Routing

.forge-snapshots/V4Router_Bytecode.snap

@@ -1 +1 @@
-6129
+6214

.forge-snapshots/V4Router_ExactIn1Hop_oneForZero.snap

@@ -1 +1 @@
-129132
+129205

.forge-snapshots/V4Router_ExactIn1Hop_zeroForOne.snap

@@ -1 +1 @@
-135962
+136035

.forge-snapshots/V4Router_ExactIn2Hops.snap

@@ -1 +1 @@
-187241
+187387

.forge-snapshots/V4Router_ExactIn3Hops.snap

@@ -1 +1 @@
-238549
+238768

.forge-snapshots/V4Router_ExactOut1Hop_oneForZero.snap

@@ -1 +1 @@
-129979
+130046

.forge-snapshots/V4Router_ExactOut1Hop_zeroForOne.snap

@@ -1 +1 @@
-134780
+134847

.forge-snapshots/V4Router_ExactOut2Hops.snap

@@ -1 +1 @@
-186674
+186808

.forge-snapshots/V4Router_ExactOut3Hops.snap

@@ -1 +1 @@
-238612
+238813

src/V4Router.sol

@@ -14,12 +14,14 @@ import {IV4Router} from "./interfaces/IV4Router.sol";
 import {BaseActionsRouter} from "./base/BaseActionsRouter.sol";
 import {DeltaResolver} from "./base/DeltaResolver.sol";
 import {Actions} from "./libraries/Actions.sol";
+import {SafeCast} from "./libraries/SafeCast.sol";
 
 /// @title UniswapV4Router
 /// @notice Abstract contract that contains all internal logic needed for routing through Uniswap V4 pools
 /// @dev the entry point to executing actions in this contract is calling `BaseActionsRouter._executeActions`
 /// An inheriting contract should call _executeActions at the point that they wish actions to be executed
 abstract contract V4Router is IV4Router, BaseActionsRouter, DeltaResolver {
+    using SafeCast for *;
     using PathKeyLib for PathKey;
     using CalldataDecoder for bytes;
     using TransientStateLibrary for IPoolManager;
@@ -98,7 +100,8 @@ abstract contract V4Router is IV4Router, BaseActionsRouter, DeltaResolver {
             for (uint256 i = 0; i < pathLength; i++) {
                 pathKey = params.path[i];
                 (PoolKey memory poolKey, bool zeroForOne) = pathKey.getPoolAndSwapDirection(currencyIn);
-                amountOut = uint128(_swap(poolKey, zeroForOne, -int256(uint256(amountIn)), 0, pathKey.hookData));
+                // The output delta will always be positive, except for when interacting with certain hook pools
+                amountOut = _swap(poolKey, zeroForOne, -int256(uint256(amountIn)), 0, pathKey.hookData).toUint128();
 
                 amountIn = amountOut;
                 currencyIn = pathKey.intermediateCurrency;
@@ -130,7 +133,8 @@ abstract contract V4Router is IV4Router, BaseActionsRouter, DeltaResolver {
             for (uint256 i = pathLength; i > 0; i--) {
                 pathKey = params.path[i - 1];
                 (PoolKey memory poolKey, bool oneForZero) = pathKey.getPoolAndSwapDirection(currencyOut);
-                amountIn = uint128(-_swap(poolKey, !oneForZero, int256(uint256(amountOut)), 0, pathKey.hookData));
+                // The output delta will always be negative, except for when interacting with certain hook pools
+                amountIn = (-_swap(poolKey, !oneForZero, int256(uint256(amountOut)), 0, pathKey.hookData)).toUint128();
 
                 amountOut = amountIn;
                 currencyOut = pathKey.intermediateCurrency;

src/libraries/SafeCast.sol

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.0;
+
+import {CustomRevert} from "@uniswap/v4-core/src/libraries/CustomRevert.sol";
+
+/// @title Safe casting methods
+/// @notice Contains methods for safely casting between types
+library SafeCast {
+    using CustomRevert for bytes4;
+
+    error SafeCastOverflow();
+
+    /// @notice Cast a int128 to a uint128, revert on overflow or underflow
+    /// @param x The int128 to be casted
+    /// @return y The casted integer, now type uint128
+    function toUint128(int128 x) internal pure returns (uint128 y) {
+        if (x < 0) SafeCastOverflow.selector.revertWith();
+        y = uint128(x);
+    }
+}

test/router/V4Router.gas.t.sol

@@ -29,8 +29,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
             IV4Router.ExactInputSingleParams(key0, true, uint128(amountIn), 0, 0, bytes(""));
 
         plan = plan.add(Actions.SWAP_EXACT_IN_SINGLE, abi.encode(params));
-        _finalizePlan(key0.currency0, key0.currency1, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(key0.currency0, key0.currency1, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactInputSingle");
@@ -44,8 +43,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
         IV4Router.ExactInputParams memory params = _getExactInputParams(tokenPath, amountIn);
 
         plan = plan.add(Actions.SWAP_EXACT_IN, abi.encode(params));
-        _finalizePlan(currency0, currency1, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency1, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactIn1Hop_zeroForOne");
@@ -59,8 +57,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
         IV4Router.ExactInputParams memory params = _getExactInputParams(tokenPath, amountIn);
 
         plan = plan.add(Actions.SWAP_EXACT_IN, abi.encode(params));
-        _finalizePlan(currency1, currency0, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency1, currency0, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactIn1Hop_oneForZero");
@@ -75,8 +72,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
         IV4Router.ExactInputParams memory params = _getExactInputParams(tokenPath, amountIn);
 
         plan = plan.add(Actions.SWAP_EXACT_IN, abi.encode(params));
-        _finalizePlan(currency0, currency2, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency2, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactIn2Hops");
@@ -92,8 +88,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
         IV4Router.ExactInputParams memory params = _getExactInputParams(tokenPath, amountIn);
 
         plan = plan.add(Actions.SWAP_EXACT_IN, abi.encode(params));
-        _finalizePlan(currency0, currency3, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency3, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactIn3Hops");
@@ -106,8 +101,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
             IV4Router.ExactOutputSingleParams(key0, true, uint128(amountOut), 0, 0, bytes(""));
 
         plan = plan.add(Actions.SWAP_EXACT_OUT_SINGLE, abi.encode(params));
-        _finalizePlan(key0.currency0, key0.currency1, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(key0.currency0, key0.currency1, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactOutputSingle");
@@ -121,8 +115,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
         IV4Router.ExactOutputParams memory params = _getExactOutputParams(tokenPath, amountOut);
 
         plan = plan.add(Actions.SWAP_EXACT_OUT, abi.encode(params));
-        _finalizePlan(currency0, currency1, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency1, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactOut1Hop_zeroForOne");
@@ -136,8 +129,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
         IV4Router.ExactOutputParams memory params = _getExactOutputParams(tokenPath, amountOut);
 
         plan = plan.add(Actions.SWAP_EXACT_OUT, abi.encode(params));
-        _finalizePlan(currency1, currency0, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency1, currency0, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactOut1Hop_oneForZero");
@@ -152,8 +144,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
         IV4Router.ExactOutputParams memory params = _getExactOutputParams(tokenPath, amountOut);
 
         plan = plan.add(Actions.SWAP_EXACT_OUT, abi.encode(params));
-        _finalizePlan(currency0, currency2, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency2, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactOut2Hops");
@@ -169,8 +160,7 @@ contract V4RouterTest is RoutingTestHelpers, GasSnapshot {
         IV4Router.ExactOutputParams memory params = _getExactOutputParams(tokenPath, amountOut);
 
         plan = plan.add(Actions.SWAP_EXACT_OUT, abi.encode(params));
-        _finalizePlan(currency0, currency3, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency3, address(this));
 
         router.executeActions(data);
         snapLastCall("V4Router_ExactOut3Hops");

test/router/V4Router.t.sol

@@ -27,8 +27,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance1 = key0.currency1.balanceOf(address(this));
 
         plan = plan.add(Actions.SWAP_EXACT_IN_SINGLE, abi.encode(params));
-        _finalizePlan(key0.currency0, key0.currency1, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(key0.currency0, key0.currency1, address(this));
 
         router.executeActions(data);
 
@@ -50,8 +49,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance1 = key0.currency1.balanceOf(address(this));
 
         plan = plan.add(Actions.SWAP_EXACT_IN_SINGLE, abi.encode(params));
-        _finalizePlan(key0.currency1, key0.currency0, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(key0.currency1, key0.currency0, address(this));
 
         router.executeActions(data);
 
@@ -74,8 +72,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance1 = currency1.balanceOfSelf();
 
         plan = plan.add(Actions.SWAP_EXACT_IN, abi.encode(params));
-        _finalizePlan(currency0, currency1, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency1, address(this));
 
         router.executeActions(data);
 
@@ -97,8 +94,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance1 = currency1.balanceOfSelf();
 
         plan = plan.add(Actions.SWAP_EXACT_IN, abi.encode(params));
-        _finalizePlan(currency1, currency0, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency1, currency0, address(this));
 
         router.executeActions(data);
 
@@ -123,8 +119,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance2 = currency2.balanceOfSelf();
 
         plan = plan.add(Actions.SWAP_EXACT_IN, abi.encode(params));
-        _finalizePlan(currency0, currency2, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency2, address(this));
 
         router.executeActions(data);
 
@@ -154,8 +149,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance3 = currency3.balanceOfSelf();
 
         plan = plan.add(Actions.SWAP_EXACT_IN, abi.encode(params));
-        _finalizePlan(currency0, currency3, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency3, address(this));
 
         router.executeActions(data);
 
@@ -181,8 +175,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance1 = key0.currency1.balanceOf(address(this));
 
         plan = plan.add(Actions.SWAP_EXACT_OUT_SINGLE, abi.encode(params));
-        _finalizePlan(key0.currency0, key0.currency1, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(key0.currency0, key0.currency1, address(this));
 
         router.executeActions(data);
 
@@ -204,8 +197,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance1 = key0.currency1.balanceOf(address(this));
 
         plan = plan.add(Actions.SWAP_EXACT_OUT_SINGLE, abi.encode(params));
-        _finalizePlan(key0.currency1, key0.currency0, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(key0.currency1, key0.currency0, address(this));
 
         router.executeActions(data);
 
@@ -228,8 +220,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance1 = currency1.balanceOfSelf();
 
         plan = plan.add(Actions.SWAP_EXACT_OUT, abi.encode(params));
-        _finalizePlan(currency0, currency1, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency1, address(this));
 
         router.executeActions(data);
 
@@ -252,8 +243,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance1 = currency1.balanceOfSelf();
 
         plan = plan.add(Actions.SWAP_EXACT_OUT, abi.encode(params));
-        _finalizePlan(currency1, currency0, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency1, currency0, address(this));
 
         router.executeActions(data);
 
@@ -278,8 +268,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance2 = currency2.balanceOfSelf();
 
         plan = plan.add(Actions.SWAP_EXACT_OUT, abi.encode(params));
-        _finalizePlan(currency0, currency2, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency2, address(this));
 
         router.executeActions(data);
 
@@ -309,8 +298,7 @@ contract V4RouterTest is RoutingTestHelpers {
         uint256 prevBalance3 = currency3.balanceOfSelf();
 
         plan = plan.add(Actions.SWAP_EXACT_OUT, abi.encode(params));
-        _finalizePlan(currency0, currency3, address(this));
-        bytes memory data = plan.encode();
+        bytes memory data = plan.finalizeSwap(currency0, currency3, address(this));
 
         router.executeActions(data);
 

test/shared/ActionsRouterPlanner.sol

@@ -1,12 +1,17 @@
 // SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.24;
 
+import {Currency} from "@uniswap/v4-core/src/types/Currency.sol";
+import {Actions} from "../../src/libraries/Actions.sol";
+
 struct Plan {
     uint256[] actions;
     bytes[] params;
 }
 
 library ActionsRouterPlanner {
+    using ActionsRouterPlanner for Plan;
+
     function init() internal pure returns (Plan memory plan) {
         return Plan({actions: new uint256[](0), params: new bytes[](0)});
     }
@@ -33,4 +38,14 @@ library ActionsRouterPlanner {
     function encode(Plan memory plan) internal pure returns (bytes memory) {
         return abi.encode(plan.actions, plan.params);
     }
+
+    function finalizeSwap(Plan memory plan, Currency inputCurrency, Currency outputCurrency, address recipient)
+        internal
+        pure
+        returns (bytes memory)
+    {
+        plan = plan.add(Actions.SETTLE_ALL, abi.encode(inputCurrency));
+        plan = plan.add(Actions.TAKE_ALL, abi.encode(outputCurrency, recipient));
+        return plan.encode();
+    }
 }

test/shared/RoutingTestHelpers.sol

@@ -19,7 +19,7 @@ import {IERC20} from "forge-std/interfaces/IERC20.sol";
 import {LiquidityOperations} from "./LiquidityOperations.sol";
 import {IV4Router} from "../../src/interfaces/IV4Router.sol";
 
-/// @notice A shared test contract that wraps the v4-core deployers contract and exposes basic liquidity operations on posm.
+/// @notice A shared test contract that wraps the v4-core deployers contract and exposes basic helpers for swapping with the router.
 contract RoutingTestHelpers is Test, Deployers {
     using ActionsRouterPlanner for Plan;
 
@@ -107,9 +107,4 @@ contract RoutingTestHelpers is Test, Deployers {
         params.amountOut = uint128(amountOut);
         params.amountInMaximum = type(uint128).max;
     }
-
-    function _finalizePlan(Currency inputCurrency, Currency outputCurrency, address recipient) internal {
-        plan = plan.add(Actions.SETTLE_ALL, abi.encode(inputCurrency));
-        plan = plan.add(Actions.TAKE_ALL, abi.encode(outputCurrency, recipient));
-    }
 }