Change ERC721Common to ERC721ACommon. (#31)

* Change ERC721Common to ERC721ACommon.

Both ERC721CommonAutoIncrement and ERC721CommonEnumerable are removed. The former is
the default behaviour of ERC721A and the latter is generally unnecessary (+ goes
against the point of ERC721A).

* Remove unnecessary import

contracts/erc721/ERC721ACommon.sol

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2022 the ethier authors (github.com/divergencetech/ethier)
+pragma solidity >=0.8.0 <0.9.0;
+
+import "./ERC721APreApproval.sol";
+import "../utils/OwnerPausable.sol";
+
+/**
+@notice An ERC721A contract with common functionality:
+ - OpenSea gas-free listings
+ - Pausable with toggling functions exposed to Owner only
+ */
+contract ERC721ACommon is ERC721APreApproval, OwnerPausable {
+    constructor(string memory name, string memory symbol)
+        ERC721A(name, symbol)
+    {} // solhint-disable-line no-empty-blocks
+
+    /// @notice Requires that the token exists.
+    modifier tokenExists(uint256 tokenId) {
+        require(ERC721A._exists(tokenId), "ERC721ACommon: Token doesn't exist");
+        _;
+    }
+
+    /// @notice Requires that msg.sender owns or is approved for the token.
+    modifier onlyApprovedOrOwner(uint256 tokenId) {
+        require(
+            _ownershipOf(tokenId).addr == _msgSender() ||
+                getApproved(tokenId) == _msgSender(),
+            "ERC721ACommon: Not approved nor owner"
+        );
+        _;
+    }
+
+    function _beforeTokenTransfers(
+        address from,
+        address to,
+        uint256 startTokenId,
+        uint256 quantity
+    ) internal virtual override {
+        require(!paused(), "ERC721ACommon: paused");
+        super._beforeTokenTransfers(from, to, startTokenId, quantity);
+    }
+
+    /// @notice Overrides supportsInterface as required by inheritance.
+    function supportsInterface(bytes4 interfaceId)
+        public
+        view
+        virtual
+        override(ERC721A)
+        returns (bool)
+    {
+        return super.supportsInterface(interfaceId);
+    }
+}

contracts/erc721/ERC721PreApproval.sol → contracts/erc721/ERC721APreApproval.sol

@@ -3,7 +3,7 @@
 pragma solidity >=0.8.0 <0.9.0;
 
 import "../thirdparty/opensea/OpenSeaGasFreeListing.sol";
-import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
+import "erc721a/contracts/ERC721A.sol";
 
 /// @notice Pre-approval of OpenSea proxies for gas-less listing
 /// @dev This wrapper allows users to revoke the pre-approval of their
@@ -15,7 +15,7 @@ import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
 /// @dev This wrapper optimizes for the following scenario:
 /// - The majority of users already have a wyvern proxy
 /// - Most of them want to transfer tokens via wyvern exchanges
-abstract contract ERC721PreApproval is ERC721 {
+abstract contract ERC721APreApproval is ERC721A {
     /// @dev It is important that Active remains at first position, since this
     /// is the scenario that we are trying to optimize for.
     enum State {
@@ -57,18 +57,19 @@ abstract contract ERC721PreApproval is ERC721 {
             state[owner] = approved ? State.Active : State.Inactive;
             emit ApprovalForAll(owner, operator, approved);
         } else {
-            super._setApprovalForAll(owner, operator, approved);
+            super.setApprovalForAll(operator, approved);
         }
     }
 
     /// @dev Checks if the receiver has an existing proxy. If not, the
     /// pre-approval is disabled.
-    function _beforeTokenTransfer(
+    function _beforeTokenTransfers(
         address from,
         address to,
-        uint256 tokenId
+        uint256 startTokenId,
+        uint256 quantity
     ) internal virtual override {
-        super._beforeTokenTransfer(from, to, tokenId);
+        super._beforeTokenTransfers(from, to, startTokenId, quantity);
 
         // Exclude burns and inactive pre-approvals
         if (to == address(0) || state[to] == State.Inactive) {

ethtest/revert/revert.go

@@ -23,7 +23,7 @@ const (
 
 // Checkers for ethier libraries and contracts.
 const (
-	ERC721ApproveOrOwner = Checker("ERC721Common: Not approved nor owner")
+	ERC721ApproveOrOwner = Checker("ERC721ACommon: Not approved nor owner")
 	InvalidSignature     = Checker("SignatureChecker: Invalid signature")
 	NotStarted           = Checker("LinearDutchAuction: Not started")
 	SoldOut              = Checker("Seller: Sold out")

package.json

@@ -19,7 +19,8 @@
   "dependencies": {
     "@chainlink/contracts": "^0.3.0",
     "@openzeppelin/contracts": "^4.4.1",
-    "@openzeppelin/contracts-upgradeable": "^4.4.1"
+    "@openzeppelin/contracts-upgradeable": "^4.4.1",
+    "erc721a": "^3.1.0"
   },
   "directories": {
     "test": "tests"

tests/erc721/TestableERC721ACommon.sol

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021 the ethier authors (github.com/divergencetech/ethier)
+pragma solidity >=0.8.0 <0.9.0;
+
+import "../../contracts/erc721/ERC721ACommon.sol";
+import "../../contracts/erc721/BaseTokenURI.sol";
+
+/// @notice Exposes a functions modified with the modifiers under test.
+contract TestableERC721ACommon is ERC721ACommon, BaseTokenURI {
+    // solhint-disable-next-line no-empty-blocks
+    constructor() ERC721ACommon("Token", "JRR") BaseTokenURI("") {}
+
+    function mint() public {
+        mintN(1);
+    }
+
+    function mintN(uint256 num) public {
+        ERC721A._safeMint(msg.sender, num);
+    }
+
+    function burn(uint256 tokenId) public {
+        ERC721A._burn(tokenId);
+    }
+
+    /// @dev For testing the tokenExists() modifier.
+    // solhint-disable-next-line no-empty-blocks
+    function mustExist(uint256 tokenId) public view tokenExists(tokenId) {}
+
+    /// @dev For testing the onlyApprovedOrOwner() modifier.
+    function mustBeApprovedOrOwner(uint256 tokenId)
+        public
+        onlyApprovedOrOwner(tokenId)
+    {} // solhint-disable-line no-empty-blocks
+
+    function _baseURI()
+        internal
+        view
+        override(ERC721A, BaseTokenURI)
+        returns (string memory)
+    {
+        return BaseTokenURI._baseURI();
+    }
+}