feat(genesis): add batch builder account

crates/store/src/genesis/config/mod.rs

@@ -58,6 +58,9 @@ pub const FAUCET_OPERATOR_FILE_NAME: &str = "faucet_operator.mac";
 /// Name of the account file written for the pass-through account.
 pub const PASS_THROUGH_ACCOUNT_FILE_NAME: &str = "pass_through.mac";
 
+/// Name of the account file written for the generated batch builder.
+pub const BATCH_BUILDER_FILE_NAME: &str = "batch_builder.mac";
+
 // GENESIS CONFIG
 // ================================================================================================
 
@@ -234,6 +237,13 @@ impl GenesisConfig {
             Some(pass_through_secret),
         ));
 
+        let (batch_builder_account, batch_builder_secret) = build_batch_builder()?;
+        secrets.push((
+            BATCH_BUILDER_FILE_NAME.to_string(),
+            batch_builder_account.id(),
+            Some(batch_builder_secret),
+        ));
+
         faucet_accounts.insert(symbol.clone(), native_faucet_account);
 
         // Setup additional fungible faucets from parameters
@@ -368,6 +378,7 @@ impl GenesisConfig {
         all_accounts.extend(wallet_accounts);
 
         all_accounts.push(pass_through_account);
+        all_accounts.push(batch_builder_account);
 
         // Append file-loaded accounts as-is
         all_accounts.extend(file_loaded_accounts);
@@ -475,6 +486,19 @@ fn build_faucet_operator() -> Result<(Account, RpoSecretKey), GenesisConfigError
     Ok((operator, secret_key))
 }
 
+/// Builds the private wallet that receives the batch builder's fee notes.
+fn build_batch_builder() -> Result<(Account, RpoSecretKey), GenesisConfigError> {
+    let mut rng = ChaCha20Rng::from_seed(rand::random());
+
+    let secret_key = RpoSecretKey::with_rng(&mut rng);
+    let auth = Approver::new(secret_key.public_key().into(), AuthScheme::Falcon512Poseidon2);
+    let init_seed: [u8; 32] = rng.random();
+    let mut account = create_basic_wallet(init_seed, auth, AccountType::Private)?;
+    account.set_nonce(ONE)?;
+
+    Ok((account, secret_key))
+}
+
 // NATIVE FAUCET
 // ================================================================================================
 

crates/store/src/genesis/config/tests.rs

@@ -108,10 +108,10 @@ async fn genesis_accounts_have_nonce_one() -> TestResult {
     let gcfg = GenesisConfig::default();
     let (state, secrets) = gcfg.into_state(dev_validator_config()).unwrap();
 
-    // The default configuration generates the native faucet, its operator, and the pass-through
-    // account.
+    // The default configuration generates the native faucet, its operator, the pass-through
+    // account, and the batch builder.
     let account_files = secrets.as_account_files(&state).collect::<Result<Vec<_>, _>>()?;
-    assert_eq!(account_files.len(), 3);
+    assert_eq!(account_files.len(), 4);
     for AccountFileWithName { account_file, name } in account_files {
         assert_eq!(account_file.account.nonce(), ONE, "{name} should be deployed at genesis");
     }
@@ -148,6 +148,33 @@ fn pass_through_account_is_part_of_genesis() -> TestResult {
     Ok(())
 }
 
+#[test]
+fn generated_batch_builder_is_a_private_wallet() -> TestResult {
+    use miden_standards::account::wallets::BasicWallet;
+
+    let (state, secrets) = GenesisConfig::default().into_state(dev_validator_config())?;
+
+    let (_, account_id, secret) = secrets
+        .secrets
+        .iter()
+        .find(|(name, ..)| name == BATCH_BUILDER_FILE_NAME)
+        .expect("the batch builder account file should be generated");
+    assert!(secret.is_some());
+
+    let account = state
+        .accounts
+        .iter()
+        .find(|account| account.id() == *account_id)
+        .expect("the batch builder account should be part of the genesis state");
+    assert!(account.id().is_private());
+    assert_eq!(account.nonce(), ONE);
+    assert!(account.vault().is_empty());
+    assert!(account.code().has_procedure(BasicWallet::receive_asset_root().as_word()));
+    assert!(account.code().has_procedure(BasicWallet::create_note_root().as_word()));
+
+    Ok(())
+}
+
 #[test]
 fn parsing_account_from_file() -> TestResult {
     use miden_protocol::account::auth::AuthScheme;
@@ -222,7 +249,6 @@ fn generated_native_faucet_is_a_network_account_owned_by_an_operator() -> TestRe
             .find(|(name, ..)| name == file_name)
             .unwrap_or_else(|| panic!("{file_name} should be generated"))
     };
-    assert_eq!(secrets.secrets.len(), 3);
     let (_, faucet_id, faucet_secret) = find(NATIVE_FAUCET_FILE_NAME);
     let (_, operator_id, operator_secret) = find(FAUCET_OPERATOR_FILE_NAME);
     assert_eq!(*faucet_id, native_faucet.id());
@@ -349,11 +375,17 @@ verification_base_fee = 0
     let (state, secrets) = gcfg.into_state(dev_validator_config())?;
     assert!(state.accounts.iter().any(|a| a.id() == faucet_id));
 
-    // A file-loaded faucet creates no additional secret.
-    assert_eq!(secrets.secrets.len(), 1);
-    let (name, _, secret) = &secrets.secrets[0];
-    assert_eq!(name, PASS_THROUGH_ACCOUNT_FILE_NAME);
-    assert!(secret.is_some());
+    // A file-loaded faucet creates no new secret. The generated accounts are still present.
+    assert_eq!(secrets.secrets.len(), 2);
+    let find = |file_name| {
+        secrets
+            .secrets
+            .iter()
+            .find(|(name, ..)| name == file_name)
+            .unwrap_or_else(|| panic!("{file_name} should be generated"))
+    };
+    assert!(find(PASS_THROUGH_ACCOUNT_FILE_NAME).2.is_some());
+    assert!(find(BATCH_BUILDER_FILE_NAME).2.is_some());
 
     Ok(())
 }