Mimo August 2022 contest - jag's results

contracts/actions/MIMOEmptyVault.sol

1. Use local variable instead of calldata array indexing.

diff --git a/contracts/actions/MIMOEmptyVault.sol b/contracts/actions/MIMOEmptyVault.sol
index e9e853a..17933be 100644
--- a/contracts/actions/MIMOEmptyVault.sol
+++ b/contracts/actions/MIMOEmptyVault.sol
@@ -79,7 +79,8 @@ contract MIMOEmptyVault is MIMOSwap, MIMOFlashloan, IMIMOEmtpyVault {

     IERC20 vaultCollateral = IERC20(assets[0]);
     uint256 amount = amounts[0];
-    vaultCollateral.safeTransfer(address(mimoProxy), amounts[0]);
+    // Use local variable instead of calldata array indexing.
+    vaultCollateral.safeTransfer(address(mimoProxy), amount);
     uint256 flashloanRepayAmount = amount + premiums[0];

     IMIMOProxy(mimoProxy).execute(

contracts/actions/MIMOLeverage.sol

1. Use local variable instead of calldata array indexing.
2. unchecked code

diff --git a/contracts/actions/MIMOLeverage.sol b/contracts/actions/MIMOLeverage.sol
index 8a876fc..b1bad1a 100644
--- a/contracts/actions/MIMOLeverage.sol
+++ b/contracts/actions/MIMOLeverage.sol
@@ -83,8 +83,10 @@ contract MIMOLeverage is MIMOFlashloan, MIMOSwap, IMIMOLeverage {
     }

     IERC20 asset = IERC20(assets[0]);
-    asset.safeTransfer(address(mimoProxy), amounts[0]);
-    uint256 flashloanRepayAmount = amounts[0] + premiums[0];
+    //Use local variable to cache amounts[0]
+    uint256 _amounts = amounts[0];
+    asset.safeTransfer(address(mimoProxy), _amounts);
+    uint256 flashloanRepayAmount = _amounts + premiums[0];

     IMIMOProxy(mimoProxy).execute(
       address(this),
@@ -130,8 +132,11 @@ contract MIMOLeverage is MIMOFlashloan, MIMOSwap, IMIMOLeverage {
     require(collateralBalanceAfter >= flashloanRepayAmount, Errors.CANNOT_REPAY_FLASHLOAN);

     if (collateralBalanceAfter > flashloanRepayAmount) {
-      token.safeIncreaseAllowance(address(core), collateralBalanceAfter - flashloanRepayAmount);
-      core.deposit(address(token), collateralBalanceAfter - flashloanRepayAmount);
+      // collateralBalanceAfter is guaranteed to be greater than flashloanRepayAmount, so no underflow
+      unchecked {
+        token.safeIncreaseAllowance(address(core), collateralBalanceAfter - flashloanRepayAmount);
+        core.deposit(address(token), collateralBalanceAfter - flashloanRepayAmount);
+      }
     }

     token.safeTransfer(msg.sender, flashloanRepayAmount);

contracts/actions/MIMORebalance.sol

1. Use local variable instead of calldata array indexing.

diff --git a/contracts/actions/MIMORebalance.sol b/contracts/actions/MIMORebalance.sol
index f932ef8..0486ec1 100644
--- a/contracts/actions/MIMORebalance.sol
+++ b/contracts/actions/MIMORebalance.sol
@@ -82,7 +82,8 @@ contract MIMORebalance is MIMOFlashloan, MIMOSwap, IMIMORebalance {

     IERC20 fromCollateral = IERC20(assets[0]);
     uint256 amount = amounts[0];
-    fromCollateral.safeTransfer(address(mimoProxy), amounts[0]);
+    //Use local variable instead of calldata array
+    fromCollateral.safeTransfer(address(mimoProxy), amount);
     uint256 flashloanRepayAmount = amount + premiums[0];

     IMIMOProxy(mimoProxy).execute(

contracts/actions/automated/MIMOAutoRebalance.sol

1. Use local variable instead of calldata array indexing.

diff --git a/contracts/actions/automated/MIMOAutoRebalance.sol b/contracts/actions/automated/MIMOAutoRebalance.sol
index 56fea38..e5c598b 100644
--- a/contracts/actions/automated/MIMOAutoRebalance.sol
+++ b/contracts/actions/automated/MIMOAutoRebalance.sol
@@ -110,8 +110,9 @@ contract MIMOAutoRebalance is MIMOAutoAction, MIMOFlashloan, IMIMOAutoRebalance

     IERC20 fromCollateral = IERC20(assets[0]);
     uint256 amount = amounts[0];
-    fromCollateral.safeTransfer(address(mimoProxy), amounts[0]);
-    uint256 flashloanRepayAmount = amounts[0] + premiums[0];
+    // Use local variable amount further
+    fromCollateral.safeTransfer(address(mimoProxy), amount);
+    uint256 flashloanRepayAmount = amount + premiums[0];

     IMIMOProxy(mimoProxy).execute(
       mimoRebalance,

contracts/actions/managed/MIMOManagedAction.sol

1. Use named return variable ; saves 12 gas approx

diff --git a/contracts/actions/managed/MIMOManagedAction.sol b/contracts/actions/managed/MIMOManagedAction.sol
index 4a80a6a..c2744f4 100644
--- a/contracts/actions/managed/MIMOManagedAction.sol
+++ b/contracts/actions/managed/MIMOManagedAction.sol
@@ -87,9 +87,9 @@ contract MIMOManagedAction is IMIMOManagedAction {

   /**
     @notice Helper function calculating LTV ratio
-    @return Vault collateral value / vault debt
+    @return vaultRatio collateral value / vault debt
    */
-  function _getVaultRatio(uint256 vaultId) internal view returns (uint256) {
+  function _getVaultRatio(uint256 vaultId) internal view returns (uint256 vaultRatio) {
     IAddressProvider _a = a;
     IVaultsDataProvider vaultsData = _a.vaultsData();
     IPriceFeed priceFeed = _a.priceFeed();
@@ -103,9 +103,7 @@ contract MIMOManagedAction is IMIMOManagedAction {
       return (type(uint256).max);
     }

-    uint256 vaultRatio = collateralValue.wadDiv(vaultDebt);
-
-    return (vaultRatio);
+    vaultRatio = collateralValue.wadDiv(vaultDebt);
   }

   /**

contracts/actions/managed/MIMOManagedRebalance.sol 1.Use local variable instead of calldata array indexing.

diff --git a/contracts/actions/managed/MIMOManagedRebalance.sol b/contracts/actions/managed/MIMOManagedRebalance.sol
index d1da1ec..7a807c4 100644
--- a/contracts/actions/managed/MIMOManagedRebalance.sol
+++ b/contracts/actions/managed/MIMOManagedRebalance.sol
@@ -111,8 +111,9 @@ contract MIMOManagedRebalance is MIMOManagedAction, MIMOFlashloan, IMIMOManagedR

     IERC20 fromCollateral = IERC20(assets[0]);
     uint256 amount = amounts[0];
-    fromCollateral.safeTransfer(address(mimoProxy), amounts[0]);
-    uint256 flashloanRepayAmount = amounts[0] + premiums[0];
+    // Use local variable amount
+    fromCollateral.safeTransfer(address(mimoProxy), amount);
+    uint256 flashloanRepayAmount = amount + premiums[0];

     IMIMOProxy(mimoProxy).execute(
       mimoRebalance,

contracts/proxy/MIMOProxy.sol

1. Optimize for loop, unchecked ++i

diff --git a/contracts/proxy/MIMOProxy.sol b/contracts/proxy/MIMOProxy.sol
index eca654c..2171d82 100644
--- a/contracts/proxy/MIMOProxy.sol
+++ b/contracts/proxy/MIMOProxy.sol
@@ -129,7 +129,9 @@ contract MIMOProxy is IMIMOProxy, Initializable, BoringBatchable {
       revert CustomErrors.NOT_OWNER(owner, msg.sender);
     }
     bytes[] memory results = new bytes[](data.length);
-    for (uint256 i = 0; i < targets.length; i++) {
+    // Optimize for loop
+    uint256 _len = targets.length;
+    for (uint256 i; i < _len;) {
       (bool success, bytes memory response) = targets[i].call(data[i]);
       if (!success) {
         if (response.length > 0) {
@@ -142,6 +144,9 @@ contract MIMOProxy is IMIMOProxy, Initializable, BoringBatchable {
         }
       }
       results[i] = response;
+      unchecked {
+        ++i;
+      }
     }
     return results;
   }