feat(coins): check fee growth inside lps before collecting (#1385)

* feat(coins): check fee growth inside lps before collecting

* chore: add changeset

* chore: lint

* fix: add missing package specification to changeset

Co-authored-by: Dan Oved <[email protected]>

---------

Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
Co-authored-by: Dan Oved <[email protected]>

Author: 3 people

.changeset/many-cows-sneeze.md

@@ -0,0 +1,5 @@
+---
+"@zoralabs/coins": patch
+---
+
+Ignore collecting from liquidity positions with empty fee growth

packages/coins/src/libs/V4Liquidity.sol

@@ -167,6 +167,12 @@ library V4Liquidity {
                 continue;
             }
 
+            // skip lps with no fees to collect
+            (uint256 feeGrowthInside0DeltaX128, uint256 feeGrowthInside1DeltaX128) = getFeeGrowth(poolManager, poolKey, positions[i]);
+            if (feeGrowthInside0DeltaX128 == 0 && feeGrowthInside1DeltaX128 == 0) {
+                continue;
+            }
+
             params = ModifyLiquidityParams({
                 tickLower: positions[i].tickLower,
                 tickUpper: positions[i].tickUpper,
@@ -221,6 +227,30 @@ library V4Liquidity {
         liquidity = StateLibrary.getPositionLiquidity(poolManager, poolKey.toId(), positionId);
     }
 
+    function getFeeGrowth(
+        IPoolManager poolManager,
+        PoolKey memory poolKey,
+        LpPosition memory position
+    ) private view returns (uint256 feeGrowthInside0DeltaX128, uint256 feeGrowthInside1DeltaX128) {
+        (, uint256 feeGrowthInside0LastX128, uint256 feeGrowthInside1LastX128) = StateLibrary.getPositionInfo(
+            poolManager,
+            poolKey.toId(),
+            address(this),
+            position.tickLower,
+            position.tickUpper,
+            bytes32(0)
+        );
+        (uint256 feeGrowthInside0X128, uint256 feeGrowthInside1X128) = StateLibrary.getFeeGrowthInside(
+            poolManager,
+            poolKey.toId(),
+            position.tickLower,
+            position.tickUpper
+        );
+
+        feeGrowthInside0DeltaX128 = feeGrowthInside0X128 - feeGrowthInside0LastX128;
+        feeGrowthInside1DeltaX128 = feeGrowthInside1X128 - feeGrowthInside1LastX128;
+    }
+
     function mintPositions(IPoolManager poolManager, PoolKey memory poolKey, LpPosition[] memory positions) internal returns (int128 amount0, int128 amount1) {
         ModifyLiquidityParams memory params;
         uint256 numPositions = positions.length;