feat: add serialize() to plugin contracts

contracts/core/DefaultAccountFactoryV3.sol

@@ -67,6 +67,9 @@ contract DefaultAccountFactoryV3 is IDefaultAccountFactoryV3, Ownable {
         );
     }
 
+    /// @notice Empty state serialization
+    function serialize() external view override returns (bytes memory) {}
+
     /// @notice Provides a reusable credit account from the queue to the credit manager.
     ///         If there are no accounts that can be reused in the queue, deploys a new one.
     /// @return creditAccount Address of the provided credit account

contracts/interfaces/base/IAccountFactory.sol

@@ -4,11 +4,12 @@
 pragma solidity ^0.8.17;
 
 import {IVersion} from "./IVersion.sol";
+import {IStateSerializer} from "./IStateSerializer.sol";
 
 /// @title Account factory interface
 /// @notice Generic interface for an account factory that can be used by credit managers to create credit accounts
 /// @dev Account factories must have type `ACCOUNT_FACTORY::{POSTFIX}`
-interface IAccountFactory is IVersion {
+interface IAccountFactory is IVersion, IStateSerializer {
     /// @notice Takes `creditAccount` from the account factory
     /// @dev Parameters are kept for backward compatibility
     function takeCreditAccount(uint256, uint256) external returns (address creditAccount);

contracts/interfaces/base/IAdapter.sol

@@ -4,12 +4,13 @@
 pragma solidity ^0.8.17;
 
 import {IVersion} from "./IVersion.sol";
+import {IStateSerializer} from "./IStateSerializer.sol";
 
 /// @title Adapter interface
 /// @notice Generic interface for an adapter that can be used to interact with external protocols.
 ///         Adapters can be assumed to be non-malicious since they are developed by Gearbox DAO.
 /// @dev Adapters must have type `ADAPTER::{POSTFIX}`
-interface IAdapter is IVersion {
+interface IAdapter is IVersion, IStateSerializer {
     /// @notice Credit manager this adapter is connected to
     /// @dev Assumed to be an immutable state variable
     function creditManager() external view returns (address);

contracts/interfaces/base/IBot.sol

@@ -4,11 +4,12 @@
 pragma solidity ^0.8.17;
 
 import {IVersion} from "./IVersion.sol";
+import {IStateSerializer} from "./IStateSerializer.sol";
 
 /// @title Bot interface
 /// @notice Minimal interface contracts must conform to in order to be used as bots in Gearbox V3
 /// @dev Bots must have type `BOT::{POSTFIX}`
-interface IBot is IVersion {
+interface IBot is IVersion, IStateSerializer {
     /// @notice Mask of permissions required for bot operation, see `ICreditFacadeV3Multicall`
     function requiredPermissions() external view returns (uint192);
 }

contracts/interfaces/base/IDegenNFT.sol

@@ -4,11 +4,12 @@
 pragma solidity ^0.8.17;
 
 import {IVersion} from "./IVersion.sol";
+import {IStateSerializer} from "./IStateSerializer.sol";
 
 /// @title Degen NFT interface
 /// @notice Generic interface for a Degen NFT contract that can be used to restrict
 ///         non-whitelisted users from opening accounts through the credit facade
 /// @dev Degen NFTs must have type `DEGEN_NFT::{POSTFIX}`
-interface IDegenNFT is IVersion {
+interface IDegenNFT is IVersion, IStateSerializer {
     function burn(address from, uint256 amount) external;
 }

contracts/interfaces/base/IInterestRateModel.sol

@@ -4,11 +4,12 @@
 pragma solidity ^0.8.17;
 
 import {IVersion} from "./IVersion.sol";
+import {IStateSerializer} from "./IStateSerializer.sol";
 
 /// @title Interest rate model interface
 /// @notice Generic interface for an interest rate model contract that can be used in a pool
 /// @dev Interest rate models must have type `IRM::{POSTFIX}`
-interface IInterestRateModel is IVersion {
+interface IInterestRateModel is IVersion, IStateSerializer {
     /// @notice Calculates borrow rate based on utilization
     /// @dev The last parameter can be used to prevent borrowing above maximum allowed utilization
     /// @dev This function can be state-changing in case the IRM is stateful

contracts/interfaces/base/ILossPolicy.sol

@@ -4,14 +4,15 @@
 pragma solidity ^0.8.17;
 
 import {IVersion} from "./IVersion.sol";
+import {IStateSerializer} from "./IStateSerializer.sol";
 
 /// @title Loss policy interface
 /// @notice Generic interface for a loss policy contract that dictates conditions under which a liquidation with bad debt
 ///         can proceed. For example, it can restrict such liquidations to only be performed by whitelisted accounts that
 ///         can return premium to the DAO to recover part of the losses, or prevent liquidations of an asset whose market
 ///         price drops for a short period of time while its fundamental value doesn't change.
 /// @dev Loss policies must have type `LOSS_POLICY::{POSTFIX}`
-interface ILossPolicy is IVersion {
+interface ILossPolicy is IVersion, IStateSerializer {
     /// @notice Whether `creditAccount` can be liquidated with loss by `caller`, `data` is an optional field
     ///         that can be used to pass some off-chain data specific to the loss policy implementation
     function isLiquidatable(address creditAccount, address caller, bytes calldata data) external returns (bool);

contracts/interfaces/base/IPriceFeed.sol

@@ -4,11 +4,12 @@
 pragma solidity ^0.8.17;
 
 import {IVersion} from "./IVersion.sol";
+import {IStateSerializer} from "./IStateSerializer.sol";
 
 /// @title Price feed interface
 /// @notice Interface for Chainlink-like price feeds that can be plugged into Gearbox's price oracle
 /// @dev Price feeds must have type `PRICE_FEED::{POSTFIX}`
-interface IPriceFeed is IVersion {
+interface IPriceFeed is IVersion, IStateSerializer {
     /// @notice Whether price feed implements its own staleness and sanity checks
     function skipPriceCheck() external view returns (bool);
 

contracts/interfaces/base/IRateKeeper.sol

@@ -3,12 +3,13 @@
 // (c) Gearbox Foundation, 2024.
 pragma solidity ^0.8.17;
 
+import {IStateSerializer} from "./IStateSerializer.sol";
 import {IVersion} from "./IVersion.sol";
 
 /// @title Rate keeper interface
 /// @notice Generic interface for a contract that can provide rates to the quota keeper
 /// @dev Bots must have type `RATE_KEEPER::{POSTFIX}`
-interface IRateKeeper is IVersion {
+interface IRateKeeper is IVersion, IStateSerializer {
     /// @notice Pool rates are provided for
     function pool() external view returns (address);
 

contracts/interfaces/base/IStateSerializer.sol

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: MIT
+// Gearbox Protocol. Generalized leverage for DeFi protocols
+// (c) Gearbox Foundation, 2024.
+pragma solidity ^0.8.17;
+
+/// @title State serializer interface
+/// @notice Generic interface for a contract that can serialize its state into a bytes array
+interface IStateSerializer {
+    /// @notice Serializes the state of the contract into a bytes array `serializedData`
+    function serialize() external view returns (bytes memory serializedData);
+}

contracts/interfaces/base/IZapper.sol

@@ -3,13 +3,14 @@
 // (c) Gearbox Foundation, 2024.
 pragma solidity ^0.8.17;
 
+import {IStateSerializer} from "./IStateSerializer.sol";
 import {IVersion} from "./IVersion.sol";
 
 /// @title Zapper interface
 /// @notice Generic interface for a zapper contract contract that can be used to perform complex batched
 ///         deposits into a pool which can, e.g., involve native token wrapping or staking pool's shares
 /// @dev Zappers must have contract type `ZAPPER::{POSTFIX}`
-interface IZapper is IVersion {
+interface IZapper is IVersion, IStateSerializer {
     /// @notice Pool a zapper deposits into
     function pool() external view returns (address);
 

contracts/pool/GaugeV3.sol

@@ -2,7 +2,6 @@
 // Gearbox Protocol. Generalized leverage for DeFi protocols
 // (c) Gearbox Foundation, 2024.
 pragma solidity ^0.8.17;
-pragma abicoder v1;
 
 // INTERFACES
 import {IGaugeV3, QuotaRateParams, UserVotes} from "../interfaces/IGaugeV3.sol";
@@ -80,6 +79,17 @@ contract GaugeV3 is IGaugeV3, ACLTrait, SanityCheckTrait {
         emit SetFrozenEpoch(true); // U:[GA-1]
     }
 
+    /// @notice Returns serialized gauge state
+    function serialize() external view override returns (bytes memory) {
+        address[] memory tokens = _poolQuotaKeeper().quotedTokens();
+        uint256 numTokens = tokens.length;
+        QuotaRateParams[] memory tokenParams = new QuotaRateParams[](numTokens);
+        for (uint256 i; i < numTokens; ++i) {
+            tokenParams[i] = quotaRateParams[tokens[i]];
+        }
+        return abi.encode(voter, epochLastUpdate, epochFrozen, tokens, tokenParams); // U:[GA-1]
+    }
+
     /// @notice Updates the epoch and, unless frozen, rates in the quota keeper
     function updateEpoch() external override {
         _checkAndUpdateEpoch(); // U:[GA-14]

contracts/pool/LinearInterestRateModelV3.sol

@@ -81,6 +81,14 @@ contract LinearInterestRateModelV3 is ILinearInterestRateModelV3 {
         isBorrowingMoreU2Forbidden = _isBorrowingMoreU2Forbidden; // U:[LIM-1]
     }
 
+    /// @notice Returns serialized IRM parameters
+    function serialize() external view override returns (bytes memory) {
+        (uint16 U_1, uint16 U_2, uint16 R_base, uint16 R_slope1, uint16 R_slope2, uint16 R_slope3) =
+            getModelParameters();
+
+        return abi.encode(U_1, U_2, R_base, R_slope1, R_slope2, R_slope3, isBorrowingMoreU2Forbidden); // U:[LIM-1]
+    }
+
     /// @notice Returns the borrow rate calculated based on expected and available liquidity
     /// @param expectedLiquidity Expected liquidity in the pool
     /// @param availableLiquidity Available liquidity in the pool
@@ -135,7 +143,7 @@ contract LinearInterestRateModelV3 is ILinearInterestRateModelV3 {
 
     /// @notice Returns the model's parameters in basis points
     function getModelParameters()
-        external
+        public
         view
         override
         returns (uint16 U_1, uint16 U_2, uint16 R_base, uint16 R_slope1, uint16 R_slope2, uint16 R_slope3)

contracts/pool/TumblerV3.sol

@@ -62,6 +62,18 @@ contract TumblerV3 is ITumblerV3, ACLTrait, SanityCheckTrait {
         epochLength = epochLength_;
     }
 
+    /// @notice Returns serialized tumbler state
+    /// @custom:tests U:[TU-1]
+    function serialize() external view override returns (bytes memory) {
+        address[] memory tokens = _tokensSet.values();
+        uint256 numTokens = tokens.length;
+        uint16[] memory rates = new uint16[](numTokens);
+        for (uint256 i; i < numTokens; ++i) {
+            rates[i] = _rates[tokens[i]];
+        }
+        return abi.encode(epochLength, tokens, rates);
+    }
+
     /// @notice Whether `token` is added
     /// @custom:tests U:[TU-2]
     function isTokenAdded(address token) external view override returns (bool) {

contracts/test/mocks/core/AccountFactoryMock.sol

@@ -27,6 +27,8 @@ contract AccountFactoryMock is Test, IAccountFactory {
         version = _version;
     }
 
+    function serialize() external view override returns (bytes memory) {}
+
     /// @dev Provides a new credit account to a Credit Manager
     /// @return creditAccount Address of credit account
     function takeCreditAccount(uint256, uint256) external view override returns (address creditAccount) {

contracts/test/mocks/core/AdapterMock.sol

@@ -21,6 +21,8 @@ contract AdapterMock is IAdapter {
         targetContract = _targetContract;
     }
 
+    function serialize() external view override returns (bytes memory) {}
+
     function dumbCall() external returns (bool) {
         _execute(dumbCallData());
         return _return_useSafePrices;

contracts/test/mocks/core/BotMock.sol

@@ -10,6 +10,8 @@ contract BotMock is IBot {
     bytes32 public constant override contractType = "BOT::MOCK";
     uint192 public override requiredPermissions;
 
+    function serialize() external view override returns (bytes memory) {}
+
     function setRequiredPermissions(uint192 permissions) external {
         requiredPermissions = permissions;
     }

contracts/test/mocks/core/LossPolicyMock.sol

@@ -11,6 +11,8 @@ contract LossPolicyMock is ILossPolicy {
 
     bool public enabled = true;
 
+    function serialize() external view override returns (bytes memory) {}
+
     function isLiquidatable(address, address, bytes calldata) external view override returns (bool) {
         return enabled;
     }

contracts/test/mocks/oracles/PriceFeedMock.sol

@@ -39,6 +39,8 @@ contract PriceFeedMock is IPriceFeed {
         updatedAt = block.timestamp + 36500 days;
     }
 
+    function serialize() external view override returns (bytes memory) {}
+
     function setParams(uint80 _roundId, uint256 _startedAt, uint256 _updatedAt, uint80 _answerInRound) external {
         roundId = _roundId;
         startedAt = _startedAt;

contracts/test/mocks/token/DegenNFTMock.sol

@@ -17,6 +17,8 @@ contract DegenNFTMock is ERC721, IDegenNFT {
         minter = msg.sender;
     }
 
+    function serialize() external view override returns (bytes memory) {}
+
     function mint(address to, uint256 amount) external {
         uint256 balanceBefore = balanceOf(to);
         for (uint256 i; i < amount; ++i) {

contracts/test/mocks/token/PhantomTokenMock.sol

@@ -50,7 +50,7 @@ contract PhantomTokenMock is IPhantomToken, ERC20 {
 
 contract PhantomTokenWithdrawerMock is IAdapter, IPhantomTokenWithdrawer {
     uint256 public constant override version = 3_10;
-    bytes32 public constant override contractType = "PHANTOM_TOKEN_WITHDRAWER::MOCK";
+    bytes32 public constant override contractType = "ADAPTER::PT_WITHDRAWER_MOCK";
 
     address public immutable override creditManager;
     address public immutable override targetContract;
@@ -64,6 +64,8 @@ contract PhantomTokenWithdrawerMock is IAdapter, IPhantomTokenWithdrawer {
         (targetContract, depositedToken) = IPhantomToken(phantomToken_).getPhantomTokenInfo();
     }
 
+    function serialize() external view override returns (bytes memory) {}
+
     function withdrawPhantomToken(address, uint256 amount) external override returns (bool) {
         address creditAccount = ICreditManagerV3(creditManager).getActiveCreditAccountOrRevert();
         PhantomTokenMock(phantomToken).burn(creditAccount, amount);

contracts/test/unit/pool/GaugeV3.unit.t.sol

@@ -54,6 +54,9 @@ contract GauageV3UnitTest is TestHelper, IGaugeV3Events {
         poolMock = new PoolMock(address(addressProvider), underlying);
 
         poolQuotaKeeperMock = address(new GeneralMock());
+        vm.mockCall(
+            poolQuotaKeeperMock, abi.encodeCall(IPoolQuotaKeeperV3.quotedTokens, ()), abi.encode(new address[](0))
+        );
         poolMock.setPoolQuotaKeeper(poolQuotaKeeperMock);
 
         gearStakingMock = new GearStakingMock();
@@ -72,6 +75,11 @@ contract GauageV3UnitTest is TestHelper, IGaugeV3Events {
         assertEq(gauge.voter(), address(gearStakingMock), "Incorrect voter");
         assertEq(gauge.epochLastUpdate(), 900, "Incorrect epoch");
         assertTrue(gauge.epochFrozen(), "Epoch not frozen");
+        assertEq(
+            gauge.serialize(),
+            abi.encode(address(gearStakingMock), 900, true, new address[](0), new address[](0)),
+            "Incorrect serialized state"
+        );
 
         vm.expectRevert(ZeroAddressException.selector);
         new GaugeV3Harness(address(poolMock), address(0));

contracts/test/unit/pool/LinearInterestRateModelV3.unit.t.sol

@@ -42,6 +42,7 @@ contract LinearInterestRateModelV3UnitTest is TestHelper {
         assertEq(R_slope2, 3000);
         assertEq(R_slope3, 4000);
         assertTrue(irm.isBorrowingMoreU2Forbidden());
+        assertEq(irm.serialize(), abi.encode(8000, 9500, 1000, 2000, 3000, 4000, true), "Incorrect serialized state");
     }
 
     struct IncorrectParamCase {

contracts/test/unit/pool/TumblerV3.unit.t.sol

@@ -50,6 +50,9 @@ contract TumblerV3UnitTest is Test, ITumblerV3Events {
         assertEq(tumbler.poolQuotaKeeper(), address(poolQuotaKeeper), "Incorrect poolQuotaKeeper");
         assertEq(tumbler.epochLength(), 1 days, "Incorrect epochLength");
         assertEq(tumbler.getTokens().length, 0, "Non-empty quoted tokens set");
+        assertEq(
+            tumbler.serialize(), abi.encode(1 days, new address[](0), new address[](0)), "Incorrect serialized state"
+        );
     }
 
     /// @notice U:[TU-2]: `addToken` works as expected