custom error message

contracts/OperatorRewardsCollector.sol

@@ -49,7 +49,9 @@ contract OperatorRewardsCollector is IOperatorRewardsCollector, AccessControlUpg
         // If the liquidation is not repaid, check balance and then proceed with repayment
         if (!operatorLiquidation.isRepaid) {
             // Ensure that the balance is sufficient
-            require(balances[operator] >= operatorLiquidation.totalAmountInEth, 'Insufficient balance');
+            if (balances[operator] < operatorLiquidation.totalAmountInEth) {
+                revert InsufficientBalance();
+            }
 
             // Repay the liquidation and update the operator's balance
             sdUtilityPool.repayLiquidation(operator);

contracts/SDIncentiveController.sol

@@ -39,6 +39,7 @@ contract SDIncentiveController is ISDIncentiveController, AccessControlUpgradeab
     /// @param _staderConfig The address of the Stader configuration contract.
     function initialize(address _admin, address _staderConfig) external initializer {
         UtilLib.checkNonZeroAddress(_staderConfig);
+        UtilLib.checkNonZeroAddress(_admin);
 
         staderConfig = IStaderConfig(_staderConfig);
 
@@ -55,7 +56,9 @@ contract SDIncentiveController is ISDIncentiveController, AccessControlUpgradeab
         updateReward(account);
 
         uint256 reward = rewards[account];
-        require(reward > 0, 'No rewards to claim.');
+        if (reward == 0) {
+            revert NoRewardsToClaim();
+        }
         rewards[account] = 0;
         IERC20(staderConfig.getStaderToken()).transfer(account, reward);
 

contracts/SDUtilityPool.sol

@@ -356,7 +356,9 @@ contract SDUtilityPool is ISDUtilityPool, AccessControlUpgradeable, PausableUpgr
     function liquidationCall(address account) external override {
         UserData memory userData = getUserData(account);
 
-        require(userData.healthFactor <= 1, 'Not liquidatable');
+        if (userData.healthFactor > 1) {
+            revert NotLiquidatable();
+        }
 
         accrueFee();
         utilizerData[account].utilizeIndex = utilizeIndex;
@@ -395,9 +397,15 @@ contract SDUtilityPool is ISDUtilityPool, AccessControlUpgradeable, PausableUpgr
     function claimLiquidation(uint256 index) external override {
         OperatorLiquidation storage liquidation = liquidations[index];
 
-        require(liquidation.isRepaid == true, 'Not claimable');
-        require(liquidation.isClaimed == false, 'Already claimed');
-        require(liquidation.liquidator == msg.sender, 'Not liquidator');
+        if (!liquidation.isRepaid) {
+            revert NotClaimable();
+        }
+        if (liquidation.isClaimed) {
+            revert AlreadyClaimed();
+        }
+        if (liquidation.liquidator != msg.sender) {
+            revert NotLiquidator();
+        }
 
         liquidation.isClaimed = true;
 

contracts/interfaces/IOperatorRewardsCollector.sol

@@ -2,6 +2,8 @@
 pragma solidity 0.8.16;
 
 interface IOperatorRewardsCollector {
+    //errors
+    error InsufficientBalance();
     // events
     event UpdatedStaderConfig(address indexed staderConfig);
     event Claimed(address indexed receiver, uint256 amount);

contracts/interfaces/ISDIncentiveController.sol

@@ -4,6 +4,8 @@ pragma solidity 0.8.16;
 import './IStaderConfig.sol';
 
 interface ISDIncentiveController {
+    //errors
+    error NoRewardsToClaim();
     // events
     event UpdatedStaderConfig(address staderConfig);
 

contracts/interfaces/ISDUtilityPool.sol

@@ -25,6 +25,10 @@ struct OperatorLiquidation {
 
 interface ISDUtilityPool {
     error InvalidInput();
+    error NotClaimable();
+    error AlreadyClaimed();
+    error NotLiquidator();
+    error NotLiquidatable();
     error SDTransferFailed();
     error CannotFindRequestId();
     error SDUtilizeLimitReached();