Merge and update snapshots

.forge-snapshots/add liquidity to already existing position with salt.snap

@@ -1 +1 @@
-151062
+151104

.forge-snapshots/addLiquidity CA fee.snap

@@ -1 +1 @@
-329402
+329444

.forge-snapshots/addLiquidity with empty hook.snap

@@ -1 +1 @@
-284043
+284085

.forge-snapshots/addLiquidity with native token.snap

@@ -1 +1 @@
-141238
+141237

.forge-snapshots/addLiquidity.snap

@@ -1 +1 @@
-151038
+151080

.forge-snapshots/create new liquidity to a position with salt.snap

@@ -1 +1 @@
-299590
+299632

.forge-snapshots/donate gas with 1 token.snap

@@ -1 +1 @@
-108878
+108687

.forge-snapshots/donate gas with 2 tokens.snap

@@ -1 +1 @@
-149370
+149222

.forge-snapshots/poolManager bytecode size.snap

@@ -1 +1 @@
-23450
+23738

.forge-snapshots/removeLiquidity CA fee.snap

@@ -1 +1 @@
-184975
+184931

.forge-snapshots/removeLiquidity with empty hook.snap

@@ -1 +1 @@
-121019
+120975

.forge-snapshots/removeLiquidity with native token.snap

@@ -1 +1 @@
-117794
+117750

.forge-snapshots/removeLiquidity.snap

@@ -1 +1 @@
-121007
+120963

.forge-snapshots/simple swap with native.snap

@@ -1 +1 @@
-130998
+117339

.forge-snapshots/simple swap.snap

@@ -1 +1 @@
-149357
+132578

.forge-snapshots/sparse external sload.snap

@@ -0,0 +1 @@
+2023

.forge-snapshots/swap CA custom curve + swap noop.snap

@@ -1 +1 @@
-139347
+135860

.forge-snapshots/swap CA fee on unspecified.snap

@@ -1 +1 @@
-184801
+184809

.forge-snapshots/swap against liquidity with native token.snap

@@ -1 +1 @@
-113901
+113800

.forge-snapshots/swap against liquidity.snap

@@ -1 +1 @@
-125279
+125221

.forge-snapshots/swap burn 6909 for input.snap

@@ -1 +1 @@
-137268
+137207

.forge-snapshots/swap burn native 6909 for input.snap

@@ -1 +1 @@
-126384
+126323

.forge-snapshots/swap mint native output as 6909.snap

@@ -1 +1 @@
-148403
+148385

.forge-snapshots/swap mint output as 6909.snap

@@ -1 +1 @@
-165306
+165202

.forge-snapshots/swap skips hook call if hook is caller.snap

@@ -1 +1 @@
-224956
+224701

.forge-snapshots/swap with dynamic fee.snap

@@ -1 +1 @@
-149573
+149469

.forge-snapshots/swap with hooks.snap

@@ -1 +1 @@
-125291
+125233

.forge-snapshots/swap with lp fee and protocol fee.snap

@@ -1 +1 @@
-181915
+181791

.forge-snapshots/update dynamic fee in before swap.snap

@@ -1 +1 @@
-160206
+160022

.github/workflows/tests-pr.yml

@@ -2,6 +2,9 @@ name: Tests
 
 on:
   pull_request:
+    branches:
+      - main
+      - dev
 
 jobs:
   forge-tests:

src/Extsload.sol

@@ -25,4 +25,23 @@ abstract contract Extsload is IExtsload {
 
         return value;
     }
+
+    /// @dev since the function is external and enters a new call context and exits right after execution, Solidity's memory management convention can be disregarded and a direct slice of memory can be returned
+    function extsload(bytes32[] calldata slots) external view returns (bytes32[] memory) {
+        assembly ("memory-safe") {
+            // abi offset for dynamic array
+            mstore(0, 0x20)
+            mstore(0x20, slots.length)
+            let end := add(0x40, shl(5, slots.length))
+            let memptr := 0x40
+            let calldataptr := slots.offset
+            for {} 1 {} {
+                mstore(memptr, sload(calldataload(calldataptr)))
+                memptr := add(memptr, 0x20)
+                calldataptr := add(calldataptr, 0x20)
+                if iszero(lt(memptr, end)) { break }
+            }
+            return(0, end)
+        }
+    }
 }

src/PoolManager.sol

@@ -17,6 +17,7 @@ import {ProtocolFees} from "./ProtocolFees.sol";
 import {ERC6909Claims} from "./ERC6909Claims.sol";
 import {PoolId, PoolIdLibrary} from "./types/PoolId.sol";
 import {BalanceDelta, BalanceDeltaLibrary, toBalanceDelta} from "./types/BalanceDelta.sol";
+import {BeforeSwapDelta} from "./types/BeforeSwapDelta.sol";
 import {Lock} from "./libraries/Lock.sol";
 import {CurrencyDelta} from "./libraries/CurrencyDelta.sol";
 import {NonZeroDeltaCount} from "./libraries/NonZeroDeltaCount.sol";
@@ -174,7 +175,7 @@ contract PoolManager is IPoolManager, ProtocolFees, NoDelegateCall, ERC6909Claim
 
         key.hooks.afterInitialize(key, sqrtPriceX96, tick, hookData);
 
-        // On intitalize we emit the key's fee, which tells us all fee settings a pool can have: either a static swap fee or dynamic swap fee and if the hook has enabled swap or withdraw fees.
+        // On initialize we emit the key's fee, which tells us all fee settings a pool can have: either a static swap fee or dynamic swap fee and if the hook has enabled swap or withdraw fees.
         emit Initialize(id, key.currency0, key.currency1, key.fee, key.tickSpacing, key.hooks);
     }
 
@@ -270,7 +271,7 @@ contract PoolManager is IPoolManager, ProtocolFees, NoDelegateCall, ERC6909Claim
         PoolId id = key.toId();
         _checkPoolInitialized(id);
 
-        (int256 amountToSwap, int128 hookDeltaSpecified) = key.hooks.beforeSwap(key, params, hookData);
+        (int256 amountToSwap, BeforeSwapDelta beforeSwapDelta) = key.hooks.beforeSwap(key, params, hookData);
 
         // execute swap, account protocol fees, and emit swap event
         swapDelta = _swap(
@@ -285,7 +286,7 @@ contract PoolManager is IPoolManager, ProtocolFees, NoDelegateCall, ERC6909Claim
         );
 
         BalanceDelta hookDelta;
-        (swapDelta, hookDelta) = key.hooks.afterSwap(key, params, swapDelta, hookData, hookDeltaSpecified);
+        (swapDelta, hookDelta) = key.hooks.afterSwap(key, params, swapDelta, hookData, beforeSwapDelta);
 
         // if the hook doesnt have the flag to be able to return deltas, hookDelta will always be 0
         if (hookDelta != BalanceDeltaLibrary.ZERO_DELTA) _accountPoolBalanceDelta(key, hookDelta, address(key.hooks));

src/interfaces/IExtsload.sol

@@ -12,4 +12,9 @@ interface IExtsload {
     /// @param nSlots Number of slots to load into return value
     /// @return value The value of the sload-ed slots concatenated as dynamic bytes
     function extsload(bytes32 slot, uint256 nSlots) external view returns (bytes memory value);
+
+    /// @notice Called by external contracts to access sparse pool state
+    /// @param slots List of slots to SLOAD from.
+    /// @return values List of loaded values.
+    function extsload(bytes32[] calldata slots) external view returns (bytes32[] memory values);
 }

src/interfaces/IHooks.sol

@@ -4,6 +4,7 @@ pragma solidity ^0.8.24;
 import {PoolKey} from "../types/PoolKey.sol";
 import {BalanceDelta} from "../types/BalanceDelta.sol";
 import {IPoolManager} from "./IPoolManager.sol";
+import {BeforeSwapDelta} from "../types/BeforeSwapDelta.sol";
 
 /// @notice The PoolManager contract decides whether to invoke specific hooks by inspecting the leading bits
 /// of the hooks contract address. For example, a 1 bit in the first bit of the address will
@@ -97,13 +98,13 @@ interface IHooks {
     /// @param params The parameters for the swap
     /// @param hookData Arbitrary data handed into the PoolManager by the swapper to be be passed on to the hook
     /// @return bytes4 The function selector for the hook
-    /// @return int128 The hook's delta in specified currency. Positive: the hook is owed/took currency, negative: the hook owes/sent currency
+    /// @return BeforeSwapDelta The hook's delta in specified and unspecified currencies. Positive: the hook is owed/took currency, negative: the hook owes/sent currency
     function beforeSwap(
         address sender,
         PoolKey calldata key,
         IPoolManager.SwapParams calldata params,
         bytes calldata hookData
-    ) external returns (bytes4, int128);
+    ) external returns (bytes4, BeforeSwapDelta);
 
     /// @notice The hook called after a swap
     /// @param sender The initial msg.sender for the swap call

src/libraries/Hooks.sol

@@ -6,6 +6,7 @@ import {IHooks} from "../interfaces/IHooks.sol";
 import {SafeCast} from "../libraries/SafeCast.sol";
 import {LPFeeLibrary} from "./LPFeeLibrary.sol";
 import {BalanceDelta, toBalanceDelta, BalanceDeltaLibrary} from "../types/BalanceDelta.sol";
+import {BeforeSwapDelta, BeforeSwapDeltaLibrary} from "../types/BeforeSwapDelta.sol";
 import {IPoolManager} from "../interfaces/IPoolManager.sol";
 
 /// @notice V4 decides whether to invoke specific hooks by inspecting the leading bits of the address that
@@ -16,6 +17,7 @@ library Hooks {
     using LPFeeLibrary for uint24;
     using Hooks for IHooks;
     using SafeCast for int256;
+    using BeforeSwapDeltaLibrary for BeforeSwapDelta;
 
     uint256 internal constant BEFORE_INITIALIZE_FLAG = 1 << 159;
     uint256 internal constant AFTER_INITIALIZE_FLAG = 1 << 158;
@@ -141,6 +143,7 @@ library Hooks {
     {
         bytes memory result = callHook(self, data);
 
+        // If this hook wasnt meant to return something, default to 0 delta
         if (!parseReturn) return 0;
         (, delta) = abi.decode(result, (bytes4, int256));
     }
@@ -233,21 +236,31 @@ library Hooks {
     /// @notice calls beforeSwap hook if permissioned and validates return value
     function beforeSwap(IHooks self, PoolKey memory key, IPoolManager.SwapParams memory params, bytes calldata hookData)
         internal
-        returns (int256 amountToSwap, int128 hookDeltaSpecified)
+        returns (int256 amountToSwap, BeforeSwapDelta hookReturn)
     {
         amountToSwap = params.amountSpecified;
-        if (msg.sender == address(self)) return (amountToSwap, hookDeltaSpecified);
+        if (msg.sender == address(self)) return (amountToSwap, BeforeSwapDeltaLibrary.ZERO_DELTA);
+
         if (self.hasPermission(BEFORE_SWAP_FLAG)) {
-            hookDeltaSpecified = self.callHookWithReturnDelta(
-                abi.encodeWithSelector(IHooks.beforeSwap.selector, msg.sender, key, params, hookData),
-                self.hasPermission(BEFORE_SWAP_RETURNS_DELTA_FLAG)
-            ).toInt128();
+            bool canReturnDelta = self.hasPermission(BEFORE_SWAP_RETURNS_DELTA_FLAG);
+            hookReturn = BeforeSwapDelta.wrap(
+                self.callHookWithReturnDelta(
+                    abi.encodeWithSelector(IHooks.beforeSwap.selector, msg.sender, key, params, hookData),
+                    canReturnDelta
+                )
+            );
 
-            // Update the swap amount according to the hook's return, and check that the swap type doesnt change (exact input/output)
-            if (hookDeltaSpecified != 0) {
-                bool exactInput = amountToSwap < 0;
-                amountToSwap += hookDeltaSpecified;
-                if (exactInput ? amountToSwap > 0 : amountToSwap < 0) revert HookDeltaExceedsSwapAmount();
+            // skip this logic for the case where the hook return is 0
+            if (canReturnDelta) {
+                // any return in unspecified is passed to the afterSwap hook for handling
+                int128 hookDeltaSpecified = hookReturn.getSpecifiedDelta();
+
+                // Update the swap amount according to the hook's return, and check that the swap type doesnt change (exact input/output)
+                if (hookDeltaSpecified != 0) {
+                    bool exactInput = amountToSwap < 0;
+                    amountToSwap += hookDeltaSpecified;
+                    if (exactInput ? amountToSwap > 0 : amountToSwap < 0) revert HookDeltaExceedsSwapAmount();
+                }
             }
         }
     }
@@ -259,27 +272,30 @@ library Hooks {
         IPoolManager.SwapParams memory params,
         BalanceDelta swapDelta,
         bytes calldata hookData,
-        int128 hookDeltaSpecified
-    ) internal returns (BalanceDelta swapperDelta, BalanceDelta hookDelta) {
+        BeforeSwapDelta beforeSwapHookReturn
+    ) internal returns (BalanceDelta, BalanceDelta) {
         if (msg.sender == address(self)) return (swapDelta, BalanceDeltaLibrary.ZERO_DELTA);
 
-        int128 hookDeltaUnspecified;
-        swapperDelta = swapDelta;
+        int128 hookDeltaSpecified = beforeSwapHookReturn.getSpecifiedDelta();
+        int128 hookDeltaUnspecified = beforeSwapHookReturn.getUnspecifiedDelta();
+
         if (self.hasPermission(AFTER_SWAP_FLAG)) {
-            hookDeltaUnspecified = self.callHookWithReturnDelta(
+            hookDeltaUnspecified += self.callHookWithReturnDelta(
                 abi.encodeWithSelector(IHooks.afterSwap.selector, msg.sender, key, params, swapDelta, hookData),
                 self.hasPermission(AFTER_SWAP_RETURNS_DELTA_FLAG)
             ).toInt128();
         }
 
+        BalanceDelta hookDelta;
         if (hookDeltaUnspecified != 0 || hookDeltaSpecified != 0) {
             hookDelta = (params.amountSpecified < 0 == params.zeroForOne)
                 ? toBalanceDelta(hookDeltaSpecified, hookDeltaUnspecified)
                 : toBalanceDelta(hookDeltaUnspecified, hookDeltaSpecified);
 
             // the caller has to pay for (or receive) the hook's delta
-            swapperDelta = swapDelta - hookDelta;
+            swapDelta = swapDelta - hookDelta;
         }
+        return (swapDelta, hookDelta);
     }
 
     /// @notice calls beforeDonate hook if permissioned and validates return value