add getPoolState method to the StateLibrary

.forge-snapshots/extsload getPoolState.snap

@@ -0,0 +1 @@
+973

src/libraries/StateLibrary.sol

@@ -2,6 +2,7 @@
 pragma solidity ^0.8.21;
 
 import {PoolId} from "../types/PoolId.sol";
+import {Slot0} from "../types/Slot0.sol";
 import {IPoolManager} from "../interfaces/IPoolManager.sol";
 import {Currency} from "../types/Currency.sol";
 import {Position} from "./Position.sol";
@@ -30,6 +31,31 @@ library StateLibrary {
     // index of Position.Info mapping in Pool.State: mapping(bytes32 => Position.Info) positions;
     uint256 public constant POSITIONS_OFFSET = 6;
 
+    /**
+     * @notice Get the global state of a pool.
+     * @dev Corresponds to pools[poolId]
+     * @param manager The pool manager contract.
+     * @param poolId The ID of the pool.
+     * @return slot0 The slot0 of the pool.
+     * @return feeGrowthGlobal0X128 The global fee growth for token0.
+     * @return feeGrowthGlobal1X128 The global fee growth for token1.
+     * @return liquidity The liquidity of the pool.
+     */
+    function getPoolState(IPoolManager manager, PoolId poolId)
+        internal
+        view
+        returns (Slot0 slot0, uint256 feeGrowthGlobal0X128, uint256 feeGrowthGlobal1X128, uint128 liquidity)
+    {
+        bytes32 stateSlot = _getPoolStateSlot(poolId);
+        bytes memory data = manager.extsload(stateSlot, 4);
+        assembly {
+            slot0 := mload(add(data, 32))
+            feeGrowthGlobal0X128 := mload(add(data, 64))
+            feeGrowthGlobal1X128 := mload(add(data, 96))
+            liquidity := mload(add(data, 128))
+        }
+    }
+
     /**
      * @notice Get Slot0 of the pool: sqrtPriceX96, tick, protocolFee, lpFee
      * @dev Corresponds to pools[poolId].slot0

test/libraries/StateLibrary.t.sol

@@ -8,6 +8,7 @@ import {Hooks} from "../../src/libraries/Hooks.sol";
 import {TickMath} from "../../src/libraries/TickMath.sol";
 import {IPoolManager} from "../../src/interfaces/IPoolManager.sol";
 import {PoolKey} from "../../src/types/PoolKey.sol";
+import {Slot0} from "../../src/types/Slot0.sol";
 import {BalanceDelta} from "../../src/types/BalanceDelta.sol";
 import {PoolId, PoolIdLibrary} from "../../src/types/PoolId.sol";
 import {CurrencyLibrary, Currency} from "../../src/types/Currency.sol";
@@ -37,6 +38,38 @@ contract StateLibraryTest is Test, Deployers, Fuzzers, GasSnapshot {
         manager.initialize(key, SQRT_PRICE_1_1, ZERO_BYTES);
     }
 
+    function test_getPoolState() public {
+        // create liquidity
+        modifyLiquidityRouter.modifyLiquidity(
+            key, IPoolManager.ModifyLiquidityParams(-60, 60, 10_000 ether, 0), ZERO_BYTES
+        );
+
+        modifyLiquidityRouter.modifyLiquidity(
+            key, IPoolManager.ModifyLiquidityParams(-600, 600, 10_000 ether, 0), ZERO_BYTES
+        );
+
+        // swap to create fees, crossing a tick
+        uint256 swapAmount = 100 ether;
+        swap(key, true, -int256(swapAmount), ZERO_BYTES);
+
+        (Slot0 slot0, uint256 feeGrowthGlobal0X128, uint256 feeGrowthGlobal1X128, uint128 liquidity) =
+            StateLibrary.getPoolState(manager, poolId);
+        snapLastCall("extsload getPoolState");
+
+        assertEq(slot0.sqrtPriceX96(), 78680104762184586858280382455);
+        assertEq(slot0.tick(), -139);
+        assertEq(slot0.protocolFee(), 0);
+        assertEq(slot0.lpFee(), 3000);
+
+        uint256 liquidityExpected = StateLibrary.getLiquidity(manager, poolId);
+        assertEq(liquidity, liquidityExpected);
+
+        (uint256 feeGrowthGlobal0Expected, uint256 feeGrowthGlobal1Expected) =
+            StateLibrary.getFeeGrowthGlobals(manager, poolId);
+        assertEq(feeGrowthGlobal0X128, feeGrowthGlobal0Expected);
+        assertEq(feeGrowthGlobal1X128, feeGrowthGlobal1Expected);
+    }
+
     function test_getSlot0() public {
         // create liquidity
         modifyLiquidityRouter.modifyLiquidity(
@@ -50,15 +83,15 @@ contract StateLibraryTest is Test, Deployers, Fuzzers, GasSnapshot {
         // swap to create fees, crossing a tick
         uint256 swapAmount = 100 ether;
         swap(key, true, -int256(swapAmount), ZERO_BYTES);
-        (uint160 sqrtPriceX96, int24 tick, uint24 protocolFee, uint24 swapFee) = StateLibrary.getSlot0(manager, poolId);
+
+        (uint160 sqrtPriceX96, int24 tick, uint24 protocolFee, uint24 lpFee) = StateLibrary.getSlot0(manager, poolId);
         snapLastCall("extsload getSlot0");
-        assertEq(tick, -139);
 
         // magic number verified against a native getter
         assertEq(sqrtPriceX96, 78680104762184586858280382455);
         assertEq(tick, -139);
         assertEq(protocolFee, 0); // tested in protocol fee tests
-        assertEq(swapFee, 3000);
+        assertEq(lpFee, 3000);
     }
 
     function test_getTickLiquidity() public {