Merge branch 'main' into encoding/tnl/fix-wrapping-indices

foundry/src/CallbackVerificationDispatcher.sol

@@ -13,7 +13,7 @@ error CallbackVerificationDispatcher__NonContractVerifier();
  *  verification. This allows dynamically adding new supported protocols
  *  without needing to upgrade any contracts.
  *
- *  Note Verifier contracts need to implement the ICallbackVerifier interface
+ *  Note: Verifier contracts need to implement the ICallbackVerifier interface
  */
 contract CallbackVerificationDispatcher {
     mapping(address => bool) public callbackVerifiers;

foundry/src/ExecutionDispatcher.sol

@@ -15,7 +15,7 @@ error ExecutionDispatcher__NonContractExecutor();
  *  be called using delegatecall so they can share state with the main
  *  contract if needed.
  *
- *  Note Executor contracts need to implement the IExecutor interface unless
+ *  Note: Executor contracts need to implement the IExecutor interface unless
  *  an alternate selector is specified.
  */
 contract ExecutionDispatcher {

foundry/src/TychoRouter.sol

@@ -18,6 +18,7 @@ import {LibSwap} from "../lib/LibSwap.sol";
 error TychoRouter__WithdrawalFailed();
 error TychoRouter__AddressZero();
 error TychoRouter__NegativeSlippage(uint256 amount, uint256 minAmount);
+error TychoRouter__AmountInNotFullySpent(uint256 leftoverAmount);
 error TychoRouter__MessageValueMismatch(uint256 value, uint256 amount);
 
 contract TychoRouter is
@@ -73,32 +74,6 @@ contract TychoRouter is
         _usv3Factory = usv3Factory;
     }
 
-    /**
-     * @dev We use the fallback function to allow flexibility on callback.
-     * This function will delegate call a verifier contract and should revert if the
-     *  caller is not a pool.
-     */
-    fallback() external {
-        _executeGenericCallback(msg.data);
-    }
-
-    /**
-     * @dev Check if the sender is correct and executes callback actions.
-     *  @param msgData encoded data. It must includes data for the verification.
-     */
-    function _executeGenericCallback(bytes calldata msgData) internal {
-        (uint256 amountOwed, address tokenOwed) = _callVerifyCallback(msgData);
-
-        IERC20(tokenOwed).safeTransfer(msg.sender, amountOwed);
-    }
-
-    /**
-     * @dev Pauses the contract
-     */
-    function pause() external onlyRole(PAUSER_ROLE) {
-        _pause();
-    }
-
     /**
      * @dev Unpauses the contract
      */
@@ -115,7 +90,7 @@ contract TychoRouter is
      * - If `wrapEth` is true, the contract wraps the provided native ETH into WETH and uses it as the sell token.
      * - If `unwrapEth` is true, the contract converts the resulting WETH back into native ETH before sending it to the receiver.
      * - For ERC20 tokens, Permit2 is used to approve and transfer tokens from the caller to the router.
-     * - Swaps are executed sequentially using the `_splitSwap` function.
+     * - Swaps are executed sequentially using the `_swap` function.
      * - A fee is deducted from the output token if `fee > 0`, and the remaining amount is sent to the receiver.
      * - Reverts with `TychoRouter__NegativeSlippage` if the output amount is less than `minAmountOut` and `minAmountOut` is bigger than 0.
      *
@@ -153,6 +128,7 @@ contract TychoRouter is
         // For native ETH, assume funds already in our router. Else, transfer and handle approval.
         if (wrapEth) {
             _wrapETH(amountIn);
+            tokenIn = address(_weth);
         } else if (tokenIn != address(0)) {
             permit2.permit(msg.sender, permitSingle, signature);
             permit2.transferFrom(
@@ -175,6 +151,11 @@ contract TychoRouter is
             revert TychoRouter__NegativeSlippage(amountOut, minAmountOut);
         }
 
+        uint256 leftoverAmountIn = IERC20(tokenIn).balanceOf(address(this));
+        if (leftoverAmountIn > 0) {
+            revert TychoRouter__AmountInNotFullySpent(leftoverAmountIn);
+        }
+
         if (unwrapEth) {
             _unwrapETH(amountOut);
         }
@@ -186,6 +167,26 @@ contract TychoRouter is
         }
     }
 
+    /**
+     * @dev Executes sequential swaps as defined by the provided swap graph.
+     *
+     * This function processes a series of swaps encoded in the `swaps_` byte array. Each swap operation determines:
+     * - The indices of the input and output tokens (via `tokenInIndex()` and `tokenOutIndex()`).
+     * - The portion of the available amount to be used for the swap, indicated by the `split` value.
+     *
+     * Two important notes:
+     * - The contract assumes that token indexes follow a specific order: the sell token is at index 0, followed by any
+     *  intermediary tokens, and finally the buy token.
+     * - A `split` value of 0 is interpreted as 100% of the available amount (i.e., the entire remaining balance).
+     *  This means that in scenarios without explicit splits the value should be 0, and when splits are present,
+     *  the last swap should also have a split value of 0.
+     *
+     * @param amountIn The initial amount of the sell token to be swapped.
+     * @param nTokens The total number of tokens involved in the swap path, used to initialize arrays for internal tracking.
+     * @param swaps_ Encoded swap graph data containing the details of each swap operation.
+     *
+     * @return The total amount of the buy token obtained after all swaps have been executed.
+     */
     function _swap(uint256 amountIn, uint256 nTokens, bytes calldata swaps_)
         internal
         returns (uint256)
@@ -225,6 +226,32 @@ contract TychoRouter is
         return amounts[tokenOutIndex];
     }
 
+    /**
+     * @dev We use the fallback function to allow flexibility on callback.
+     * This function will static call a verifier contract and should revert if the
+     *  caller is not a pool.
+     */
+    fallback() external {
+        _executeGenericCallback(msg.data);
+    }
+
+    /**
+     * @dev Check if the sender is correct and executes callback actions.
+     *  @param msgData encoded data. It must includes data for the verification.
+     */
+    function _executeGenericCallback(bytes calldata msgData) internal {
+        (uint256 amountOwed, address tokenOwed) = _callVerifyCallback(msgData);
+
+        IERC20(tokenOwed).safeTransfer(msg.sender, amountOwed);
+    }
+
+    /**
+     * @dev Pauses the contract
+     */
+    function pause() external onlyRole(PAUSER_ROLE) {
+        _pause();
+    }
+
     /**
      * @dev Allows granting roles to multiple accounts in a single call.
      */