Implement Non Fungible Token Royalty (EIP2981)

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## Unreleased
 
- * `ERC2891`: add a new extension of `ERC721` to handle royalty information.([]())
+ * `ERC2891`: add a new extension of `ERC721` to handle royalty information.([#3012](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3012))
  * `GovernorTimelockControl`: improve the `state()` function to have it reflect cases where a proposal has been canceled directly on the timelock. ([#2977](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2977))
  * `Math`: add a `abs(int256)` method that returns the unsigned absolute value of a signed value. ([#2984](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2984))
  * Preset contracts are now deprecated in favor of [Contracts Wizard](https://wizard.openzeppelin.com). ([#2986](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2986))

contracts/mocks/ERC721RoyaltyMock.sol

@@ -5,9 +5,7 @@ pragma solidity ^0.8.0;
 import "../token/ERC721/extensions/draft-ERC721Royalty.sol";
 
 contract ERC721RoyaltyMock is ERC721Royalty {
-    bytes4 private constant _INTERFACE_ID_ERC2981 = 0x2a55205a;
-
-    constructor() public {}
+    constructor(string memory name, string memory symbol) ERC721(name, symbol) {}
 
     function setTokenRoyalty(
         uint256 tokenId,
@@ -20,4 +18,12 @@ contract ERC721RoyaltyMock is ERC721Royalty {
     function setGlobalRoyalty(address recipient, uint256 fraction) public {
         _setGlobalRoyalty(recipient, fraction);
     }
+
+    function mint(address to, uint256 tokenId) public {
+        _mint(to, tokenId);
+    }
+
+    function burn(uint256 tokenId) public {
+        _burn(tokenId);
+    }
 }

contracts/token/ERC721/extensions/draft-ERC721Royalty.sol

@@ -3,6 +3,7 @@
 
 pragma solidity ^0.8.0;
 
+import "../ERC721.sol";
 import "./draft-IERC721Royalty.sol";
 import "../../../utils/introspection/ERC165.sol";
 
@@ -15,7 +16,7 @@ import "../../../utils/introspection/ERC165.sol";
  *
  * _Available since v4.5._
  */
-abstract contract ERC721Royalty is ERC165, IERC721Royalty {
+abstract contract ERC721Royalty is IERC721Royalty, ERC721 {
     struct RoyaltyInfo {
         address receiver;
         uint256 royaltyFraction;
@@ -24,7 +25,7 @@ abstract contract ERC721Royalty is ERC165, IERC721Royalty {
     RoyaltyInfo private _globalRoyaltyInfo;
     mapping(uint256 => RoyaltyInfo) private _tokenRoyaltyInfo;
 
-    /*
+    /**
      * @dev Sets tokens royalties
      *
      * Requirements:
@@ -40,11 +41,12 @@ abstract contract ERC721Royalty is ERC165, IERC721Royalty {
         require(fraction > 0, "ERC2981: Royalty percentage is too low");
         require(fraction <= _feeDenominator(), "ERC2981: Royalty percentage will exceed salePrice");
         require(receiver != address(0), "ERC2981: Invalid receiver");
+        require(_exists(tokenId), "ERC2981: Nonexistent token");
 
         _tokenRoyaltyInfo[tokenId] = RoyaltyInfo(receiver, fraction);
     }
 
-    /*
+    /**
      *
      * @dev Sets global royalty
      *
@@ -81,7 +83,7 @@ abstract contract ERC721Royalty is ERC165, IERC721Royalty {
     /**
      * @dev See {IERC165-supportsInterface}.
      */
-    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
+    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC721, IERC165) returns (bool) {
         return interfaceId == type(IERC721Royalty).interfaceId || super.supportsInterface(interfaceId);
     }
 
@@ -93,6 +95,21 @@ abstract contract ERC721Royalty is ERC165, IERC721Royalty {
         return 10000;
     }
 
+    /**
+     * @dev Removes `tokenId` royalty information.
+     * The royalty information is cleared when the token is burned.
+     *
+     * Requirements:
+     *
+     * - `tokenId` royalty information must exist.
+     *
+     */
+    function _deleteTokenRoyalty(uint256 tokenId) internal virtual {
+        if (_tokenRoyaltyInfo[tokenId].royaltyFraction != 0) {
+            delete _tokenRoyaltyInfo[tokenId];
+        }
+    }
+
     /**
      * @dev Destroys `tokenId`.
      * The royalty information is cleared when the token is burned.
@@ -102,12 +119,9 @@ abstract contract ERC721Royalty is ERC165, IERC721Royalty {
      * - `tokenId` must exist.
      *
      * Emits a {Transfer} event.
-
+     */
     function _burn(uint256 tokenId) internal virtual override {
         super._burn(tokenId);
-
-        if (_tokenRoyaltyInfo[tokenId].royaltyFraction != 0) {
-            delete _tokenRoyaltyInfo[tokenId];
-        }
-    }   */
+        _deleteTokenRoyalty(tokenId);
+    }
 }

contracts/token/ERC721/extensions/draft-IERC721Royalty.sol

@@ -6,8 +6,10 @@ pragma solidity ^0.8.0;
 import "../../../interfaces/IERC165.sol";
 
 /**
- * @dev Interface for the NFT Royalty Standard
+ * @dev Interface for the NFT Royalty Standard.
  *
+ * A standardized way to retrieve royalty payment information for non-fungible tokens (NFTs) to enable universal
+ * support for royalty payments across all NFT marketplaces and ecosystem participants.
  * _Available since v4.5._
  */
 interface IERC721Royalty is IERC165 {

test/token/ERC721/extensions/ERC721Royalty.test.js

@@ -14,7 +14,10 @@ contract('ERC721Royalty', function (accounts) {
   const royaltyFraction = new BN('10');
 
   beforeEach(async function () {
-    this.token = await ERC721RoyaltyMock.new();
+    this.token = await ERC721RoyaltyMock.new('My Token', 'TKN');
+
+    await this.token.mint(account1, tokenId1);
+    await this.token.mint(account1, tokenId2);
   });
 
   shouldSupportInterfaces(['ERC2981']);
@@ -119,6 +122,24 @@ contract('ERC721Royalty', function (accounts) {
         this.token.setTokenRoyalty(tokenId1, account1, new BN('11000')),
         'ERC2981: Royalty percentage will exceed salePrice',
       );
+
+      await expectRevert(
+        this.token.setTokenRoyalty(new BN('787'), account1, new BN('100')),
+        'ERC2981: Nonexistent token',
+      );
+    });
+
+    it('removes royalty information after burn', async function () {
+      await this.token.burn(tokenId1);
+      const tokenInfo = await this.token.royaltyInfo(tokenId1, salePrice);
+
+      expect(tokenInfo[0]).to.be.equal(ZERO_ADDRESS);
+      expect(tokenInfo[1]).to.be.bignumber.equal(new BN('0'));
+
+      await expectRevert(
+        this.token.setTokenRoyalty(tokenId1, account1, new BN('100')),
+        'ERC2981: Nonexistent token',
+      );
     });
   });
 });