Refactor ERC404NullOwnerCappedUpgradeable contract by removing IERC404 interface and DoubleEndedQueue library. Simplified function overrides for ERC20 and ERC721 operations, enhancing clarity and maintainability. Updated storage accessor and error handling for improved functionality.

Author: RogerPodacter

contracts/src/ERC404NullOwnerCappedUpgradeable.sol

@@ -3,13 +3,10 @@ pragma solidity 0.8.24;
 
 import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import {IERC20Metadata} from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
-import {IERC721Receiver} from "@openzeppelin/contracts/interfaces/IERC721Receiver.sol";
 import {ContextUpgradeable} from "@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol";
 import {IERC20Errors} from "@openzeppelin/contracts/interfaces/draft-IERC6093.sol";
 import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
 import {IERC165} from "@openzeppelin/contracts/interfaces/IERC165.sol";
-import "./interfaces/IERC404.sol";
-import "./lib/DoubleEndedQueue.sol";
 
 /// @title ERC404NullOwnerCappedUpgradeable
 /// @notice Hybrid ERC20/ERC721 implementation with null owner support, supply cap, and upgradeability
@@ -20,11 +17,8 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
     IERC165,
     IERC20,
     IERC20Metadata,
-    IERC20Errors,
-    IERC404
+    IERC20Errors
 {
-    using DoubleEndedQueue for DoubleEndedQueue.Uint256Deque;
-
     struct TokenData {
         address owner; // current owner (can be address(0) for null-owner)
         uint88 index; // position in owned[owner] array
@@ -43,44 +37,26 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         uint256 totalSupply;
         uint256 cap;
 
-        // === ERC404 NFT State ===
-        DoubleEndedQueue.Uint256Deque storedERC721Ids;
         mapping(address => uint256[]) owned;
         mapping(uint256 => TokenData) tokens;
         mapping(uint256 => address) getApproved;
         mapping(address => mapping(address => bool)) isApprovedForAll;
-        mapping(address => bool) erc721TransferExempt;
         uint256 minted; // Number of NFTs minted
         uint256 units; // Units for NFT minting (e.g., 1000 * 10^18)
-        uint256 initialChainId;
-        bytes32 initialDomainSeparator;
-        mapping(address => uint256) nonces;
 
         // === Metadata ===
         string name;
         string symbol;
     }
-
-    // =============================================================
-    //                         CONSTANTS
-    // =============================================================
-
-    /// @dev Unique storage slot for EIP-7201 namespaced storage
-    /// keccak256(abi.encode(uint256(keccak256("ethscriptions.storage.ERC404NullOwnerCapped")) - 1)) & ~bytes32(uint256(0xff))
-    bytes32 private constant STORAGE_LOCATION = 0x8a0c9d8e5f7b3a2c1d4e6f8a9b7c5d3e2f1a4b6c8d9e7f5a3b2c1d4e6f8a9b00;
-
+    
     // =============================================================
     //                         EVENTS
     // =============================================================
 
     // ERC20 Events are inherited from IERC20 (Transfer, Approval)
 
     // ERC721 Events (using different names to avoid conflicts with ERC20)
-    // event Transfer(address indexed from, address indexed to, uint256 value);
-    event ERC20Transfer(address indexed from, address indexed to, uint256 value);
     event ERC721Transfer(address indexed from, address indexed to, uint256 indexed id);
-    event ERC721Approval(address indexed owner, address indexed spender, uint256 indexed id);
-    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
 
     // =============================================================
     //                      CUSTOM ERRORS
@@ -91,14 +67,22 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
     error ERC20InvalidCap(uint256 cap);
     error InvalidUnits(uint256 units);
     error NotImplemented();
+    error NotFound();
+    error InvalidTokenId();
+    error AlreadyExists();
+    error InvalidRecipient();
+    error Unauthorized();
+    error OwnedIndexOverflow();
 
     // =============================================================
     //                    STORAGE ACCESSOR
     // =============================================================
 
     function _getS() internal pure returns (TokenStorage storage $) {
+        bytes32 slot = keccak256("ethscriptions.storage.ERC404NullOwnerCapped");
+        
         assembly {
-            $.slot := STORAGE_LOCATION
+            $.slot := slot
         }
     }
 
@@ -132,38 +116,36 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         $.symbol = symbol_;
         $.cap = cap_;
         $.units = units_;
-        $.initialChainId = block.chainid;
-        $.initialDomainSeparator = _computeDomainSeparator();
     }
 
     // =============================================================
     //                    ERC20 METADATA VIEWS
     // =============================================================
 
-    function name() public view virtual override(IERC404, IERC20Metadata) returns (string memory) {
+    function name() public view virtual override(IERC20Metadata) returns (string memory) {
         TokenStorage storage $ = _getS();
         return $.name;
     }
 
-    function symbol() public view virtual override(IERC404, IERC20Metadata) returns (string memory) {
+    function symbol() public view virtual override(IERC20Metadata) returns (string memory) {
         TokenStorage storage $ = _getS();
         return $.symbol;
     }
 
-    function decimals() public pure override(IERC404, IERC20Metadata) returns (uint8) {
+    function decimals() public pure override(IERC20Metadata) returns (uint8) {
         return 18;
     }
 
     // =============================================================
     //                     ERC20 VIEWS
     // =============================================================
 
-    function totalSupply() public view virtual override(IERC404, IERC20) returns (uint256) {
+    function totalSupply() public view virtual override returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.totalSupply;
     }
 
-    function balanceOf(address account) public view virtual override(IERC404, IERC20) returns (uint256) {
+    function balanceOf(address account) public view virtual override returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.balances[account];
     }
@@ -179,7 +161,7 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         return t.owner == owner_ ? 1 : 0;
     }
 
-    function allowance(address owner, address spender) public view virtual override(IERC404, IERC20) returns (uint256) {
+    function allowance(address owner, address spender) public view virtual override returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.allowances[owner][spender];
     }
@@ -196,17 +178,17 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
     //                     ERC721 VIEWS
     // =============================================================
 
-    function erc721TotalSupply() public view virtual override(IERC404) returns (uint256) {
+    function erc721TotalSupply() public view virtual returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.minted;
     }
 
-    function erc721BalanceOf(address owner_) public view virtual override(IERC404) returns (uint256) {
+    function erc721BalanceOf(address owner_) public view virtual returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.owned[owner_].length;
     }
 
-    function ownerOf(uint256 id_) public view virtual override(IERC404) returns (address) {
+    function ownerOf(uint256 id_) public view virtual returns (address) {
         _validateTokenId(id_);
         TokenStorage storage $ = _getS();
         TokenData storage t = $.tokens[id_];
@@ -216,7 +198,7 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         return t.owner;
     }
 
-    function owned(address owner_) public view virtual override(IERC404) returns (uint256[] memory) {
+    function owned(address owner_) public view virtual returns (uint256[] memory) {
         TokenStorage storage $ = _getS();
         return $.owned[owner_];
     }
@@ -229,42 +211,11 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         return $.getApproved[id_];
     }
 
-    function isApprovedForAll(address owner_, address operator_) public view virtual override(IERC404) returns (bool) {
+    function isApprovedForAll(address owner_, address operator_) public view virtual returns (bool) {
         TokenStorage storage $ = _getS();
         return $.isApprovedForAll[owner_][operator_];
     }
 
-    function erc721TransferExempt(address account_) public view virtual override returns (bool) {
-        TokenStorage storage $ = _getS();
-        return $.erc721TransferExempt[account_];
-    }
-
-    // =============================================================
-    //                       QUEUE VIEWS
-    // =============================================================
-
-    function getERC721QueueLength() public view virtual override returns (uint256) {
-        TokenStorage storage $ = _getS();
-        return $.storedERC721Ids.length();
-    }
-
-    function getERC721TokensInQueue(
-        uint256 start_,
-        uint256 count_
-    ) public view virtual override returns (uint256[] memory) {
-        TokenStorage storage $ = _getS();
-        uint256[] memory tokensInQueue = new uint256[](count_);
-
-        for (uint256 i = start_; i < start_ + count_;) {
-            tokensInQueue[i - start_] = $.storedERC721Ids.at(i);
-            unchecked {
-                ++i;
-            }
-        }
-
-        return tokensInQueue;
-    }
-
     // =============================================================
     //                      OTHER VIEWS
     // =============================================================
@@ -285,57 +236,53 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
     }
 
     /// @notice tokenURI must be implemented by child contract
-    function tokenURI(uint256 id_) public view virtual override(IERC404) returns (string memory);
+    function tokenURI(uint256 id_) public view virtual returns (string memory);
 
     // =============================================================
     //                   ERC20 OPERATIONS
     // =============================================================
 
-    function transfer(address, uint256) public pure virtual override(IERC404, IERC20) returns (bool) {
+    function transfer(address, uint256) public pure virtual override returns (bool) {
         revert NotImplemented();
     }
 
-    function approve(address, uint256) public pure virtual override(IERC404, IERC20) returns (bool) {
+    function approve(address, uint256) public pure virtual override returns (bool) {
         revert NotImplemented();
     }
 
-    function transferFrom(address, address, uint256) public pure virtual override(IERC404, IERC20) returns (bool) {
+    function transferFrom(address, address, uint256) public pure virtual override returns (bool) {
         revert NotImplemented();
     }
 
-    function erc20Approve(address, uint256) public pure virtual override returns (bool) {
+    function erc20Approve(address, uint256) public pure virtual returns (bool) {
         revert NotImplemented();
     }
 
-    function erc20TransferFrom(address, address, uint256) public pure virtual override returns (bool) {
+    function erc20TransferFrom(address, address, uint256) public pure virtual returns (bool) {
         revert NotImplemented();
     }
 
     // =============================================================
     //                   ERC721 OPERATIONS
     // =============================================================
 
-    function erc721Approve(address, uint256) public pure virtual override {
+    function erc721Approve(address, uint256) public pure virtual {
         revert NotImplemented();
     }
 
-    function erc721TransferFrom(address, address, uint256) public pure virtual override {
+    function erc721TransferFrom(address, address, uint256) public pure virtual {
         revert NotImplemented();
     }
 
-    function setApprovalForAll(address, bool) public pure virtual override {
+    function setApprovalForAll(address, bool) public pure virtual {
         revert NotImplemented();
     }
 
-    function safeTransferFrom(address, address, uint256) public pure virtual override {
+    function safeTransferFrom(address, address, uint256) public pure virtual {
         revert NotImplemented();
     }
 
-    function safeTransferFrom(address, address, uint256, bytes memory) public pure virtual override {
-        revert NotImplemented();
-    }
-
-    function setSelfERC721TransferExempt(bool) public pure virtual override {
+    function safeTransferFrom(address, address, uint256, bytes memory) public pure virtual {
         revert NotImplemented();
     }
 
@@ -367,7 +314,6 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         }
 
         emit Transfer(from_, to_, value_);
-        // emit ERC20Transfer(from_, to_, value_);
     }
 
     /// @notice Transfer an ERC721 token
@@ -454,44 +400,6 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         return
             interfaceId == type(IERC165).interfaceId ||
             interfaceId == type(IERC20).interfaceId ||
-            interfaceId == type(IERC20Metadata).interfaceId ||
-            interfaceId == type(IERC404).interfaceId;
-    }
-    
-  /// @notice Internal function to compute domain separator for EIP-2612 permits
-    function _computeDomainSeparator() internal view virtual returns (bytes32) {
-        return
-        keccak256(
-            abi.encode(
-            keccak256(
-                "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
-            ),
-            keccak256(bytes(name())),
-            keccak256("1"),
-            block.chainid,
-            address(this)
-            )
-        );
-    }
-    
-    function permit(
-        address owner_,
-        address spender_,
-        uint256 value_,
-        uint256 deadline_,
-        uint8 v_,
-        bytes32 r_,
-        bytes32 s_
-    ) public virtual {
-        revert NotImplemented();
-    }
-
-    /// @notice EIP-2612 domain separator
-    function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
-        TokenStorage storage $ = _getS();
-        return
-            block.chainid == $.initialChainId
-                ? $.initialDomainSeparator
-                : _computeDomainSeparator();
+            interfaceId == type(IERC20Metadata).interfaceId;
     }
 }