🎨 Style nits

.forge-snapshots/permitBatchCleanWrite.snap

@@ -1 +1 @@
-89564
+89516

.forge-snapshots/permitBatchDirtyWrite.snap

@@ -1 +1 @@
-55364
+55316

.forge-snapshots/permitBatchTransferFromMultipleTokens.snap

@@ -1 +1 @@
-145155
+145107

.forge-snapshots/permitBatchTransferFromSingleToken.snap

@@ -1 +1 @@
-90375
+90327

.forge-snapshots/permitCleanWrite.snap

@@ -1 +1 @@
-61245
+61197

.forge-snapshots/permitDirtyNonce.snap

@@ -1 +1 @@
-42146
+42098

.forge-snapshots/permitDirtyWrite.snap

@@ -1 +1 @@
-44145
+44097

.forge-snapshots/permitInvalidSigner.snap

@@ -1 +1 @@
-42875
+42827

.forge-snapshots/permitSetMaxAllowanceCleanWrite.snap

@@ -1 +1 @@
-59246
+59198

.forge-snapshots/permitSetMaxAllowanceDirtyWrite.snap

@@ -1 +1 @@
-42146
+42098

.forge-snapshots/permitTransferFromSingleToken.snap

@@ -1 +1 @@
-88572
+88524

.forge-snapshots/single recipient 2 tokens.snap

@@ -1 +1 @@
-120178
+120130

.forge-snapshots/single recipient many tokens.snap

@@ -1 +1 @@
-136103
+136055

.gas-snapshot

@@ -1,53 +1,53 @@
 AllowanceTransferTest:testApprove() (gas: 42144)
-AllowanceTransferTest:testBatchTransferFrom() (gas: 156043)
-AllowanceTransferTest:testBatchTransferFromLengthMismatch() (gas: 75628)
-AllowanceTransferTest:testBatchTransferFromWithGasSnapshot() (gas: 156439)
-AllowanceTransferTest:testExcessiveInvalidation() (gas: 59214)
+AllowanceTransferTest:testBatchTransferFrom() (gas: 155995)
+AllowanceTransferTest:testBatchTransferFromLengthMismatch() (gas: 75580)
+AllowanceTransferTest:testBatchTransferFromWithGasSnapshot() (gas: 156391)
+AllowanceTransferTest:testExcessiveInvalidation() (gas: 59166)
 AllowanceTransferTest:testInvalidateNonces() (gas: 56453)
-AllowanceTransferTest:testMaxAllowance() (gas: 132582)
-AllowanceTransferTest:testMaxAllowanceDirtyWrite() (gas: 115306)
-AllowanceTransferTest:testPartialAllowance() (gas: 102786)
-AllowanceTransferTest:testReuseOrderedNonceInvalid() (gas: 62020)
-AllowanceTransferTest:testSetAllowance() (gas: 87131)
-AllowanceTransferTest:testSetAllowanceBatch() (gas: 129988)
-AllowanceTransferTest:testSetAllowanceBatchDirtyWrite() (gas: 95549)
+AllowanceTransferTest:testMaxAllowance() (gas: 132534)
+AllowanceTransferTest:testMaxAllowanceDirtyWrite() (gas: 115258)
+AllowanceTransferTest:testPartialAllowance() (gas: 102738)
+AllowanceTransferTest:testReuseOrderedNonceInvalid() (gas: 61972)
+AllowanceTransferTest:testSetAllowance() (gas: 87083)
+AllowanceTransferTest:testSetAllowanceBatch() (gas: 129940)
+AllowanceTransferTest:testSetAllowanceBatchDirtyWrite() (gas: 95501)
 AllowanceTransferTest:testSetAllowanceDeadlinePassed() (gas: 57607)
-AllowanceTransferTest:testSetAllowanceDirtyWrite() (gas: 69789)
-AllowanceTransferTest:testSetAllowanceInvalidSignature() (gas: 66207)
-AllowanceTransferTest:testSetAllowanceTransfer() (gas: 100965)
-AllowanceTransferTest:testSetAllowanceTransferDirtyNonceDirtyTransfer() (gas: 95235)
-AllowanceTransferTest:testTransferFromWithGasSnapshot() (gas: 130852)
-EIP712Test:testDomainSeparator() (gas: 5785)
-EIP712Test:testDomainSeparatorAfterFork() (gas: 10730)
+AllowanceTransferTest:testSetAllowanceDirtyWrite() (gas: 69741)
+AllowanceTransferTest:testSetAllowanceInvalidSignature() (gas: 66159)
+AllowanceTransferTest:testSetAllowanceTransfer() (gas: 100917)
+AllowanceTransferTest:testSetAllowanceTransferDirtyNonceDirtyTransfer() (gas: 95187)
+AllowanceTransferTest:testTransferFromWithGasSnapshot() (gas: 130804)
+EIP712Test:testDomainSeparator() (gas: 5737)
+EIP712Test:testDomainSeparatorAfterFork() (gas: 10586)
 NonceBitmapTest:testHighNonces() (gas: 36214)
 NonceBitmapTest:testInvalidateFullWord() (gas: 62732)
 NonceBitmapTest:testInvalidateNonzeroWord() (gas: 85931)
 NonceBitmapTest:testLowNonces() (gas: 41250)
 NonceBitmapTest:testNonceWordBoundary() (gas: 58074)
-NonceBitmapTest:testUseTwoRandomNonces(uint256,uint256) (runs: 256, μ: 49388, ~: 51913)
+NonceBitmapTest:testUseTwoRandomNonces(uint256,uint256) (runs: 256, μ: 49473, ~: 51913)
 NonceBitmapTest:testUsingNonceTwiceFails(uint256) (runs: 256, μ: 32679, ~: 32679)
-SignatureTransferTest:testGasMultiplePermitBatchTransferFrom() (gas: 266625)
-SignatureTransferTest:testGasSinglePermitBatchTransferFrom() (gas: 183516)
-SignatureTransferTest:testGasSinglePermitTransferFrom() (gas: 123494)
+SignatureTransferTest:testGasMultiplePermitBatchTransferFrom() (gas: 266577)
+SignatureTransferTest:testGasSinglePermitBatchTransferFrom() (gas: 183468)
+SignatureTransferTest:testGasSinglePermitTransferFrom() (gas: 123446)
 SignatureTransferTest:testInvalidateUnorderedNonces() (gas: 55784)
-SignatureTransferTest:testPermitBatchTransferFrom() (gas: 159502)
-SignatureTransferTest:testPermitBatchTransferFromSingleRecipient() (gas: 186009)
-SignatureTransferTest:testPermitBatchTransferFromTypedWitness() (gas: 163580)
-SignatureTransferTest:testPermitBatchTransferFromTypedWitnessInvalidType() (gas: 82819)
-SignatureTransferTest:testPermitBatchTransferFromTypedWitnessInvalidTypeHash() (gas: 82530)
-SignatureTransferTest:testPermitBatchTransferFromTypedWitnessInvalidTypeName() (gas: 83698)
-SignatureTransferTest:testPermitBatchTransferFromTypedWitnessInvalidWitness() (gas: 83731)
+SignatureTransferTest:testPermitBatchTransferFrom() (gas: 159454)
+SignatureTransferTest:testPermitBatchTransferFromSingleRecipient() (gas: 185961)
+SignatureTransferTest:testPermitBatchTransferFromTypedWitness() (gas: 163532)
+SignatureTransferTest:testPermitBatchTransferFromTypedWitnessInvalidType() (gas: 82771)
+SignatureTransferTest:testPermitBatchTransferFromTypedWitnessInvalidTypeHash() (gas: 82482)
+SignatureTransferTest:testPermitBatchTransferFromTypedWitnessInvalidTypeName() (gas: 83650)
+SignatureTransferTest:testPermitBatchTransferFromTypedWitnessInvalidWitness() (gas: 83683)
 SignatureTransferTest:testPermitBatchTransferInvalidAmountsLength() (gas: 43943)
 SignatureTransferTest:testPermitBatchTransferInvalidRecipientsLength() (gas: 43210)
 SignatureTransferTest:testPermitBatchTransferInvalidSingleAddr() (gas: 41912)
-SignatureTransferTest:testPermitBatchTransferMultiAddr() (gas: 157816)
-SignatureTransferTest:testPermitBatchTransferSingleRecipientManyTokens() (gas: 195744)
-SignatureTransferTest:testPermitTransferFrom() (gas: 92654)
-SignatureTransferTest:testPermitTransferFromInvalidNonce() (gas: 92270)
-SignatureTransferTest:testPermitTransferFromRandomNonceAndAmount(uint256,uint128) (runs: 256, μ: 95241, ~: 96217)
-SignatureTransferTest:testPermitTransferFromToSpender() (gas: 97019)
-SignatureTransferTest:testPermitTransferFromTypedWitness() (gas: 96460)
-SignatureTransferTest:testPermitTransferFromTypedWitnessInvalidType() (gas: 57391)
-SignatureTransferTest:testPermitTransferFromTypedWitnessInvalidTypeName() (gas: 58358)
-SignatureTransferTest:testPermitTransferFromTypedWitnessInvalidTypehash() (gas: 56738)
-SignatureTransferTest:testPermitTransferSpendLessThanFull(uint256,uint128) (runs: 256, μ: 97554, ~: 99272)
+SignatureTransferTest:testPermitBatchTransferMultiAddr() (gas: 157768)
+SignatureTransferTest:testPermitBatchTransferSingleRecipientManyTokens() (gas: 195696)
+SignatureTransferTest:testPermitTransferFrom() (gas: 92606)
+SignatureTransferTest:testPermitTransferFromInvalidNonce() (gas: 92222)
+SignatureTransferTest:testPermitTransferFromRandomNonceAndAmount(uint256,uint128) (runs: 256, μ: 95193, ~: 96169)
+SignatureTransferTest:testPermitTransferFromToSpender() (gas: 96971)
+SignatureTransferTest:testPermitTransferFromTypedWitness() (gas: 96412)
+SignatureTransferTest:testPermitTransferFromTypedWitnessInvalidType() (gas: 57343)
+SignatureTransferTest:testPermitTransferFromTypedWitnessInvalidTypeName() (gas: 58310)
+SignatureTransferTest:testPermitTransferFromTypedWitnessInvalidTypehash() (gas: 56690)
+SignatureTransferTest:testPermitTransferSpendLessThanFull(uint256,uint128) (runs: 256, μ: 97506, ~: 99224)

src/AllowanceTransfer.sol

@@ -17,10 +17,6 @@ contract AllowanceTransfer is IAllowanceTransfer, EIP712 {
 
     event InvalidateNonces(address indexed owner, uint32 indexed toNonce, address token, address spender);
 
-    /*//////////////////////////////////////////////////////////////
-                            ALLOWANCE STORAGE
-    //////////////////////////////////////////////////////////////*/
-
     /// @notice Maps users to tokens to spender addresses and information about the approval on the token
     /// @dev Indexed in the order of token owner address, token address, spender address
     /// @dev The stored word saves the allowed amount, expiration on the allowance, and nonce
@@ -33,10 +29,6 @@ contract AllowanceTransfer is IAllowanceTransfer, EIP712 {
         allowed.expiration = expiration;
     }
 
-    /*/////////////////////////////////////////////////////f/////////
-                              PERMIT LOGIC
-    //////////////////////////////////////////////////////////////*/
-
     /// @inheritdoc IAllowanceTransfer
     function permit(Permit calldata permitData, address owner, bytes calldata signature) external {
         PackedAllowance storage allowed = allowance[owner][permitData.token][permitData.spender];
@@ -89,10 +81,6 @@ contract AllowanceTransfer is IAllowanceTransfer, EIP712 {
         if (nonce != signedNonce) revert InvalidNonce();
     }
 
-    /*//////////////////////////////////////////////////////////////
-                             TRANSFER LOGIC
-    //////////////////////////////////////////////////////////////*/
-
     /// @inheritdoc IAllowanceTransfer
     function transferFrom(address token, address from, address to, uint160 amount) external {
         _transfer(token, from, to, amount);
@@ -119,11 +107,9 @@ contract AllowanceTransfer is IAllowanceTransfer, EIP712 {
     function _transfer(address token, address from, address to, uint160 amount) private {
         PackedAllowance storage allowed = allowance[from][token][msg.sender];
 
-        if (block.timestamp > allowed.expiration) {
-            revert AllowanceExpired();
-        }
+        if (block.timestamp > allowed.expiration) revert AllowanceExpired();
 
-        uint160 maxAmount = allowed.amount;
+        uint256 maxAmount = allowed.amount;
         if (maxAmount != type(uint160).max) {
             if (amount > maxAmount) {
                 revert InsufficientAllowance();
@@ -133,14 +119,11 @@ contract AllowanceTransfer is IAllowanceTransfer, EIP712 {
                 }
             }
         }
+
         // Transfer the tokens from the from address to the recipient.
         ERC20(token).safeTransferFrom(from, to, amount);
     }
 
-    /*//////////////////////////////////////////////////////////////
-                             LOCKDOWN LOGIC
-    //////////////////////////////////////////////////////////////*/
-
     /// @inheritdoc IAllowanceTransfer
     function lockdown(address[] calldata tokens, address[] calldata spenders) external {
         // Each index should correspond to an index in the other array.

src/EIP712.sol

@@ -2,37 +2,32 @@
 pragma solidity 0.8.17;
 
 /// @notice EIP712 helpers for permit2
-/// @dev maintains cross-chain replay protection in the event of a fork
-/// @dev reference: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/cryptography/EIP712.sol
+/// @dev Maintains cross-chain replay protection in the event of a fork
+/// @dev Reference: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/cryptography/EIP712.sol
 contract EIP712 {
-    /* solhint-disable var-name-mixedcase */
-    // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to
-    // invalidate the cached domain separator if the chain id changes.
+    // Cache the domain separator as an immutable value, but also store the chain id that it
+    // corresponds to, in order to invalidate the cached domain separator if the chain id changes.
     bytes32 private immutable _CACHED_DOMAIN_SEPARATOR;
     uint256 private immutable _CACHED_CHAIN_ID;
-    address private immutable _CACHED_THIS;
 
     bytes32 private constant _HASHED_NAME = keccak256("Permit2");
     bytes32 private constant _TYPE_HASH =
         keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
 
     constructor() {
         _CACHED_CHAIN_ID = block.chainid;
-        _CACHED_THIS = address(this);
         _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME);
     }
 
-    /// @notice returns the domain separator for the current chain
-    /// @dev uses cached version if chainid and address are unchanged from construction
+    /// @notice Returns the domain separator for the current chain.
+    /// @dev Uses cached version if chainid and address are unchanged from construction.
     function DOMAIN_SEPARATOR() public view returns (bytes32) {
-        if (address(this) == _CACHED_THIS && block.chainid == _CACHED_CHAIN_ID) {
-            return _CACHED_DOMAIN_SEPARATOR;
-        } else {
-            return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME);
-        }
+        return block.chainid == _CACHED_CHAIN_ID
+            ? _CACHED_DOMAIN_SEPARATOR
+            : _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME);
     }
 
-    /// @notice builds a domain separator using the current chainId and contract address
+    /// @notice Builds a domain separator using the current chainId and contract address.
     function _buildDomainSeparator(bytes32 typeHash, bytes32 nameHash) private view returns (bytes32) {
         return keccak256(abi.encode(typeHash, nameHash, block.chainid, address(this)));
     }

src/SignatureTransfer.sol

@@ -124,6 +124,7 @@ contract SignatureTransfer is ISignatureTransfer, EIP712 {
     ) internal {
         _validatePermit(permit.spender, permit.deadline);
         _validateInputLengths(permit.tokens.length, to.length, permit.signedAmounts.length, requestedAmounts.length);
+
         unchecked {
             for (uint256 i = 0; i < permit.tokens.length; ++i) {
                 if (requestedAmounts[i] > permit.signedAmounts[i]) revert InvalidAmount();
@@ -144,6 +145,7 @@ contract SignatureTransfer is ISignatureTransfer, EIP712 {
     /// @inheritdoc ISignatureTransfer
     function invalidateUnorderedNonces(uint256 wordPos, uint256 mask) external {
         nonceBitmap[msg.sender][wordPos] |= mask;
+
         emit InvalidateUnorderedNonces(msg.sender, wordPos, mask);
     }
 
@@ -164,9 +166,9 @@ contract SignatureTransfer is ISignatureTransfer, EIP712 {
     function _useUnorderedNonce(address from, uint256 nonce) internal {
         (uint248 wordPos, uint8 bitPos) = bitmapPositions(nonce);
         uint256 bitmap = nonceBitmap[from][wordPos];
-        if ((bitmap >> bitPos) & 1 == 1) {
-            revert InvalidNonce();
-        }
+
+        if ((bitmap >> bitPos) & 1 == 1) revert InvalidNonce();
+
         nonceBitmap[from][wordPos] = bitmap | (1 << bitPos);
     }