以 Truffle 教程为基础 - 添加返回 Pet 函数 - RPC 错误

Question

我正在建立在 Truffle 提供的教程之上：https://trufflesuite.com/tutorial/index.html

我正在尝试添加类似于以下内容的 returnPet 函数：Adding a return function to Truffles Pet Shop

但是，当我点击宠物上的“返回”按钮时，我在使用元掩码时遇到了 RPC 错误。

MetaMask - RPC Error: [ethjs-query] while formatting outputs from RPC '{"value":{"code":-32603,"data":{"message":"VM Exception while processing transaction: revert","code":-32000,"data":{"0x36735e441b9c6ffeb61bcebce098576993c38580ecc207f99043706a074a06e4":{"error":"revert","program_counter":70,"return":"0x"},"stack":"RuntimeError: VM Exception while processing transaction: revert\n    at Function.RuntimeError.fromResults (/tmp/.mount_ganachz4CZxO/resources/static/node/node_modules/ganache-core/lib/utils/runtimeerror.js:94:13)\n    at BlockchainDouble.processBlock (/tmp/.mount_ganachz4CZxO/resources/static/node/node_modules/ganache-core/lib/blockchain_double.js:627:24)\n    at runMicrotasks (<anonymous>)\n    at processTicksAndRejections (internal/process/task_queues.js:93:5)","name":"RuntimeError"}}}}' 
Object { code: -32603, message: "[ethjs-query] while formatting outputs from RPC '{\"value\":{\"code\":-32603,\"data\":{\"message\":\"VM Exception while processing transaction: revert\",\"code\":-32000,\"data\":{\"0x36735e441b9c6ffeb61bcebce098576993c38580ecc207f99043706a074a06e4\":{\"error\":\"revert\",\"program_counter\":70,\"return\":\"0x\"},\"stack\":\"RuntimeError: VM Exception while processing transaction: revert\\n    at Function.RuntimeError.fromResults (/tmp/.mount_ganachz4CZxO/resources/static/node/node_modules/ganache-core/lib/utils/runtimeerror.js:94:13)\\n    at BlockchainDouble.processBlock (/tmp/.mount_ganachz4CZxO/resources/static/node/node_modules/ganache-core/lib/blockchain_double.js:627:24)\\n    at runMicrotasks (<anonymous>)\\n    at processTicksAndRejections (internal/process/task_queues.js:93:5)\",\"name\":\"RuntimeError\"}}}}'" }

我在这里维护这项工作：https://github.com/mpoletiek/pet-shop-tutorial

我不知道从哪里开始。在 Metamask 中批准交易之前，它会警告：

This transaction is expected to fail. Trying to execute it is expected to be expensive but fail, and is not recommended.

我单击“无论如何我都会尝试”以生成 RPC 错误。

这是我的 Solidity 合约：

pragma solidity ^0.5.0;

contract Adoption {
    address[16] public adopters;

    // Adopting a pet
    function adopt(uint petId) public returns (uint) {
        require(petId >= 0 && petId <= 15);

        adopters[petId] = msg.sender;

        return petId;
    }

    // Retrieving the adopters
    function getAdopters() public view returns (address[16] memory) {
        return adopters;
    }
    
    // Return Pet
    function returnPet(uint petId) public returns (address) {
        require(petId >= 0 && petId <= 15);
        
        // Address must own the pet
        require(msg.sender == adopters[petId]);
        
        // Clear the adopter for this pet
        adopters[petId] = address(0);
        
        return adopters[petId];
    }

}

和 app.js：

App = {
  web3Provider: null,
  accounts: [],
  contracts: {},
  adoptionInstance: null,

  init: async function() {
    // Load pets.
    $.getJSON('../pets.json', function(data) {
      var petsRow = $('#petsRow');
      var petTemplate = $('#petTemplate');

      for (i = 0; i < data.length; i ++) {
        petTemplate.find('.panel-title').text(data[i].name);
        petTemplate.find('img').attr('src', data[i].picture);
        petTemplate.find('.pet-breed').text(data[i].breed);
        petTemplate.find('.pet-age').text(data[i].age);
        petTemplate.find('.pet-location').text(data[i].location);
        petTemplate.find('.btn-adopt').attr('data-id', data[i].id);
        petTemplate.find('.btn-return').attr('data-id', data[i].id);

        petsRow.append(petTemplate.html());
      }
    });

    return await App.initWeb3();
  },

  initWeb3: async function() {

    // Modern dapp browsers...
    if (window.ethereum){
      try {
        //Request account access
        App.accounts = await window.ethereum.request({ method: "eth_requestAccounts" });
      } catch (error) {
        // User denied account access...
        console.error("User denied account access");
      }
      
      // User granted access to accounts
      console.log("Account[0]: "+App.accounts[0]);
      
      App.web3Provider = window.ethereum;
      console.log("modern dapp browser");
    }
    // Legacy dapp browsers...
    else if (window.web3) {
      App.web3Provider = window.web3.currentProvider;
      App.accounts = window.eth.accounts;
      console.log("legacy dapp browser");
    }
    // if no injected web3 instance is detected, fall back to Ganache
    else {
      App.web3Provider = new Web3.providers.HttpProvider('http://localhost:7545');
    }
    
    web3 = new Web3(App.web3Provider);

    return App.initContract();
    
  },

  initContract: function() {

    $.getJSON('Adoption.json', function(data) {
      // Get the necessary contract artifact file and instantiate it with @truffle/contract
      var AdoptionArtifact = data;
      try { App.contracts.Adoption = TruffleContract(AdoptionArtifact); } catch (error) { console.error(error); }

      // Set the provider for our contract
      try {
        App.contracts.Adoption.setProvider(App.web3Provider);
      } catch (error){
        console.log(error);
      }
      // Use our contract to retrieve and mark the adopted pets
      return App.markAdopted();
    });

    return App.bindEvents();
  },

  bindEvents: function() {
    $(document).on('click', '.btn-adopt', App.handleAdopt);
    $(document).on('click', '.btn-return', App.handleReturn);
  },

  markAdopted: function() {

    var adoptionInstance;

    App.contracts.Adoption.deployed().then(function(instance) {
      App.adoptionInstance = instance;

      return App.adoptionInstance.getAdopters.call();
    }).then(function(adopters) {
        
        for(i=0;i<adopters.length;i++){
            if (adopters[i] != '0x0000000000000000000000000000000000000000') {
                if (adopters[i] == App.accounts[0]){
                    $('.panel-pet').eq(i).find('.btn-return').text('Return').attr('disabled', false);
                    $('.panel-pet').eq(i).find('.btn-adopt').text('Adopted').attr('disabled', true);
                } else {
                    $('.panel-pet').eq(i).find('.btn-return').text('-').attr('disabled', true);
                    $('.panel-pet').eq(i).find('.btn-adopt').text('Adopted').attr('disabled', true);
                }
            } else {
                $('.panel-pet').eq(i).find('.btn-return').text('-').attr('disabled', true);
            }
        }
        
        
        
    }).catch(function(err) {
      console.log(err.message);
    });
  },

  handleReturn: function(event) {
    event.preventDefault();
    
    var petId = parseInt($(event.target).data('id'));
    
    console.log("petID:"+petId);
        
    App.contracts.Adoption.deployed().then(function(instance) {

        // Execute adopt as a transaction by sending account
        return App.adoptionInstance.returnPet(petId, {from: App.accounts[0]});
      }).then(function(result) {
        return App.markAdopted();
      }).catch(function(err) {
        console.log(err.message);
      });
    
  },


  handleAdopt: function(event) {
    event.preventDefault();

    var petId = parseInt($(event.target).data('id'));
    console.log("petId:"+petId);

    App.contracts.Adoption.deployed().then(function(instance) {

        // Execute adopt as a transaction by sending account
        return App.adoptionInstance.adopt(petId, {from: account[0]});
        }).then(function(result) {
            return App.markAdopted();
        }).catch(function(err) {
            console.log(err.message);
    });
    
  }

};

$(function() {
  $(window).load(function() {
    App.init();
  });
});

一切都编译并且我的测试运行正常。在我确认之前不确定 Metamask 如何知道交易是坏的，但这是一个提示吗？如果有帮助，我会在 Firefox 和 Chrome 中得到相同的结果。

任何想法我应该首先检查什么？

谢谢，

Answer 1

根据提供的代码，您正试图归还一只尚未被领养的宠物，因此由于此逻辑错误而失败。

首先部署合约。由于构造函数中没有收养机制，所以这一步之后就没有收养宠物了。

App.contracts.Adoption.deployed()

然后你会立即尝试归还宠物

return adoptionInstance.returnPet

这行失败了，因为 所有 采用者此时的默认值是 0x0。

require(msg.sender == adopters[petId]);

解决方案：根据您的 JS 代码的上下文（注释和 return App.markAdopted()），您可能希望在 JS 测试中调用 adopt() 函数 - 而不是 returnPet() .

Answer 2

所以在重置整个环境并使用truffle migrate --reset 重建后，我终于得到了这个工作。我还必须确保我只有 1 个浏览器选项卡向应用程序打开，多个选项卡会导致多笔交易，出于某种我仍然不知道的原因。

app.js

App = {
  web3Provider: null,
  accounts: [],
  contracts: {},

  init: async function() {
    // Load pets.
    $.getJSON('../pets.json', function(data) {
      var petsRow = $('#petsRow');
      var petTemplate = $('#petTemplate');

      for (i = 0; i < data.length; i ++) {
        petTemplate.find('.panel-title').text(data[i].name);
        petTemplate.find('img').attr('src', data[i].picture);
        petTemplate.find('.pet-breed').text(data[i].breed);
        petTemplate.find('.pet-age').text(data[i].age);
        petTemplate.find('.pet-location').text(data[i].location);
        petTemplate.find('.btn-adopt').attr('data-id', data[i].id);
        petTemplate.find('.btn-return').attr('data-id', data[i].id);

        petsRow.append(petTemplate.html());
      }
    });

    return await App.initWeb3();
  },

  initWeb3: async function() {

    // Modern dapp browsers...
    if (window.ethereum){
      try {
        //Request account access
        App.accounts = await window.ethereum.request({ method: "eth_requestAccounts" });
      } catch (error) {
        // User denied account access...
        console.error("User denied account access");
      }
      
      // User granted access to accounts
      console.log("Account[0]: "+App.accounts[0]);
      
      App.web3Provider = window.ethereum;
      console.log("modern dapp browser");
    }
    // Legacy dapp browsers...
    else if (window.web3) {
      App.web3Provider = window.web3.currentProvider;
      App.accounts = window.eth.accounts;
      console.log("legacy dapp browser");
    }
    // if no injected web3 instance is detected, fall back to Ganache
    else {
      App.web3Provider = new Web3.providers.HttpProvider('http://localhost:7545');
    }
    
    //web3 = new Web3(App.web3Provider);

    return App.initContract();
    
  },

  initContract: function() {

    $.getJSON('Adoption.json', function(data) {
      // Get the necessary contract artifact file and instantiate it with @truffle/contract
      var AdoptionArtifact = data;
      try { App.contracts.Adoption = TruffleContract(AdoptionArtifact); } catch (error) { console.error(error); }

      // Set the provider for our contract
      try {
        App.contracts.Adoption.setProvider(App.web3Provider);
      } catch (error){
        console.log(error);
      }
      // Use our contract to retrieve and mark the adopted pets
      return App.markAdopted();
    });

    return App.bindEvents();
  },

  bindEvents: function() {
    $(document).on('click', '.btn-adopt', App.handleAdopt);
    $(document).on('click', '.btn-return', App.handleReturn);
  },

  markAdopted: function() {

    var adoptionInstance;
    App.contracts.Adoption.deployed().then(function(instance) {
      adoptionInstance = instance;

      return adoptionInstance.getAdopters.call();
    }).then(function(adopters) {
        
        for(i=0;i<adopters.length;i++){
            if (adopters[i] != '0x0000000000000000000000000000000000000000') {
                if (adopters[i] == App.accounts[0]){
                    $('.panel-pet').eq(i).find('.btn-return').text('Return').attr('disabled', false);
                    $('.panel-pet').eq(i).find('.btn-adopt').text('Adopted').attr('disabled', true);
                } else {
                    $('.panel-pet').eq(i).find('.btn-return').text('-').attr('disabled', true);
                    $('.panel-pet').eq(i).find('.btn-adopt').text('Adopted').attr('disabled', true);
                }
            } else {
                $('.panel-pet').eq(i).find('.btn-return').text('-').attr('disabled', true);
            }
        }

        
    }).catch(function(err) {
      console.log(err.message);
    });
  },

  handleReturn: function(event) {
    event.preventDefault();
    
    var petId = parseInt($(event.target).data('id'));
    
    console.log("handleReturn petId: "+petId+" Account[0]: "+App.accounts[0]);
    console.log("petID:"+petId);
    console.log("Account[0]: "+App.accounts[0]);
    
    var adoptionInstance;
    App.contracts.Adoption.deployed().then(function(instance) {
      adoptionInstance = instance;

      return adoptionInstance.returnPet(petId, {from: App.accounts[0]});
    }).then(function(result){
        App.markAdopted();
    });
    
  },


  handleAdopt: function(event) {
    event.preventDefault();

    var petId = parseInt($(event.target).data('id'));
    console.log("handleAdopt petId: "+petId+" Account[0]: "+App.accounts[0]);
    console.log("petId:"+petId);

    var adoptionInstance;
    App.contracts.Adoption.deployed().then(function(instance) {
      adoptionInstance = instance;

      return adoptionInstance.adopt(petId, {from: App.accounts[0]});
    }).then(function(result){
        App.markAdopted();
    });
    
  }

};

$(function() {
  $(window).load(function() {
    App.init();
  });
});

Adoption.sol

pragma solidity ^0.5.0;

contract Adoption {
    address[16] public adopters;

    // Adopting a pet
    function adopt(uint petId) public returns (uint) {
        require(petId >= 0 && petId <= 15);

        adopters[petId] = msg.sender;

        return petId;
    }

    // Retrieving the adopters
    function getAdopters() public view returns (address[16] memory) {
        return adopters;
    }
    
    // Return Pet
    function returnPet(uint petId) public returns (uint) {
        require(petId >= 0 && petId <= 15);
        
        // Address must own the pet
        require(msg.sender == adopters[petId]);
        
        // Clear the adopter for this pet
        adopters[petId] = address(0);
        
        return petId;
    }

}