Fix linter warnings in the Disctributor

contracts/CommonErrors.sol

@@ -27,3 +27,4 @@ error GroupIndexIsInvalid(uint256 index);
 error IsNotContract(address account);
 error NotEnoughFunds();
 error RoleRequired(bytes32 role);
+error TokensTransferFailure();

contracts/delegation/Distributor.sol

@@ -19,24 +19,21 @@
     along with SKALE Manager.  If not, see <https://www.gnu.org/licenses/>.
 */
 
-pragma solidity 0.8.17;
-
-import {IERC1820Registry} from "@openzeppelin/contracts/utils/introspection/IERC1820Registry.sol";
-import {IERC777Recipient} from "@openzeppelin/contracts/token/ERC777/IERC777Recipient.sol";
-import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
-
-import {IDistributor} from "@skalenetwork/skale-manager-interfaces/delegation/IDistributor.sol";
-import {
-    IValidatorService
-} from "@skalenetwork/skale-manager-interfaces/delegation/IValidatorService.sol";
-import {
-    IDelegationController
-} from "@skalenetwork/skale-manager-interfaces/delegation/IDelegationController.sol";
-import {ITimeHelpers} from "@skalenetwork/skale-manager-interfaces/delegation/ITimeHelpers.sol";
-
-import {Permissions} from "../Permissions.sol";
-import {ConstantsHolder} from "../ConstantsHolder.sol";
-import {MathUtils} from "../utils/MathUtils.sol";
+pragma solidity 0.8.26;
+
+import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import { IERC777Recipient } from "@openzeppelin/contracts/token/ERC777/IERC777Recipient.sol";
+import { IERC1820Registry } from "@openzeppelin/contracts/utils/introspection/IERC1820Registry.sol";
+import { IDelegationController }
+from "@skalenetwork/skale-manager-interfaces/delegation/IDelegationController.sol";
+import { IDistributor } from "@skalenetwork/skale-manager-interfaces/delegation/IDistributor.sol";
+import { ITimeHelpers } from "@skalenetwork/skale-manager-interfaces/delegation/ITimeHelpers.sol";
+import { IValidatorService }
+from "@skalenetwork/skale-manager-interfaces/delegation/IValidatorService.sol";
+import { IConstantsHolder } from "@skalenetwork/skale-manager-interfaces/IConstantsHolder.sol";
+import { TokensTransferFailure } from "./../CommonErrors.sol";
+import { Permissions } from "./../Permissions.sol";
+import { MathUtils } from "./../utils/MathUtils.sol";
 
 /**
  * @title Distributor
@@ -48,15 +45,17 @@
 
     IERC1820Registry private _erc1820;
 
-    // validatorId =>        month => token
-    mapping(uint256 => mapping(uint256 => uint256)) private _bountyPaid;
-    // validatorId =>        month => token
-    mapping(uint256 => mapping(uint256 => uint256)) private _feePaid;
-    //        holder =>   validatorId => month
-    mapping(address => mapping(uint256 => uint256))
-        private _firstUnwithdrawnMonth;
-    // validatorId => month
-    mapping(uint256 => uint256) private _firstUnwithdrawnMonthForValidator;
+    mapping(uint256 validatorId => mapping(uint256 month => uint256 amount)) private _bountyPaid;
+    mapping(uint256 validatorId => mapping(uint256 month => uint256 amount)) private _feePaid;
+    mapping(
+        address holder => mapping(uint256 validatorId => uint256 month)
+    ) private _firstUnwithdrawnMonth;
+    mapping(uint256 validatorId => uint256 month) private _firstUnwithdrawnMonthForValidator;
+
+    error BountyIsLocked();
+    error DataLengthIsIncorrect();
+    error FeeIsLocked();
+    error ReceiverIsIncorrect();
 
     function initialize(address contractsAddress) public override initializer {
         Permissions.initialize(contractsAddress);
@@ -91,18 +90,16 @@
         ITimeHelpers timeHelpers = ITimeHelpers(
             contractManager.getContract("TimeHelpers")
         );
-        ConstantsHolder constantsHolder = ConstantsHolder(
+        IConstantsHolder constantsHolder = IConstantsHolder(
             contractManager.getContract("ConstantsHolder")
         );
 
-        require(
-            block.timestamp >=
-                timeHelpers.addMonths(
+        if (block.timestamp < timeHelpers.addMonths(
                     constantsHolder.launchTimestamp(),
                     constantsHolder.BOUNTY_LOCKUP_MONTHS()
-                ),
-            "Bounty is locked"
-        );
+        )) {
+            revert BountyIsLocked();
+        }
 
         uint256 bounty;
         uint256 endMonth;
@@ -114,7 +111,9 @@
         _firstUnwithdrawnMonth[msg.sender][validatorId] = endMonth;
 
         IERC20 skaleToken = IERC20(contractManager.getContract("SkaleToken"));
-        require(skaleToken.transfer(to, bounty), "Failed to transfer tokens");
+        if(!skaleToken.transfer(to, bounty)) {
+            revert TokensTransferFailure();
+        }
 
         emit WithdrawBounty(msg.sender, validatorId, to, bounty);
     }
@@ -137,18 +136,17 @@
         ITimeHelpers timeHelpers = ITimeHelpers(
             contractManager.getContract("TimeHelpers")
         );
-        ConstantsHolder constantsHolder = ConstantsHolder(
+        IConstantsHolder constantsHolder = IConstantsHolder(
             contractManager.getContract("ConstantsHolder")
         );
 
-        require(
-            block.timestamp >=
-                timeHelpers.addMonths(
-                    constantsHolder.launchTimestamp(),
-                    constantsHolder.BOUNTY_LOCKUP_MONTHS()
-                ),
-            "Fee is locked"
-        );
+        if (block.timestamp < timeHelpers.addMonths(
+            constantsHolder.launchTimestamp(),
+            constantsHolder.BOUNTY_LOCKUP_MONTHS()
+        )) {
+            revert FeeIsLocked();
+        }
+
         // check Validator Exist inside getValidatorId
         uint256 validatorId = validatorService.getValidatorId(msg.sender);
 
@@ -158,7 +156,9 @@
 
         _firstUnwithdrawnMonthForValidator[validatorId] = endMonth;
 
-        require(skaleToken.transfer(to, fee), "Failed to transfer tokens");
+        if(!skaleToken.transfer(to, fee)) {
+            revert TokensTransferFailure();
+        }
 
         emit WithdrawFee(validatorId, to, fee);
     }
@@ -171,8 +171,12 @@
         bytes calldata userData,
         bytes calldata
     ) external override allow("SkaleToken") {
-        require(to == address(this), "Receiver is incorrect");
-        require(userData.length == 32, "Data length is incorrect");
+        if (to != address(this)) {
+            revert ReceiverIsIncorrect();
+        }
+        if (userData.length != 32) {
+            revert DataLengthIsIncorrect();
+        }
         uint256 validatorId = abi.decode(userData, (uint256));
         _distributeBounty(amount, validatorId);
     }

contracts/test/SkaleTokenInternalTester.sol

@@ -21,6 +21,7 @@
 
 pragma solidity 0.8.17;
 
+import { IERC777Recipient } from "@openzeppelin/contracts/token/ERC777/IERC777Recipient.sol";
 import { SkaleToken } from "../SkaleToken.sol";
 import { ISkaleTokenInterfaceTester } from "./interfaces/ISkaleTokenInterfaceTester.sol";
 
@@ -32,6 +33,30 @@ contract SkaleTokenInternalTester is SkaleToken, ISkaleTokenInterfaceTester {
     // solhint-disable-next-line no-empty-blocks
     { }
 
+    function callTokensReceived(
+        address implementer,
+        address operator,
+        address from,
+        address to,
+        uint256 amount,
+        bytes memory userData,
+        bytes memory operatorData
+    )
+    external
+    override
+    {
+        if (implementer != address(0)) {
+            IERC777Recipient(implementer).tokensReceived({
+                operator: operator,
+                from: from,
+                to: to,
+                amount: amount,
+                userData: userData,
+                operatorData: operatorData
+            });
+        }
+    }
+
     function getMsgData() external view override returns (bytes memory msgData) {
         return _msgData();
     }

contracts/test/interfaces/ISkaleTokenInterfaceTester.sol

@@ -23,5 +23,15 @@ pragma solidity 0.8.17;
 
 
 interface ISkaleTokenInterfaceTester {
+    function callTokensReceived(
+        address implementer,
+        address operator,
+        address from,
+        address to,
+        uint256 amount,
+        bytes memory userData,
+        bytes memory operatorData
+    )
+    external;
     function getMsgData() external view returns (bytes memory msgData);
 }

contracts/utils/MathUtils.sol

@@ -19,7 +19,7 @@
     along with SKALE Manager.  If not, see <https://www.gnu.org/licenses/>.
 */
 
-pragma solidity 0.8.17;
+pragma solidity ^0.8.17;
 
 
 library MathUtils {

package.json

@@ -48,7 +48,7 @@
     "@skalenetwork/ima-interfaces": "2.0.0-develop.67",
     "@skalenetwork/marionette-interfaces": "^0.0.0-main.6",
     "@skalenetwork/paymaster-interfaces": "^1.0.0-main.10",
-    "@skalenetwork/skale-manager-interfaces": "3.2.0-develop.0",
+    "@skalenetwork/skale-manager-interfaces": "3.2.0-develop.1",
     "@skalenetwork/upgrade-tools": "^3.0.0-linter.42",
     "@typechain/hardhat": "^9.1.0",
     "dotenv": "^16.3.1",

test/delegation/Delegation.ts

@@ -234,6 +234,30 @@ describe("Delegation", () => {
             .should.be.eventually.rejectedWith("Limit of validators is reached");
     });
 
+    it("should revert on incorrect transfers", async () => {
+        const skaleTokenInternalTesterFactory = await ethers.getContractFactory("SkaleTokenInternalTester");
+        const skaleTokenInternalTester = await skaleTokenInternalTesterFactory.deploy(contractManager, []);
+        await contractManager.setContractsAddress("SkaleToken", skaleTokenInternalTester);
+        await skaleTokenInternalTester.callTokensReceived(
+            distributor,
+            ethers.ZeroAddress,
+            holder1,
+            holder2, // Receiver always needs to be the Distributor
+            5,
+            "0x",
+            "0x"
+        ).should.be.revertedWithCustomError(distributor, "ReceiverIsIncorrect");
+        await skaleTokenInternalTester.callTokensReceived(
+            distributor,
+            ethers.ZeroAddress,
+            holder1,
+            distributor,
+            5,
+            "0x", // Data length always must be 32 bytes
+            "0x"
+        ).should.be.revertedWithCustomError(distributor, "DataLengthIsIncorrect");
+    })
+
     describe("when holders have tokens and validator is registered", () => {
         let validatorId: bigint;
         fastBeforeEach(async () => {
@@ -599,9 +623,9 @@ describe("Delegation", () => {
                     validatorId))[0].should.be.equal(31);
 
                 await distributor.connect(validator).withdrawFee(bountyAddress.address)
-                    .should.be.eventually.rejectedWith("Fee is locked");
+                    .should.be.revertedWithCustomError(distributor, "FeeIsLocked");
                 await distributor.connect(holder1).withdrawBounty(validatorId, bountyAddress.address)
-                    .should.be.eventually.rejectedWith("Bounty is locked");
+                    .should.be.revertedWithCustomError(distributor, "BountyIsLocked");
 
                 await nextMonth(contractManager, 3);
 

yarn.lock

@@ -1741,10 +1741,10 @@
   dependencies:
     axios "^1.4.0"
 
-"@skalenetwork/[email protected].0":
-  version "3.2.0-develop.0"
-  resolved "https://registry.yarnpkg.com/@skalenetwork/skale-manager-interfaces/-/skale-manager-interfaces-3.2.0-develop.0.tgz#01e64eeabf2b14b320074eb588b557bbd33bab39"
-  integrity sha512-f++aLtSwjLJgAb3dHAm/SMHvx2a0L3uWwF7aam1wCtB6YZrFLR3flzlH3Ms3JlLZtfl5iE7VBmsuidhAqpbfpw==
+"@skalenetwork/[email protected].1":
+  version "3.2.0-develop.1"
+  resolved "https://registry.yarnpkg.com/@skalenetwork/skale-manager-interfaces/-/skale-manager-interfaces-3.2.0-develop.1.tgz#ec4ad8f2b4d12a5ff8d03763674a214be61c773d"
+  integrity sha512-ACugcMzRFa7nbHcJ8mZE/J60M8GW9gJKsqmQYEYoElzZBMTCstEeWy1ff6Vj7kcv+xESHPPhTzJ34ieMCL3pFg==
 
 "@skalenetwork/skale-manager-interfaces@^3.2.0-develop.0":
   version "3.2.0-paymaster.2"