feat: Support generic interface implemented on contract

sylvia-derive/src/check_generics.rs

@@ -1,26 +1,51 @@
 use syn::visit::Visit;
-use syn::GenericParam;
+use syn::{GenericArgument, GenericParam, Type};
+
+pub trait AsIdent {
+    fn as_ident(&self) -> Option<&syn::Ident>;
+}
+
+impl AsIdent for GenericParam {
+    fn as_ident(&self) -> Option<&syn::Ident> {
+        match self {
+            GenericParam::Type(ty) => Some(&ty.ident),
+            _ => None,
+        }
+    }
+}
+
+impl AsIdent for GenericArgument {
+    fn as_ident(&self) -> Option<&syn::Ident> {
+        match self {
+            GenericArgument::Type(Type::Path(path)) => path.path.get_ident(),
+            _ => None,
+        }
+    }
+}
 
 #[derive(Debug)]
-pub struct CheckGenerics<'g> {
-    generics: &'g [&'g GenericParam],
-    used: Vec<&'g GenericParam>,
+pub struct CheckGenerics<'g, Generic> {
+    generics: &'g [&'g Generic],
+    used: Vec<&'g Generic>,
 }
 
-impl<'g> CheckGenerics<'g> {
-    pub fn new(generics: &'g [&'g GenericParam]) -> Self {
+impl<'g, Generic> CheckGenerics<'g, Generic>
+where
+    Generic: AsIdent + PartialEq,
+{
+    pub fn new(generics: &'g [&'g Generic]) -> Self {
         Self {
             generics,
             used: vec![],
         }
     }
 
-    pub fn used(self) -> Vec<&'g GenericParam> {
+    pub fn used(self) -> Vec<&'g Generic> {
         self.used
     }
 
     /// Returns split between used and unused generics
-    pub fn used_unused(self) -> (Vec<&'g GenericParam>, Vec<&'g GenericParam>) {
+    pub fn used_unused(self) -> (Vec<&'g Generic>, Vec<&'g Generic>) {
         let unused = self
             .generics
             .iter()
@@ -32,14 +57,13 @@ impl<'g> CheckGenerics<'g> {
     }
 }
 
-impl<'ast, 'g> Visit<'ast> for CheckGenerics<'g> {
+impl<'ast, 'g, Generic> Visit<'ast> for CheckGenerics<'g, Generic>
+where
+    Generic: AsIdent + PartialEq,
+{
     fn visit_path(&mut self, p: &'ast syn::Path) {
         if let Some(p) = p.get_ident() {
-            if let Some(gen) = self
-                .generics
-                .iter()
-                .find(|gen| matches!(gen, GenericParam::Type(ty) if ty.ident == *p))
-            {
+            if let Some(gen) = self.generics.iter().find(|gen| gen.as_ident() == Some(p)) {
                 if !self.used.contains(gen) {
                     self.used.push(gen);
                 }

sylvia-derive/src/input.rs

@@ -3,7 +3,10 @@ use proc_macro_error::emit_error;
 use quote::quote;
 use syn::parse::{Parse, Parser};
 use syn::spanned::Spanned;
-use syn::{parse_quote, GenericParam, Ident, ItemImpl, ItemTrait, TraitItem, Type};
+use syn::{
+    parse_quote, GenericArgument, GenericParam, Ident, ItemImpl, ItemTrait, PathArguments,
+    TraitItem, Type,
+};
 
 use crate::crate_module;
 use crate::interfaces::Interfaces;
@@ -156,42 +159,48 @@ impl<'a> ImplInput<'a> {
     }
 
     pub fn process(&self) -> TokenStream {
-        let is_trait = self.item.trait_.is_some();
+        let Self {
+            item,
+            generics,
+            error,
+            custom,
+            override_entry_points,
+            interfaces,
+            ..
+        } = self;
+        let is_trait = item.trait_.is_some();
         let multitest_helpers = if cfg!(feature = "mt") {
+            let interface_generics = self.extract_generic_argument();
             MultitestHelpers::new(
-                self.item,
+                item,
                 is_trait,
-                &self.error,
-                &self.generics,
-                &self.custom,
-                &self.override_entry_points,
-                &self.interfaces,
+                error,
+                &interface_generics,
+                custom,
+                override_entry_points,
+                interfaces,
             )
             .emit()
         } else {
             quote! {}
         };
 
-        let unbonded_generics = &vec![];
+        let where_clause = &item.generics.where_clause;
         let variants = MsgVariants::new(
             self.item.as_variants(),
             MsgType::Query,
-            unbonded_generics,
-            &None,
+            generics,
+            where_clause,
         );
 
         match is_trait {
-            true => self.process_interface(variants, multitest_helpers),
+            true => self.process_interface(multitest_helpers),
             false => self.process_contract(variants, multitest_helpers),
         }
     }
 
-    fn process_interface(
-        &self,
-        variants: MsgVariants<'a>,
-        multitest_helpers: TokenStream,
-    ) -> TokenStream {
-        let querier_bound_for_impl = self.emit_querier_for_bound_impl(variants);
+    fn process_interface(&self, multitest_helpers: TokenStream) -> TokenStream {
+        let querier_bound_for_impl = self.emit_querier_for_bound_impl();
 
         #[cfg(not(tarpaulin_include))]
         quote! {
@@ -203,7 +212,7 @@ impl<'a> ImplInput<'a> {
 
     fn process_contract(
         &self,
-        variants: MsgVariants<'a>,
+        variants: MsgVariants<'a, GenericParam>,
         multitest_helpers: TokenStream,
     ) -> TokenStream {
         let messages = self.emit_messages();
@@ -285,13 +294,31 @@ impl<'a> ImplInput<'a> {
         .emit()
     }
 
-    fn emit_querier_for_bound_impl(&self, variants: MsgVariants<'a>) -> TokenStream {
+    /// This method should only be called for trait impl block
+    fn extract_generic_argument(&self) -> Vec<&GenericArgument> {
+        let interface_generics = &self.item.trait_.as_ref();
+        let args = match interface_generics {
+            Some((_, path, _)) => path.segments.last().map(|segment| &segment.arguments),
+            None => None,
+        };
+
+        match args {
+            Some(PathArguments::AngleBracketed(args)) => {
+                args.args.pairs().map(|pair| *pair.value()).collect()
+            }
+            _ => vec![],
+        }
+    }
+
+    fn emit_querier_for_bound_impl(&self) -> TokenStream {
         let trait_module = self
             .interfaces
-            .interfaces()
-            .first()
+            .get_only_interface()
             .map(|interface| &interface.module);
         let contract_module = self.attributes.module.as_ref();
+        let generics = self.extract_generic_argument();
+
+        let variants = MsgVariants::new(self.item.as_variants(), MsgType::Query, &generics, &None);
 
         variants.emit_querier_for_bound_impl(trait_module, contract_module)
     }

sylvia-derive/src/interfaces.rs

@@ -83,30 +83,23 @@ impl Interfaces {
             .collect()
     }
 
-    pub fn emit_glue_message_variants(
-        &self,
-        msg_ty: &MsgType,
-        msg_name: &Ident,
-    ) -> Vec<TokenStream> {
+    pub fn emit_glue_message_variants(&self, msg_ty: &MsgType) -> Vec<TokenStream> {
+        let sylvia = crate_module();
+
         self.interfaces
             .iter()
             .map(|interface| {
                 let ContractMessageAttr {
-                    module,
-                    exec_generic_params,
-                    query_generic_params,
-                    variant,
-                    ..
+                    module, variant, ..
                 } = interface;
 
-                let generics = match msg_ty {
-                    MsgType::Exec => exec_generic_params.as_slice(),
-                    MsgType::Query => query_generic_params.as_slice(),
-                    _ => &[],
-                };
-
-                let enum_name = Self::merge_module_with_name(interface, msg_name);
-                quote! { #variant(#module :: #enum_name<#(#generics,)*>) }
+                let interface_enum =
+                    quote! { <#module ::InterfaceTypes as #sylvia ::types::InterfaceMessages> };
+                if msg_ty == &MsgType::Query {
+                    quote! { #variant ( #interface_enum :: Query) }
+                } else {
+                    quote! { #variant ( #interface_enum :: Exec)}
+                }
             })
             .collect()
     }
@@ -158,4 +151,23 @@ impl Interfaces {
     pub fn as_modules(&self) -> impl Iterator<Item = &Path> {
         self.interfaces.iter().map(|interface| &interface.module)
     }
+
+    pub fn get_only_interface(&self) -> Option<&ContractMessageAttr> {
+        let interfaces = &self.interfaces;
+        match interfaces.len() {
+            0 => None,
+            1 => Some(&interfaces[0]),
+            _ => {
+                let first = &interfaces[0];
+                for redefined in &interfaces[1..] {
+                    emit_error!(
+                      redefined.module, "The attribute `messages` is redefined";
+                      note = first.module.span() => "Previous definition of the attribute `messsages`";
+                      note = "Only one `messages` attribute can exist on an interface implementation on contract"
+                    );
+                }
+                None
+            }
+        }
+    }
 }