Move permitAndStake and permitAndStakeMore into an extension cont…

…ract

src/GovernanceStaker.sol

@@ -380,32 +380,6 @@ abstract contract GovernanceStaker is INotifiableRewardReceiver, Multicall, EIP7
     _depositId = _stake(msg.sender, _amount, _delegatee, _beneficiary);
   }
 
-  /// @notice Method to stake tokens to a new deposit. Before the staking operation occurs, a
-  /// signature is passed to the token contract's permit method to spend the would-be staked amount
-  /// of the token.
-  /// @param _amount Quantity of the staking token to stake.
-  /// @param _delegatee Address to assign the governance voting weight of the staked tokens.
-  /// @param _beneficiary Address that will accrue rewards for this stake.
-  /// @param _deadline The timestamp after which the permit signature should expire.
-  /// @param _v ECDSA signature component: Parity of the `y` coordinate of point `R`
-  /// @param _r ECDSA signature component: x-coordinate of `R`
-  /// @param _s ECDSA signature component: `s` value of the signature
-  /// @return _depositId Unique identifier for this deposit.
-  /// @dev Neither the delegatee nor the beneficiary may be the zero address. The deposit will be
-  /// owned by the message sender.
-  function permitAndStake(
-    uint256 _amount,
-    address _delegatee,
-    address _beneficiary,
-    uint256 _deadline,
-    uint8 _v,
-    bytes32 _r,
-    bytes32 _s
-  ) external virtual returns (DepositIdentifier _depositId) {
-    try STAKE_TOKEN.permit(msg.sender, address(this), _amount, _deadline, _v, _r, _s) {} catch {}
-    _depositId = _stake(msg.sender, _amount, _delegatee, _beneficiary);
-  }
-
   /// @notice Stake tokens to a new deposit on behalf of a user, using a signature to validate the
   /// user's intent. The caller must pre-approve the staking contract to spend at least the
   /// would-be staked amount of the token.
@@ -458,32 +432,6 @@ abstract contract GovernanceStaker is INotifiableRewardReceiver, Multicall, EIP7
     _stakeMore(deposit, _depositId, _amount);
   }
 
-  /// @notice Add more staking tokens to an existing deposit. A staker should call this method when
-  /// they have an existing deposit, and wish to stake more while retaining the same delegatee and
-  /// beneficiary. Before the staking operation occurs, a signature is passed to the token
-  /// contract's permit method to spend the would-be staked amount of the token.
-  /// @param _depositId Unique identifier of the deposit to which stake will be added.
-  /// @param _amount Quantity of stake to be added.
-  /// @param _deadline The timestamp after which the permit signature should expire.
-  /// @param _v ECDSA signature component: Parity of the `y` coordinate of point `R`
-  /// @param _r ECDSA signature component: x-coordinate of `R`
-  /// @param _s ECDSA signature component: `s` value of the signature
-  /// @dev The message sender must be the owner of the deposit.
-  function permitAndStakeMore(
-    DepositIdentifier _depositId,
-    uint256 _amount,
-    uint256 _deadline,
-    uint8 _v,
-    bytes32 _r,
-    bytes32 _s
-  ) external virtual {
-    Deposit storage deposit = deposits[_depositId];
-    _revertIfNotDepositOwner(deposit, msg.sender);
-
-    try STAKE_TOKEN.permit(msg.sender, address(this), _amount, _deadline, _v, _r, _s) {} catch {}
-    _stakeMore(deposit, _depositId, _amount);
-  }
-
   /// @notice Add more staking tokens to an existing deposit on behalf of a user, using a signature
   /// to validate the user's intent. A staker should call this method when they have an existing
   /// deposit, and wish to stake more while retaining the same delegatee and beneficiary.

src/extensions/GovernanceStakerPermitAndStake.sol

@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+pragma solidity ^0.8.23;
+
+import {GovernanceStaker} from "src/GovernanceStaker.sol";
+
+/// @title GovernanceStakerPermitAndStake
+/// @author [ScopeLift](https://scopelift.co)
+/// @notice This contract extension adds permit functionality to the GovernanceStaker base contract,
+/// allowing token approvals to happen via signatures rather than requiring a separate transaction.
+/// The permit functionality is used in conjunction with staking operations, improving UX by
+/// enabling users to approve and stake tokens in a single transaction.
+/// Note that this extension requires the stake token to support EIP-2612 permit functionality.
+abstract contract GovernanceStakerPermitAndStake is GovernanceStaker {
+  /// @notice Method to stake tokens to a new deposit. Before the staking operation occurs, a
+  /// signature is passed to the token contract's permit method to spend the would-be staked amount
+  /// of the token.
+  /// @param _amount Quantity of the staking token to stake.
+  /// @param _delegatee Address to assign the governance voting weight of the staked tokens.
+  /// @param _beneficiary Address that will accrue rewards for this stake.
+  /// @param _deadline The timestamp after which the permit signature should expire.
+  /// @param _v ECDSA signature component: Parity of the `y` coordinate of point `R`
+  /// @param _r ECDSA signature component: x-coordinate of `R`
+  /// @param _s ECDSA signature component: `s` value of the signature
+  /// @return _depositId Unique identifier for this deposit.
+  /// @dev Neither the delegatee nor the beneficiary may be the zero address. The deposit will be
+  /// owned by the message sender.
+  function permitAndStake(
+    uint256 _amount,
+    address _delegatee,
+    address _beneficiary,
+    uint256 _deadline,
+    uint8 _v,
+    bytes32 _r,
+    bytes32 _s
+  ) external virtual returns (DepositIdentifier _depositId) {
+    try STAKE_TOKEN.permit(msg.sender, address(this), _amount, _deadline, _v, _r, _s) {} catch {}
+    _depositId = _stake(msg.sender, _amount, _delegatee, _beneficiary);
+  }
+
+  /// @notice Add more staking tokens to an existing deposit. A staker should call this method when
+  /// they have an existing deposit, and wish to stake more while retaining the same delegatee and
+  /// beneficiary. Before the staking operation occurs, a signature is passed to the token
+  /// contract's permit method to spend the would-be staked amount of the token.
+  /// @param _depositId Unique identifier of the deposit to which stake will be added.
+  /// @param _amount Quantity of stake to be added.
+  /// @param _deadline The timestamp after which the permit signature should expire.
+  /// @param _v ECDSA signature component: Parity of the `y` coordinate of point `R`
+  /// @param _r ECDSA signature component: x-coordinate of `R`
+  /// @param _s ECDSA signature component: `s` value of the signature
+  /// @dev The message sender must be the owner of the deposit.
+  function permitAndStakeMore(
+    DepositIdentifier _depositId,
+    uint256 _amount,
+    uint256 _deadline,
+    uint8 _v,
+    bytes32 _r,
+    bytes32 _s
+  ) external virtual {
+    Deposit storage deposit = deposits[_depositId];
+    _revertIfNotDepositOwner(deposit, msg.sender);
+
+    try STAKE_TOKEN.permit(msg.sender, address(this), _amount, _deadline, _v, _r, _s) {} catch {}
+    _stakeMore(deposit, _depositId, _amount);
+  }
+}

test/harnesses/GovernanceStakerHarness.sol

@@ -3,15 +3,15 @@ pragma solidity ^0.8.23;
 
 import {DelegationSurrogateVotes} from "src/DelegationSurrogateVotes.sol";
 import {GovernanceStaker} from "src/GovernanceStaker.sol";
-
+import {GovernanceStakerPermitAndStake} from "src/extensions/GovernanceStakerPermitAndStake.sol";
 import {IERC20} from "openzeppelin/token/ERC20/IERC20.sol";
 import {SafeERC20} from "openzeppelin/token/ERC20/utils/SafeERC20.sol";
 import {EIP712} from "openzeppelin/utils/cryptography/EIP712.sol";
 import {IERC20Delegates} from "src/interfaces/IERC20Delegates.sol";
 import {IEarningPowerCalculator} from "src/interfaces/IEarningPowerCalculator.sol";
 import {DelegationSurrogate} from "src/DelegationSurrogate.sol";
 
-contract GovernanceStakerHarness is GovernanceStaker {
+contract GovernanceStakerHarness is GovernanceStaker, GovernanceStakerPermitAndStake {
   constructor(
     IERC20 _rewardsToken,
     IERC20Delegates _stakeToken,