chore: review nits

Author: meetmangukiya

test/e2e/BalancerSwap.t.sol

@@ -105,6 +105,7 @@ contract BalancerSwapTest is Helper(true) {
                 userData: abi.encode(maxAmountsIn, poolFees),
                 fromInternalBalance: false
             });
+            // poolerAddr declared as separate var to prevent stack too deep errors
             address poolerAddr = pooler.addr;
             bytes32 poolId = pool.getPoolId();
             vm.prank(poolerAddr);

test/libraries/encoders/SwapEncoder.sol

@@ -124,8 +124,8 @@ library SwapEncoder {
     function toSwapStep(State storage state, Swap memory swap) private returns (IVault.BatchSwapStep memory step) {
         TokenRegistry.State storage tokenRegistry = state.tokenRegistry.tokenRegistry();
         step.poolId = swap.poolId;
-        step.assetInIndex = TokenRegistry.tokenIndices(tokenRegistry, swap.assetIn);
-        step.assetOutIndex = TokenRegistry.tokenIndices(tokenRegistry, swap.assetOut);
+        step.assetInIndex = TokenRegistry.tokenIndex(tokenRegistry, swap.assetIn);
+        step.assetOutIndex = TokenRegistry.tokenIndex(tokenRegistry, swap.assetOut);
         step.amount = swap.amount;
         step.userData = swap.userData;
     }

test/libraries/encoders/TokenRegistry.sol

@@ -105,8 +105,8 @@ library TokenRegistry {
         return (sellTokenIndex - 1, buyTokenIndex - 1);
     }
 
-    /// @dev Returns the token indices for the specified token
-    function tokenIndices(State storage state, IERC20 token) internal hydrateArray(state) returns (uint256) {
+    /// @dev Returns the token index for the specified token
+    function tokenIndex(State storage state, IERC20 token) internal hydrateArray(state) returns (uint256) {
         uint256 index = pushIfNotPresentIndexOf(state, token);
         return index - 1;
     }