added test for grifting case

Author: d10r

packages/ethereum-contracts/test/foundry/superfluid/GrifterContract.sol

@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.23;
+
+import {
+    ISuperToken
+} from "../../../contracts/interfaces/superfluid/ISuperfluid.sol";
+import {
+    IERC20
+} from "../../../contracts/interfaces/superfluid/ISuperfluid.sol";
+
+import { ISETH } from "../../../contracts/interfaces/tokens/ISETH.sol";
+
+import "forge-std/console.sol";
+
+contract GrifterContract {
+    ISuperToken public immutable superToken;
+    IERC20 public immutable underlyingToken;
+    IERC20 public immutable aToken;
+    uint256 public immutable amount;
+
+    constructor(ISuperToken _superToken, IERC20 _aToken, uint256 _amount) {
+        superToken = _superToken;
+        aToken = _aToken;
+        underlyingToken = IERC20(superToken.getUnderlyingToken());
+        amount = _amount;
+
+        if (address(underlyingToken) != address(0)) {
+            // Approve SuperToken to move underlying
+            underlyingToken.approve(address(superToken), type(uint256).max);
+        }
+    }
+
+    receive() external payable {}
+
+    function grift(uint256 iterations) external {
+        if (address(underlyingToken) == address(0)) {
+            // Native ETH path
+            for (uint256 i = 0; i < iterations; ++i) {
+                uint256 bal0 = aToken.balanceOf(address(superToken));
+
+                // Upgrade ETH
+                ISETH(address(superToken)).upgradeByETH{ value: amount }();
+
+                uint256 bal1 = aToken.balanceOf(address(superToken));
+
+                // Downgrade ETH
+                ISETH(address(superToken)).downgradeToETH(amount);
+
+                uint256 bal2 = aToken.balanceOf(address(superToken));
+
+                // Analyze Downgrade
+                if (bal2 < bal1) {
+                    uint256 burned = bal1 - bal2;
+                    if (burned > amount) {
+                        uint256 diff = burned - amount;
+                        console.log("ETHx Downgrade Excess FOUND:");
+                        console.log(" Req: %s", amount);
+                        console.log(" Burn: %s", burned);
+                        console.log(" Diff: %s", diff);
+                        revert("FOUND EXCESS BURN");
+                    }
+                }
+            }
+        } else {
+            // ERC20 Path
+            for (uint256 i = 0; i < iterations; ++i) {
+                uint256 bal0 = aToken.balanceOf(address(superToken));
+
+                superToken.upgrade(amount);
+
+                uint256 bal1 = aToken.balanceOf(address(superToken));
+
+                superToken.downgrade(amount);
+                uint256 bal2 = aToken.balanceOf(address(superToken));
+
+                // Analyze Downgrade
+                if (bal2 < bal1) {
+                    uint256 burned = bal1 - bal2;
+                    if (burned > amount) {
+                        uint256 diff = burned - amount;
+                        console.log("ERC20 Downgrade Excess FOUND:");
+                        console.log(" Req: %s", amount);
+                        console.log(" Burn: %s", burned);
+                        console.log(" Diff: %s", diff);
+                        revert("FOUND EXCESS BURN");
+                    }
+                }
+            }
+        }
+    }
+}