feat: example usage in nft testing of our foundry library and hardhat plugin (#191)

contracts/HtsSystemContractJson.sol

@@ -192,7 +192,7 @@ contract HtsSystemContractJson is HtsSystemContract {
         tokenInfo.token = _getHederaToken(json);
         tokenInfo.fixedFees = _getFixedFees(json);
         tokenInfo.fractionalFees = _getFractionalFees(json);
-        tokenInfo.royaltyFees = _getRoyaltyFees(json);
+        tokenInfo.royaltyFees = _getRoyaltyFees(_sanitizeFeesStructure(json));
         tokenInfo.ledgerId = _getLedgerId();
         tokenInfo.defaultKycStatus = false; // not available in the fetched JSON from mirror node
         tokenInfo.totalSupply = int64(vm.parseInt(vm.parseJsonString(json, ".total_supply")));
@@ -201,6 +201,16 @@ contract HtsSystemContractJson is HtsSystemContract {
         return tokenInfo;
     }
 
+    // In order to properly decode the bytes returned by the parseJson into the Solidity Structure, the full,
+    // correct structure has to be provided in the input json, with all of the corresponding fields.
+    function _sanitizeFeesStructure(string memory json) private pure returns (string memory) {
+        return vm.replace(
+            json,
+            "\"fallback_fee\":null}",
+            "\"fallback_fee\":{\"amount\":0,\"denominating_token_id\":\"\"}}"
+        );
+    }
+
     function _getHederaToken(string memory json) private returns (HederaToken memory token) {
         token.tokenKeys = _getTokenKeys(json);
         token.name = vm.parseJsonString(json, ".name");
@@ -369,7 +379,6 @@ contract HtsSystemContractJson is HtsSystemContract {
         if (!vm.keyExistsJson(json, ".custom_fees.royalty_fees")) {
             return new RoyaltyFee[](0);
         }
-
         try vm.parseJson(json, ".custom_fees.royalty_fees") returns (bytes memory royaltyFeesBytes) {
             if (royaltyFeesBytes.length == 0) {
                 return new RoyaltyFee[](0);
@@ -379,11 +388,16 @@ contract HtsSystemContractJson is HtsSystemContract {
             for (uint i = 0; i < fees.length; i++) {
                 string memory path = vm.replace(".custom_fees.royalty_fees[{i}]", "{i}", vm.toString(i));
                 address collectorAccount = mirrorNode().getAccountAddress(vm.parseJsonString(json, string.concat(path, ".collector_account_id")));
+                bytes memory denominatingTokenBytes = vm.parseJson(json, string.concat(path, ".denominating_token_id"));
+                address denominatingToken;
+                if (keccak256(denominatingTokenBytes) != keccak256("")) {
+                    denominatingToken = mirrorNode().getAccountAddress(vm.parseJsonString(json, string.concat(path, ".denominating_token_id")));
+                }
                 royaltyFees[i] = RoyaltyFee(
                     int64(vm.parseJsonInt(json, string.concat(path, ".amount.numerator"))),
                     int64(vm.parseJsonInt(json, string.concat(path, ".amount.denominator"))),
                     int64(vm.parseJsonInt(json, string.concat(path, ".fallback_fee.amount"))),
-                    mirrorNode().getAccountAddress(vm.parseJsonString(json, string.concat(path, ".denominating_token_id"))),
+                    denominatingToken,
                     collectorAccount == address(0),
                     collectorAccount
                 );

examples/foundry-hts/NFT.t.sol

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity ^0.8.0;
+
+import {Test} from "forge-std/Test.sol";
+import {htsSetup} from "hedera-forking/contracts/htsSetup.sol";
+import {IERC721} from "hedera-forking/contracts/IERC721.sol";
+
+contract NFTExampleTest is Test {
+    // https://hashscan.io/mainnet/token/0.0.5083205
+    address NFT_mainnet = 0x00000000000000000000000000000000004d9045;
+
+    address private user;
+
+    function setUp() external {
+        htsSetup();
+
+        user = makeAddr("user");
+        dealERC721(NFT_mainnet, user, 3);
+    }
+
+    function test_get_owner_of_existing_account() view external {
+        address owner = IERC721(NFT_mainnet).ownerOf(1);
+        assertNotEq(IERC721(NFT_mainnet).ownerOf(1), address(0));
+
+        // The assertion below cannot be guaranteed, since we can only query the current owner of the NFT,
+        // Note that the ownership of the NFT may change over time.
+        assertEq(owner, 0x000000000000000000000000000000000006889a);
+    }
+
+    function test_dealt_nft_assigned_to_local_account() view external {
+        assertEq(IERC721(NFT_mainnet).ownerOf(3), user);
+    }
+}

examples/foundry-hts/NFTConsole.t.sol

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity ^0.8.0;
+
+import {Test, console} from "forge-std/Test.sol";
+import {htsSetup} from "hedera-forking/contracts/htsSetup.sol";
+import {IERC721} from "hedera-forking/contracts/IERC721.sol";
+
+contract NFTConsoleExampleTest is Test {
+    function setUp() external {
+        htsSetup();
+    }
+
+    function test_using_console_log() view external {
+        // https://hashscan.io/mainnet/token/0.0.5083205
+        address NFT_mainnet = 0x00000000000000000000000000000000004d9045;
+
+        string memory name = IERC721(NFT_mainnet).name();
+        string memory symbol = IERC721(NFT_mainnet).symbol();
+        string memory tokenURI = IERC721(NFT_mainnet).tokenURI(1);
+        assertEq(name, "THE BARKANEERS");
+        assertEq(symbol, "BARKANEERS");
+        assertEq(tokenURI, "ipfs://bafkreif4hpsgflzzvd7c4abx5u5xwrrjl7wkimbjtndvkxodklxdam5upm");
+        console.log("name: %s, symbol: %s, tokenURI: %s", name, symbol, tokenURI);
+    }
+}

examples/hardhat-hts/contracts/CallNFT.sol

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity ^0.8.0;
+
+import {IERC721} from "./IERC721.sol";
+import {console} from "hardhat/console.sol";
+
+contract CallNFT {
+    function getTokenName(address tokenAddress) external view returns (string memory) {
+        return IERC721(tokenAddress).name();
+    }
+
+    function invokeTransferFrom(address tokenAddress, address to, uint256 serialId) external {
+        // You can use `console.log` as usual
+        // https://hardhat.org/tutorial/debugging-with-hardhat-network#solidity--console.log
+        console.log("Transferring from %s to %s %s tokens", msg.sender, to, serialId);
+        address owner = IERC721(tokenAddress).ownerOf(serialId);
+        IERC721(tokenAddress).transferFrom(owner, to, serialId);
+    }
+}

examples/hardhat-hts/contracts/IERC721.sol

@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity ^0.8.0;
+
+/**
+ * See https://ethereum.org/en/developers/docs/standards/tokens/erc-721/#events for more information.
+ */
+interface IERC721Events {
+    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
+}
+
+/**
+ * This interface is used to get the selectors and for testing.
+ *
+ * https://hips.hedera.com/hip/hip-218
+ * https://hips.hedera.com/hip/hip-376
+ */
+interface IERC721 {
+    /**
+     * @dev Returns the token collection name.
+     */
+    function name() external view returns (string memory);
+
+    /**
+     * @dev Returns the token collection symbol.
+     */
+    function symbol() external view returns (string memory);
+
+    /**
+     * @dev Returns the Uniform Resource Identifier (URI) for `serialId` token.
+     */
+    function tokenURI(uint256 serialId) external view returns (string memory);
+
+    /**
+     * @dev Returns the total amount of tokens stored by the contract.
+     */
+    function totalSupply() external view returns (uint256);
+
+    /**
+     * @dev Returns the number of tokens in `owner`'s account.
+     */
+    function balanceOf(address owner) external view returns (uint256 balance);
+
+    /**
+     * @dev Returns the owner of the `serialId` token.
+     *
+     * Requirements:
+     * - `serialId` must exist.
+     */
+    function ownerOf(uint256 serialId) external view returns (address);
+
+    /**
+     * @dev Transfers `serialId` token from `sender` to `recipient`.
+     *
+     * Requirements:
+     * - `sender` cannot be the zero address.
+     * - `recipient` cannot be the zero address.
+     * - `serialId` token must be owned by `sender`.
+     * - If the caller is not `sender`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
+     *
+     * Emits a {Transfer} event.
+     */
+    function transferFrom(address sender, address recipient, uint256 serialId) external payable;
+
+    /**
+     * @dev Gives permission to `spender` to transfer `serialId` token to another account.
+     * The approval is cleared when the token is transferred.
+     *
+     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
+     *
+     * Requirements:
+     * - The caller must own the token or be an approved operator.
+     * - `serialId` must exist.
+     *
+     * Emits an {Approval} event.
+     */
+    function approve(address spender, uint256 serialId) external payable;
+
+    /**
+     * @dev Approve or remove `operator` as an operator for the caller.
+     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
+     *
+     * Requirements:
+     * - The `operator` cannot be the address zero.
+     *
+     * Emits an {ApprovalForAll} event.
+     */
+    function setApprovalForAll(address operator, bool approved) external;
+
+    /**
+     * @dev Returns the account approved for `serialId` token.
+     *
+     * Requirements:
+     * - `serialId` must exist.
+     */
+    function getApproved(uint256 serialId) external view returns (address operator);
+
+    /**
+     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
+     *
+     * See {setApprovalForAll}
+     */
+    function isApprovedForAll(address owner, address operator) external view returns (bool);
+}

examples/hardhat-hts/test/nft-info.test.js

@@ -0,0 +1,30 @@
+/*-
+ * Hedera Hardhat Forking Plugin
+ *
+ * Copyright (C) 2024 Hedera Hashgraph, LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const { expect } = require('chai');
+// prettier-ignore
+const { ethers: { getContractAt } } = require('hardhat');
+
+describe('NFT example -- informational', function () {
+    it('should get name and symbol', async function () {
+        // https://hashscan.io/mainnet/token/0.0.4970613
+        const nft = await getContractAt('IERC721', '0x00000000000000000000000000000000004bd875');
+        expect(await nft['name']()).to.be.equal('Concierge Collectibles');
+        expect(await nft['symbol']()).to.be.equal('Concierge Collectibles');
+    });
+});

examples/hardhat-hts/test/nft-ownerof.test.js

@@ -0,0 +1,31 @@
+/*-
+ * Hedera Hardhat Forking Plugin
+ *
+ * Copyright (C) 2024 Hedera Hashgraph, LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const { expect } = require('chai');
+// prettier-ignore
+const { ethers: { getContractAt } } = require('hardhat');
+
+describe('NFT example -- ownerOf', function () {
+    it('should get `ownerOf` account holder', async function () {
+        // https://hashscan.io/mainnet/token/0.0.4970613
+        const nft = await getContractAt('IERC721', '0x00000000000000000000000000000000004bd875');
+        expect(await nft['ownerOf'](1)).to.not.be.equal(
+            '0x0000000000000000000000000000000000000000'
+        );
+    });
+});

examples/hardhat-hts/test/nft-transfer.test.js

@@ -0,0 +1,47 @@
+/*-
+ * Hedera Hardhat Forking Plugin
+ *
+ * Copyright (C) 2024 Hedera Hashgraph, LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const { expect } = require('chai');
+// prettier-ignore
+const { ethers: { getSigner, getSigners, getContractAt }, network: { provider } } = require('hardhat');
+const { loadFixture } = require('@nomicfoundation/hardhat-toolbox/network-helpers');
+
+describe('NFT example -- transferFrom', function () {
+    async function id() {
+        return [(await getSigners())[0]];
+    }
+
+    it("should `transferFrom` tokens from account holder to one of Hardhat' signers", async function () {
+        const [receiver] = await loadFixture(id);
+
+        // https://hashscan.io/mainnet/token/0.0.4970613
+        const nft = await getContractAt('IERC721', '0x00000000000000000000000000000000004bd875');
+
+        const holderAddress = await nft['ownerOf'](1n);
+
+        await provider.request({
+            method: 'hardhat_impersonateAccount',
+            params: [holderAddress],
+        });
+
+        const holder = await getSigner(holderAddress);
+        await nft.connect(holder)['transferFrom'](holder, receiver, 1n);
+
+        expect(await nft['ownerOf'](1n)).to.be.equal(receiver.address);
+    });
+});