Upgradable contracts implementation

abi/contracts/Bridge/Bridge.abi.json

@@ -1,24 +1,13 @@
 [
   {
-    "inputs": [
-      {
-        "internalType": "address[]",
-        "name": "board",
-        "type": "address[]"
-      },
-      {
-        "internalType": "uint256",
-        "name": "initialQuorum",
-        "type": "uint256"
-      },
-      {
-        "internalType": "contract ERC20Safe",
-        "name": "erc20Safe",
-        "type": "address"
-      }
-    ],
-    "stateMutability": "nonpayable",
-    "type": "constructor"
+    "inputs": [],
+    "name": "InvalidInitialization",
+    "type": "error"
+  },
+  {
+    "inputs": [],
+    "name": "NotInitializing",
+    "type": "error"
   },
   {
     "anonymous": false,
@@ -39,6 +28,19 @@
     "name": "AdminRoleTransferred",
     "type": "event"
   },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": false,
+        "internalType": "uint64",
+        "name": "version",
+        "type": "uint64"
+      }
+    ],
+    "name": "Initialized",
+    "type": "event"
+  },
   {
     "anonymous": false,
     "inputs": [
@@ -389,6 +391,29 @@
     "stateMutability": "view",
     "type": "function"
   },
+  {
+    "inputs": [
+      {
+        "internalType": "address[]",
+        "name": "board",
+        "type": "address[]"
+      },
+      {
+        "internalType": "uint256",
+        "name": "initialQuorum",
+        "type": "uint256"
+      },
+      {
+        "internalType": "contract ERC20Safe",
+        "name": "erc20Safe",
+        "type": "address"
+      }
+    ],
+    "name": "initialize",
+    "outputs": [],
+    "stateMutability": "nonpayable",
+    "type": "function"
+  },
   {
     "inputs": [
       {

abi/contracts/ERC20Safe/ERC20Safe.abi.json

@@ -26,6 +26,16 @@
     "name": "FailedInnerCall",
     "type": "error"
   },
+  {
+    "inputs": [],
+    "name": "InvalidInitialization",
+    "type": "error"
+  },
+  {
+    "inputs": [],
+    "name": "NotInitializing",
+    "type": "error"
+  },
   {
     "inputs": [
       {
@@ -119,6 +129,19 @@
     "name": "ERC20SCDeposit",
     "type": "event"
   },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": false,
+        "internalType": "uint64",
+        "name": "version",
+        "type": "uint64"
+      }
+    ],
+    "name": "Initialized",
+    "type": "event"
+  },
   {
     "anonymous": false,
     "inputs": [
@@ -534,6 +557,13 @@
     "stateMutability": "nonpayable",
     "type": "function"
   },
+  {
+    "inputs": [],
+    "name": "initialize",
+    "outputs": [],
+    "stateMutability": "nonpayable",
+    "type": "function"
+  },
   {
     "inputs": [],
     "name": "isAnyBatchInProgress",

abi/contracts/MintBurnERC20/MintBurnERC20.abi.json

@@ -1,25 +1,4 @@
 [
-  {
-    "inputs": [
-      {
-        "internalType": "string",
-        "name": "name",
-        "type": "string"
-      },
-      {
-        "internalType": "string",
-        "name": "symbol",
-        "type": "string"
-      },
-      {
-        "internalType": "uint8",
-        "name": "providedNumDecimals",
-        "type": "uint8"
-      }
-    ],
-    "stateMutability": "nonpayable",
-    "type": "constructor"
-  },
   {
     "inputs": [],
     "name": "AccessControlBadConfirmation",
@@ -138,6 +117,16 @@
     "name": "ERC20InvalidSpender",
     "type": "error"
   },
+  {
+    "inputs": [],
+    "name": "InvalidInitialization",
+    "type": "error"
+  },
+  {
+    "inputs": [],
+    "name": "NotInitializing",
+    "type": "error"
+  },
   {
     "anonymous": false,
     "inputs": [
@@ -163,6 +152,19 @@
     "name": "Approval",
     "type": "event"
   },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": false,
+        "internalType": "uint64",
+        "name": "version",
+        "type": "uint64"
+      }
+    ],
+    "name": "Initialized",
+    "type": "event"
+  },
   {
     "anonymous": false,
     "inputs": [
@@ -461,6 +463,29 @@
     "stateMutability": "view",
     "type": "function"
   },
+  {
+    "inputs": [
+      {
+        "internalType": "string",
+        "name": "name",
+        "type": "string"
+      },
+      {
+        "internalType": "string",
+        "name": "symbol",
+        "type": "string"
+      },
+      {
+        "internalType": "uint8",
+        "name": "providedNumDecimals",
+        "type": "uint8"
+      }
+    ],
+    "name": "initialize",
+    "outputs": [],
+    "stateMutability": "nonpayable",
+    "type": "function"
+  },
   {
     "inputs": [
       {

contracts/Bridge.sol

@@ -2,6 +2,8 @@
 
 pragma solidity ^0.8.20;
 
+import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
+
 import "./SharedStructs.sol";
 import "./ERC20Safe.sol";
 import "./access/RelayerRole.sol";
@@ -22,7 +24,7 @@ In order to use it:
 @dev This contract mimics a multisign contract by sending the signatures from all
 relayers with the execute call, in order to save gas.
  */
-contract Bridge is RelayerRole, Pausable {
+contract Bridge is Initializable, RelayerRole, Pausable {
     /*============================ EVENTS ============================*/
     event QuorumChanged(uint256 quorum);
 
@@ -31,10 +33,10 @@ contract Bridge is RelayerRole, Pausable {
     string private constant executeTransferAction = "ExecuteBatchedTransfer";
     string private constant prefix = "\x19Ethereum Signed Message:\n32";
     uint256 private constant minimumQuorum = 3;
-    uint256 public batchSettleBlockCount = 40;
+    uint256 public batchSettleBlockCount;
 
     uint256 public quorum;
-    ERC20Safe internal immutable safe;
+    ERC20Safe internal safe;
 
     mapping(uint256 => bool) public executedBatches;
     mapping(uint256 => CrossTransferStatus) public crossTransferStatuses;
@@ -48,14 +50,21 @@ contract Bridge is RelayerRole, Pausable {
      *   - add/remove relayers
      *   - add/remove tokens that can be bridged
      */
-    constructor(address[] memory board, uint256 initialQuorum, ERC20Safe erc20Safe) {
+    function initialize(address[] memory board, uint256 initialQuorum, ERC20Safe erc20Safe) public virtual initializer {
+        __RelayerRole_init();
+        __Bridge__init_unchained(board, initialQuorum, erc20Safe);
+    }
+
+    function __Bridge__init_unchained(address[] memory board, uint256 initialQuorum, ERC20Safe erc20Safe) internal onlyInitializing {
         require(initialQuorum >= minimumQuorum, "Quorum is too low.");
         require(board.length >= initialQuorum, "The board should be at least the quorum size.");
 
         _addRelayers(board);
 
         quorum = initialQuorum;
         safe = erc20Safe;
+
+        batchSettleBlockCount = 40;
     }
 
     /**

contracts/ERC20Safe.sol

@@ -3,12 +3,13 @@
 pragma solidity ^0.8.20;
 
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
-import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
+import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
+import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20BurnableUpgradeable.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import "./SharedStructs.sol";
 import "./access/BridgeRole.sol";
-import "./lib/BoolTokenTransfer.sol";
 import "./lib/Pausable.sol";
+import "./lib/BoolTokenTransfer.sol";
 
 interface IMintableERC20 is IERC20 {
     function mint(address to, uint256 amount) external;
@@ -27,16 +28,16 @@ In order to use it:
 @dev The deposits are requested by the Bridge, and in order to save gas spent by the relayers
 they will be batched either by time (batchTimeLimit) or size (batchSize).
  */
-contract ERC20Safe is BridgeRole, Pausable {
+contract ERC20Safe is Initializable, BridgeRole, Pausable {
     using SafeERC20 for IERC20;
     using BoolTokenTransfer for IERC20;
 
     uint64 public batchesCount;
     uint64 public depositsCount;
-    uint16 public batchSize = 10;
+    uint16 public batchSize;
     uint16 private constant maxBatchSize = 100;
-    uint8 public batchBlockLimit = 40;
-    uint8 public batchSettleLimit = 40;
+    uint8 public batchBlockLimit;
+    uint8 public batchSettleLimit;
 
     mapping(uint256 => Batch) public batches;
     mapping(address => bool) public whitelistedTokens;
@@ -52,6 +53,18 @@ contract ERC20Safe is BridgeRole, Pausable {
     event ERC20Deposit(uint112 batchId, uint112 depositNonce);
     event ERC20SCDeposit(uint112 indexed batchId, uint112 depositNonce, bytes callData);
 
+    function initialize() public initializer {
+        __BridgeRole_init();
+        __Pausable_init();
+        __ERC20Safe__init_unchained();
+    }
+
+    function __ERC20Safe__init_unchained() internal onlyInitializing {
+        batchSize = 10;
+        batchBlockLimit = 40;
+        batchSettleLimit = 40;
+    }
+
     /**
       @notice Whitelist a token. Only whitelisted tokens can be bridged.
       @param token Address of the ERC20 token that will be whitelisted

contracts/MintBurnERC20.sol

@@ -2,18 +2,26 @@
 
 pragma solidity ^0.8.20;
 
-import { AccessControl } from "@openzeppelin/contracts/access/AccessControl.sol";
-import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
-import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
+import { AccessControlUpgradeable } from "@openzeppelin/contracts-upgradeable/access/AccessControlUpgradeable.sol";
+import { ERC20Upgradeable } from "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20BurnableUpgradeable.sol";
 
-contract MintBurnERC20 is ERC20, AccessControl, ERC20Burnable {
+contract MintBurnERC20 is ERC20Upgradeable, AccessControlUpgradeable, ERC20BurnableUpgradeable {
     // Create a new role identifier for the minter role
     bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
     uint8 private numDecimals;
 
     error CallerNotMinter(address caller);
 
-    constructor(string memory name, string memory symbol, uint8 providedNumDecimals) ERC20(name, symbol) {
+    function initialize(string memory name, string memory symbol, uint8 providedNumDecimals) public initializer {
+        __ERC20_init(name, symbol);
+        __AccessControl_init();
+        __ERC20Burnable_init();
+
+        __MintBurnERC20__init_unchained(providedNumDecimals);
+    }
+
+    function __MintBurnERC20__init_unchained(uint8 providedNumDecimals) internal onlyInitializing {
         numDecimals = providedNumDecimals;
         _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);
     }

contracts/access/AdminRole.sol

@@ -2,6 +2,8 @@
 
 pragma solidity ^0.8.20;
 
+import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
+
 /**
  * @dev Contract module which provides a basic access control mechanism, where
  * there is an account (an admin) that can be granted exclusive access to
@@ -14,15 +16,19 @@ pragma solidity ^0.8.20;
  * `onlyAdmin`, which can be applied to your functions to restrict their use to
  * the admin.
  */
-abstract contract AdminRole {
+abstract contract AdminRole is Initializable {
     address private _admin;
 
     event AdminRoleTransferred(address indexed previousAdmin, address indexed newAdmin);
 
     /**
      * @dev Initializes the contract setting the deployer as the initial admin.
      */
-    constructor() {
+    function __AdminRole_init() internal onlyInitializing {
+        __AdminRole_init_unchained();
+    }
+
+    function __AdminRole_init_unchained() internal onlyInitializing {
         address msgSender = msg.sender;
         _admin = msgSender;
         emit AdminRoleTransferred(address(0), msgSender);