From 72a0c6f60214ee1531720e62da7fde3e4ed80600 Mon Sep 17 00:00:00 2001
From: Josh <josh.weintraub@smartcontract.com>
Date: Mon, 23 Sep 2024 14:23:05 -0400
Subject: [PATCH 1/7] add additional safety checks and add new token pool type

---
 .../BurnMintWithLockReleaseFlagTokenPool.sol  | 35 ++++++++++
 .../USDC/HybridLockReleaseUSDCTokenPool.sol   | 16 ++---
 .../ccip/pools/USDC/USDCBridgeMigrator.sol    | 14 ++--
 ...BurnMintWithLockReleaseFlagTokenPool.t.sol | 70 +++++++++++++++++++
 .../HybridLockReleaseUSDCTokenPool.t.sol      | 69 ++++++++++++++----
 5 files changed, 177 insertions(+), 27 deletions(-)
 create mode 100644 contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol
 create mode 100644 contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol

diff --git a/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol b/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol
new file mode 100644
index 0000000000..3e33fccc63
--- /dev/null
+++ b/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol
@@ -0,0 +1,35 @@
+pragma solidity ^0.8.0;
+
+import {IBurnMintERC20} from "../../../shared/token/ERC20/IBurnMintERC20.sol";
+
+import {Pool} from "../../libraries/Pool.sol";
+import {BurnMintTokenPool} from "../BurnMintTokenPool.sol";
+
+contract BurnMintWithLockReleaseFlagTokenPool is BurnMintTokenPool {
+  /// bytes4(keccak256("NO_CCTP_USE_LOCK_RELEASE"))
+  bytes4 public constant LOCK_RELEASE_FLAG = 0xfa7c07de;
+
+  constructor(
+    IBurnMintERC20 token,
+    address[] memory allowlist,
+    address rmnProxy,
+    address router
+  ) BurnMintTokenPool(token, allowlist, rmnProxy, router) {}
+
+  /// @notice Burn the token in the pool
+  /// @dev The _validateLockOrBurn check is an essential security check
+  function lockOrBurn(
+    Pool.LockOrBurnInV1 calldata lockOrBurnIn
+  ) external virtual override returns (Pool.LockOrBurnOutV1 memory) {
+    _validateLockOrBurn(lockOrBurnIn);
+
+    _burn(lockOrBurnIn.amount);
+
+    emit Burned(msg.sender, lockOrBurnIn.amount);
+
+    return Pool.LockOrBurnOutV1({
+      destTokenAddress: getRemoteToken(lockOrBurnIn.remoteChainSelector),
+      destPoolData: abi.encode(LOCK_RELEASE_FLAG)
+    });
+  }
+}
diff --git a/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol b/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
index 5fbd71bb2c..8eaa2463cd 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
@@ -34,8 +34,8 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
   error LanePausedForCCTPMigration(uint64 remoteChainSelector);
   error TokenLockingNotAllowedAfterMigration(uint64 remoteChainSelector);
 
-  /// bytes4(keccak256("NO_CTTP_USE_LOCK_RELEASE"))
-  bytes4 public constant LOCK_RELEASE_FLAG = 0xd43c7897;
+  /// bytes4(keccak256("NO_CCTP_USE_LOCK_RELEASE"))
+  bytes4 public constant LOCK_RELEASE_FLAG = 0xfa7c07de;
 
   /// @notice The address of the liquidity provider for a specific chain.
   /// External liquidity is not required when there is one canonical token deployed to a chain,
@@ -114,7 +114,6 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
       s_lockedTokensByChainSelector[releaseOrMintIn.remoteChainSelector] -= releaseOrMintIn.amount;
     }
 
-    // Release to the offRamp, which forwards it to the recipient
     getToken().safeTransfer(releaseOrMintIn.receiver, releaseOrMintIn.amount);
 
     emit Released(msg.sender, releaseOrMintIn.receiver, releaseOrMintIn.amount);
@@ -171,6 +170,10 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
   function provideLiquidity(uint64 remoteChainSelector, uint256 amount) external {
     if (s_liquidityProvider[remoteChainSelector] != msg.sender) revert TokenPool.Unauthorized(msg.sender);
 
+    if (remoteChainSelector == s_proposedUSDCMigrationChain) {
+      revert LanePausedForCCTPMigration(remoteChainSelector);
+    }
+
     s_lockedTokensByChainSelector[remoteChainSelector] += amount;
 
     i_token.safeTransferFrom(msg.sender, address(this), amount);
@@ -211,13 +214,6 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
   /// @param from The address of the old pool.
   /// @param remoteChainSelector The chain for which liquidity is being transferred.
   function transferLiquidity(address from, uint64 remoteChainSelector) external onlyOwner {
-    // Prevent Liquidity Transfers when a migration is pending. This prevents requiring the new pool to manage
-    // token exclusions for edge-case messages and ensures that the migration is completed before any new liquidity
-    // is added to the pool.
-    if (HybridLockReleaseUSDCTokenPool(from).getCurrentProposedCCTPChainMigration() == remoteChainSelector) {
-      revert LanePausedForCCTPMigration(remoteChainSelector);
-    }
-
     OwnerIsCreator(from).acceptOwnership();
 
     // Withdraw all available liquidity from the old pool.
diff --git a/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol b/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
index 98616cd79f..41077eb4ec 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
@@ -23,9 +23,8 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
 
   error onlyCircle();
   error ExistingMigrationProposal();
-  error NoExistingMigrationProposal();
   error NoMigrationProposalPending();
-  error InvalidChainSelector(uint64 remoteChainSelector);
+  error InvalidChainSelector();
 
   IBurnMintERC20 internal immutable i_USDC;
   Router internal immutable i_router;
@@ -49,9 +48,9 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
   /// @dev proposeCCTPMigration must be called first on an approved lane to execute properly.
   /// @dev This function signature should NEVER be overwritten, otherwise it will be unable to be called by
   /// circle to properly migrate USDC over to CCTP.
-  function burnLockedUSDC() public {
+  function burnLockedUSDC() external {
     if (msg.sender != s_circleUSDCMigrator) revert onlyCircle();
-    if (s_proposedUSDCMigrationChain == 0) revert ExistingMigrationProposal();
+    if (s_proposedUSDCMigrationChain == 0) revert NoMigrationProposalPending();
 
     uint64 burnChainSelector = s_proposedUSDCMigrationChain;
 
@@ -84,6 +83,9 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
     // Prevent overwriting existing migration proposals until the current one is finished
     if (s_proposedUSDCMigrationChain != 0) revert ExistingMigrationProposal();
 
+    // Ensure that the chain is currently using lock/release and not CCTP
+    if (!s_shouldUseLockRelease[remoteChainSelector]) revert InvalidChainSelector();
+
     s_proposedUSDCMigrationChain = remoteChainSelector;
 
     emit CCTPMigrationProposed(remoteChainSelector);
@@ -92,7 +94,7 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
   /// @notice Cancel an existing proposal to migrate a lane to CCTP.
   /// @notice This function will revert if no proposal is currently in progress.
   function cancelExistingCCTPMigrationProposal() external onlyOwner {
-    if (s_proposedUSDCMigrationChain == 0) revert NoExistingMigrationProposal();
+    if (s_proposedUSDCMigrationChain == 0) revert NoMigrationProposalPending();
 
     uint64 currentProposalChainSelector = s_proposedUSDCMigrationChain;
     delete s_proposedUSDCMigrationChain;
@@ -136,6 +138,8 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
   /// @dev This function should ONLY be called on the home chain, where tokens are locked, NOT on the remote chain
   /// and strict scrutiny should be applied to ensure that the amount of tokens excluded is accurate.
   function excludeTokensFromBurn(uint64 remoteChainSelector, uint256 amount) external onlyOwner {
+    if (s_proposedUSDCMigrationChain != remoteChainSelector) revert NoMigrationProposalPending();
+
     s_tokensExcludedFromBurn[remoteChainSelector] += amount;
 
     uint256 burnableAmountAfterExclusion =
diff --git a/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
new file mode 100644
index 0000000000..88f2075425
--- /dev/null
+++ b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity 0.8.24;
+
+import {Pool} from "../../libraries/Pool.sol";
+import {RateLimiter} from "../../libraries/RateLimiter.sol";
+
+import {TokenPool} from "../../pools/TokenPool.sol";
+import {BurnMintWithLockReleaseFlagTokenPool} from "../../pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol";
+import {BurnMintSetup} from "./BurnMintSetup.t.sol";
+
+import {IERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
+
+contract BurnMintWithLockReleaseFlagTokenPoolSetup is BurnMintSetup {
+  BurnMintWithLockReleaseFlagTokenPool internal s_pool;
+
+  function setUp() public virtual override {
+    BurnMintSetup.setUp();
+
+    s_pool = new BurnMintWithLockReleaseFlagTokenPool(
+      s_burnMintERC677, new address[](0), address(s_mockRMN), address(s_sourceRouter)
+    );
+    s_burnMintERC677.grantMintAndBurnRoles(address(s_pool));
+
+    _applyChainUpdates(address(s_pool));
+  }
+}
+
+contract BurnMintWithLockReleaseFlagTokenPool_lockOrBurn is BurnMintWithLockReleaseFlagTokenPoolSetup {
+  function test_Setup_Success() public view {
+    assertEq(address(s_burnMintERC677), address(s_pool.getToken()));
+    assertEq(address(s_mockRMN), s_pool.getRmnProxy());
+    assertEq(false, s_pool.getAllowListEnabled());
+    assertEq("BurnMintTokenPool 1.5.0", s_pool.typeAndVersion());
+  }
+
+  function test_PoolBurn_CorrectReturnData_Success() public {
+    uint256 burnAmount = 20_000e18;
+
+    deal(address(s_burnMintERC677), address(s_pool), burnAmount);
+    assertEq(s_burnMintERC677.balanceOf(address(s_pool)), burnAmount);
+
+    vm.startPrank(s_burnMintOnRamp);
+
+    vm.expectEmit();
+    emit RateLimiter.TokensConsumed(burnAmount);
+
+    vm.expectEmit();
+    emit IERC20.Transfer(address(s_pool), address(0), burnAmount);
+
+    vm.expectEmit();
+    emit TokenPool.Burned(address(s_burnMintOnRamp), burnAmount);
+
+    bytes4 expectedSignature = bytes4(keccak256("burn(uint256)"));
+    vm.expectCall(address(s_burnMintERC677), abi.encodeWithSelector(expectedSignature, burnAmount));
+
+    Pool.LockOrBurnOutV1 memory lockOrBurnOut = s_pool.lockOrBurn(
+      Pool.LockOrBurnInV1({
+        originalSender: OWNER,
+        receiver: bytes(""),
+        amount: burnAmount,
+        remoteChainSelector: DEST_CHAIN_SELECTOR,
+        localToken: address(s_burnMintERC677)
+      })
+    );
+
+    assertEq(s_burnMintERC677.balanceOf(address(s_pool)), 0);
+
+    assertEq(bytes4(lockOrBurnOut.destPoolData), s_pool.LOCK_RELEASE_FLAG());
+  }
+}
diff --git a/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol b/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol
index ddb8c29dc2..906ff2b113 100644
--- a/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol
+++ b/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol
@@ -373,6 +373,12 @@ contract HybridUSDCTokenPoolTests is USDCTokenPoolSetup {
   }
 
   function test_LockOrBurn_WhileMigrationPause_Revert() public {
+    // Mark the destination chain as supporting CCTP, so use L/R instead.
+    uint64[] memory destChainAdds = new uint64[](1);
+    destChainAdds[0] = DEST_CHAIN_SELECTOR;
+
+    s_usdcTokenPool.updateChainSelectorMechanisms(new uint64[](0), destChainAdds);
+
     // Create a fake migration proposal
     s_usdcTokenPool.proposeCCTPMigration(DEST_CHAIN_SELECTOR);
 
@@ -380,12 +386,6 @@ contract HybridUSDCTokenPoolTests is USDCTokenPoolSetup {
 
     bytes32 receiver = bytes32(uint256(uint160(STRANGER)));
 
-    // Mark the destination chain as supporting CCTP, so use L/R instead.
-    uint64[] memory destChainAdds = new uint64[](1);
-    destChainAdds[0] = DEST_CHAIN_SELECTOR;
-
-    s_usdcTokenPool.updateChainSelectorMechanisms(new uint64[](0), destChainAdds);
-
     assertTrue(
       s_usdcTokenPool.shouldUseLockRelease(DEST_CHAIN_SELECTOR),
       "Lock Release mech not configured for outgoing message to DEST_CHAIN_SELECTOR"
@@ -527,6 +527,12 @@ contract HybridUSDCTokenPoolTests is USDCTokenPoolSetup {
     // Set as the OWNER so we can provide liquidity
     vm.startPrank(OWNER);
 
+    // Mark the destination chain as supporting CCTP, so use L/R instead.
+    uint64[] memory destChainAdds = new uint64[](1);
+    destChainAdds[0] = DEST_CHAIN_SELECTOR;
+
+    s_usdcTokenPool.updateChainSelectorMechanisms(new uint64[](0), destChainAdds);
+
     s_usdcTokenPool.setLiquidityProvider(DEST_CHAIN_SELECTOR, OWNER);
     s_token.approve(address(s_usdcTokenPool), type(uint256).max);
 
@@ -643,6 +649,12 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
   function test_cancelExistingCCTPMigrationProposal() public {
     vm.startPrank(OWNER);
 
+    // Mark the destination chain as supporting CCTP, so use L/R instead.
+    uint64[] memory destChainAdds = new uint64[](1);
+    destChainAdds[0] = DEST_CHAIN_SELECTOR;
+
+    s_usdcTokenPool.updateChainSelectorMechanisms(new uint64[](0), destChainAdds);
+
     vm.expectEmit();
     emit USDCBridgeMigrator.CCTPMigrationProposed(DEST_CHAIN_SELECTOR);
 
@@ -665,7 +677,7 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
       "migration proposal exists, but shouldn't after being cancelled"
     );
 
-    vm.expectRevert(USDCBridgeMigrator.NoExistingMigrationProposal.selector);
+    vm.expectRevert(USDCBridgeMigrator.NoMigrationProposalPending.selector);
     s_usdcTokenPool.cancelExistingCCTPMigrationProposal();
   }
 
@@ -684,7 +696,7 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
 
     vm.startPrank(CIRCLE);
 
-    vm.expectRevert(abi.encodeWithSelector(USDCBridgeMigrator.ExistingMigrationProposal.selector));
+    vm.expectRevert(abi.encodeWithSelector(USDCBridgeMigrator.NoMigrationProposalPending.selector));
     s_usdcTokenPool.burnLockedUSDC();
   }
 
@@ -700,7 +712,7 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
   }
 
   function test_cannotCancelANonExistentMigrationProposal() public {
-    vm.expectRevert(USDCBridgeMigrator.NoExistingMigrationProposal.selector);
+    vm.expectRevert(USDCBridgeMigrator.NoMigrationProposalPending.selector);
 
     // Proposal to migrate doesn't exist, and so the chain selector is zero, and therefore should revert
     s_usdcTokenPool.cancelExistingCCTPMigrationProposal();
@@ -784,7 +796,7 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
 
     // Mark the destination chain as supporting CCTP, so use L/R instead.
     uint64[] memory destChainAdds = new uint64[](1);
-    destChainAdds[0] = DEST_CHAIN_SELECTOR;
+    destChainAdds[0] = SOURCE_CHAIN_SELECTOR;
 
     s_usdcTokenPool.updateChainSelectorMechanisms(new uint64[](0), destChainAdds);
 
@@ -805,6 +817,8 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
     // since there's no corresponding attestation to use for minting.
     vm.startPrank(OWNER);
 
+    s_usdcTokenPool.proposeCCTPMigration(SOURCE_CHAIN_SELECTOR);
+
     // Exclude the tokens from being burned and check for the event
     vm.expectEmit();
     emit USDCBridgeMigrator.TokensExcludedFromBurn(SOURCE_CHAIN_SELECTOR, amount, (amount * 3) - amount);
@@ -825,8 +839,6 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
 
     s_usdcTokenPool.setCircleMigratorAddress(CIRCLE);
 
-    s_usdcTokenPool.proposeCCTPMigration(SOURCE_CHAIN_SELECTOR);
-
     vm.startPrank(CIRCLE);
 
     s_usdcTokenPool.burnLockedUSDC();
@@ -881,4 +893,37 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
     // We also want to check that the system uses CCTP Burn/Mint for all other messages that don't have that flag
     test_MintOrRelease_incomingMessageWithPrimaryMechanism();
   }
+
+  function test_ProposeMigration_ChainNotUsingLockRelease_Revert() public {
+    vm.expectRevert(abi.encodeWithSelector(USDCBridgeMigrator.InvalidChainSelector.selector));
+
+    vm.startPrank(OWNER);
+
+    s_usdcTokenPool.proposeCCTPMigration(0x98765);
+  }
+
+  function test_excludeTokensWhenNoMigrationProposalPending_Revert() public {
+    vm.expectRevert(abi.encodeWithSelector(USDCBridgeMigrator.NoMigrationProposalPending.selector));
+
+    vm.startPrank(OWNER);
+
+    s_usdcTokenPool.excludeTokensFromBurn(SOURCE_CHAIN_SELECTOR, 1e6);
+  }
+
+  function test_cannotProvideLiquidityWhenMigrationProposalPending_Revert() public {
+    vm.startPrank(OWNER);
+
+    // Mark the destination chain as supporting CCTP, so use L/R instead.
+    uint64[] memory destChainAdds = new uint64[](1);
+    destChainAdds[0] = DEST_CHAIN_SELECTOR;
+
+    s_usdcTokenPool.updateChainSelectorMechanisms(new uint64[](0), destChainAdds);
+
+    s_usdcTokenPool.proposeCCTPMigration(DEST_CHAIN_SELECTOR);
+
+    vm.expectRevert(
+      abi.encodeWithSelector(HybridLockReleaseUSDCTokenPool.LanePausedForCCTPMigration.selector, DEST_CHAIN_SELECTOR)
+    );
+    s_usdcTokenPool.provideLiquidity(DEST_CHAIN_SELECTOR, 1e6);
+  }
 }

From eb531ccd227f1fb321ae2d3cc5c44bca5e9e647d Mon Sep 17 00:00:00 2001
From: Josh <josh.weintraub@smartcontract.com>
Date: Fri, 27 Sep 2024 11:11:14 -0400
Subject: [PATCH 2/7] additional checks to prevent ownership abuse

---
 contracts/gas-snapshots/ccip.gas-snapshot     | 51 +++++++++++--------
 .../USDC/HybridLockReleaseUSDCTokenPool.sol   | 15 ++++--
 .../ccip/pools/USDC/USDCBridgeMigrator.sol    |  4 ++
 .../HybridLockReleaseUSDCTokenPool.t.sol      | 32 ++++++++++++
 4 files changed, 77 insertions(+), 25 deletions(-)

diff --git a/contracts/gas-snapshots/ccip.gas-snapshot b/contracts/gas-snapshots/ccip.gas-snapshot
index 9861ed236c..5c9bf92f18 100644
--- a/contracts/gas-snapshots/ccip.gas-snapshot
+++ b/contracts/gas-snapshots/ccip.gas-snapshot
@@ -30,6 +30,8 @@ BurnMintTokenPool_lockOrBurn:test_Setup_Success() (gas: 17851)
 BurnMintTokenPool_releaseOrMint:test_ChainNotAllowed_Revert() (gas: 28805)
 BurnMintTokenPool_releaseOrMint:test_PoolMintNotHealthy_Revert() (gas: 56253)
 BurnMintTokenPool_releaseOrMint:test_PoolMint_Success() (gas: 112391)
+BurnMintWithLockReleaseFlagTokenPool_lockOrBurn:test_PoolBurn_CorrectReturnData_Success() (gas: 243221)
+BurnMintWithLockReleaseFlagTokenPool_lockOrBurn:test_Setup_Success() (gas: 17873)
 BurnWithFromMintTokenPool_lockOrBurn:test_ChainNotAllowed_Revert() (gas: 28842)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurnRevertNotHealthy_Revert() (gas: 55271)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurn_Success() (gas: 244050)
@@ -431,33 +433,38 @@ FeeQuoter_validateDestFamilyAddress:test_InvalidEVMAddressPrecompiles_Revert() (
 FeeQuoter_validateDestFamilyAddress:test_InvalidEVMAddress_Revert() (gas: 10839)
 FeeQuoter_validateDestFamilyAddress:test_ValidEVMAddress_Success() (gas: 6731)
 FeeQuoter_validateDestFamilyAddress:test_ValidNonEVMAddress_Success() (gas: 6511)
-HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_LockReleaseMechanism_then_switchToPrimary_Success() (gas: 209248)
-HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_PrimaryMechanism_Success() (gas: 135879)
-HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_WhileMigrationPause_Revert() (gas: 107090)
-HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_onLockReleaseMechanism_Success() (gas: 144586)
-HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_OnLockReleaseMechanism_Success() (gas: 214817)
-HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_OnLockReleaseMechanism_then_switchToPrimary_Success() (gas: 423641)
+HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_LockReleaseMechanism_then_switchToPrimary_Success() (gas: 209230)
+HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_PrimaryMechanism_Success() (gas: 135861)
+HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_WhileMigrationPause_Revert() (gas: 109814)
+HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_onLockReleaseMechanism_Success() (gas: 147081)
+HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_OnLockReleaseMechanism_Success() (gas: 217718)
+HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_OnLockReleaseMechanism_then_switchToPrimary_Success() (gas: 426564)
 HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_incomingMessageWithPrimaryMechanism() (gas: 268928)
-HybridUSDCTokenPoolMigrationTests:test_ReleaseOrMint_WhileMigrationPause_Revert() (gas: 111484)
+HybridUSDCTokenPoolMigrationTests:test_ProposeMigration_ChainNotUsingLockRelease_Revert() (gas: 15821)
+HybridUSDCTokenPoolMigrationTests:test_ReleaseOrMint_WhileMigrationPause_Revert() (gas: 114166)
 HybridUSDCTokenPoolMigrationTests:test_burnLockedUSDC_invalidPermissions_Revert() (gas: 39362)
-HybridUSDCTokenPoolMigrationTests:test_cancelExistingCCTPMigrationProposal() (gas: 33189)
-HybridUSDCTokenPoolMigrationTests:test_cannotCancelANonExistentMigrationProposal() (gas: 12669)
-HybridUSDCTokenPoolMigrationTests:test_cannotModifyLiquidityWithoutPermissions_Revert() (gas: 13329)
-HybridUSDCTokenPoolMigrationTests:test_cannotTransferLiquidityDuringPendingMigration_Revert() (gas: 160900)
-HybridUSDCTokenPoolMigrationTests:test_lockOrBurn_then_BurnInCCTPMigration_Success() (gas: 255982)
-HybridUSDCTokenPoolMigrationTests:test_transferLiquidity_Success() (gas: 165921)
-HybridUSDCTokenPoolMigrationTests:test_unstickManualTxAfterMigration_destChain_Success() (gas: 154242)
-HybridUSDCTokenPoolMigrationTests:test_unstickManualTxAfterMigration_homeChain_Success() (gas: 463740)
+HybridUSDCTokenPoolMigrationTests:test_cancelExistingCCTPMigrationProposal() (gas: 56207)
+HybridUSDCTokenPoolMigrationTests:test_cannotCancelANonExistentMigrationProposal() (gas: 12736)
+HybridUSDCTokenPoolMigrationTests:test_cannotModifyLiquidityWithoutPermissions_Revert() (gas: 13373)
+HybridUSDCTokenPoolMigrationTests:test_cannotProvideLiquidityWhenMigrationProposalPending_Revert() (gas: 67304)
+HybridUSDCTokenPoolMigrationTests:test_cannotRevertChainMechanism_afterMigration_Revert() (gas: 313390)
+HybridUSDCTokenPoolMigrationTests:test_cannotTransferLiquidityDuringPendingMigration_Revert() (gas: 177033)
+HybridUSDCTokenPoolMigrationTests:test_cnanotProvideLiquidity_AfterMigration_Revert() (gas: 313775)
+HybridUSDCTokenPoolMigrationTests:test_excludeTokensWhenNoMigrationProposalPending_Revert() (gas: 13657)
+HybridUSDCTokenPoolMigrationTests:test_lockOrBurn_then_BurnInCCTPMigration_Success() (gas: 309952)
+HybridUSDCTokenPoolMigrationTests:test_transferLiquidity_Success() (gas: 167124)
+HybridUSDCTokenPoolMigrationTests:test_unstickManualTxAfterMigration_destChain_Success() (gas: 156736)
+HybridUSDCTokenPoolMigrationTests:test_unstickManualTxAfterMigration_homeChain_Success() (gas: 516552)
 HybridUSDCTokenPoolTests:test_LockOrBurn_LockReleaseMechanism_then_switchToPrimary_Success() (gas: 209230)
 HybridUSDCTokenPoolTests:test_LockOrBurn_PrimaryMechanism_Success() (gas: 135880)
-HybridUSDCTokenPoolTests:test_LockOrBurn_WhileMigrationPause_Revert() (gas: 107135)
-HybridUSDCTokenPoolTests:test_LockOrBurn_onLockReleaseMechanism_Success() (gas: 144607)
-HybridUSDCTokenPoolTests:test_MintOrRelease_OnLockReleaseMechanism_Success() (gas: 214795)
-HybridUSDCTokenPoolTests:test_MintOrRelease_OnLockReleaseMechanism_then_switchToPrimary_Success() (gas: 423619)
+HybridUSDCTokenPoolTests:test_LockOrBurn_WhileMigrationPause_Revert() (gas: 109814)
+HybridUSDCTokenPoolTests:test_LockOrBurn_onLockReleaseMechanism_Success() (gas: 147079)
+HybridUSDCTokenPoolTests:test_MintOrRelease_OnLockReleaseMechanism_Success() (gas: 217696)
+HybridUSDCTokenPoolTests:test_MintOrRelease_OnLockReleaseMechanism_then_switchToPrimary_Success() (gas: 426520)
 HybridUSDCTokenPoolTests:test_MintOrRelease_incomingMessageWithPrimaryMechanism() (gas: 268910)
-HybridUSDCTokenPoolTests:test_ReleaseOrMint_WhileMigrationPause_Revert() (gas: 111528)
-HybridUSDCTokenPoolTests:test_cannotTransferLiquidityDuringPendingMigration_Revert() (gas: 160845)
-HybridUSDCTokenPoolTests:test_transferLiquidity_Success() (gas: 165904)
+HybridUSDCTokenPoolTests:test_ReleaseOrMint_WhileMigrationPause_Revert() (gas: 114210)
+HybridUSDCTokenPoolTests:test_cannotTransferLiquidityDuringPendingMigration_Revert() (gas: 176989)
+HybridUSDCTokenPoolTests:test_transferLiquidity_Success() (gas: 167107)
 LockReleaseTokenPoolAndProxy_setRebalancer:test_SetRebalancer_Revert() (gas: 10989)
 LockReleaseTokenPoolAndProxy_setRebalancer:test_SetRebalancer_Success() (gas: 18028)
 LockReleaseTokenPoolPoolAndProxy_canAcceptLiquidity:test_CanAcceptLiquidity_Success() (gas: 3051552)
diff --git a/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol b/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
index 8eaa2463cd..91db9c1b29 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
@@ -99,7 +99,7 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
     _validateReleaseOrMint(releaseOrMintIn);
 
     // Circle requires a supply-lock to prevent incoming messages once the migration process begins.
-    // This prevents new outgoing messages once the migration has begun to ensure any the procedure runs as expected
+    // This prevents new incoming messages once the migration has begun to ensure any the procedure runs as expected
     if (s_proposedUSDCMigrationChain == releaseOrMintIn.remoteChainSelector) {
       revert LanePausedForCCTPMigration(s_proposedUSDCMigrationChain);
     }
@@ -170,6 +170,10 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
   function provideLiquidity(uint64 remoteChainSelector, uint256 amount) external {
     if (s_liquidityProvider[remoteChainSelector] != msg.sender) revert TokenPool.Unauthorized(msg.sender);
 
+    if (s_migratedChains.contains(remoteChainSelector)) {
+      revert TokenLockingNotAllowedAfterMigration(remoteChainSelector);
+    }
+
     if (remoteChainSelector == s_proposedUSDCMigrationChain) {
       revert LanePausedForCCTPMigration(remoteChainSelector);
     }
@@ -236,9 +240,10 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
     return s_shouldUseLockRelease[remoteChainSelector];
   }
 
-  /// @notice Updates Updates designations for chains on whether to use primary or alt mechanism on CCIP messages
+  /// @notice Updates designations for chains on whether to use primary or alt mechanism on CCIP messages
   /// @param removes A list of chain selectors to disable Lock-Release, and enforce BM
-  /// @param adds A list of chain selectors to enable LR instead of BM
+  /// @param adds A list of chain selectors to enable LR instead of BM. These chains must not have been migrated
+  /// to CCTP yet or the transaction will revert
   function updateChainSelectorMechanisms(uint64[] calldata removes, uint64[] calldata adds) external onlyOwner {
     for (uint256 i = 0; i < removes.length; ++i) {
       delete s_shouldUseLockRelease[removes[i]];
@@ -246,6 +251,10 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
     }
 
     for (uint256 i = 0; i < adds.length; ++i) {
+      // Prevent enabling lock release on chains which have already been migrated
+      if (s_migratedChains.contains(adds[i])) {
+        revert TokenLockingNotAllowedAfterMigration(adds[i]);
+      }
       s_shouldUseLockRelease[adds[i]] = true;
       emit LockReleaseEnabled(adds[i]);
     }
diff --git a/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol b/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
index 41077eb4ec..12264c5d37 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
@@ -37,6 +37,8 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
 
   mapping(uint64 chainSelector => bool shouldUseLockRelease) internal s_shouldUseLockRelease;
 
+  EnumerableSet.UintSet internal s_migratedChains;
+
   constructor(address token, address router) {
     i_USDC = IBurnMintERC20(token);
     i_router = Router(router);
@@ -70,6 +72,8 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
     // Disable L/R automatically on burned chain and enable CCTP
     delete s_shouldUseLockRelease[burnChainSelector];
 
+    s_migratedChains.add(burnChainSelector);
+
     emit CCTPMigrationExecuted(burnChainSelector, tokensToBurn);
   }
 
diff --git a/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol b/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol
index 906ff2b113..de92219435 100644
--- a/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol
+++ b/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol
@@ -926,4 +926,36 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
     );
     s_usdcTokenPool.provideLiquidity(DEST_CHAIN_SELECTOR, 1e6);
   }
+
+  function test_cannotRevertChainMechanism_afterMigration_Revert() public {
+    test_lockOrBurn_then_BurnInCCTPMigration_Success();
+
+    vm.startPrank(OWNER);
+
+    // Mark the destination chain as supporting CCTP, so use L/R instead.
+    uint64[] memory destChainAdds = new uint64[](1);
+    destChainAdds[0] = DEST_CHAIN_SELECTOR;
+
+    vm.expectRevert(
+      abi.encodeWithSelector(
+        HybridLockReleaseUSDCTokenPool.TokenLockingNotAllowedAfterMigration.selector, DEST_CHAIN_SELECTOR
+      )
+    );
+
+    s_usdcTokenPool.updateChainSelectorMechanisms(new uint64[](0), destChainAdds);
+  }
+
+  function test_cnanotProvideLiquidity_AfterMigration_Revert() public {
+    test_lockOrBurn_then_BurnInCCTPMigration_Success();
+
+    vm.startPrank(OWNER);
+
+    vm.expectRevert(
+      abi.encodeWithSelector(
+        HybridLockReleaseUSDCTokenPool.TokenLockingNotAllowedAfterMigration.selector, DEST_CHAIN_SELECTOR
+      )
+    );
+
+    s_usdcTokenPool.provideLiquidity(DEST_CHAIN_SELECTOR, 1e6);
+  }
 }

From b7067b5f7741d75af8d26cb0d1bcd8dcfd4b7675 Mon Sep 17 00:00:00 2001
From: Josh <josh.weintraub@smartcontract.com>
Date: Thu, 3 Oct 2024 12:52:34 -0400
Subject: [PATCH 3/7] formatting, remove unnec. state vars, and better natspec

---
 .../USDC/BurnMintWithLockReleaseFlagTokenPool.sol     | 10 ++++++++--
 .../pools/USDC/HybridLockReleaseUSDCTokenPool.sol     | 11 +++++++----
 .../src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol   |  9 +++------
 .../pools/BurnMintWithLockReleaseFlagTokenPool.t.sol  |  1 -
 4 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol b/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol
index 3e33fccc63..e260300bd7 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol
@@ -1,10 +1,16 @@
-pragma solidity ^0.8.0;
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity 0.8.24;
 
 import {IBurnMintERC20} from "../../../shared/token/ERC20/IBurnMintERC20.sol";
 
 import {Pool} from "../../libraries/Pool.sol";
 import {BurnMintTokenPool} from "../BurnMintTokenPool.sol";
 
+/// @notice A standard BurnMintTokenPool with modified destPoolData so that the remote pool knows to release tokens
+/// instead of minting. This enables interoperability with HybridLockReleaseUSDCTokenPool which uses
+// the destPoolData to determine whether to mint or release tokens.
+/// @dev The only difference between this contract and BurnMintTokenPool is the destPoolData returns the
+/// abi-encoded LOCK_RELEASE_FLAG instead of an empty string.
 contract BurnMintWithLockReleaseFlagTokenPool is BurnMintTokenPool {
   /// bytes4(keccak256("NO_CCTP_USE_LOCK_RELEASE"))
   bytes4 public constant LOCK_RELEASE_FLAG = 0xfa7c07de;
@@ -20,7 +26,7 @@ contract BurnMintWithLockReleaseFlagTokenPool is BurnMintTokenPool {
   /// @dev The _validateLockOrBurn check is an essential security check
   function lockOrBurn(
     Pool.LockOrBurnInV1 calldata lockOrBurnIn
-  ) external virtual override returns (Pool.LockOrBurnOutV1 memory) {
+  ) external override returns (Pool.LockOrBurnOutV1 memory) {
     _validateLockOrBurn(lockOrBurnIn);
 
     _burn(lockOrBurnIn.amount);
diff --git a/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol b/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
index 91db9c1b29..c034fcad75 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
@@ -49,7 +49,7 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
     address[] memory allowlist,
     address rmnProxy,
     address router
-  ) USDCTokenPool(tokenMessenger, token, allowlist, rmnProxy, router) USDCBridgeMigrator(address(token), router) {}
+  ) USDCTokenPool(tokenMessenger, token, allowlist, rmnProxy, router) USDCBridgeMigrator(address(token)) {}
 
   // ================================================================
   // │                   Incoming/Outgoing Mechanisms               |
@@ -170,10 +170,12 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
   function provideLiquidity(uint64 remoteChainSelector, uint256 amount) external {
     if (s_liquidityProvider[remoteChainSelector] != msg.sender) revert TokenPool.Unauthorized(msg.sender);
 
+    // Prevent adding liquidity to a chain which has already been migrated
     if (s_migratedChains.contains(remoteChainSelector)) {
       revert TokenLockingNotAllowedAfterMigration(remoteChainSelector);
     }
 
+    // prevent adding liquidity to a chain which has been proposed for migration
     if (remoteChainSelector == s_proposedUSDCMigrationChain) {
       revert LanePausedForCCTPMigration(remoteChainSelector);
     }
@@ -192,7 +194,7 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
   /// withdrawn on this chain, otherwise a mismatch may occur between locked token balance and remote circulating supply
   /// which may block a potential future migration of the chain to CCTP.
   function withdrawLiquidity(uint64 remoteChainSelector, uint256 amount) external onlyOwner {
-    // Circle requires a supply-lock to prevent outgoing messages once the migration process begins.
+    // A supply-lock is required to prevent outgoing messages once the migration process begins.
     // This prevents new outgoing messages once the migration has begun to ensure any the procedure runs as expected
     if (remoteChainSelector == s_proposedUSDCMigrationChain) {
       revert LanePausedForCCTPMigration(remoteChainSelector);
@@ -220,7 +222,8 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
   function transferLiquidity(address from, uint64 remoteChainSelector) external onlyOwner {
     OwnerIsCreator(from).acceptOwnership();
 
-    // Withdraw all available liquidity from the old pool.
+    // Withdraw all available liquidity from the old pool. No check is needed for pending migrations, as the old pool
+    // will revert if the migration has begun.
     uint256 withdrawAmount = HybridLockReleaseUSDCTokenPool(from).getLockedTokensForChain(remoteChainSelector);
     HybridLockReleaseUSDCTokenPool(from).withdrawLiquidity(remoteChainSelector, withdrawAmount);
 
@@ -235,7 +238,7 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
 
   /// @notice Return whether a lane should use the alternative L/R mechanism in the token pool.
   /// @param remoteChainSelector the remote chain the lane is interacting with
-  /// @return bool Return true if the alternative L/R mechanism should be used
+  /// @return bool Return true if the alternative L/R mechanism should be used, and is decided by the Owner
   function shouldUseLockRelease(uint64 remoteChainSelector) public view virtual returns (bool) {
     return s_shouldUseLockRelease[remoteChainSelector];
   }
diff --git a/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol b/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
index 12264c5d37..82532e97f5 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: BUSL-1.1
 pragma solidity ^0.8.24;
 
 import {OwnerIsCreator} from "../../../shared/access/OwnerIsCreator.sol";
@@ -5,8 +6,6 @@ import {IBurnMintERC20} from "../../../shared/token/ERC20/IBurnMintERC20.sol";
 
 import {EnumerableSet} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/utils/structs/EnumerableSet.sol";
 
-import {Router} from "../../Router.sol";
-
 /// @notice Allows migration of a lane in a token pool from Lock/Release to CCTP supported Burn/Mint. Contract
 /// functionality is based on hard requirements defined by Circle to allow for future CCTP compatibility
 /// https://github.com/circlefin/stablecoin-evm/blob/master/doc/bridged_USDC_standard.md
@@ -26,8 +25,7 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
   error NoMigrationProposalPending();
   error InvalidChainSelector();
 
-  IBurnMintERC20 internal immutable i_USDC;
-  Router internal immutable i_router;
+  IBurnMintERC20 private immutable i_USDC;
 
   address internal s_circleUSDCMigrator;
   uint64 internal s_proposedUSDCMigrationChain;
@@ -39,9 +37,8 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
 
   EnumerableSet.UintSet internal s_migratedChains;
 
-  constructor(address token, address router) {
+  constructor(address token) {
     i_USDC = IBurnMintERC20(token);
-    i_router = Router(router);
   }
 
   /// @notice Burn USDC locked for a specific lane so that destination USDC can be converted from
diff --git a/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
index 88f2075425..b341624798 100644
--- a/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
+++ b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
@@ -3,7 +3,6 @@ pragma solidity 0.8.24;
 
 import {Pool} from "../../libraries/Pool.sol";
 import {RateLimiter} from "../../libraries/RateLimiter.sol";
-
 import {TokenPool} from "../../pools/TokenPool.sol";
 import {BurnMintWithLockReleaseFlagTokenPool} from "../../pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol";
 import {BurnMintSetup} from "./BurnMintSetup.t.sol";

From 16a43d6dca2e86b12c3ad831453df6c5780a53b0 Mon Sep 17 00:00:00 2001
From: Josh <josh.weintraub@smartcontract.com>
Date: Thu, 17 Oct 2024 10:16:48 -0400
Subject: [PATCH 4/7] lock pragma and update function visibility

---
 contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol b/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
index 82532e97f5..f323ee7d81 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/USDCBridgeMigrator.sol
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: BUSL-1.1
-pragma solidity ^0.8.24;
+pragma solidity 0.8.24;
 
 import {OwnerIsCreator} from "../../../shared/access/OwnerIsCreator.sol";
 import {IBurnMintERC20} from "../../../shared/token/ERC20/IBurnMintERC20.sol";
@@ -153,7 +153,7 @@ abstract contract USDCBridgeMigrator is OwnerIsCreator {
   /// @dev The sum of locked tokens and excluded tokens should equal the supply of the token on the remote chain
   /// @param remoteChainSelector The chain for which the excluded tokens are being queried
   /// @return uint256 amount of tokens excluded from being burned in a CCTP-migration
-  function getExcludedTokensByChain(uint64 remoteChainSelector) public view returns (uint256) {
+  function getExcludedTokensByChain(uint64 remoteChainSelector) external view returns (uint256) {
     return s_tokensExcludedFromBurn[remoteChainSelector];
   }
 }

From 2d89158c663679824c0c3ebeafeab9adc404d5e4 Mon Sep 17 00:00:00 2001
From: Josh <josh.weintraub@smartcontract.com>
Date: Tue, 22 Oct 2024 11:30:45 -0400
Subject: [PATCH 5/7] remove unnecessary test

---
 contracts/gas-snapshots/ccip.gas-snapshot                  | 3 +--
 .../test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol  | 7 -------
 2 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/contracts/gas-snapshots/ccip.gas-snapshot b/contracts/gas-snapshots/ccip.gas-snapshot
index f643d81b43..371bd6fda2 100644
--- a/contracts/gas-snapshots/ccip.gas-snapshot
+++ b/contracts/gas-snapshots/ccip.gas-snapshot
@@ -30,8 +30,7 @@ BurnMintTokenPool_lockOrBurn:test_Setup_Success() (gas: 17851)
 BurnMintTokenPool_releaseOrMint:test_ChainNotAllowed_Revert() (gas: 28805)
 BurnMintTokenPool_releaseOrMint:test_PoolMintNotHealthy_Revert() (gas: 56253)
 BurnMintTokenPool_releaseOrMint:test_PoolMint_Success() (gas: 112391)
-BurnMintWithLockReleaseFlagTokenPool_lockOrBurn:test_PoolBurn_CorrectReturnData_Success() (gas: 243221)
-BurnMintWithLockReleaseFlagTokenPool_lockOrBurn:test_Setup_Success() (gas: 17873)
+BurnMintWithLockReleaseFlagTokenPool_lockOrBurn:test_PoolBurn_CorrectReturnData_Success() (gas: 242931)
 BurnWithFromMintTokenPool_lockOrBurn:test_ChainNotAllowed_Revert() (gas: 28842)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurnRevertNotHealthy_Revert() (gas: 55271)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurn_Success() (gas: 244050)
diff --git a/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
index b341624798..c84fc2efc5 100644
--- a/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
+++ b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
@@ -25,13 +25,6 @@ contract BurnMintWithLockReleaseFlagTokenPoolSetup is BurnMintSetup {
 }
 
 contract BurnMintWithLockReleaseFlagTokenPool_lockOrBurn is BurnMintWithLockReleaseFlagTokenPoolSetup {
-  function test_Setup_Success() public view {
-    assertEq(address(s_burnMintERC677), address(s_pool.getToken()));
-    assertEq(address(s_mockRMN), s_pool.getRmnProxy());
-    assertEq(false, s_pool.getAllowListEnabled());
-    assertEq("BurnMintTokenPool 1.5.0", s_pool.typeAndVersion());
-  }
-
   function test_PoolBurn_CorrectReturnData_Success() public {
     uint256 burnAmount = 20_000e18;
 

From 9802bc0052b41269f273cb63a2b05d9aa469331e Mon Sep 17 00:00:00 2001
From: Josh <josh.weintraub@smartcontract.com>
Date: Tue, 22 Oct 2024 13:04:40 -0400
Subject: [PATCH 6/7] update BurnMintWithLockReleaseFlag to import the flag
 instead of redefining it for safety

---
 contracts/gas-snapshots/ccip.gas-snapshot     | 64 +++++++++----------
 .../BurnMintWithLockReleaseFlagTokenPool.sol  |  7 +-
 .../USDC/HybridLockReleaseUSDCTokenPool.sol   |  6 +-
 ...BurnMintWithLockReleaseFlagTokenPool.t.sol |  4 +-
 .../HybridLockReleaseUSDCTokenPool.t.sol      |  9 +--
 5 files changed, 47 insertions(+), 43 deletions(-)

diff --git a/contracts/gas-snapshots/ccip.gas-snapshot b/contracts/gas-snapshots/ccip.gas-snapshot
index 371bd6fda2..3695e6d458 100644
--- a/contracts/gas-snapshots/ccip.gas-snapshot
+++ b/contracts/gas-snapshots/ccip.gas-snapshot
@@ -30,7 +30,7 @@ BurnMintTokenPool_lockOrBurn:test_Setup_Success() (gas: 17851)
 BurnMintTokenPool_releaseOrMint:test_ChainNotAllowed_Revert() (gas: 28805)
 BurnMintTokenPool_releaseOrMint:test_PoolMintNotHealthy_Revert() (gas: 56253)
 BurnMintTokenPool_releaseOrMint:test_PoolMint_Success() (gas: 112391)
-BurnMintWithLockReleaseFlagTokenPool_lockOrBurn:test_PoolBurn_CorrectReturnData_Success() (gas: 242931)
+BurnMintWithLockReleaseFlagTokenPool_lockOrBurn:test_PoolBurn_CorrectReturnData_Success() (gas: 242252)
 BurnWithFromMintTokenPool_lockOrBurn:test_ChainNotAllowed_Revert() (gas: 28842)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurnRevertNotHealthy_Revert() (gas: 55271)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurn_Success() (gas: 244050)
@@ -425,38 +425,38 @@ FeeQuoter_validateDestFamilyAddress:test_InvalidEVMAddressPrecompiles_Revert() (
 FeeQuoter_validateDestFamilyAddress:test_InvalidEVMAddress_Revert() (gas: 10839)
 FeeQuoter_validateDestFamilyAddress:test_ValidEVMAddress_Success() (gas: 6731)
 FeeQuoter_validateDestFamilyAddress:test_ValidNonEVMAddress_Success() (gas: 6511)
-HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_LockReleaseMechanism_then_switchToPrimary_Success() (gas: 209230)
-HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_PrimaryMechanism_Success() (gas: 135861)
-HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_WhileMigrationPause_Revert() (gas: 109814)
-HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_onLockReleaseMechanism_Success() (gas: 147081)
-HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_OnLockReleaseMechanism_Success() (gas: 217718)
-HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_OnLockReleaseMechanism_then_switchToPrimary_Success() (gas: 426564)
-HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_incomingMessageWithPrimaryMechanism() (gas: 268928)
-HybridUSDCTokenPoolMigrationTests:test_ProposeMigration_ChainNotUsingLockRelease_Revert() (gas: 15821)
-HybridUSDCTokenPoolMigrationTests:test_ReleaseOrMint_WhileMigrationPause_Revert() (gas: 114166)
-HybridUSDCTokenPoolMigrationTests:test_burnLockedUSDC_invalidPermissions_Revert() (gas: 39362)
-HybridUSDCTokenPoolMigrationTests:test_cancelExistingCCTPMigrationProposal() (gas: 56207)
-HybridUSDCTokenPoolMigrationTests:test_cannotCancelANonExistentMigrationProposal() (gas: 12736)
-HybridUSDCTokenPoolMigrationTests:test_cannotModifyLiquidityWithoutPermissions_Revert() (gas: 13373)
-HybridUSDCTokenPoolMigrationTests:test_cannotProvideLiquidityWhenMigrationProposalPending_Revert() (gas: 67304)
-HybridUSDCTokenPoolMigrationTests:test_cannotRevertChainMechanism_afterMigration_Revert() (gas: 313390)
-HybridUSDCTokenPoolMigrationTests:test_cannotTransferLiquidityDuringPendingMigration_Revert() (gas: 177033)
-HybridUSDCTokenPoolMigrationTests:test_cnanotProvideLiquidity_AfterMigration_Revert() (gas: 313775)
+HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_LockReleaseMechanism_then_switchToPrimary_Success() (gas: 209283)
+HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_PrimaryMechanism_Success() (gas: 135879)
+HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_WhileMigrationPause_Revert() (gas: 109794)
+HybridUSDCTokenPoolMigrationTests:test_LockOrBurn_onLockReleaseMechanism_Success() (gas: 147082)
+HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_OnLockReleaseMechanism_Success() (gas: 217024)
+HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_OnLockReleaseMechanism_then_switchToPrimary_Success() (gas: 425913)
+HybridUSDCTokenPoolMigrationTests:test_MintOrRelease_incomingMessageWithPrimaryMechanism() (gas: 268945)
+HybridUSDCTokenPoolMigrationTests:test_ProposeMigration_ChainNotUsingLockRelease_Revert() (gas: 15843)
+HybridUSDCTokenPoolMigrationTests:test_ReleaseOrMint_WhileMigrationPause_Revert() (gas: 113503)
+HybridUSDCTokenPoolMigrationTests:test_burnLockedUSDC_invalidPermissions_Revert() (gas: 39300)
+HybridUSDCTokenPoolMigrationTests:test_cancelExistingCCTPMigrationProposal() (gas: 56208)
+HybridUSDCTokenPoolMigrationTests:test_cannotCancelANonExistentMigrationProposal() (gas: 12758)
+HybridUSDCTokenPoolMigrationTests:test_cannotModifyLiquidityWithoutPermissions_Revert() (gas: 13395)
+HybridUSDCTokenPoolMigrationTests:test_cannotProvideLiquidityWhenMigrationProposalPending_Revert() (gas: 67370)
+HybridUSDCTokenPoolMigrationTests:test_cannotRevertChainMechanism_afterMigration_Revert() (gas: 313252)
+HybridUSDCTokenPoolMigrationTests:test_cannotTransferLiquidityDuringPendingMigration_Revert() (gas: 177053)
+HybridUSDCTokenPoolMigrationTests:test_cnanotProvideLiquidity_AfterMigration_Revert() (gas: 313637)
 HybridUSDCTokenPoolMigrationTests:test_excludeTokensWhenNoMigrationProposalPending_Revert() (gas: 13657)
-HybridUSDCTokenPoolMigrationTests:test_lockOrBurn_then_BurnInCCTPMigration_Success() (gas: 309952)
-HybridUSDCTokenPoolMigrationTests:test_transferLiquidity_Success() (gas: 167124)
-HybridUSDCTokenPoolMigrationTests:test_unstickManualTxAfterMigration_destChain_Success() (gas: 156736)
-HybridUSDCTokenPoolMigrationTests:test_unstickManualTxAfterMigration_homeChain_Success() (gas: 516552)
-HybridUSDCTokenPoolTests:test_LockOrBurn_LockReleaseMechanism_then_switchToPrimary_Success() (gas: 209230)
-HybridUSDCTokenPoolTests:test_LockOrBurn_PrimaryMechanism_Success() (gas: 135880)
-HybridUSDCTokenPoolTests:test_LockOrBurn_WhileMigrationPause_Revert() (gas: 109814)
-HybridUSDCTokenPoolTests:test_LockOrBurn_onLockReleaseMechanism_Success() (gas: 147079)
-HybridUSDCTokenPoolTests:test_MintOrRelease_OnLockReleaseMechanism_Success() (gas: 217696)
-HybridUSDCTokenPoolTests:test_MintOrRelease_OnLockReleaseMechanism_then_switchToPrimary_Success() (gas: 426520)
-HybridUSDCTokenPoolTests:test_MintOrRelease_incomingMessageWithPrimaryMechanism() (gas: 268910)
-HybridUSDCTokenPoolTests:test_ReleaseOrMint_WhileMigrationPause_Revert() (gas: 114210)
-HybridUSDCTokenPoolTests:test_cannotTransferLiquidityDuringPendingMigration_Revert() (gas: 176989)
-HybridUSDCTokenPoolTests:test_transferLiquidity_Success() (gas: 167107)
+HybridUSDCTokenPoolMigrationTests:test_lockOrBurn_then_BurnInCCTPMigration_Success() (gas: 309797)
+HybridUSDCTokenPoolMigrationTests:test_transferLiquidity_Success() (gas: 167051)
+HybridUSDCTokenPoolMigrationTests:test_unstickManualTxAfterMigration_destChain_Success() (gas: 156096)
+HybridUSDCTokenPoolMigrationTests:test_unstickManualTxAfterMigration_homeChain_Success() (gas: 515988)
+HybridUSDCTokenPoolTests:test_LockOrBurn_LockReleaseMechanism_then_switchToPrimary_Success() (gas: 209283)
+HybridUSDCTokenPoolTests:test_LockOrBurn_PrimaryMechanism_Success() (gas: 135897)
+HybridUSDCTokenPoolTests:test_LockOrBurn_WhileMigrationPause_Revert() (gas: 109794)
+HybridUSDCTokenPoolTests:test_LockOrBurn_onLockReleaseMechanism_Success() (gas: 147080)
+HybridUSDCTokenPoolTests:test_MintOrRelease_OnLockReleaseMechanism_Success() (gas: 217002)
+HybridUSDCTokenPoolTests:test_MintOrRelease_OnLockReleaseMechanism_then_switchToPrimary_Success() (gas: 425869)
+HybridUSDCTokenPoolTests:test_MintOrRelease_incomingMessageWithPrimaryMechanism() (gas: 268928)
+HybridUSDCTokenPoolTests:test_ReleaseOrMint_WhileMigrationPause_Revert() (gas: 113547)
+HybridUSDCTokenPoolTests:test_cannotTransferLiquidityDuringPendingMigration_Revert() (gas: 177009)
+HybridUSDCTokenPoolTests:test_transferLiquidity_Success() (gas: 167033)
 LockReleaseTokenPoolAndProxy_setRebalancer:test_SetRebalancer_Revert() (gas: 10989)
 LockReleaseTokenPoolAndProxy_setRebalancer:test_SetRebalancer_Success() (gas: 18028)
 LockReleaseTokenPoolPoolAndProxy_canAcceptLiquidity:test_CanAcceptLiquidity_Success() (gas: 3051552)
diff --git a/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol b/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol
index e260300bd7..fd54387620 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol
@@ -5,6 +5,7 @@ import {IBurnMintERC20} from "../../../shared/token/ERC20/IBurnMintERC20.sol";
 
 import {Pool} from "../../libraries/Pool.sol";
 import {BurnMintTokenPool} from "../BurnMintTokenPool.sol";
+import {LOCK_RELEASE_FLAG} from "./HybridLockReleaseUSDCTokenPool.sol";
 
 /// @notice A standard BurnMintTokenPool with modified destPoolData so that the remote pool knows to release tokens
 /// instead of minting. This enables interoperability with HybridLockReleaseUSDCTokenPool which uses
@@ -12,9 +13,6 @@ import {BurnMintTokenPool} from "../BurnMintTokenPool.sol";
 /// @dev The only difference between this contract and BurnMintTokenPool is the destPoolData returns the
 /// abi-encoded LOCK_RELEASE_FLAG instead of an empty string.
 contract BurnMintWithLockReleaseFlagTokenPool is BurnMintTokenPool {
-  /// bytes4(keccak256("NO_CCTP_USE_LOCK_RELEASE"))
-  bytes4 public constant LOCK_RELEASE_FLAG = 0xfa7c07de;
-
   constructor(
     IBurnMintERC20 token,
     address[] memory allowlist,
@@ -24,6 +22,8 @@ contract BurnMintWithLockReleaseFlagTokenPool is BurnMintTokenPool {
 
   /// @notice Burn the token in the pool
   /// @dev The _validateLockOrBurn check is an essential security check
+  /// @dev Performs the exact same functionality as BurnMintTokenPool, but returns the LOCK_RELEASE_FLAG
+  /// as the destPoolData to signal to the remote pool to release tokens instead of minting them.
   function lockOrBurn(
     Pool.LockOrBurnInV1 calldata lockOrBurnIn
   ) external override returns (Pool.LockOrBurnOutV1 memory) {
@@ -33,6 +33,7 @@ contract BurnMintWithLockReleaseFlagTokenPool is BurnMintTokenPool {
 
     emit Burned(msg.sender, lockOrBurnIn.amount);
 
+    // LOCK_RELEASE_FLAG = bytes4(keccak256("NO_CCTP_USE_LOCK_RELEASE"))
     return Pool.LockOrBurnOutV1({
       destTokenAddress: getRemoteToken(lockOrBurnIn.remoteChainSelector),
       destPoolData: abi.encode(LOCK_RELEASE_FLAG)
diff --git a/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol b/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
index c034fcad75..e61f0cc7dd 100644
--- a/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
+++ b/contracts/src/v0.8/ccip/pools/USDC/HybridLockReleaseUSDCTokenPool.sol
@@ -14,6 +14,9 @@ import {IERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/tok
 import {SafeERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/utils/SafeERC20.sol";
 import {EnumerableSet} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/utils/structs/EnumerableSet.sol";
 
+// bytes4(keccak256("NO_CCTP_USE_LOCK_RELEASE"))
+bytes4 constant LOCK_RELEASE_FLAG = 0xfa7c07de;
+
 /// @notice A token pool for USDC which uses CCTP for supported chains and Lock/Release for all others
 /// @dev The functionality from LockReleaseTokenPool.sol has been duplicated due to lack of compiler support for shared
 /// constructors between parents
@@ -34,9 +37,6 @@ contract HybridLockReleaseUSDCTokenPool is USDCTokenPool, USDCBridgeMigrator {
   error LanePausedForCCTPMigration(uint64 remoteChainSelector);
   error TokenLockingNotAllowedAfterMigration(uint64 remoteChainSelector);
 
-  /// bytes4(keccak256("NO_CCTP_USE_LOCK_RELEASE"))
-  bytes4 public constant LOCK_RELEASE_FLAG = 0xfa7c07de;
-
   /// @notice The address of the liquidity provider for a specific chain.
   /// External liquidity is not required when there is one canonical token deployed to a chain,
   /// and CCIP is facilitating mint/burn on all the other chains, in which case the invariant
diff --git a/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
index c84fc2efc5..9fc7e160e9 100644
--- a/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
+++ b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
@@ -5,6 +5,8 @@ import {Pool} from "../../libraries/Pool.sol";
 import {RateLimiter} from "../../libraries/RateLimiter.sol";
 import {TokenPool} from "../../pools/TokenPool.sol";
 import {BurnMintWithLockReleaseFlagTokenPool} from "../../pools/USDC/BurnMintWithLockReleaseFlagTokenPool.sol";
+
+import {LOCK_RELEASE_FLAG} from "../../pools/USDC/HybridLockReleaseUSDCTokenPool.sol";
 import {BurnMintSetup} from "./BurnMintSetup.t.sol";
 
 import {IERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
@@ -57,6 +59,6 @@ contract BurnMintWithLockReleaseFlagTokenPool_lockOrBurn is BurnMintWithLockRele
 
     assertEq(s_burnMintERC677.balanceOf(address(s_pool)), 0);
 
-    assertEq(bytes4(lockOrBurnOut.destPoolData), s_pool.LOCK_RELEASE_FLAG());
+    assertEq(bytes4(lockOrBurnOut.destPoolData), LOCK_RELEASE_FLAG);
   }
 }
diff --git a/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol b/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol
index de92219435..60f3c6720f 100644
--- a/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol
+++ b/contracts/src/v0.8/ccip/test/pools/HybridLockReleaseUSDCTokenPool.t.sol
@@ -14,6 +14,7 @@ import {RateLimiter} from "../../libraries/RateLimiter.sol";
 
 import {TokenPool} from "../../pools/TokenPool.sol";
 import {HybridLockReleaseUSDCTokenPool} from "../../pools/USDC/HybridLockReleaseUSDCTokenPool.sol";
+import {LOCK_RELEASE_FLAG} from "../../pools/USDC/HybridLockReleaseUSDCTokenPool.sol";
 import {USDCBridgeMigrator} from "../../pools/USDC/USDCBridgeMigrator.sol";
 import {USDCTokenPool} from "../../pools/USDC/USDCTokenPool.sol";
 import {BaseTest} from "../BaseTest.t.sol";
@@ -224,7 +225,7 @@ contract HybridUSDCTokenPoolTests is USDCTokenPoolSetup {
         localToken: address(s_token),
         remoteChainSelector: SOURCE_CHAIN_SELECTOR,
         sourcePoolAddress: sourceTokenData.sourcePoolAddress,
-        sourcePoolData: abi.encode(s_usdcTokenPool.LOCK_RELEASE_FLAG()),
+        sourcePoolData: abi.encode(LOCK_RELEASE_FLAG),
         offchainTokenData: ""
       })
     );
@@ -442,7 +443,7 @@ contract HybridUSDCTokenPoolTests is USDCTokenPoolSetup {
       destGasAmount: USDC_DEST_TOKEN_GAS
     });
 
-    bytes memory sourcePoolDataLockRelease = abi.encode(s_usdcTokenPool.LOCK_RELEASE_FLAG());
+    bytes memory sourcePoolDataLockRelease = abi.encode(LOCK_RELEASE_FLAG);
 
     uint256 amount = 1e6;
 
@@ -757,7 +758,7 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
         localToken: address(s_token),
         remoteChainSelector: SOURCE_CHAIN_SELECTOR,
         sourcePoolAddress: sourceTokenData.sourcePoolAddress,
-        sourcePoolData: abi.encode(s_usdcTokenPool.LOCK_RELEASE_FLAG()),
+        sourcePoolData: abi.encode(LOCK_RELEASE_FLAG),
         offchainTokenData: ""
       })
     );
@@ -876,7 +877,7 @@ contract HybridUSDCTokenPoolMigrationTests is HybridUSDCTokenPoolTests {
         localToken: address(s_token),
         remoteChainSelector: SOURCE_CHAIN_SELECTOR,
         sourcePoolAddress: sourceTokenData.sourcePoolAddress,
-        sourcePoolData: abi.encode(s_usdcTokenPool.LOCK_RELEASE_FLAG()),
+        sourcePoolData: abi.encode(LOCK_RELEASE_FLAG),
         offchainTokenData: ""
       })
     );

From 11bd6350d9f13f387caf52e387841c1478466113 Mon Sep 17 00:00:00 2001
From: Josh <josh.weintraub@smartcontract.com>
Date: Tue, 22 Oct 2024 13:54:57 -0400
Subject: [PATCH 7/7] test rename

---
 contracts/gas-snapshots/ccip.gas-snapshot                       | 2 +-
 .../ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/contracts/gas-snapshots/ccip.gas-snapshot b/contracts/gas-snapshots/ccip.gas-snapshot
index 3695e6d458..ea2a893702 100644
--- a/contracts/gas-snapshots/ccip.gas-snapshot
+++ b/contracts/gas-snapshots/ccip.gas-snapshot
@@ -30,7 +30,7 @@ BurnMintTokenPool_lockOrBurn:test_Setup_Success() (gas: 17851)
 BurnMintTokenPool_releaseOrMint:test_ChainNotAllowed_Revert() (gas: 28805)
 BurnMintTokenPool_releaseOrMint:test_PoolMintNotHealthy_Revert() (gas: 56253)
 BurnMintTokenPool_releaseOrMint:test_PoolMint_Success() (gas: 112391)
-BurnMintWithLockReleaseFlagTokenPool_lockOrBurn:test_PoolBurn_CorrectReturnData_Success() (gas: 242252)
+BurnMintWithLockReleaseFlagTokenPool_lockOrBurn:test_LockOrBurn_CorrectReturnData_Success() (gas: 242268)
 BurnWithFromMintTokenPool_lockOrBurn:test_ChainNotAllowed_Revert() (gas: 28842)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurnRevertNotHealthy_Revert() (gas: 55271)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurn_Success() (gas: 244050)
diff --git a/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
index 9fc7e160e9..c9080a0e14 100644
--- a/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
+++ b/contracts/src/v0.8/ccip/test/pools/BurnMintWithLockReleaseFlagTokenPool.t.sol
@@ -27,7 +27,7 @@ contract BurnMintWithLockReleaseFlagTokenPoolSetup is BurnMintSetup {
 }
 
 contract BurnMintWithLockReleaseFlagTokenPool_lockOrBurn is BurnMintWithLockReleaseFlagTokenPoolSetup {
-  function test_PoolBurn_CorrectReturnData_Success() public {
+  function test_LockOrBurn_CorrectReturnData_Success() public {
     uint256 burnAmount = 20_000e18;
 
     deal(address(s_burnMintERC677), address(s_pool), burnAmount);