ساخت بازار NFT با استفاده از سالیدیتی و استاندارد ERC-721

npm install -g truffle

truffle init

// SPDX-License-Identifier: MIT
pragma solidity ^.8.;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract MyNFT is ERC721, Ownable {
    uint public nextTokenId;
    mapping(uint => string) public tokenURI;

    constructor() ERC721("MyNFT", "MNFT") {}

    function mint(string memory _tokenURI) external onlyOwner {
        uint tokenId = nextTokenId;
        nextTokenId++;
        _safeMint(msg.sender, tokenId);
        tokenURI[tokenId] = _tokenURI;
    }

    function _baseURI() internal view virtual override returns (string memory) {
        return "https://myapi.com/api/token/";
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^.8.;

import "./MyNFT.sol";

contract Marketplace {
    struct Listing {
        uint tokenId;
        address seller;
        uint price;
    }

    MyNFT public nft;
    mapping(uint => Listing) public listings;

    constructor(address _nftAddress) {
        nft = MyNFT(_nftAddress);
    }

    function listNFT(uint _tokenId, uint _price) external {
        require(nft.ownerOf(_tokenId) == msg.sender, "You are not the owner");
        require(_price > , "Price must be greater than ");

        listings[_tokenId] = Listing(_tokenId, msg.sender, _price);
    }

    function buyNFT(uint _tokenId) external payable {
        Listing memory listing = listings[_tokenId];
        require(msg.value == listing.price, "Incorrect price");
        
        nft.transferFrom(listing.seller, msg.sender, _tokenId);
        payable(listing.seller).transfer(msg.value);

        delete listings[_tokenId];
    }
}

const MyNFT = artifacts.require("MyNFT");
const Marketplace = artifacts.require("Marketplace");

module.exports = function(deployer) {
    deployer.deploy(MyNFT).then(function() {
        return deployer.deploy(Marketplace, MyNFT.address);
    });
};

truffle develop

migrate --reset

const MyNFT = artifacts.require("MyNFT");
const Marketplace = artifacts.require("Marketplace");

contract("Marketplace", (accounts) => {
    it("should list and buy nft", async () => {
        const nftInstance = await MyNFT.new();
        const marketplaceInstance = await Marketplace.new(nftInstance.address);

        await nftInstance.mint("https://example.com/token1.json");
        await nftInstance.approve(marketplaceInstance.address, , { from: accounts[] });
        
        await marketplaceInstance.listNFT(, web3.utils.toWei("1", "ether"), { from: accounts[] });

        const listing = await marketplaceInstance.listings();
        assert.equal(listing.tokenId.toString(), "");
        
        await marketplaceInstance.buyNFT(, { from: accounts[1], value: web3.utils.toWei("1", "ether") });

        const newOwner = await nftInstance.ownerOf();
        assert.equal(newOwner, accounts[1]);
    });
});

truffle test