Remove enumerable from ERC721 and add an ERC721Enumerable extension (#…

…2511)

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

CHANGELOG.md

@@ -10,6 +10,7 @@
  * `GSN`: Deprecate GSNv1 support in favor of upcomming support for GSNv2. ([#2521](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2521))
  * `ERC165`: Remove uses of storage in the base ERC165 implementation. ERC165 based contracts now use storage-less virtual functions. Old behaviour remains available in the `ERC165Storage` extension. ([#2505](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2505))
  * `Initializable`: Make initializer check stricter during construction. ([#2531](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2531))
+ * `ERC721`: remove enumerability of tokens from the base implementation. This feature is now provided separately through the `ERC721Enumerable` extension. ([#2511](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2511))
 
 ## 3.4.0 (2021-02-02)
 

contracts/mocks/ERC721EnumerableMock.sol

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "../token/ERC721/ERC721Enumerable.sol";
+
+/**
+ * @title ERC721Mock
+ * This mock just provides a public safeMint, mint, and burn functions for testing purposes
+ */
+contract ERC721EnumerableMock is ERC721Enumerable {
+    string private _baseTokenURI;
+
+    constructor (string memory name, string memory symbol) ERC721(name, symbol) { }
+
+    function _baseURI() internal view virtual override returns (string memory) {
+        return _baseTokenURI;
+    }
+
+    function setBaseURI(string calldata newBaseTokenURI) public {
+        _baseTokenURI = newBaseTokenURI;
+    }
+
+    function baseURI() public view returns (string memory) {
+        return _baseURI();
+    }
+
+    function mint(address to, uint256 tokenId) public {
+        _mint(to, tokenId);
+    }
+
+    function safeMint(address to, uint256 tokenId) public {
+        _safeMint(to, tokenId);
+    }
+
+    function safeMint(address to, uint256 tokenId, bytes memory _data) public {
+        _safeMint(to, tokenId, _data);
+    }
+
+    function burn(uint256 tokenId) public {
+        _burn(tokenId);
+    }
+}

contracts/mocks/ERC721Mock.sol

@@ -9,18 +9,24 @@ import "../token/ERC721/ERC721.sol";
  * This mock just provides a public safeMint, mint, and burn functions for testing purposes
  */
 contract ERC721Mock is ERC721 {
+    string private _baseTokenURI;
+
     constructor (string memory name, string memory symbol) ERC721(name, symbol) { }
 
-    function exists(uint256 tokenId) public view returns (bool) {
-        return _exists(tokenId);
+    function _baseURI() internal view virtual override returns (string memory) {
+        return _baseTokenURI;
     }
 
-    function setTokenURI(uint256 tokenId, string memory uri) public {
-        _setTokenURI(tokenId, uri);
+    function setBaseURI(string calldata newBaseTokenURI) public {
+        _baseTokenURI = newBaseTokenURI;
     }
 
-    function setBaseURI(string memory baseURI) public {
-        _setBaseURI(baseURI);
+    function baseURI() public view returns (string memory) {
+        return _baseURI();
+    }
+
+    function exists(uint256 tokenId) public view returns (bool) {
+        return _exists(tokenId);
     }
 
     function mint(address to, uint256 tokenId) public {

contracts/presets/ERC721PresetMinterPauserAutoId.sol

@@ -6,6 +6,7 @@ import "../access/AccessControl.sol";
 import "../utils/Context.sol";
 import "../utils/Counters.sol";
 import "../token/ERC721/ERC721.sol";
+import "../token/ERC721/ERC721Enumerable.sol";
 import "../token/ERC721/ERC721Burnable.sol";
 import "../token/ERC721/ERC721Pausable.sol";
 
@@ -24,28 +25,34 @@ import "../token/ERC721/ERC721Pausable.sol";
  * roles, as well as the default admin role, which will let it grant both minter
  * and pauser roles to other accounts.
  */
-contract ERC721PresetMinterPauserAutoId is Context, AccessControl, ERC721Burnable, ERC721Pausable {
+contract ERC721PresetMinterPauserAutoId is Context, AccessControl, ERC721Enumerable, ERC721Burnable, ERC721Pausable {
     using Counters for Counters.Counter;
 
     bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
     bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE");
 
     Counters.Counter private _tokenIdTracker;
 
+    string private _baseTokenURI;
+
     /**
      * @dev Grants `DEFAULT_ADMIN_ROLE`, `MINTER_ROLE` and `PAUSER_ROLE` to the
      * account that deploys the contract.
      *
      * Token URIs will be autogenerated based on `baseURI` and their token IDs.
      * See {ERC721-tokenURI}.
      */
-    constructor(string memory name, string memory symbol, string memory baseURI) ERC721(name, symbol) {
+    constructor(string memory name, string memory symbol, string memory baseTokenURI) ERC721(name, symbol) {
+        _baseTokenURI = baseTokenURI;
+
         _setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
 
         _setupRole(MINTER_ROLE, _msgSender());
         _setupRole(PAUSER_ROLE, _msgSender());
+    }
 
-        _setBaseURI(baseURI);
+    function _baseURI() internal view virtual override returns (string memory) {
+        return _baseTokenURI;
     }
 
     /**
@@ -96,7 +103,14 @@ contract ERC721PresetMinterPauserAutoId is Context, AccessControl, ERC721Burnabl
         _unpause();
     }
 
-    function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override(ERC721, ERC721Pausable) {
+    function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override(ERC721, ERC721Enumerable, ERC721Pausable) {
         super._beforeTokenTransfer(from, to, tokenId);
     }
+
+    /**
+     * @dev See {IERC165-supportsInterface}.
+     */
+    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC721, ERC721Enumerable) returns (bool) {
+        return super.supportsInterface(interfaceId);
+    }
 }