feat: Upgrade Remote Pool to include RateLimitAdmin (#16)

* feat: enable remote rateLimitAdmin

* chore: prettier

* fix: remove unnecessary modifer

* chore: reorder state variables

* feat: upgrade remote pool

* test: add tests after upgrading

* feat: reserve storage space for future upgrades

* diff: Update diff for UpgradeableBurnMintTokenPool

* ci: Fix ci

* ci: Fix ci

* test: show init reverting after upgrade

* fix: remove gap

* fix: return to original test suite

* test: simple tests showing upgrade

* fix: add and correct comments

* fix: comments to match parent contract

* chore: prettier

---------

Co-authored-by: miguelmtzinf <miguelmtz.mail@gmail.com>

contracts/src/v0.8/ccip/pools/GHO/UpgradeableBurnMintTokenPoolOld.sol

@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.0;
+
+import {Initializable} from "solidity-utils/contracts/transparent-proxy/Initializable.sol";
+
+import {ITypeAndVersion} from "../../../shared/interfaces/ITypeAndVersion.sol";
+import {IBurnMintERC20} from "../../../shared/token/ERC20/IBurnMintERC20.sol";
+
+import {UpgradeableTokenPool} from "./UpgradeableTokenPool.sol";
+import {UpgradeableBurnMintTokenPoolAbstract} from "./UpgradeableBurnMintTokenPoolAbstract.sol";
+
+import {IRouter} from "../../interfaces/IRouter.sol";
+
+/// @title UpgradeableBurnMintTokenPoolOld
+/// @author Aave Labs
+/// @notice Upgradeable version of Chainlink's CCIP BurnMintTokenPool
+/// @dev Contract adaptations:
+/// - Implementation of Initializable to allow upgrades
+/// - Move of allowlist and router definition to initialization stage
+contract UpgradeableBurnMintTokenPoolOld is Initializable, UpgradeableBurnMintTokenPoolAbstract, ITypeAndVersion {
+  string public constant override typeAndVersion = "BurnMintTokenPool 1.4.0";
+
+  /// @dev Constructor
+  /// @param token The bridgeable token that is managed by this pool.
+  /// @param armProxy The address of the arm proxy
+  /// @param allowlistEnabled True if pool is set to access-controlled mode, false otherwise
+  constructor(
+    address token,
+    address armProxy,
+    bool allowlistEnabled
+  ) UpgradeableTokenPool(IBurnMintERC20(token), armProxy, allowlistEnabled) {}
+
+  /// @dev Initializer
+  /// @dev The address passed as `owner` must accept ownership after initialization.
+  /// @dev The `allowlist` is only effective if pool is set to access-controlled mode
+  /// @param owner The address of the owner
+  /// @param allowlist A set of addresses allowed to trigger lockOrBurn as original senders
+  /// @param router The address of the router
+  function initialize(address owner, address[] memory allowlist, address router) public virtual initializer {
+    if (owner == address(0)) revert ZeroAddressNotAllowed();
+    if (router == address(0)) revert ZeroAddressNotAllowed();
+    _transferOwnership(owner);
+
+    s_router = IRouter(router);
+
+    // Pool can be set as permissioned or permissionless at deployment time only to save hot-path gas.
+    if (i_allowlistEnabled) {
+      _applyAllowListUpdates(new address[](0), allowlist);
+    }
+  }
+
+  /// @inheritdoc UpgradeableBurnMintTokenPoolAbstract
+  function _burn(uint256 amount) internal virtual override {
+    IBurnMintERC20(address(i_token)).burn(amount);
+  }
+}

contracts/src/v0.8/ccip/test/pools/GHO/GhoBaseTest.t.sol

@@ -8,6 +8,7 @@ import {IBurnMintERC20} from "../../../../shared/token/ERC20/IBurnMintERC20.sol"
 import {IPool} from "../../../interfaces/pools/IPool.sol";
 import {UpgradeableLockReleaseTokenPool} from "../../../pools/GHO/UpgradeableLockReleaseTokenPool.sol";
 import {UpgradeableBurnMintTokenPool} from "../../../pools/GHO/UpgradeableBurnMintTokenPool.sol";
+import {UpgradeableBurnMintTokenPoolOld} from "../../../pools/GHO/UpgradeableBurnMintTokenPoolOld.sol";
 import {UpgradeableTokenPool} from "../../../pools/GHO/UpgradeableTokenPool.sol";
 import {RateLimiter} from "../../../libraries/RateLimiter.sol";
 import {BaseTest} from "../../BaseTest.t.sol";
@@ -65,6 +66,36 @@ abstract contract GhoBaseTest is BaseTest {
     return address(tokenPoolProxy);
   }
 
+  function _deployUpgradeableBurnMintTokenPoolOld(
+    address ghoToken,
+    address arm,
+    address router,
+    address owner,
+    address proxyAdmin
+  ) internal returns (address) {
+    // Deploy BurnMintTokenPool for GHO token on source chain
+    UpgradeableBurnMintTokenPoolOld tokenPoolImpl = new UpgradeableBurnMintTokenPoolOld(ghoToken, arm, false);
+    // proxy deploy and init
+    address[] memory emptyArray = new address[](0);
+    bytes memory tokenPoolInitParams = abi.encodeWithSignature(
+      "initialize(address,address[],address)",
+      owner,
+      emptyArray,
+      router
+    );
+    TransparentUpgradeableProxy tokenPoolProxy = new TransparentUpgradeableProxy(
+      address(tokenPoolImpl),
+      proxyAdmin,
+      tokenPoolInitParams
+    );
+    // Manage ownership
+    changePrank(owner);
+    UpgradeableBurnMintTokenPoolOld(address(tokenPoolProxy)).acceptOwnership();
+    vm.stopPrank();
+
+    return address(tokenPoolProxy);
+  }
+
   function _deployUpgradeableLockReleaseTokenPool(
     address ghoToken,
     address arm,

contracts/src/v0.8/ccip/test/pools/GHO/GhoTokenPoolRemoteUpgrade.t.sol

@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity 0.8.19;
+
+import {TransparentUpgradeableProxy} from "solidity-utils/contracts/transparent-proxy/TransparentUpgradeableProxy.sol";
+
+import {UpgradeableBurnMintTokenPool} from "../../../pools/GHO/UpgradeableBurnMintTokenPool.sol";
+import {GhoTokenPoolRemoteSetup} from "./GhoTokenPoolRemoteSetup.t.sol";
+
+contract GhoTokenPoolRemoteUpgrade is GhoTokenPoolRemoteSetup {
+  // Unable to call setRateLimitAdmin() before upgrade
+  function testSetRateLimitAdminRevertsBeforeUpgrade() public {
+    s_pool = UpgradeableBurnMintTokenPool(
+      _deployUpgradeableBurnMintTokenPoolOld(
+        address(s_burnMintERC677),
+        address(s_mockARM),
+        address(s_sourceRouter),
+        AAVE_DAO,
+        PROXY_ADMIN
+      )
+    );
+    vm.prank(AAVE_DAO);
+    vm.expectRevert();
+    s_pool.setRateLimitAdmin(AAVE_DAO);
+  }
+
+  // Able to call setRateLimitAdmin() after upgrade
+  function testUpgradeAndSetRateLimitAdmin() public {
+    // Assume existing remote pool as is deployed
+    s_pool = UpgradeableBurnMintTokenPool(
+      _deployUpgradeableBurnMintTokenPoolOld(
+        address(s_burnMintERC677),
+        address(s_mockARM),
+        address(s_sourceRouter),
+        AAVE_DAO,
+        PROXY_ADMIN
+      )
+    );
+
+    // Deploy new implementation
+    UpgradeableBurnMintTokenPool tokenPoolImpl = new UpgradeableBurnMintTokenPool(
+      address(s_burnMintERC677),
+      address(s_mockARM),
+      false
+    );
+    // Do the upgrade
+    vm.prank(PROXY_ADMIN);
+    TransparentUpgradeableProxy(payable(address(s_pool))).upgradeTo(address(tokenPoolImpl));
+
+    // Set rate limit admin now works
+    vm.prank(AAVE_DAO);
+    s_pool.setRateLimitAdmin(OWNER);
+    assertEq(OWNER, s_pool.getRateLimitAdmin());
+  }
+
+  // Unable to call initialize() on proxy after upgrade
+  function testInitializeRevertsAfterUpgrade() public {
+    s_pool = UpgradeableBurnMintTokenPool(
+      _deployUpgradeableBurnMintTokenPoolOld(
+        address(s_burnMintERC677),
+        address(s_mockARM),
+        address(s_sourceRouter),
+        AAVE_DAO,
+        PROXY_ADMIN
+      )
+    );
+
+    // Deploy new implementation
+    UpgradeableBurnMintTokenPool tokenPoolImpl = new UpgradeableBurnMintTokenPool(
+      address(s_burnMintERC677),
+      address(s_mockARM),
+      false
+    );
+    // Do the upgrade
+    vm.prank(PROXY_ADMIN);
+    TransparentUpgradeableProxy(payable(address(s_pool))).upgradeTo(address(tokenPoolImpl));
+
+    vm.startPrank(OWNER);
+    vm.expectRevert("Initializable: contract is already initialized");
+    s_pool.initialize(OWNER, new address[](0), address(s_sourceRouter));
+  }
+}