<&Path>,
+        unbonded_generics: &Vec<&GenericParam>,
+    ) -> TokenStream {
         let sylvia = crate_module();
         let Self {
             name,
@@ -637,6 +642,12 @@ impl<'a> MsgVariant<'a> {
             .map(|module| quote! { #module ::QueryMsg })
             .unwrap_or_else(|| quote! { QueryMsg });
 
+        let msg = if !unbonded_generics.is_empty() {
+            quote! { #msg ::< #(#unbonded_generics,)* > }
+        } else {
+            quote! { #msg }
+        };
+
         #[cfg(not(tarpaulin_include))]
         {
             quote! {
@@ -741,18 +752,15 @@ impl<'a> MsgVariants<'a> {
         let methods_impl = variants
             .iter()
             .filter(|variant| variant.msg_type == MsgType::Query)
-            .map(|variant| variant.emit_querier_impl(None));
+            .map(|variant| variant.emit_querier_impl(None, unbonded_generics));
 
         let methods_declaration = variants
             .iter()
             .filter(|variant| variant.msg_type == MsgType::Query)
             .map(MsgVariant::emit_querier_declaration);
 
-        let querier = if !unbonded_generics.is_empty() {
-            quote! { Querier < #(#unbonded_generics,)* > }
-        } else {
-            quote! { Querier }
-        };
+        let braced_generics = brace_generics(unbonded_generics);
+        let querier = quote! { Querier #braced_generics };
 
         #[cfg(not(tarpaulin_include))]
         {
@@ -803,7 +811,7 @@ impl<'a> MsgVariants<'a> {
         let methods_impl = variants
             .iter()
             .filter(|variant| variant.msg_type == MsgType::Query)
-            .map(|variant| variant.emit_querier_impl(trait_module));
+            .map(|variant| variant.emit_querier_impl(trait_module, unbonded_generics));
 
         let mut querier = trait_module
             .map(|module| quote! { #module ::Querier })

sylvia-derive/src/utils.rs

@@ -1,9 +1,11 @@
+use proc_macro2::TokenStream;
 use proc_macro_error::emit_error;
+use quote::quote;
 use syn::spanned::Spanned;
 use syn::visit::Visit;
 use syn::{
-    FnArg, GenericArgument, GenericParam, Path, PathArguments, ReturnType, Signature, Type,
-    WhereClause, WherePredicate,
+    parse_quote, FnArg, GenericArgument, GenericParam, Path, PathArguments, ReturnType, Signature,
+    Type, WhereClause, WherePredicate,
 };
 
 use crate::check_generics::CheckGenerics;
@@ -84,3 +86,17 @@ pub fn extract_return_type(ret_type: &ReturnType) -> &Path {
 
     &type_path.path
 }
+
+pub fn as_where_clause(where_predicates: &[&WherePredicate]) -> Option<WhereClause> {
+    match where_predicates.is_empty() {
+        true => None,
+        false => Some(parse_quote! { where #(#where_predicates),* }),
+    }
+}
+
+pub fn brace_generics(unbonded_generics: &[&GenericParam]) -> TokenStream {
+    match unbonded_generics.is_empty() {
+        true => quote! {},
+        false => quote! { < #(#unbonded_generics,)* > },
+    }
+}

sylvia/tests/generics.rs

@@ -1,17 +1,18 @@
 use cosmwasm_schema::cw_serde;
 
 pub mod cw1 {
-    use cosmwasm_std::{CosmosMsg, CustomMsg, Response, StdError};
+    use cosmwasm_std::{CosmosMsg, CustomMsg, CustomQuery, Response, StdError};
 
-    use serde::Deserialize;
+    use serde::{de::DeserializeOwned, Deserialize};
     use sylvia::types::{ExecCtx, QueryCtx};
     use sylvia_derive::interface;
 
     #[interface(module=msg)]
-    pub trait Cw1<Msg, Param>
+    pub trait Cw1<Msg, Param, QueryRet>
     where
         for<'msg_de> Msg: CustomMsg + Deserialize<'msg_de>,
         Param: sylvia::types::CustomMsg,
+        for<'msg_de> QueryRet: CustomQuery + DeserializeOwned,
     {
         type Error: From<StdError>;
 
@@ -20,7 +21,7 @@ pub mod cw1 {
             -> Result<Response, Self::Error>;
 
         #[msg(query)]
-        fn query(&self, ctx: QueryCtx, param: Param) -> Result<String, Self::Error>;
+        fn some_query(&self, ctx: QueryCtx, param: Param) -> Result<QueryRet, Self::Error>;
     }
 }
 
@@ -37,7 +38,7 @@ mod tests {
 
     #[test]
     fn construct_messages() {
-        let _ = crate::cw1::QueryMsg::query(ExternalMsg {});
+        let _ = crate::cw1::QueryMsg::<_, Empty>::some_query(ExternalMsg {});
         let _ = crate::cw1::ExecMsg::execute(vec![CosmosMsg::Custom(ExternalMsg {})]);
         let _ = crate::cw1::ExecMsg::execute(vec![CosmosMsg::Custom(Empty {})]);
     }