Merge pull request #2376 from CosmWasm/co/add-migrate-error

Add compiler error for incorrect `entry_point` macro usage

Author: chipshort

packages/derive/src/lib.rs

@@ -130,7 +130,15 @@ fn expand_bindings(crate_path: &syn::Path, mut function: syn::ItemFn) -> TokenSt
     let fn_name = &function.sig.ident;
     let wasm_export = format_ident!("__wasm_export_{fn_name}");
 
-    // Migrate entry point can take 2 or 3 arguments
+    // Prevent contract dev from using the wrong identifier for the do_migrate_with_info function
+    if fn_name == "migrate_with_info" {
+        return syn::Error::new_spanned(
+            &function.sig.ident,
+            r#"To use the new migrate function signature, you should provide a "migrate" entry point with 4 arguments, not "migrate_with_info""#,
+        ).into_compile_error();
+    }
+
+    // Migrate entry point can take 2 or 3 arguments (not counting deps)
     let do_call = if fn_name == "migrate" && args == 3 {
         format_ident!("do_migrate_with_info")
     } else {
@@ -263,6 +271,26 @@ mod test {
         };
 
         assert_eq!(actual.to_string(), expected.to_string());
+
+        // this should cause a compiler error
+        let code = quote! {
+            #[entry_point]
+            pub fn migrate_with_info(
+                deps: DepsMut,
+                env: Env,
+                msg: MigrateMsg,
+                migrate_info: MigrateInfo,
+            ) -> Result<Response, ()> {
+                // Logic here
+            }
+        };
+
+        let actual = entry_point_impl(TokenStream::new(), code);
+        let expected = quote! {
+            ::core::compile_error! { "To use the new migrate function signature, you should provide a \"migrate\" entry point with 4 arguments, not \"migrate_with_info\"" }
+        };
+
+        assert_eq!(actual.to_string(), expected.to_string());
     }
 
     #[test]