feat: add support for notes without asset in transctions (#654)

* feat: support txs with notes without assets

* feat: add unit test

* chore: update CHANGELOG

CHANGELOG.md

@@ -19,6 +19,7 @@
 
 ### Changes
 
+* Add support for notes without assets in transaction requests (#654).
 * Refactored RPC functions and structs to improve code quality (#616).
 * [BREAKING] Added support for new two `Felt` account ID (#639).
 * [BREAKING] Removed unnecessary methods from `Client` (#631).

crates/rust-client/src/tests.rs

@@ -4,6 +4,7 @@ use alloc::vec::Vec;
 // ================================================================================================
 use miden_lib::{
     accounts::{auth::RpoFalcon512, faucets::BasicFungibleFaucet, wallets::BasicWallet},
+    notes::utils,
     transaction::TransactionKernel,
 };
 use miden_objects::{
@@ -13,22 +14,28 @@ use miden_objects::{
     },
     assets::{FungibleAsset, TokenSymbol},
     crypto::{dsa::rpo_falcon512::SecretKey, rand::FeltRng},
-    notes::{NoteFile, NoteTag},
+    notes::{
+        Note, NoteAssets, NoteExecutionHint, NoteExecutionMode, NoteFile, NoteMetadata, NoteTag,
+        NoteType,
+    },
     testing::account_id::{
         ACCOUNT_ID_FUNGIBLE_FAUCET_ON_CHAIN_1, ACCOUNT_ID_FUNGIBLE_FAUCET_ON_CHAIN_2,
         ACCOUNT_ID_REGULAR_ACCOUNT_IMMUTABLE_CODE_ON_CHAIN,
         ACCOUNT_ID_REGULAR_ACCOUNT_UPDATABLE_CODE_OFF_CHAIN,
         ACCOUNT_ID_REGULAR_ACCOUNT_UPDATABLE_CODE_ON_CHAIN,
     },
-    Felt, FieldElement, Word,
+    transaction::OutputNote,
+    Felt, FieldElement, Word, ZERO,
 };
 use miden_tx::utils::{Deserializable, Serializable};
 
 use crate::{
     mock::create_test_client,
     rpc::NodeRpcClient,
     store::{InputNoteRecord, NoteFilter, Store, StoreError},
-    transactions::TransactionRequestBuilder,
+    transactions::{
+        TransactionRequestBuilder, TransactionRequestError, TransactionScriptBuilderError,
+    },
     Client, ClientError,
 };
 
@@ -631,3 +638,60 @@ async fn test_no_nonce_change_transaction_request() {
         Err(ClientError::StoreError(StoreError::AccountHashAlreadyExists(_)))
     ));
 }
+
+#[tokio::test]
+async fn test_note_without_asset() {
+    let (mut client, _rpc_api) = create_test_client().await;
+
+    let (faucet, _seed) = insert_new_fungible_faucet(&mut client, AccountStorageMode::Private)
+        .await
+        .unwrap();
+
+    let (wallet, _seed) =
+        insert_new_wallet(&mut client, AccountStorageMode::Private).await.unwrap();
+
+    client.sync_state().await.unwrap();
+
+    // Create note without assets
+    let serial_num = client.rng().draw_word();
+    let recipient = utils::build_p2id_recipient(wallet.id(), serial_num).unwrap();
+    let tag = NoteTag::from_account_id(wallet.id(), NoteExecutionMode::Local).unwrap();
+    let metadata =
+        NoteMetadata::new(wallet.id(), NoteType::Private, tag, NoteExecutionHint::always(), ZERO)
+            .unwrap();
+    let vault = NoteAssets::new(vec![]).unwrap();
+
+    let note = Note::new(vault.clone(), metadata, recipient.clone());
+
+    // Create and execute transaction
+    let transaction_request = TransactionRequestBuilder::new()
+        .with_own_output_notes(vec![OutputNote::Full(note)])
+        .unwrap()
+        .build();
+
+    let transaction = client.new_transaction(wallet.id(), transaction_request.clone()).await;
+
+    assert!(transaction.is_ok());
+
+    // Create the same transaction for the faucet
+    let metadata =
+        NoteMetadata::new(faucet.id(), NoteType::Private, tag, NoteExecutionHint::always(), ZERO)
+            .unwrap();
+    let note = Note::new(vault, metadata, recipient);
+
+    let transaction_request = TransactionRequestBuilder::new()
+        .with_own_output_notes(vec![OutputNote::Full(note)])
+        .unwrap()
+        .build();
+
+    let error = client.new_transaction(faucet.id(), transaction_request).await.unwrap_err();
+
+    assert!(matches!(
+        error,
+        ClientError::TransactionRequestError(
+            TransactionRequestError::TransactionScriptBuilderError(
+                TransactionScriptBuilderError::FaucetNoteWithoutAsset
+            )
+        )
+    ));
+}

crates/rust-client/src/transactions/script_builder.rs

@@ -36,8 +36,8 @@ impl AccountInterface {
     /// Errors:
     /// - [TransactionScriptBuilderError::InvalidSenderAccount] if the sender of the note isn't the
     ///   account for which the script is being built.
-    /// - [TransactionScriptBuilderError::InvalidAssetAmount] if the note doesn't contain exactly
-    ///   one asset.
+    /// - [TransactionScriptBuilderError::FaucetNoteWithoutAsset] if the note created by the faucet
+    ///   doesn't contain exactly one asset.
     /// - [TransactionScriptBuilderError::InvalidAsset] if a faucet tries to distribute an asset
     ///   with a different faucet ID.
     fn send_note_procedure(
@@ -54,8 +54,6 @@ impl AccountInterface {
                 ));
             }
 
-            let asset = partial_note.assets().iter().next().expect("There should be an asset");
-
             body.push_str(&format!(
                 "
                     push.{recipient}
@@ -73,6 +71,14 @@ impl AccountInterface {
 
             match self {
                 AccountInterface::BasicFungibleFaucet => {
+                    if partial_note.assets().num_assets() != 1 {
+                        return Err(TransactionScriptBuilderError::FaucetNoteWithoutAsset);
+                    }
+
+                    // SAFETY: We checked that the note contains exactly one asset
+                    let asset =
+                        partial_note.assets().iter().next().expect("note should contain an asset");
+
                     if asset.faucet_id_prefix() != account_id.prefix() {
                         return Err(TransactionScriptBuilderError::InvalidAsset(
                             asset.faucet_id_prefix(),
@@ -90,15 +96,13 @@ impl AccountInterface {
                 AccountInterface::BasicWallet => {
                     body.push_str(
                         "
-                        call.wallet::create_note",
+                        call.wallet::create_note\n",
                     );
 
                     for asset in partial_note.assets().iter() {
                         body.push_str(&format!(
-                            "
-                        push.{asset}
-                        call.wallet::move_asset_to_note dropw
-                        ",
+                            "push.{asset}
+                            call.wallet::move_asset_to_note dropw\n",
                             asset = prepare_word(&asset.into())
                         ))
                     }
@@ -223,6 +227,8 @@ impl TransactionScriptBuilder {
 pub enum TransactionScriptBuilderError {
     #[error("invalid asset: {0}")]
     InvalidAsset(AccountIdPrefix),
+    #[error("note created by the faucet doesn't contain exactly one asset")]
+    FaucetNoteWithoutAsset,
     #[error("invalid transaction script")]
     InvalidTransactionScript(#[source] TransactionScriptError),
     #[error("invalid sender account: {0}")]