feat: pull token wrapper

contracts/partners/tokenWrappers/PullTokenWrapper.sol

@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: BUSL-1.1
+
+pragma solidity ^0.8.17;
+
+import { ERC20Upgradeable } from "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
+import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import { IERC20 } from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
+import "../../DistributionCreator.sol";
+
+import "../../utils/UUPSHelper.sol";
+
+/// @title PullTokenWrapper
+/// @notice Wrapper for a reward token on Merkl so campaigns do not have to be prefunded
+contract PullTokenWrapper is UUPSHelper, ERC20Upgradeable {
+    using SafeERC20 for IERC20;
+
+    // ================================= VARIABLES =================================
+
+    /// @notice `Core` contract handling access control
+    IAccessControlManager public core;
+
+    // Could be put as immutable in a non upgradeable contract
+    address public token;
+    address public holder;
+    address public distributor;
+    address public distributionCreator;
+
+    // ================================= MODIFIERS =================================
+
+    /// @notice Checks whether the `msg.sender` has the governor role or the guardian role
+    modifier onlyHolderOrGovernor() {
+        if (msg.sender != holder && !core.isGovernor(msg.sender)) revert NotAllowed();
+        _;
+    }
+
+    // ================================= FUNCTIONS =================================
+
+    function initialize(
+        address underlyingToken,
+        address _core,
+        address _distributionCreator,
+        address _holder,
+        string memory name,
+        string memory symbol
+    ) public initializer {
+        __ERC20_init(string.concat(name), string.concat(symbol));
+        __UUPSUpgradeable_init();
+        if (underlyingToken == address(0) || holder == address(0)) revert ZeroAddress();
+        IAccessControlManager(_core).isGovernor(msg.sender);
+        distributor = DistributionCreator(_distributionCreator).distributor();
+        token = underlyingToken;
+        distributionCreator = _distributionCreator;
+        holder = _holder;
+        core = IAccessControlManager(_core);
+    }
+
+    function _beforeTokenTransfer(address from, address to, uint256 amount) internal override {
+        // During claim transactions, tokens are pulled and transferred to the `to` address
+        if (from == distributor || to == _getFeeRecipient()) IERC20(token).safeTransferFrom(holder, to, amount);
+    }
+
+    function _afterTokenTransfer(address, address to, uint256 amount) internal override {
+        // No leftover tokens can be kept except on the holder address
+        if (to != address(distributor) && to != holder) _burn(to, amount);
+    }
+
+    function _getFeeRecipient() internal view returns (address feeRecipient) {
+        address _distributionCreator = distributionCreator;
+        feeRecipient = DistributionCreator(_distributionCreator).feeRecipient();
+        feeRecipient = feeRecipient == address(0) ? _distributionCreator : feeRecipient;
+    }
+
+    function setHolder(address _newHolder) external onlyHolderOrGovernor {
+        holder = _newHolder;
+    }
+
+    function mint(uint256 amount) external onlyHolderOrGovernor {
+        _mint(holder, amount);
+    }
+
+    /// @inheritdoc UUPSUpgradeable
+    function _authorizeUpgrade(address) internal view override onlyGovernorUpgrader(core) {}
+}

contracts/utils/Errors.sol

@@ -20,6 +20,7 @@ error InvalidReward();
 error InvalidSignature();
 error NoDispute();
 error NoOverrideForCampaign();
+error NotAllowed();
 error NotGovernor();
 error NotGovernorOrGuardian();
 error NotSigned();

scripts/mintMockToken.ts

@@ -7,11 +7,11 @@ import { MockToken__factory } from '../typechain';
 async function main() {
   const { deployer } = await ethers.getNamedSigners();
 
-  const MockToken = MockToken__factory.connect('0xA7c167f58833c5e25848837f45A1372491A535eD', deployer);
+  const MockToken = MockToken__factory.connect('0xC011882d0f7672D8942e7fE2248C174eeD640c8f', deployer);
 
   console.log(`Minting MockToken to ${deployer.address}...`);
   await (
-    await MockToken.mint(deployer.address, parseUnits('100000', 6), {
+    await MockToken.mint('0x81Dd955D02D337DB81BA6c9C5F6213E647672052', parseUnits('1000', 18), {
       // gasLimit: 300_000,
       // maxPriorityFeePerGas: 100e9,
       // maxFeePerGas: 700e9,