From f82458446b64a64f32f7d989875fa7b5fbcc8965 Mon Sep 17 00:00:00 2001
From: r4bbit <445106+0x-r4bbit@users.noreply.github.com>
Date: Mon, 4 May 2026 14:54:07 +0200
Subject: [PATCH] chore(amm): validate fee tier in `sync_reserves`

All other entry functions validate the pools fee tier, except for this
function. This is likely because it doesn't make use of the fees.

To make the code consistent (and auditing easier), we're now validating
the fees in `sync_reserves` the same way.
---
 amm/src/sync.rs  |  5 ++++-
 amm/src/tests.rs | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/amm/src/sync.rs b/amm/src/sync.rs
index 957457e..4ac1ab7 100644
--- a/amm/src/sync.rs
+++ b/amm/src/sync.rs
@@ -1,4 +1,6 @@
-use amm_core::{read_vault_fungible_balances, PoolDefinition, MINIMUM_LIQUIDITY};
+use amm_core::{
+    assert_supported_fee_tier, read_vault_fungible_balances, PoolDefinition, MINIMUM_LIQUIDITY,
+};
 use nssa_core::{
     account::{AccountWithMetadata, Data},
     program::{AccountPostState, ChainedCall},
@@ -11,6 +13,7 @@ pub fn sync_reserves(
 ) -> (Vec<AccountPostState>, Vec<ChainedCall>) {
     let pool_def_data = PoolDefinition::try_from(&pool.account.data)
         .expect("Sync reserves: AMM Program expects a valid Pool Definition Account");
+    assert_supported_fee_tier(pool_def_data.fees);
 
     assert!(
         pool_def_data.liquidity_pool_supply >= MINIMUM_LIQUIDITY,
diff --git a/amm/src/tests.rs b/amm/src/tests.rs
index f925047..c845815 100644
--- a/amm/src/tests.rs
+++ b/amm/src/tests.rs
@@ -2983,6 +2983,21 @@ fn test_sync_reserves_rejects_pool_below_minimum_liquidity() {
     );
 }
 
+#[should_panic(expected = "Fee tier must be one of 1, 5, 30, or 100 basis points")]
+#[test]
+fn test_sync_reserves_rejects_unsupported_fee_tier() {
+    let mut pool = AccountWithMetadataForTests::pool_definition_init();
+    let mut pool_def = PoolDefinition::try_from(&pool.account.data).unwrap();
+    pool_def.fees = 2;
+    pool.account.data = Data::from(&pool_def);
+
+    let _ = sync_reserves(
+        pool,
+        AccountWithMetadataForTests::vault_a_init(),
+        AccountWithMetadataForTests::vault_b_init(),
+    );
+}
+
 #[test]
 fn test_donation_then_add_liquidity_sync_mitigates_mispricing() {
     let donation_a = 100u128;