Refactor liquidation on deprecated market

contracts/aave-v2/ExitPositionsManager.sol

@@ -128,6 +128,8 @@ contract ExitPositionsManager is IExitPositionsManager, PositionsManagerUtils {
         uint256 collateralTokenUnit; // The collateral token unit considering its decimals.
         uint256 borrowedReserveDecimals; // The number of decimals of the borrowed asset in the reserve.
         uint256 borrowedTokenUnit; // The unit of borrowed token considering its decimals.
+        uint256 closeFactor; // The close factor used during the liquidation.
+        bool liquidationAllowed; // Whether the liquidation is allowed or not.
     }
 
     // Struct to avoid stack too deep.
@@ -221,23 +223,22 @@ contract ExitPositionsManager is IExitPositionsManager, PositionsManagerUtils {
         _updateIndexes(_poolTokenBorrowed);
         _updateIndexes(_poolTokenCollateral);
 
-        if (!borrowedMarket.isDeprecated && !_liquidationAllowed(_borrower))
-            revert UnauthorisedLiquidate();
-
-        address tokenBorrowedAddress = market[_poolTokenBorrowed].underlyingToken;
+        LiquidateVars memory vars;
+        (vars.closeFactor, vars.liquidationAllowed) = _liquidationAllowed(
+            _borrower,
+            borrowedMarket.isDeprecated
+        );
+        if (!vars.liquidationAllowed) revert UnauthorisedLiquidate();
 
         uint256 amountToLiquidate = Math.min(
             _amount,
-            _getUserBorrowBalanceInOf(_poolTokenBorrowed, _borrower).percentMul(
-                DEFAULT_LIQUIDATION_CLOSE_FACTOR
-            ) // Max liquidatable debt.
+            _getUserBorrowBalanceInOf(_poolTokenBorrowed, _borrower).percentMul(vars.closeFactor) // Max liquidatable debt.
         );
 
-        address tokenCollateralAddress = market[_poolTokenCollateral].underlyingToken;
-
         IPriceOracleGetter oracle = IPriceOracleGetter(addressesProvider.getPriceOracle());
 
-        LiquidateVars memory vars;
+        address tokenCollateralAddress = market[_poolTokenCollateral].underlyingToken;
+        address tokenBorrowedAddress = market[_poolTokenBorrowed].underlyingToken;
         {
             ILendingPool poolMem = pool;
             (, , vars.liquidationBonus, vars.collateralReserveDecimals, ) = poolMem
@@ -316,7 +317,6 @@ contract ExitPositionsManager is IExitPositionsManager, PositionsManagerUtils {
         emit P2PBorrowDeltaUpdated(_poolToken, deltasMem.p2pBorrowDelta);
 
         ERC20 underlyingToken = ERC20(market[_poolToken].underlyingToken);
-
         _borrowFromPool(underlyingToken, _amount);
         _supplyToPool(underlyingToken, _amount);
 
@@ -691,8 +691,21 @@ contract ExitPositionsManager is IExitPositionsManager, PositionsManagerUtils {
 
     /// @dev Checks if the user is liquidatable.
     /// @param _user The user to check.
-    /// @return Whether the user is liquidatable or not.
-    function _liquidationAllowed(address _user) internal returns (bool) {
-        return _getUserHealthFactor(_user, address(0), 0) < HEALTH_FACTOR_LIQUIDATION_THRESHOLD;
+    /// @param _isDeprecated Whether the market is deprecated or not.
+    /// @return closeFactor The close factor to apply.
+    /// @return liquidationAllowed Whether the liquidation is allowed or not.
+    function _liquidationAllowed(address _user, bool _isDeprecated)
+        internal
+        returns (uint256 closeFactor, bool liquidationAllowed)
+    {
+        if (_isDeprecated) {
+            // Allow liquidation of the whole debt.
+            closeFactor = MAX_BASIS_POINTS;
+            liquidationAllowed = true;
+        } else {
+            closeFactor = DEFAULT_LIQUIDATION_CLOSE_FACTOR;
+            liquidationAllowed = (_getUserHealthFactor(_user, address(0), 0) <
+                HEALTH_FACTOR_LIQUIDATION_THRESHOLD);
+        }
     }
 }

contracts/aave-v3/ExitPositionsManager.sol

@@ -133,8 +133,8 @@ contract ExitPositionsManager is IExitPositionsManager, PositionsManagerUtils {
         uint256 borrowedTokenUnit; // The unit of borrowed token considering its decimals.
         uint256 borrowedTokenPrice; // The price of the borrowed token.
         uint256 amountToLiquidate; // The amount of debt token to repay.
-        uint256 closeFactor;
-        bool liquidationAllowed;
+        uint256 closeFactor; // The close factor used during the liquidation.
+        bool liquidationAllowed; // Whether the liquidation is allowed or not.
     }
 
     // Struct to avoid stack too deep.
@@ -229,10 +229,11 @@ contract ExitPositionsManager is IExitPositionsManager, PositionsManagerUtils {
         _updateIndexes(_poolTokenCollateral);
 
         LiquidateVars memory vars;
-        if (!borrowedMarket.isDeprecated) {
-            (vars.closeFactor, vars.liquidationAllowed) = _liquidationAllowed(_borrower);
-            if (!vars.liquidationAllowed) revert UnauthorisedLiquidate();
-        } else vars.closeFactor = DEFAULT_LIQUIDATION_CLOSE_FACTOR;
+        (vars.closeFactor, vars.liquidationAllowed) = _liquidationAllowed(
+            _borrower,
+            borrowedMarket.isDeprecated
+        );
+        if (!vars.liquidationAllowed) revert UnauthorisedLiquidate();
 
         vars.amountToLiquidate = Math.min(
             _amount,
@@ -700,23 +701,30 @@ contract ExitPositionsManager is IExitPositionsManager, PositionsManagerUtils {
 
     /// @dev Checks if the user is liquidatable.
     /// @param _user The user to check.
+    /// @param _isDeprecated Whether the market is deprecated or not.
     /// @return closeFactor The close factor to apply.
     /// @return liquidationAllowed Whether the liquidation is allowed or not.
-    function _liquidationAllowed(address _user)
+    function _liquidationAllowed(address _user, bool _isDeprecated)
         internal
         returns (uint256 closeFactor, bool liquidationAllowed)
     {
-        uint256 healthFactor = _getUserHealthFactor(_user, address(0), 0);
-        address priceOracleSentinel = addressesProvider.getPriceOracleSentinel();
-
-        closeFactor = healthFactor > MINIMUM_HEALTH_FACTOR_LIQUIDATION_THRESHOLD
-            ? DEFAULT_LIQUIDATION_CLOSE_FACTOR
-            : MAX_LIQUIDATION_CLOSE_FACTOR;
-
-        if (priceOracleSentinel != address(0))
-            liquidationAllowed = (healthFactor < MINIMUM_HEALTH_FACTOR_LIQUIDATION_THRESHOLD ||
-                (IPriceOracleSentinel(priceOracleSentinel).isLiquidationAllowed() &&
-                    healthFactor < HEALTH_FACTOR_LIQUIDATION_THRESHOLD));
-        else liquidationAllowed = healthFactor < HEALTH_FACTOR_LIQUIDATION_THRESHOLD;
+        if (_isDeprecated) {
+            // Allow liquidation of the whole debt.
+            closeFactor = MAX_BASIS_POINTS;
+            liquidationAllowed = true;
+        } else {
+            uint256 healthFactor = _getUserHealthFactor(_user, address(0), 0);
+            address priceOracleSentinel = addressesProvider.getPriceOracleSentinel();
+
+            closeFactor = healthFactor > MINIMUM_HEALTH_FACTOR_LIQUIDATION_THRESHOLD
+                ? DEFAULT_LIQUIDATION_CLOSE_FACTOR
+                : MAX_LIQUIDATION_CLOSE_FACTOR;
+
+            if (priceOracleSentinel != address(0))
+                liquidationAllowed = (healthFactor < MINIMUM_HEALTH_FACTOR_LIQUIDATION_THRESHOLD ||
+                    (IPriceOracleSentinel(priceOracleSentinel).isLiquidationAllowed() &&
+                        healthFactor < HEALTH_FACTOR_LIQUIDATION_THRESHOLD));
+            else liquidationAllowed = healthFactor < HEALTH_FACTOR_LIQUIDATION_THRESHOLD;
+        }
     }
 }

contracts/compound/PositionsManager.sol

@@ -218,6 +218,7 @@ contract PositionsManager is IPositionsManager, MatchingEngine {
         uint256 supplyBalance;
         uint256 borrowedPrice;
         uint256 amountToSeize;
+        uint256 closeFactor;
     }
 
     /// LOGIC ///
@@ -500,13 +501,17 @@ contract PositionsManager is IPositionsManager, MatchingEngine {
         _updateP2PIndexes(_poolTokenBorrowed);
         _updateP2PIndexes(_poolTokenCollateral);
 
-        if (!borrowedMarket.isDeprecated && !_isLiquidatable(_borrower, address(0), 0, 0))
-            revert UnauthorisedLiquidate();
-
         LiquidateVars memory vars;
+        if (borrowedMarket.isDeprecated)
+            vars.closeFactor = WAD; // Allow liquidation of the whole debt.
+        else {
+            if (!_isLiquidatable(_borrower, address(0), 0, 0)) revert UnauthorisedLiquidate();
+            vars.closeFactor = comptroller.closeFactorMantissa();
+        }
+
         vars.borrowBalance = _getUserBorrowBalanceInOf(_poolTokenBorrowed, _borrower);
 
-        if (_amount > vars.borrowBalance.mul(comptroller.closeFactorMantissa()))
+        if (_amount > vars.borrowBalance.mul(vars.closeFactor))
             revert AmountAboveWhatAllowedToRepay(); // Same mechanism as Compound. Liquidator cannot repay more than part of the debt (cf close factor on Compound).
 
         _safeRepayLogic(_poolTokenBorrowed, msg.sender, _borrower, _amount, 0);

test-foundry/aave-v2/TestLiquidate.t.sol

@@ -40,7 +40,7 @@ contract TestLiquidate is TestSetup {
         (, uint256 borrowOnPoolbefore) = morpho.borrowBalanceInOf(aDai, address(borrower1));
 
         // Liquidate
-        uint256 toRepay = amount / 2;
+        uint256 toRepay = amount; // Full liquidation.
         User liquidator = borrower3;
         liquidator.approve(dai, address(morpho), toRepay);
         liquidator.liquidate(aDai, aUsdc, address(borrower1), toRepay);

test-foundry/aave-v3/TestLiquidate.t.sol

@@ -40,7 +40,7 @@ contract TestLiquidate is TestSetup {
         (, uint256 borrowOnPoolbefore) = morpho.borrowBalanceInOf(aDai, address(borrower1));
 
         // Liquidate
-        uint256 toRepay = amount / 2;
+        uint256 toRepay = amount; // Full liquidation.
         User liquidator = borrower3;
         liquidator.approve(dai, address(morpho), toRepay);
         liquidator.liquidate(aDai, aUsdc, address(borrower1), toRepay);

test-foundry/compound/TestLiquidate.t.sol

@@ -41,7 +41,7 @@ contract TestLiquidate is TestSetup {
         (, uint256 borrowOnPoolbefore) = morpho.borrowBalanceInOf(cDai, address(borrower1));
 
         // Liquidate
-        uint256 toRepay = amount / 3;
+        uint256 toRepay = amount; // Full liquidation.
         User liquidator = borrower3;
         liquidator.approve(dai, address(morpho), toRepay);
         liquidator.liquidate(cDai, cUsdc, address(borrower1), toRepay);