Merge pull request #187 from Blueberryfi/liquidation-update

Emergency Funds within Liquidator Bot

contracts/liquidation/AuraLiquidator.sol

@@ -58,6 +58,7 @@ contract AuraLiquidator is BaseLiquidator {
     function initialize(
         IBank bank,
         address treasury,
+        address emergencyFund,
         address poolAddressesProvider,
         address auraSpell,
         address balancerVault,
@@ -77,6 +78,7 @@ contract AuraLiquidator is BaseLiquidator {
         _swapRouter = swapRouter;
         _weth = weth;
 
+        _emergencyFund = emergencyFund;
         _transferOwnership(owner);
     }
 

contracts/liquidation/BaseLiquidator.sol

@@ -51,6 +51,9 @@ abstract contract BaseLiquidator is IBlueberryLiquidator, SwapRegistry, IERC1155
     /// @dev aave pool addresses provider
     IPoolAddressesProvider private _poolAddressesProvider;
 
+    /// @dev The address of the emergency fund that will cover any extra costs for liquidation
+    address internal _emergencyFund;
+
     /*//////////////////////////////////////////////////////////////////////////
                                       FUNCTIONS
     //////////////////////////////////////////////////////////////////////////*/
@@ -134,6 +137,12 @@ abstract contract BaseLiquidator is IBlueberryLiquidator, SwapRegistry, IERC1155
         // forceApprove aave pool to get back debt
         IERC20(asset).forceApprove(address(_pool), amount + premium);
 
+        // Have the emergency fund cover any extra costs
+        uint256 assetBalance = IERC20(asset).balanceOf(address(this));
+        if (assetBalance < amount + premium) {
+            _accessEmergencyFunds(asset, (amount + premium) - assetBalance);
+        }
+
         // reset position id
         _POS_ID = 0;
 
@@ -151,6 +160,24 @@ abstract contract BaseLiquidator is IBlueberryLiquidator, SwapRegistry, IERC1155
         }
     }
 
+    /**
+     * @notice Sets the address of the emergency fund
+     * @param emergencyFund The address of the emergency fund
+     */
+    function setEmergencyFund(address emergencyFund) external onlyOwner {
+        if (emergencyFund == address(0)) revert Errors.ZERO_ADDRESS();
+        _emergencyFund = emergencyFund;
+    }
+
+    /**
+     * @notice Sends emergency funds to the contract to cover unprofitable liquidations
+     * @param asset The address of the asset to withdraw from the contract
+     * @param amount Amount of asset to send to the liquidator bot
+     */
+    function _accessEmergencyFunds(address asset, uint256 amount) internal {
+        IERC20(asset).transferFrom(_emergencyFund, address(this), amount);
+    }
+
     /**
      * @notice Sets the Aave Lending Pool and Aave Pool Address Provider during initialization
      * @param poolAddressesProvider Address of Aave's PoolAddressesProvider

contracts/liquidation/ConvexLiquidator.sol

@@ -63,6 +63,7 @@ contract ConvexLiquidator is BaseLiquidator {
     function initialize(
         IBank bank,
         address treasury,
+        address emergencyFund,
         address poolAddressesProvider,
         address convexSpell,
         address balancerVault,
@@ -83,6 +84,8 @@ contract ConvexLiquidator is BaseLiquidator {
         _curveOracle = IConvexSpell(convexSpell).getCrvOracle();
 
         _weth = weth;
+        _emergencyFund = emergencyFund;
+
         _transferOwnership(owner);
     }
 

contracts/liquidation/IchiLiquidator.sol

@@ -58,6 +58,7 @@ contract IchiLiquidator is BaseLiquidator {
     function initialize(
         IBank bank,
         address treasury,
+        address emergencyFund,
         address poolAddressesProvider,
         address ichiSpell,
         address swapRouter,
@@ -77,6 +78,7 @@ contract IchiLiquidator is BaseLiquidator {
         _swapRouter = swapRouter;
         _weth = weth;
 
+        _emergencyFund = emergencyFund;
         _transferOwnership(owner);
     }
 
@@ -118,7 +120,8 @@ contract IchiLiquidator is BaseLiquidator {
     function _unwrapLpToken(IBank.Position memory posInfo) internal returns (address) {
         // Withdraw ERC1155 liquidiation
         if (posInfo.collToken == address(IIchiSpell(_spell).getWIchiFarm())) {
-            IWIchiFarm(posInfo.collToken).burn(posInfo.collId, type(uint256).max);
+            uint256 balance = IERC1155(posInfo.collToken).balanceOf(address(this), posInfo.collId);
+            IWIchiFarm(posInfo.collToken).burn(posInfo.collId, balance);
             (uint256 pid, ) = IWIchiFarm(posInfo.collToken).decodeId(posInfo.collId);
 
             return IIchiFarm(IWIchiFarm(posInfo.collToken).getIchiFarm()).lpToken(pid);

contracts/liquidation/ShortLongLiquidator.sol

@@ -50,6 +50,7 @@ contract ShortLongLiquidator is BaseLiquidator {
     function initialize(
         IBank bank,
         address treasury,
+        address emergencyFund,
         address poolAddressesProvider,
         address shortLongSpell,
         address balancerVault,
@@ -67,6 +68,7 @@ contract ShortLongLiquidator is BaseLiquidator {
         _balancerVault = balancerVault;
         _swapRouter = swapRouter;
         _weth = weth;
+        _emergencyFund = emergencyFund;
         _transferOwnership(owner);
     }
 

test/liquidator/AuraLiquidation.test.ts

@@ -24,6 +24,7 @@ describe('Aura Liquidator', () => {
   let admin: SignerWithAddress;
   let alice: SignerWithAddress;
   let treasury: SignerWithAddress;
+  let emergengyFund: SignerWithAddress;
 
   let usdc: ERC20;
   let dai: ERC20;
@@ -37,7 +38,7 @@ describe('Aura Liquidator', () => {
   before(async () => {
     await fork();
 
-    [admin, alice, treasury] = await ethers.getSigners();
+    [admin, alice, treasury, emergengyFund] = await ethers.getSigners();
     usdc = <ERC20>await ethers.getContractAt('ERC20', USDC);
     usdc = <ERC20>await ethers.getContractAt('ERC20', USDC);
     dai = <ERC20>await ethers.getContractAt('ERC20', DAI);
@@ -77,6 +78,7 @@ describe('Aura Liquidator', () => {
       [
         bank.address,
         treasury.address,
+        emergengyFund.address,
         POOL_ADDRESSES_PROVIDER,
         spell.address,
         BALANCER_VAULT,

test/liquidator/ConvexLiquidation.test.ts

@@ -28,6 +28,7 @@ describe('Convex Liquidator', () => {
   let admin: SignerWithAddress;
   let alice: SignerWithAddress;
   let treasury: SignerWithAddress;
+  let emergengyFund: SignerWithAddress;
 
   let usdc: ERC20;
   let mockOracle: MockOracle;
@@ -40,7 +41,7 @@ describe('Convex Liquidator', () => {
 
   before(async () => {
     await fork(1);
-    [admin, alice, treasury] = await ethers.getSigners();
+    [admin, alice, treasury, emergengyFund] = await ethers.getSigners();
     usdc = <ERC20>await ethers.getContractAt('ERC20', USDC);
     dai = <ERC20>await ethers.getContractAt('ERC20', DAI);
     usdc = <ERC20>await ethers.getContractAt('ERC20', USDC);
@@ -80,6 +81,7 @@ describe('Convex Liquidator', () => {
       [
         bank.address,
         treasury.address,
+        emergengyFund.address,
         POOL_ADDRESSES_PROVIDER,
         spell.address,
         BALANCER_VAULT,

test/liquidator/IchiLiquidator.test.ts

@@ -34,6 +34,7 @@ describe('Ichi Liquidator', () => {
   let admin: SignerWithAddress;
   let alice: SignerWithAddress;
   let treasury: SignerWithAddress;
+  let emergengyFund: SignerWithAddress;
 
   let usdc: ERC20;
   let ichi: MockIchiV2;
@@ -50,7 +51,7 @@ describe('Ichi Liquidator', () => {
   before(async () => {
     await fork();
 
-    [admin, alice, treasury] = await ethers.getSigners();
+    [admin, alice, treasury, emergengyFund] = await ethers.getSigners();
     usdc = <ERC20>await ethers.getContractAt('ERC20', USDC);
     ichi = <MockIchiV2>await ethers.getContractAt('MockIchiV2', ICHI);
     ichiV1 = <ERC20>await ethers.getContractAt('ERC20', ICHIV1);
@@ -95,6 +96,7 @@ describe('Ichi Liquidator', () => {
       [
         bank.address,
         treasury.address,
+        emergengyFund.address,
         POOL_ADDRESSES_PROVIDER,
         spell.address,
         UNISWAP_V3_ROUTER,

test/liquidator/ShortLongLiquidator.test.ts

@@ -21,6 +21,7 @@ describe('ShortLong Liquidator', () => {
   let admin: SignerWithAddress;
   let alice: SignerWithAddress;
   let treasury: SignerWithAddress;
+  let emergengyFund: SignerWithAddress;
 
   let usdc: ERC20;
   let crv: ERC20;
@@ -31,7 +32,7 @@ describe('ShortLong Liquidator', () => {
   let positionId: BigNumber;
 
   before(async () => {
-    [admin, alice, treasury] = await ethers.getSigners();
+    [admin, alice, treasury, emergengyFund] = await ethers.getSigners();
     usdc = <ERC20>await ethers.getContractAt('ERC20', USDC);
     crv = <ERC20>await ethers.getContractAt('ERC20', CRV);
     const protocol = await setupShortLongProtocol();
@@ -46,6 +47,7 @@ describe('ShortLong Liquidator', () => {
       [
         bank.address,
         treasury.address,
+        emergengyFund.address,
         POOL_ADDRESSES_PROVIDER,
         spell.address,
         BALANCER_VAULT,