Merge pull request #574 from morpho-org/refactor/remove-skip-irm-call

Remove IRM call skip

Author: MerlinEgalite

src/Morpho.sol

@@ -474,26 +474,23 @@ contract Morpho is IMorphoStaticTyping {
 
         if (elapsed == 0) return;
 
-        if (market[id].totalBorrowAssets != 0) {
-            uint256 borrowRate = IIrm(marketParams.irm).borrowRate(marketParams, market[id]);
-            uint256 interest = market[id].totalBorrowAssets.wMulDown(borrowRate.wTaylorCompounded(elapsed));
-            market[id].totalBorrowAssets += interest.toUint128();
-            market[id].totalSupplyAssets += interest.toUint128();
-
-            uint256 feeShares;
-            if (market[id].fee != 0) {
-                uint256 feeAmount = interest.wMulDown(market[id].fee);
-                // The fee amount is subtracted from the total supply in this calculation to compensate for the fact
-                // that total supply is already increased by the full interest (including the fee amount).
-                feeShares =
-                    feeAmount.toSharesDown(market[id].totalSupplyAssets - feeAmount, market[id].totalSupplyShares);
-                position[id][feeRecipient].supplyShares += feeShares;
-                market[id].totalSupplyShares += feeShares.toUint128();
-            }
-
-            emit EventsLib.AccrueInterest(id, borrowRate, interest, feeShares);
+        uint256 borrowRate = IIrm(marketParams.irm).borrowRate(marketParams, market[id]);
+        uint256 interest = market[id].totalBorrowAssets.wMulDown(borrowRate.wTaylorCompounded(elapsed));
+        market[id].totalBorrowAssets += interest.toUint128();
+        market[id].totalSupplyAssets += interest.toUint128();
+
+        uint256 feeShares;
+        if (market[id].fee != 0) {
+            uint256 feeAmount = interest.wMulDown(market[id].fee);
+            // The fee amount is subtracted from the total supply in this calculation to compensate for the fact
+            // that total supply is already increased by the full interest (including the fee amount).
+            feeShares = feeAmount.toSharesDown(market[id].totalSupplyAssets - feeAmount, market[id].totalSupplyShares);
+            position[id][feeRecipient].supplyShares += feeShares;
+            market[id].totalSupplyShares += feeShares.toUint128();
         }
 
+        emit EventsLib.AccrueInterest(id, borrowRate, interest, feeShares);
+
         // Safe "unchecked" cast.
         market[id].lastUpdate = uint128(block.timestamp);
     }

src/libraries/periphery/MorphoBalancesLib.sol

@@ -41,6 +41,7 @@ library MorphoBalancesLib {
 
         uint256 elapsed = block.timestamp - market.lastUpdate;
 
+        // Skipped if elapsed == 0 of if totalBorrowAssets == 0 because interest would be null.
         if (elapsed != 0 && market.totalBorrowAssets != 0) {
             uint256 borrowRate = IIrm(marketParams.irm).borrowRateView(marketParams, market);
             uint256 interest = market.totalBorrowAssets.wMulDown(borrowRate.wTaylorCompounded(elapsed));

src/mocks/IrmMock.sol

@@ -10,6 +10,8 @@ contract IrmMock is IIrm {
     using MathLib for uint128;
 
     function borrowRateView(MarketParams memory, Market memory market) public pure returns (uint256) {
+        if (market.totalSupplyAssets == 0) return 0;
+
         uint256 utilization = market.totalBorrowAssets.wDivDown(market.totalSupplyAssets);
 
         // Divide by the number of seconds in a year.