feat: create IVersion interface

.eslintrc.json

@@ -26,7 +26,7 @@
     "@stylistic/function-paren-newline": ["warn", "multiline-arguments"],
     "@stylistic/indent": ["warn", 2],
     "@stylistic/indent-binary-ops": ["warn", 2],
-    "@stylistic/linebreak-style": ["warn", "unix"],
+    "@stylistic/linebreak-style": "off",
     "@stylistic/lines-around-comment": ["warn", {"beforeBlockComment": false}],
     "@stylistic/max-len": ["warn", {"code": 120, "tabWidth": 2}],
     "@stylistic/member-delimiter-style": [

contracts/Cashier.sol

@@ -21,6 +21,7 @@ import { ICashierHookable } from "./interfaces/ICashierHookable.sol";
 import { IERC20Mintable } from "./interfaces/IERC20Mintable.sol";
 
 import { CashierStorage } from "./CashierStorage.sol";
+import { Versionable } from "./Versionable.sol";
 
 /**
  * @title Cashier contract
@@ -34,7 +35,8 @@ contract Cashier is
     RescuableUpgradeable,
     UUPSUpgradeable,
     ICashier,
-    ICashierHookable
+    ICashierHookable,
+    Versionable
 {
     using SafeERC20 for IERC20;
     using EnumerableSet for EnumerableSet.Bytes32Set;

contracts/CashierShard.sol

@@ -9,13 +9,14 @@ import { ICashierShard } from "./interfaces/ICashierShard.sol";
 import { ICashierShardPrimary } from "./interfaces/ICashierShard.sol";
 import { ICashierShardConfiguration } from "./interfaces/ICashierShard.sol";
 import { CashierShardStorage } from "./CashierShardStorage.sol";
+import { Versionable } from "./Versionable.sol";
 
 /**
  * @title CashierShard contract
  * @author CloudWalk Inc. (See https://www.cloudwalk.io)
  * @dev The contract responsible for storing sharded cash-in and cash-out operations.
  */
-contract CashierShard is CashierShardStorage, OwnableUpgradeable, UUPSUpgradeable, ICashierShard {
+contract CashierShard is CashierShardStorage, OwnableUpgradeable, UUPSUpgradeable, ICashierShard, Versionable {
     // ------------------ Initializers ---------------------------- //
 
     /**

contracts/Versionable.sol

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "./interfaces/IVersion.sol";
+
+/**
+ * @title Versionable contract
+ * @author CloudWalk Inc. (See https://cloudwalk.io)
+ * @dev Defines the contract version.
+ */
+abstract contract Versionable is IVersion {
+    // ------------------ Pure functions -------------------------- //
+
+    /**
+     * @inheritdoc IVersion
+     */
+    function $__VERSION() external pure returns (Version memory) {
+        return Version(4, 0, 0);
+    }
+}

contracts/interfaces/ICashier.sol

@@ -492,4 +492,6 @@ interface ICashier is
     ICashierErrors, // Tools: this comment prevents Prettier from formatting into a single line.
     ICashierPrimary,
     ICashierConfiguration
-{}
+{
+
+}

contracts/interfaces/ICashierShard.sol

@@ -22,6 +22,7 @@ interface ICashierShardErrors {
     /// @dev Thrown if the caller is not an admin.
     error CashierShard_Unauthorized();
 }
+
 /**
  * @title ICashierShardPrimary interface
  * @author CloudWalk Inc. (See https://www.cloudwalk.io)
@@ -219,4 +220,6 @@ interface ICashierShard is
     ICashierShardErrors, // Tools: this comment prevents Prettier from formatting into a single line.
     ICashierShardPrimary,
     ICashierShardConfiguration
-{}
+{
+
+}

contracts/interfaces/IVersion.sol

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+/**
+ * @title IVersion interface
+ * @author CloudWalk Inc. (See https://cloudwalk.io)
+ * @dev Defines the function to get the contract version.
+ */
+interface IVersion {
+    /**
+     * @dev The struct for the contract version.
+     */
+    struct Version {
+        uint8 major; // -- The major version of contract
+        uint8 minor; // -- The minor version of contract
+        uint8 patch; // -- The patch version of contract
+    }
+
+    /**
+     * @dev Returns the version of the contract.
+     */
+    function $__VERSION() external pure returns (Version memory);
+}

test/CashierSharded.test.ts

@@ -71,6 +71,14 @@ interface HookConfig {
   [key: string]: number | string; // Indexing signature to ensure that fields are iterated over in a key-value style
 }
 
+interface Version {
+  major: number;
+  minor: number;
+  patch: number;
+
+  [key: string]: number; // Indexing signature to ensure that fields are iterated over in a key-value style
+}
+
 function checkCashOutEquality(
   actualOnChainCashOut: Record<string, unknown>,
   expectedCashOut: TestCashOut,
@@ -200,6 +208,12 @@ describe("Contracts 'Cashier' and `CashierShard`", async () => {
     (1 << HookIndex.CashOutReversalBefore) +
     (1 << HookIndex.CashOutReversalAfter);
 
+  const EXPECTED_VERSION: Version = {
+    major: 4,
+    minor: 0,
+    patch: 0
+  };
+
   // Errors of the lib contracts
   const REVERT_ERROR_IF_CONTRACT_INITIALIZATION_IS_INVALID = "InvalidInitialization";
   const REVERT_ERROR_IF_CONTRACT_IS_PAUSED = "EnforcedPause";
@@ -2520,6 +2534,16 @@ describe("Contracts 'Cashier' and `CashierShard`", async () => {
     });
   });
 
+  describe("Function '$__VERSION()'", async () => {
+    it("Returns expected values", async () => {
+      const { cashierRoot, cashierShards } = await setUpFixture(deployAndConfigureContracts);
+      const cashierRootVersion = await cashierRoot.$__VERSION();
+      const cashierShardVersion = await cashierShards[0].$__VERSION();
+      checkEquality(cashierRootVersion, EXPECTED_VERSION);
+      checkEquality(cashierShardVersion, EXPECTED_VERSION);
+    });
+  });
+
   describe("Scenarios with configured hooks", async () => {
     async function checkHookEvents(fixture: Fixture, props: {
       tx: TransactionResponse;