chore: Add trybuild check for two instantiate methods

sylvia-derive/src/input.rs

@@ -126,6 +126,34 @@
         let query = self.emit_msg(MsgType::Query);
         let sudo = self.emit_msg(MsgType::Sudo);
 
+        let instantiate = MsgVariants::new(
+            self.item.as_variants(),
+            MsgType::Instantiate,
+            &[] as &[&Ident],
+            &None,
+        );
+
+        if let Some(msg_variant) = instantiate.variants().next() {
+            emit_error!(
+                msg_variant.name().span(), "The message attribute `instantiate` is not supported in interfaces.";
+                note = "Contracts need to implement `instantiate` method within their `impl` block.";
+            );
+        }
+
+        let migrate = MsgVariants::new(
+            self.item.as_variants(),
+            MsgType::Migrate,
+            &[] as &[&Ident],
+            &None,
+        );
+
+        if let Some(msg_variant) = migrate.variants().next() {
+            emit_error!(
+                msg_variant.name().span(), "The message attribute `migrate` is not supported in interfaces";
+                note = "Contracts need to implement `migrate` method within their `impl` block.";
+            );
+        }
+
         quote! {
             #exec
 

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

@@ -7,7 +7,6 @@ use syn::{parenthesized, Error, Ident, MetaList, Path, Result, Token};
 
 use proc_macro_error::emit_error;
 
-use crate::parser::extract_generics_from_path;
 use crate::strip_generics::StripGenerics;
 
 #[derive(Debug)]
@@ -77,8 +76,6 @@ fn interface_has_custom(content: ParseStream) -> Result<Customs> {
 impl Parse for ContractMessageAttr {
     fn parse(input: ParseStream) -> Result<Self> {
         let module = input.parse()?;
-        // If this is not for backwards compatibility we can remove it
-        let _ = extract_generics_from_path(&module);
         let module = StripGenerics.fold_path(module);
 
         let variant = if input.parse::<Token![as]>().is_ok() {

sylvia/tests/ui/missing_method/msgs_misused.rs

@@ -0,0 +1,41 @@
+#![allow(unused_imports)]
+use sylvia::cw_std::{Response, StdResult};
+use sylvia::types::InstantiateCtx;
+
+pub struct Contract;
+
+
+mod interface {
+    use sylvia::cw_std::{Response, StdResult, StdError};
+    use sylvia::types::{InstantiateCtx, MigrateCtx};
+
+    #[sylvia::interface]
+    trait Interface {
+        type Error: From<StdError>;
+
+        #[sv::msg(instantiate)]
+        fn instantiate(&self, ctx: InstantiateCtx) -> StdResult<Response>;
+
+        #[sv::msg(migrate)]
+        fn migrate(&self, ctx: MigrateCtx) -> StdResult<Response>;
+    }
+}
+
+#[sylvia::contract]
+impl Contract {
+    pub const fn new() -> Self {
+        Contract
+    }
+
+    #[sv::msg(instantiate)]
+    pub fn instantiate(&self, ctx: InstantiateCtx) -> StdResult<Response> {
+        Ok(Response::new())
+    }
+
+    #[sv::msg(instantiate)]
+    pub fn instantiate2(&self, ctx: InstantiateCtx) -> StdResult<Response> {
+        Ok(Response::new())
+    }
+}
+
+fn main() {}

sylvia/tests/ui/missing_method/msgs_misused.stderr

@@ -0,0 +1,26 @@
+error: The message attribute `instantiate` is not supported in interfaces.
+
+         = note: Contracts need to implement `instantiate` method within their `impl` block.
+
+  --> tests/ui/missing_method/msgs_misused.rs:17:12
+   |
+17 |         fn instantiate(&self, ctx: InstantiateCtx) -> StdResult<Response>;
+   |            ^^^^^^^^^^^
+
+error: The message attribute `migrate` is not supported in interfaces
+
+         = note: Contracts need to implement `migrate` method within their `impl` block.
+
+  --> tests/ui/missing_method/msgs_misused.rs:20:12
+   |
+20 |         fn migrate(&self, ctx: MigrateCtx) -> StdResult<Response>;
+   |            ^^^^^^^
+
+error: More than one instantiation or migration message
+
+         = note: Instantiation/Migration message previously defined here
+
+  --> tests/ui/missing_method/msgs_misused.rs:35:5
+   |
+35 |     #[sv::msg(instantiate)]
+   |     ^