refactor: adding slashAVS functionality to EigenLayerSystem

src/test/recon/EigenLayerSystem.sol

@@ -2,8 +2,13 @@
 pragma solidity ^0.8.12;
 
 import {EigenLayerSetupV2} from "./EigenLayerSetupV2.sol";
+import {IStrategy} from "../../contracts/interfaces/IStrategy.sol";
+import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "forge-std/Test.sol";
+
+contract EigenLayerSystem is EigenLayerSetupV2, Test {
+    address immutable TOKEN_BURN_ADDRESS = address(0xDEADBEEF); // used to simulate token burning for tokens that don't allow transfer to 0 address
 
-contract EigenLayerSystem is EigenLayerSetupV2 {
     /// @notice simulates a native slashing event on a validator
     /// @dev when calling this through a target function, need to prank as the pod's address to allow modifying balances in EigenPodManager
     /// @param podOwner the owner of the pod being slashed
@@ -15,6 +20,52 @@ contract EigenLayerSystem is EigenLayerSetupV2 {
         ethPOSDepositMock.slash(1 ether);
     }
 
+    /// @notice simulates an AVS slashing event
+    /// @dev this assumes slashing amounts for an LST and native ETH can be different
+    function slashAVS(
+        address user,
+        address[] memory activeStrategies,
+        uint256 nativeSlashAmount,
+        uint256 lstSlashAmount
+    ) public {
+        // Slash native ETH if user has any staked in an EigenPod
+        uint256 nativeEthShares = uint256(eigenPodManager.podOwnerShares(address(user)));
+        if (nativeEthShares > 0) {
+            // user can be slashed a max amount of their entire stake
+            nativeSlashAmount = nativeSlashAmount % nativeEthShares;
+
+            // shares are 1:1 with ETH in EigenPod so can slash the share amount directly
+            ethPOSDepositMock.slash(nativeSlashAmount);
+
+            // update the OperatorDelegator's share balance in EL by calling EigenPodManager as the pod
+            address podAddress = getPodForOwner(user);
+            vm.prank(podAddress);
+            eigenPodManager.recordBeaconChainETHBalanceUpdate(address(user), -int256(nativeSlashAmount));
+        }
+
+        // loop through strategies to slash if a user has any shares in them
+        for (uint256 i; i < activeStrategies.length; i++) {
+            IStrategy strategy = IStrategy(activeStrategies[i]);
+            uint256 lstShares = strategy.shares(address(user));
+
+            // Slash LST if user has any shares of the given LST strategy
+            if (lstShares > 0) {
+                uint256 slashingAmountLSTShares = lstSlashAmount % lstShares;
+                // convert share amount to slash to amount of collateral token
+                uint256 amountLSTToken = strategy.sharesToUnderlyingView(slashingAmountLSTShares);
+
+                // "burn" tokens in strategy to ensure they don't effect accounting
+                vm.prank(activeStrategies[i]);
+                IERC20 underlyingToken = strategy.underlyingToken();
+                underlyingToken.transfer(TOKEN_BURN_ADDRESS, amountLSTToken);
+
+                // remove shares to update user's accounting
+                vm.prank(address(delegation));
+                _removeSharesFromStrategyManager(address(user), address(activeStrategies[i]), slashingAmountLSTShares);
+            }
+        }
+    }
+
     /// @notice returns the address of an EigenPod for an Owner, if one exists
     function getPodForOwner(address owner) public view returns (address eigenPod) {
         return address(eigenPodManager.getPod(address(owner)));

src/test/recon/EigenLayerSystemTest.t.sol

@@ -6,7 +6,7 @@ import {EigenLayerSystem} from "./EigenLayerSystem.sol";
 import {MockERC20} from "../mocks/MockERC20.sol";
 import "forge-std/Test.sol";
 
-contract EigenLayerSystemTest is EigenLayerSystem, Test {
+contract EigenLayerSystemTest is EigenLayerSystem {
     MockERC20 stETH;
     MockERC20 cbETH;