+ add changeRevenuePool function

! unit test

.gitignore

@@ -10,6 +10,11 @@ typechain-types
 cache
 artifacts
 
+# foundry
+cache_forge
+
+out
+
 .idea
 .DS_Store
 

contracts/FlashBuy.sol

@@ -32,6 +32,11 @@ contract FlashBuy is IERC3156FlashBorrower, OwnableUpgradeable {
 
     uint256 constant public MAX_SLIPPAGE = 10000;
 
+    // added on 2024/09/12
+    address public revenuePool;
+
+    event RevenuePoolChanged(address indexed newAddress);
+
     // --- Init ---
     function initialize(
         IERC3156FlashLender lender_,
@@ -58,8 +63,10 @@ contract FlashBuy is IERC3156FlashBorrower, OwnableUpgradeable {
     }
 
     function transfer(address token) external {
+        require(revenuePool != address(0), "Revenue pool not set");
+
         bool success = IERC20(token).transfer(
-            owner(),
+            revenuePool,
             IERC20(token).balanceOf(address(this))
         );
         require(success, "Failed to transfer");
@@ -156,4 +163,12 @@ contract FlashBuy is IERC3156FlashBorrower, OwnableUpgradeable {
         lender.flashLoan(this, token, borrowAm, data);
         require(IERC20(token).balanceOf(address(this)) > before, "Flash loan failed");
     }
+
+    function changeRevenuePool(address _revenuePool) external onlyOwner {
+        require(_revenuePool != address(0), "Invalid zero address");
+        require(_revenuePool != revenuePool, "Already set");
+
+        revenuePool = _revenuePool;
+        emit RevenuePoolChanged(_revenuePool);
+    }
 }

test/foundry/FlashBuy.t.sol

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.10;
+
+import "forge-std/Test.sol";
+import "forge-std/console.sol";
+import "@openzeppelin/contracts/proxy/transparent/TransparentUpgradeableProxy.sol";
+import "../../contracts/FlashBuy.sol";
+import "../../contracts/LisUSD.sol";
+
+
+contract FlashBuyTest is Test {
+    address proxyAdminOwner = address(0x2A11AA);
+
+    address admin;
+
+    address lisUSD;
+
+    FlashBuy flashBuy;
+
+    function setUp() public {
+        admin = msg.sender;
+        lisUSD = address(new LisUSD());
+
+        FlashBuy flashBuyImpl = new FlashBuy();
+        TransparentUpgradeableProxy flashBuyProxy = new TransparentUpgradeableProxy(
+            address(flashBuyImpl),
+            proxyAdminOwner,
+            abi.encodeWithSignature(
+                "initialize(address,address,address)",
+                address(0xffff), address(0xeeee), address(0xdddd)
+            )
+        );
+
+        flashBuy = FlashBuy(address(flashBuyProxy));
+        flashBuy.transferOwnership(admin);
+    }
+
+    function test_setup() public {
+        assertTrue(address(flashBuy) != address(0));
+        assertEq(address(0xffff), address(flashBuy.lender()));
+    }
+
+    function test_changeRevenuePool_ok() public {
+        assertEq(address(0), flashBuy.revenuePool());
+
+        vm.startPrank(admin);
+        flashBuy.changeRevenuePool(address(0x1234));
+        vm.stopPrank();
+
+        assertEq(address(0x1234), flashBuy.revenuePool());
+    }
+
+    function test_changeRevenuePool_acl() public {
+        assertEq(address(0), flashBuy.revenuePool());
+
+        vm.startPrank(address(0xffff));
+        vm.expectRevert("Ownable: caller is not the owner");
+        flashBuy.changeRevenuePool(address(0x1234));
+        vm.stopPrank();
+
+        assertEq(address(0), flashBuy.revenuePool());
+    }
+
+    function test_transfer_invalid_pool() public {
+        deal(lisUSD, address(flashBuy), 123e18);
+
+        assertEq(123e18, IERC20(lisUSD).balanceOf(address(flashBuy)));
+
+        vm.expectRevert("Revenue pool not set");
+        flashBuy.transfer(lisUSD);
+
+        assertEq(123e18, IERC20(lisUSD).balanceOf(address(flashBuy)));
+    }
+
+    function test_transfer_ok() public {
+        test_changeRevenuePool_ok();
+
+        deal(lisUSD, address(flashBuy), 123e18);
+        assertEq(123e18, IERC20(lisUSD).balanceOf(address(flashBuy)));
+
+        flashBuy.transfer(lisUSD);
+
+        assertEq(0, IERC20(lisUSD).balanceOf(address(flashBuy)));
+        assertEq(123e18, IERC20(lisUSD).balanceOf(address(0x1234)));
+    }
+}