add tests

contracts/gas-snapshots/ccip.gas-snapshot

@@ -33,7 +33,11 @@ BurnMintTokenPool_releaseOrMint:test_PoolMint_Success() (gas: 112391)
 BurnWithFromMintTokenPool_lockOrBurn:test_ChainNotAllowed_Revert() (gas: 28842)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurnRevertNotHealthy_Revert() (gas: 55271)
 BurnWithFromMintTokenPool_lockOrBurn:test_PoolBurn_Success() (gas: 244050)
-BurnWithFromMintTokenPool_lockOrBurn:test_Setup_Success() (gas: 24170)
+BurnWithFromMintTokenPool_lockOrBurn:test_Setup_Success() (gas: 24168)
+BurnWithFromMintTokenPool_releaseOrMint:test_Setup_Success() (gas: 24547)
+BurnWithFromMintTokenPool_releaseOrMint:test_releaseOrMint_NegativeMintAmount_reverts() (gas: 93840)
+BurnWithFromMintTokenPool_releaseOrMint:test_releaseOrMint_Success() (gas: 93423)
+BurnWithFromMintTokenPool_releaseOrMint:test_releaseOrMint_rebasing_success(uint16) (runs: 257, μ: 95578, ~: 97505)
 CCIPClientExample_sanity:test_ImmutableExamples_Success() (gas: 2052431)
 CCIPHome__validateConfig:test__validateConfigLessTransmittersThanSigners_Success() (gas: 334693)
 CCIPHome__validateConfig:test__validateConfigSmallerFChain_Success() (gas: 466117)

contracts/src/v0.8/ccip/pools/BurnWithFromMintRebasingTokenPool.sol

@@ -18,7 +18,7 @@ import {TokenPool} from "./TokenPool.sol";
 contract BurnWithFromMintRebasingTokenPool is BurnWithFromMintTokenPool {
   using SafeERC20 for IBurnMintERC20;
 
-  error NegativeMintAmount(uint256 pre, uint256 post);
+  error NegativeMintAmount(uint256 amountBurned);
 
   string public constant override typeAndVersion = "BurnWithFromMintRebasingTokenPool 1.5.0";
 
@@ -41,15 +41,15 @@ contract BurnWithFromMintRebasingTokenPool is BurnWithFromMintTokenPool {
     // Mint to the receiver
     IBurnMintERC20(address(i_token)).mint(releaseOrMintIn.receiver, releaseOrMintIn.amount);
 
-    emit Minted(msg.sender, releaseOrMintIn.receiver, releaseOrMintIn.amount);
-
     uint256 balancePost = IBurnMintERC20(address(i_token)).balanceOf(releaseOrMintIn.receiver);
 
     // Mint should not reduce the number of tokens in the receiver, if it does it will revert the call.
     if (balancePost < balancePre) {
-      revert NegativeMintAmount(balancePre, balancePost);
+      revert NegativeMintAmount(balancePre - balancePost);
     }
 
+    emit Minted(msg.sender, releaseOrMintIn.receiver, balancePost - balancePre);
+
     return Pool.ReleaseOrMintOutV1({destinationAmount: balancePost - balancePre});
   }
 }

contracts/src/v0.8/ccip/test/helpers/ERC20RebasingHelper.sol

@@ -5,14 +5,23 @@ import {ERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/toke
 
 contract ERC20RebasingHelper is ERC20 {
   uint16 public s_multiplierPercentage = 100;
+  bool public s_mintShouldBurn = false;
 
   constructor() ERC20("Rebasing", "REB") {}
 
   function mint(address to, uint256 amount) external {
-    _mint(to, amount * s_multiplierPercentage / 100);
+    if (!s_mintShouldBurn) {
+      _mint(to, amount * s_multiplierPercentage / 100);
+      return;
+    }
+    _burn(to, amount * s_multiplierPercentage / 100);
   }
 
   function setMultiplierPercentage(uint16 multiplierPercentage) external {
     s_multiplierPercentage = multiplierPercentage;
   }
+
+  function setMintShouldBurn(bool mintShouldBurn) external {
+    s_mintShouldBurn = mintShouldBurn;
+  }
 }

contracts/src/v0.8/ccip/test/pools/BurnWithFromMintRebasingTokenPool.t.sol

@@ -25,6 +25,8 @@ contract BurnWithFromMintRebasingTokenPoolSetup is BurnMintSetup {
 
     _applyChainUpdates(address(s_pool));
 
+    deal(address(s_rebasingToken), OWNER, 1e18);
+
     vm.startPrank(s_burnMintOffRamp);
   }
 }
@@ -40,22 +42,34 @@ contract BurnWithFromMintTokenPool_releaseOrMint is BurnWithFromMintRebasingToke
 
   function test_releaseOrMint_Success() public {
     uint256 amount = 1000;
+    uint256 balancePre = s_rebasingToken.balanceOf(address(OWNER));
 
     Pool.ReleaseOrMintOutV1 memory releaseOrMintOut = s_pool.releaseOrMint(_getReleaseOrMintIn(amount));
 
     assertEq(amount, releaseOrMintOut.destinationAmount);
-    assertEq(amount, s_rebasingToken.balanceOf(address(OWNER)));
+    assertEq(balancePre + amount, s_rebasingToken.balanceOf(address(OWNER)));
   }
 
   function test_releaseOrMint_rebasing_success(uint16 multiplierPercentage) public {
     uint256 amount = 1000;
     uint256 expectedAmount = amount * multiplierPercentage / 100;
     s_rebasingToken.setMultiplierPercentage(multiplierPercentage);
 
+    uint256 balancePre = s_rebasingToken.balanceOf(address(OWNER));
+
     Pool.ReleaseOrMintOutV1 memory releaseOrMintOut = s_pool.releaseOrMint(_getReleaseOrMintIn(amount));
 
     assertEq(expectedAmount, releaseOrMintOut.destinationAmount);
-    assertEq(expectedAmount, s_rebasingToken.balanceOf(address(OWNER)));
+    assertEq(balancePre + expectedAmount, s_rebasingToken.balanceOf(address(OWNER)));
+  }
+
+  function test_releaseOrMint_NegativeMintAmount_reverts() public {
+    uint256 amount = 1000;
+    s_rebasingToken.setMintShouldBurn(true);
+
+    vm.expectRevert(abi.encodeWithSelector(BurnWithFromMintRebasingTokenPool.NegativeMintAmount.selector, amount));
+
+    s_pool.releaseOrMint(_getReleaseOrMintIn(amount));
   }
 
   function _getReleaseOrMintIn(uint256 amount) internal view returns (Pool.ReleaseOrMintInV1 memory) {