test: add lido split integration test

src/interfaces/ISplitMain.sol

@@ -53,6 +53,27 @@ interface ISplitMain {
     address distributorAddress
   ) external;
 
+
+  /// @notice Distributes the ERC20 `token` balance for split `split`
+  /// @dev `accounts`, `percentAllocations`, and `distributorFee` are verified by hashing
+  /// & comparing to the hash in storage associated with split `split`
+  /// @dev pernicious ERC20s may cause overflow in this function inside
+  /// _scaleAmountByPercentage, but results do not affect ETH & other ERC20 balances
+  /// @param split Address of split to distribute balance for
+  /// @param token Address of ERC20 to distribute balance for
+  /// @param accounts Ordered, unique list of addresses with ownership in the split
+  /// @param percentAllocations Percent allocations associated with each address
+  /// @param distributorFee Keeper fee paid by split to cover gas costs of distribution
+  /// @param distributorAddress Address to pay `distributorFee` to
+  function distributeERC20(
+    address split,
+    ERC20 token,
+    address[] calldata accounts,
+    uint32[] calldata percentAllocations,
+    uint32 distributorFee,
+    address distributorAddress
+  ) external;
+
   /// @notice Withdraw ETH &/ ERC20 balances for account `account`
   /// @param account Address to withdraw on behalf of
   /// @param withdrawETH Withdraw all ETH if nonzero

src/test/lido/LidoSplitTestHelper.sol

@@ -5,4 +5,5 @@ pragma solidity 0.8.17;
 contract LidoSplitTestHelper {
     address internal STETH_MAINNET_ADDRESS = address(0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84);
     address internal WSTETH_MAINNET_ADDRESS = address(0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0);
+    address internal RANDOM_stETH_ACCOUNT_ADDRESS = address(0x2bf3937b8BcccE4B65650F122Bb3f1976B937B2f);
 }

src/test/lido/integration/LidoSplitIntegrationTest.sol

@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.17;
+
+import "forge-std/Test.sol";
+import {LidoSplitFactory, LidoSplit} from "src/lido/LidoSplitFactory.sol";
+import {ERC20} from 'solmate/tokens/ERC20.sol';
+import {LidoSplitTestHelper} from '../LidoSplitTestHelper.sol';
+import {ISplitMain} from "src/interfaces/ISplitMain.sol";
+
+contract LidoSplitIntegrationTest is LidoSplitTestHelper, Test {
+
+    LidoSplitFactory internal lidoSplitFactory;
+    LidoSplit internal lidoSplit;
+
+    address splitter;
+
+    address[] accounts;
+    uint32[] percentAllocations;
+
+    address internal SPLIT_MAIN_MAINNET = 0x2ed6c4B5dA6378c7897AC67Ba9e43102Feb694EE;
+
+    function setUp() public {
+        uint256 mainnetBlock = 17421005;
+        vm.createSelectFork(getChain("mainnet").rpcUrl, mainnetBlock);
+
+        lidoSplitFactory = new LidoSplitFactory(
+            ERC20(STETH_MAINNET_ADDRESS),
+            ERC20(WSTETH_MAINNET_ADDRESS)
+        );
+
+        accounts = new address[](2);
+        accounts[0] = makeAddr("accounts0");
+        accounts[1] = makeAddr("accounts1");
+
+        percentAllocations = new uint32[](2);
+        percentAllocations[0] = 400_000;
+        percentAllocations[1] = 600_000;
+
+        splitter = ISplitMain(SPLIT_MAIN_MAINNET).createSplit(
+            accounts,
+            percentAllocations,
+            0,
+            address(0)
+        );
+
+        lidoSplit = LidoSplit(
+            lidoSplitFactory.createSplit(
+                splitter
+            )
+        );
+
+    }
+
+    function test_CanDistribute() public {
+        vm.prank(RANDOM_stETH_ACCOUNT_ADDRESS);
+        ERC20(STETH_MAINNET_ADDRESS).transfer(address(lidoSplit), 100 ether);
+
+        lidoSplit.distribute();
+
+        ISplitMain(SPLIT_MAIN_MAINNET).distributeERC20(
+            splitter,
+            ERC20(WSTETH_MAINNET_ADDRESS),
+            accounts,
+            percentAllocations,
+            0,
+            address(0)
+        );
+
+        ERC20[] memory tokens = new ERC20[](1);
+        tokens[0] = ERC20(WSTETH_MAINNET_ADDRESS);
+
+        ISplitMain(SPLIT_MAIN_MAINNET).withdraw(accounts[0], 0, tokens);
+        ISplitMain(SPLIT_MAIN_MAINNET).withdraw(accounts[1], 0, tokens);
+
+        assertEq(
+            ERC20(WSTETH_MAINNET_ADDRESS).balanceOf(accounts[0]),
+            35483996363190140092, 
+            "invalid account 0 balance"
+        );
+        assertEq(
+            ERC20(WSTETH_MAINNET_ADDRESS).balanceOf(accounts[1]),
+            53225994544785210138,
+            "invalid account 1 balance"
+        );
+    }
+}
+