Add ERC1155URIStorage

CHANGELOG.md

@@ -19,6 +19,7 @@
  * `TimelockController`: Implement `IERC721Receiver` and `IERC1155Receiver` to improve token custody by timelocks. ([#3230](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3230))
  * `Initializable`: add a reinitializer modifier that enables the initialization of new modules, added to already initialized contracts through upgradeability. ([#3232](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3232))
  * `Initializable`: add an Initialized event that tracks initialized version numbers. ([#3294](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3294))
+ * `ERC1155URIStorage`: add a new extension for `ERC1155` that implements a `ERC721`-style `_setTokenURI` and `tokenURI` behavior called `ERC1155URIStorage.setURI` and `ERC1155URIStorage.uri`, respectively.
 
 ### Breaking changes
 

contracts/mocks/ERC1155URIStorageMock.sol

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "./ERC1155Mock.sol";
+import "../token/ERC1155/extensions/ERC1155URIStorage.sol";
+
+contract ERC1155URIStorageMock is ERC1155Mock, ERC1155URIStorage {
+    constructor(string memory _uri) ERC1155Mock(_uri) {}
+
+    function uri(uint256 tokenId) public view virtual override(ERC1155, ERC1155URIStorage) returns (string memory) {
+        return ERC1155URIStorage.uri(tokenId);
+    }
+
+    function setURI(uint256 tokenId, string memory _tokenURI) public {
+        _setURI(tokenId, _tokenURI);
+    }
+
+    function setBaseURI(string memory baseURI) public {
+        _setBaseURI(baseURI);
+    }
+}

contracts/token/ERC1155/extensions/ERC1155URIStorage.sol

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts v4.4.1 (token/ERC1155/extensions/ERC1155URIStorage.sol)
+
+pragma solidity ^0.8.0;
+
+import "../../../utils/Strings.sol";
+import "../ERC1155.sol";
+
+/**
+ * @dev ERC1155 token with storage based token URI management.
+ * Inspired by the ERC721URIStorage extension
+ */
+abstract contract ERC1155URIStorage is ERC1155 {
+    using Strings for uint256;
+
+    // optional base URI
+    string private _baseURI = "";
+
+    // Optional mapping for token URIs
+    mapping(uint256 => string) private _tokenURIs;
+
+    /**
+     * @dev See {IERC1155MetadataURI-uri}.
+     *
+     * This implementation returns the concatenation of the `_baseURI`
+     * and the token-specific uri if the latter is set
+     *
+     * This allowes for the following behavior:
+     *
+     * the `ERC1155URIStorage._tokenURIs[tokenId]` is set
+     * → the result is the concatenation of `_baseURI` and `ERC1155URIStorage._tokenURIs[tokenId]`
+     *   (keep in mind that `_baseURI` is empty per default)
+     *
+     * the `ERC1155URIStorage._tokenURIs[tokenId]` is NOT set
+     * → the result is `ERC1155._uri`
+     *
+     * neither `ERC1155URIStorage._tokenURIs[tokenId]` nor `ERC1155._uri` are set
+     * → the result is empty
+     */
+    function uri(uint256 tokenId) public view virtual override returns (string memory) {
+        string memory _tokenURI = _tokenURIs[tokenId];
+
+        // If token URI is set, concatenate base URI and tokenURI (via abi.encodePacked).
+        if (bytes(_tokenURI).length > 0) {
+            return string(abi.encodePacked(_baseURI, _tokenURI));
+        }
+
+        // If there is no tokenURI, return the ERC1155.uri
+        return super.uri(tokenId);
+    }
+
+    /**
+     * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.
+     *
+     * Requirements:
+     *
+     * - `tokenId` must exist.
+     */
+    function _setURI(uint256 tokenId, string memory _tokenURI) internal virtual {
+        _tokenURIs[tokenId] = _tokenURI;
+        emit URI(uri(tokenId), tokenId);
+    }
+
+    /**
+     * @dev Sets `baseURI` as the `_baseURI` for all tokens
+     */
+    function _setBaseURI(string memory baseURI) internal virtual {
+        _baseURI = baseURI;
+    }
+}

test/token/ERC1155/extensions/ERC1155URIStorage.test.js

@@ -0,0 +1,66 @@
+const { BN, expectEvent } = require('@openzeppelin/test-helpers');
+
+const { expect } = require('chai');
+const { artifacts } = require('hardhat');
+
+const ERC1155URIStorageMock = artifacts.require('ERC1155URIStorageMock');
+
+contract(['ERC1155URIStorage'], function (accounts) {
+  const [ holder ] = accounts;
+
+  const erc1155Uri = 'https://token.com/nfts/';
+  const baseUri = 'https://token.com/';
+
+  const tokenId = new BN('1');
+  const amount = new BN('3000');
+
+  describe('with base uri set', function () {
+    beforeEach(async function () {
+      this.token = await ERC1155URIStorageMock.new(erc1155Uri);
+      this.token.setBaseURI(baseUri);
+
+      await this.token.mint(holder, tokenId, amount, '0x');
+    });
+
+    it('can request the token uri, returning the erc1155 uri if no token uri was set', async function () {
+      const receivedTokenUri = await this.token.uri(tokenId);
+
+      expect(receivedTokenUri).to.be.equal(erc1155Uri);
+    });
+
+    it('can request the token uri, returning the concatenated uri if a token uri was set', async function () {
+      const tokenUri = '1234/';
+      const receipt = await this.token.setURI(tokenId, tokenUri);
+
+      const receivedTokenUri = await this.token.uri(tokenId);
+
+      const expectedUri = `${baseUri}${tokenUri}`;
+      expect(receivedTokenUri).to.be.equal(expectedUri);
+      expectEvent(receipt, 'URI', { value: expectedUri, id: tokenId });
+    });
+  });
+
+  describe('with base uri set to the empty string', function () {
+    beforeEach(async function () {
+      this.token = await ERC1155URIStorageMock.new('');
+
+      await this.token.mint(holder, tokenId, amount, '0x');
+    });
+
+    it('can request the token uri, returning an empty string if no token uri was set', async function () {
+      const receivedTokenUri = await this.token.uri(tokenId);
+
+      expect(receivedTokenUri).to.be.equal('');
+    });
+
+    it('can request the token uri, returning the token uri if a token uri was set', async function () {
+      const tokenUri = 'ipfs://1234/';
+      const receipt = await this.token.setURI(tokenId, tokenUri);
+
+      const receivedTokenUri = await this.token.uri(tokenId);
+
+      expect(receivedTokenUri).to.be.equal(tokenUri);
+      expectEvent(receipt, 'URI', { value: tokenUri, id: tokenId });
+    });
+  });
+});