注意: 这里使用的truffle版本为4.1.4,貌似使用高版本在truffle test时候会出问题,提示
truffle/Assert.sol is not found等错误
使用Truffle Box创建Truffle项目
$ mkdir petshop
$ cd petshop
$ truffle unbox pet-shop
项目目录结构
$ ls
box-img-lg.png contracts/ node_modules/ src/
box-img-sm.png LICENSE package.json test/
bs-config.json migrations/ package-lock.json truffle.js
项目
$ touch contracts/Adoption.sol
内容如下:
pragma solidity ^0.4.17;
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]) {
return adopters;
}
}
Migrations.sol代码如下:
pragma solidity ^0.4.17;
contract Migrations {
address public owner;
uint public last_completed_migration;
modifier restricted() {
if (msg.sender == owner) _;
}
function Migrations() public {
owner = msg.sender;
}
function setCompleted(uint completed) public restricted {
last_completed_migration = completed;
}
function upgrade(address new_address) public restricted {
Migrations upgraded = Migrations(new_address);
upgraded.setCompleted(last_completed_migration);
}
}
编译
将solidity代码编译成以太坊虚拟机(Ethereum Virtual Machine，简称EVM)可以执行的字节码。
$ truffle compile
Compiling .\contracts\Adoption.sol...
Compiling .\contracts\Migrations.sol...
Writing artifacts to .\build\contracts
运行ganache
Quickly fire up a personal Ethereum blockchain which you can use to run tests, execute commands, and inspect state while controlling how the chain operates.
Migration(迁移)
A migration is a deployment script meant to alter the state of your application's contracts, moving it from one state to the next.
$ touch migrations/2_deploy_contracts.js
内容如下:
var Adoption = artifacts.require("./Adoption.sol");
module.exports = function (deployer) {
deployer.deploy(Adoption);
}
$ truffle migrate
Using network 'development'.
Running migration: 1_initial_migration.js
Deploying Migrations...
... 0x69df0a2b452808f94386709c3c22f6c10607ff7473d92558eb75c743cbae0e1c
Migrations: 0x658dfbe4e9a30de42b8c48373eca4d05d6a0fe52
Saving successful migration to network...
... 0xa7fd9f435d8d942bd3e83ab8fef01ed8f7d1d161803364a9193a526e681cb7c4
Saving artifacts...
Running migration: 2_deploy_contracts.js
Deploying Adoption...
... 0x340f8e750a19a0178f54b328e59802231dd001c11ddb999776f900113e570dba
Adoption: 0xa739c709b5c06110fb15433f9f65832f5188fe43
Saving successful migration to network...
... 0x6c9b3b180ea294d968d7e607bd78c53872e08a688b01aca629e5bb6e73440c8e
Saving artifacts...
编写测试代码
$ touch test/TestAdoption.sol
内容如下:
pragma solidity ^0.4.17;
import "truffle/Assert.sol";
import "truffle/DeployedAddresses.sol";
import "../contracts/Adoption.sol";
contract TestAdoption {
Adoption adoption = Adoption(DeployedAddresses.Adoption());
function testUserCanAdoptPet() public {
uint returnedId = adoption.adopt(8);
uint expected = 8;
Assert.equal(returnedId, expected, "Adoption of pet ID 8 should be recorded.");
}
function testGetAdopterAddressByPetId() public {
// Expected owner is this contract
address expected = this;
address adopter = adoption.adopters(8);
Assert.equal(adopter, expected, "Owner of pet Id 8 should be recored.");
}
// Testing retrieval of all pet owners
function testGetAdopterAddressByPetIdInArray() public {
// Expected owner is this contract
address expected = this;
// store adopters in memory rather than contract's storage
address[16] memory adopters = adoption.getAdopters();
Assert.equal(adopters[8], expected, "Owner of pet ID 8 should be recorded.");
}
}
测试
$ truffle test
效果:
TestAdoption
√ testUserCanAdoptPet (83ms)
√ testGetAdopterAddressByPetId (87ms)
√ testGetAdopterAddressByPetIdInArray (107ms)
3 passing (1s)
虽然vscode依然有错误提示，但是能够测试通过
创建和智能合约交互的用户接口
1) 实例化web3对象
打开项目目录src/js/app.js
修改initWeb3,使用下面内容替换带多行注释:
// Is there an injected web3 instance?
if (typeof web3 !== 'undefined') {
App.web3Provider = web3.currentProvider;
} else {
// If no injected web3 instance is detected, fall back to Ganache
App.web3Provider = new Web3.providers.HttpProvider('http://localhost:7545');
}
web3 = new Web3(App.web3Provider);
2) 实例化合约
修改initContract,使用下面内容替换带多行注释:
$.getJSON('Adoption.json', function(data) {
// Get the necessary contract artifact file and instantiate it with truffle-contract
var AdoptionArtifact = data;
App.contracts.Adoption = TruffleContract(AdoptionArtifact);
// Set the provider for our contract
App.contracts.Adoption.setProvider(App.web3Provider);
// Use our contract to retrieve and mark the adopted pets
return App.markAdopted();
});
3) 获取已收养的宠物并更新UI
修改markAdopted,使用下面内容替换带多行注释:
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') {
$('.panel-pet').eq(i).find('button').text('Success').attr('disabled', true);
}
}
}).catch(function(err) {
console.log(err.message);
});
4) 处理adopt()函数
修改handleAdopt，使用下面内容替换带多行注释:
var adoptionInstance;
web3.eth.getAccounts(function(error, accounts) {
if (error) {
console.log(error);
}
var account = accounts[0];
App.contracts.Adoption.deployed().then(function(instance) {
adoptionInstance = instance;
// Execute adopt as a transaction by sending account
return adoptionInstance.adopt(petId, {from: account});
}).then(function(result) {
return App.markAdopted();
}).catch(function(err) {
console.log(err.message);
});
});
5) 安装配置metamask插件,创建并切换网络为localhost:7545
6) 启动服务
$ npm run dev
app.js代码如下:
App = {
web3Provider: null,
contracts: {},
init: 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);
petsRow.append(petTemplate.html());
}
});
return App.initWeb3();
},
initWeb3: function () {
// Is there an injected web3 instance?
if (typeof web3 !== 'undefined') {
App.web3Provider = web3.currentProvider;
} else {
// If no injected web3 instance is detected, fall back to Ganache
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;
App.contracts.Adoption = TruffleContract(AdoptionArtifact);
// Set the provider for our contract
App.contracts.Adoption.setProvider(App.web3Provider);
// 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);
},
markAdopted: function (adopters, account) {
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') {
$('.panel-pet').eq(i).find('button').text('Success').attr('disabled', true);
}
}
}).catch(function (err) {
console.log(err.message);
});
},
handleAdopt: function (event) {
event.preventDefault();
var petId = parseInt($(event.target).data('id'));
var adoptionInstance;
web3.eth.getAccounts(function (error, accounts) {
if (error) {
console.log(error);
}
var account = accounts[0];
App.contracts.Adoption.deployed().then(function (instance) {
adoptionInstance = instance;
// Execute adopt as a transaction by sending account
return adoptionInstance.adopt(petId, { from: account });
}).then(function (result) {
return App.markAdopted();
}).catch(function (err) {
console.log(err.message);
});
});
}
};
$(function () {
$(window).load(function () {
App.init();
});
});
效果:
出现的问题
1 > 执行truffle test的时候出现如下错误: truffle/Assert.sol is not found
$ npm view truffle versions
$ npm uninstall -g truffle
$ npm install -g truffle@4.1.4
删除build目录
然后重新执行命令即可。
$ truffle compile
$ truffle test
参考:
