fix(FlashMintLeveragedZeroEx): Make rounding error margin configurable (#210)

Author: ckoopmann

contracts/exchangeIssuance/FlashmintLeveragedZeroEx.sol

@@ -87,11 +87,11 @@ contract FlashMintLeveragedZeroEx is ReentrancyGuard, Ownable {
     /* ============ Constants ============= */
 
     uint256 private constant MAX_UINT256 = type(uint256).max;
-    uint256 public constant ROUNDING_ERROR_MARGIN = 2;
     address public constant ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
 
     /* ============ State Variables ============ */
 
+    uint256 public immutable ROUNDING_ERROR_MARGIN;
     IController public immutable setController;
     IDebtIssuanceModule public immutable debtIssuanceModule;
     IMorphoLeverageModule public immutable morphoLeverageModule;
@@ -140,7 +140,8 @@ contract FlashMintLeveragedZeroEx is ReentrancyGuard, Ownable {
         IMorpho _morpho,
         IPool _aavePool,
         IWETH _weth,
-        address _swapTarget
+        address _swapTarget,
+        uint256 _roundingErrorMargin
     )
         public
     {
@@ -152,6 +153,7 @@ contract FlashMintLeveragedZeroEx is ReentrancyGuard, Ownable {
         aavePool = _aavePool;
         weth = _weth;
         swapTargetWhitelist[_swapTarget] = true;
+        ROUNDING_ERROR_MARGIN = _roundingErrorMargin;
     }
 
     /* ============ External Functions ============ */

utils/deploys/deployExtensions.ts

@@ -53,7 +53,7 @@ import {
   DEXAdapterV5__factory,
   DEXAdapterV5,
   FlashMintLeveragedZeroEx__factory,
-  FlashMintLeveragedZeroExBalancerFL__factory
+  FlashMintLeveragedZeroExBalancerFL__factory,
 } from "../../typechain";
 import { AirdropExtension__factory } from "../../typechain/factories/AirdropExtension__factory";
 import { AuctionRebalanceExtension__factory } from "../../typechain/factories/AuctionRebalanceExtension__factory";
@@ -465,6 +465,7 @@ export default class DeployExtensions {
     aaveV3PoolAddress: Address,
     wethAddress: Address,
     swapTarget: Address,
+    roundingMargin: BigNumberish = 2,
   ) {
     console.log("Deploying FlashMintLeveragedZeroEx", {
       wethAddress,
@@ -486,6 +487,7 @@ export default class DeployExtensions {
       aaveV3PoolAddress,
       wethAddress,
       swapTarget,
+      roundingMargin,
     );
   }