Merge pull request lens-protocol#150 from lens-protocol/feat/collect-…

…nft-royalties

contracts/core/CollectNFT.sol

@@ -3,10 +3,12 @@
 pragma solidity 0.8.10;
 
 import {ICollectNFT} from '../interfaces/ICollectNFT.sol';
+import {IERC721} from '@openzeppelin/contracts/token/ERC721/IERC721.sol';
 import {ILensHub} from '../interfaces/ILensHub.sol';
 import {Errors} from '../libraries/Errors.sol';
 import {Events} from '../libraries/Events.sol';
 import {LensNFTBase} from './base/LensNFTBase.sol';
+import {ERC721Enumerable} from './base/ERC721Enumerable.sol';
 
 /**
  * @title CollectNFT
@@ -24,6 +26,12 @@ contract CollectNFT is LensNFTBase, ICollectNFT {
 
     bool private _initialized;
 
+    uint256 internal _royaltyBasisPoints;
+
+    // bytes4(keccak256('royaltyInfo(uint256,uint256)')) == 0x2a55205a
+    bytes4 internal constant INTERFACE_ID_ERC2981 = 0x2a55205a;
+    uint16 internal constant BASIS_POINTS = 10000;
+
     // We create the CollectNFT with the pre-computed HUB address before deploying the hub proxy in order
     // to initialize the hub proxy at construction.
     constructor(address hub) {
@@ -41,6 +49,7 @@ contract CollectNFT is LensNFTBase, ICollectNFT {
     ) external override {
         if (_initialized) revert Errors.Initialized();
         _initialized = true;
+        _royaltyBasisPoints = 1000; // 10% of royalties
         _profileId = profileId;
         _pubId = pubId;
         super._initialize(name, symbol);
@@ -67,6 +76,55 @@ contract CollectNFT is LensNFTBase, ICollectNFT {
         return ILensHub(HUB).getContentURI(_profileId, _pubId);
     }
 
+    /**
+     * @notice Changes the royalty percentage for secondary sales. Can only be called publication's
+     *         profile owner.
+     *
+     * @param royaltyBasisPoints The royalty percentage meassured in basis points. Each basis point
+     *                           represents 0.01%.
+     */
+    function setRoyalty(uint256 royaltyBasisPoints) external {
+        if (IERC721(HUB).ownerOf(_profileId) == msg.sender) {
+            if (royaltyBasisPoints > BASIS_POINTS) {
+                revert Errors.InvalidParameter();
+            } else {
+                _royaltyBasisPoints = royaltyBasisPoints;
+            }
+        } else {
+            revert Errors.NotProfileOwner();
+        }
+    }
+
+    /**
+     * @notice Called with the sale price to determine how much royalty
+     *         is owed and to whom.
+     *
+     * @param tokenId The token ID of the NFT queried for royalty information.
+     * @param salePrice The sale price of the NFT specified.
+     * @return A tuple with the address who should receive the royalties and the royalty
+     * payment amount for the given sale price.
+     */
+    function royaltyInfo(uint256 tokenId, uint256 salePrice)
+        external
+        view
+        returns (address, uint256)
+    {
+        return (IERC721(HUB).ownerOf(_profileId), (salePrice * _royaltyBasisPoints) / BASIS_POINTS);
+    }
+
+    /**
+     * @dev See {IERC165-supportsInterface}.
+     */
+    function supportsInterface(bytes4 interfaceId)
+        public
+        view
+        virtual
+        override(ERC721Enumerable)
+        returns (bool)
+    {
+        return interfaceId == INTERFACE_ID_ERC2981 || super.supportsInterface(interfaceId);
+    }
+
     /**
      * @dev Upon transfers, we emit the transfer event in the hub.
      */

contracts/libraries/Errors.sol

@@ -34,6 +34,7 @@ library Errors {
     error ArrayMismatch();
     error CannotCommentOnSelf();
     error NotWhitelisted();
+    error InvalidParameter();
 
     // Module Errors
     error InitParamsInvalid();

test/helpers/errors.ts

@@ -47,4 +47,5 @@ export const ERRORS = {
   PUBLISHING_PAUSED: 'PublishingPaused()',
   NO_REASON_ABI_DECODE:
     "Transaction reverted and Hardhat couldn't infer the reason. Please report this to help us improve Hardhat.",
+  INVALID_PARAMETER: 'InvalidParameter()',
 };

test/nft/collect-nft.spec.ts

@@ -1,5 +1,6 @@
 import '@nomiclabs/hardhat-ethers';
 import { expect } from 'chai';
+import { BigNumber } from 'ethers';
 import { CollectNFT, CollectNFT__factory } from '../../typechain-types';
 import { ZERO_ADDRESS } from '../helpers/constants';
 import { ERRORS } from '../helpers/errors';
@@ -17,6 +18,7 @@ import {
   userAddress,
   userTwo,
   abiCoder,
+  userTwoAddress,
 } from '../__setup.spec';
 
 makeSuiteCleanRoom('Collect NFT', function () {
@@ -73,6 +75,19 @@ makeSuiteCleanRoom('Collect NFT', function () {
     it('User should fail to get the URI for a token that does not exist', async function () {
       await expect(collectNFT.tokenURI(2)).to.be.revertedWith(ERRORS.TOKEN_DOES_NOT_EXIST);
     });
+
+    it('User should fail to change the royalty percentage if he is not the owner of the publication', async function () {
+      await expect(collectNFT.connect(userTwo).setRoyalty(100)).to.be.revertedWith(
+        ERRORS.NOT_PROFILE_OWNER
+      );
+    });
+
+    it('User should fail to change the royalty percentage if the value passed exceeds the royalty basis points', async function () {
+      const royaltyBasisPoints = 10000;
+      const newRoyalty = royaltyBasisPoints + 1;
+      expect(newRoyalty).to.be.greaterThan(royaltyBasisPoints);
+      await expect(collectNFT.setRoyalty(newRoyalty)).to.be.revertedWith(ERRORS.INVALID_PARAMETER);
+    });
   });
 
   context('Scenarios', function () {
@@ -89,5 +104,45 @@ makeSuiteCleanRoom('Collect NFT', function () {
     it('User should burn their collect NFT', async function () {
       await expect(collectNFT.burn(1)).to.not.be.reverted;
     });
+
+    it('Default royalties are set to 10%', async function () {
+      const royaltyInfo = await collectNFT.royaltyInfo(1, 6900);
+      expect(royaltyInfo[0]).to.eq(userAddress);
+      expect(royaltyInfo[1]).to.eq(BigNumber.from(690));
+    });
+
+    it('User should be able to change the royalties if owns the profile and passes a valid royalty percentage in basis points', async function () {
+      await expect(collectNFT.setRoyalty(5000)).to.not.be.reverted;
+      const royaltyInfo = await collectNFT.royaltyInfo(1, 3000);
+      expect(royaltyInfo[0]).to.eq(userAddress);
+      expect(royaltyInfo[1]).to.eq(BigNumber.from(1500));
+    });
+
+    it('User should be able to get the royalty info even over a token that does not exist yet', async function () {
+      const unexistentTokenId = 69;
+      await expect(collectNFT.tokenURI(unexistentTokenId)).to.be.revertedWith(
+        ERRORS.TOKEN_DOES_NOT_EXIST
+      );
+      const royaltyInfo = await collectNFT.royaltyInfo(unexistentTokenId, 3000);
+      expect(royaltyInfo[0]).to.eq(userAddress);
+      expect(royaltyInfo[1]).to.eq(BigNumber.from(300));
+    });
+
+    it('Publication owner should be able to remove royalties by setting them as zero', async function () {
+      await expect(collectNFT.setRoyalty(0)).to.not.be.reverted;
+      const royaltyInfo = await collectNFT.royaltyInfo(1, 3000);
+      expect(royaltyInfo[0]).to.eq(userAddress);
+      expect(royaltyInfo[1]).to.eq(BigNumber.from(0));
+    });
+
+    it('If the profile authoring the publication is transferred the royalty info now returns the new owner as recipient', async function () {
+      let royaltyInfo = await collectNFT.royaltyInfo(1, 69);
+      expect(royaltyInfo[0]).to.eq(userAddress);
+      await expect(
+        lensHub.transferFrom(userAddress, userTwoAddress, FIRST_PROFILE_ID)
+      ).to.not.be.reverted;
+      royaltyInfo = await collectNFT.royaltyInfo(1, 69);
+      expect(royaltyInfo[0]).to.eq(userTwoAddress);
+    });
   });
 });