ApplicationofBlockchainTechnologyMicrocoursename:SmartContractFunctionVerificationSchemeBasedonTruffleTestingMainlecturer:GuoLina區(qū)塊鏈技術(shù)的應(yīng)用微課程名稱：基于Truffle測(cè)試的智能合約功能驗(yàn)證方案主講人：郭莉娜21PARTIntroductiontoTruffleFramework第一部分：Truffle框架簡(jiǎn)介41.IntroductiontoTruffleFrameworkTruffleisaframeworkspecificallydesignedforthedevelopmentofEthereumDAppsandholdsasignificantpositioninthefieldofsmartcontractdevelopment.Ithascomprehensivefunctionsandcanprovidekeyfeaturessuchascompilation,deployment,andtesting,greatlysimplifyingthedevelopmentprocessandenablingdeveloperstobuildDAppsmoreefficiently.Atthesametime,itperformswellindevelopmentenvironmentintegration,providingidealintegrationofdevelopmenttoolsandenvironmentsettings,whichhelpsimprovecodemanagementandversioncontrolcapabilities.TruffleframeworkTruffle是一款專為以太坊去中心化應(yīng)用（DApps）開(kāi)發(fā)設(shè)計(jì)的框架，在智能合約開(kāi)發(fā)領(lǐng)域占據(jù)重要地位。該框架功能全面，可提供編譯、部署、測(cè)試等關(guān)鍵功能，極大地簡(jiǎn)化了開(kāi)發(fā)流程，使開(kāi)發(fā)者能夠更高效地構(gòu)建去中心化應(yīng)用。同時(shí)，它在開(kāi)發(fā)環(huán)境集成方面表現(xiàn)出色，能實(shí)現(xiàn)開(kāi)發(fā)工具與環(huán)境設(shè)置的理想集成，有助于提升代碼管理和版本控制能力。62PARTHelloWorldSmartContractAnalysis第二部分：“HelloWorld”智能合約分析82.AnalysisofHelloWorldSmartContractpragmasolidity^0.4.25;contractHelloWorld{stringname;functionHelloWorld(){name="Hello,World!";}functionget()constantreturns(string){returnname;}functionset(stringn){name=n;}}ThiscontractiswritteninSoliditylanguage,version0.4.25.ThecontractisnamedHelloWorld.Itcontainsastatevariablenameoftypestring,whichisusedtostorestringdata.ThecontracthasaconstructorcalledHelloWorld,whichisautomaticallycalledwhenthecontractiscreated.Itsfunctionistoinitializethenameto"Hello,World!".Inaddition,therearetwofunctionsinthecontract.Thegetfunctionismarkedasconstant,whichmeansitdoesnotmodifythestateofthecontract.Itsfunctionistoreturnastringstoredinthenamevariable;Thesetfunctionacceptsaparameternoftypestring,whichisusedtoupdatethevalueofthenamevariableandsetittothepassedstring.本合約采用Solidity語(yǔ)言編寫(xiě)，版本為0.4.25，合約名稱為“HelloWorld”。合約包含一個(gè)字符串（string）類型的狀態(tài)變量name，用于存儲(chǔ)字符串?dāng)?shù)據(jù)。合約有一個(gè)名為HelloWorld的構(gòu)造函數(shù)，在合約創(chuàng)建時(shí)會(huì)自動(dòng)調(diào)用，其功能是將name初始化為“Hello,World!”。此外，合約中還包含兩個(gè)函數(shù)：get函數(shù)被標(biāo)記為constant，表示該函數(shù)不會(huì)修改合約狀態(tài)，功能是返回存儲(chǔ)在name變量中的字符串；set函數(shù)接收一個(gè)字符串類型的參數(shù)n，用于更新name變量的值，將其設(shè)為傳入的字符串。103PARTActualoperationprocess第三部分：實(shí)際操作流程123.1.CreatingaProjectRunningTrufflerequiresnodejsasthefoundation(thisoperationusesnode-v20.18.1version)Commandtoinstalltruffle:npminstall-gtruffleAfterinstallation,createadirectoryusingthetruffleinitcommand,asshowninthefollowingfigure3.1創(chuàng)建項(xiàng)目運(yùn)行Truffle需以Node.js為基礎(chǔ)（本次操作使用的Node.js版本為v20.18.1）。安裝Truffle的命令：npminstall-gtruffle。安裝完成后，使用truffleinit命令創(chuàng)建目錄，如下所示：143.1.CreatingaProjectAftersuccessfullycreatingthedirectory,itwillgeneratedirectorystructuresandconfigurationfilesrelatedtocontractediting,contractdeployment,contractfunctionverification,etc.WecanuseVSCodetoopenthetruffleproject(asshowninthefigurebelow)forsubsequentoperations.ContractEditingContractdeploymentContractfunctionverificationconfigurationfile目錄創(chuàng)建成功后，會(huì)生成與合約編輯、合約部署、合約功能驗(yàn)證等相關(guān)的目錄結(jié)構(gòu)和配置文件。我們可以使用VSCode打開(kāi)Truffle項(xiàng)目（如下圖所示），以便進(jìn)行后續(xù)操作。163.2.InstallandstartGanacheGanacheisapersonalblockchainsimulatorusedforEthereumblockchaindevelopment,providingalocalsimulationenvironmentforourdevelopmenttesting.3.2安裝并啟動(dòng)GanacheGanache是一款用于以太坊區(qū)塊鏈開(kāi)發(fā)的個(gè)人區(qū)塊鏈模擬器，可為我們的開(kāi)發(fā)測(cè)試提供本地模擬環(huán)境。183.3.ConfigureTruffletoconnecttoGanacheWhenconfiguringTruffletoconnecttoGanache,itisimportanttoensurethatthetwoportsareconsistenttoensurenormalcommunication(asshowninthefollowingfigure).3.3配置Truffle以連接Ganache配置Truffle連接Ganache時(shí)，務(wù)必確保兩者的端口一致，以保證通信正常（如下圖所示）。203.4.ModifyTestContractVersionModifyittobethesameasoursmartcontractversion,whichis0.4.25(asshowninthefollowingfigure).3.4修改測(cè)試合約版本將測(cè)試合約版本修改為與我們的智能合約版本一致，即0.4.25（如下圖所示）。223.5.AddcontractstobetestedAddthecontractthatneedstobetested,whichisourHelloWorldcontract.3.5添加待測(cè)試合約添加需要測(cè)試的合約，即我們的“HelloWorld”合約。243.6.EditingDeploymentFilesCreatethe1_deploy_comtract.exefileinthemigrationsdirectory(asshowninthefollowingfigure).IntheTruffleproject,artifactsareglobalobjectsprovidedbyTruffle.Theartifacts.requiremethodisusedtoloadanabstractrepresentationofasmartcontract.HelloWorldhereisthecontractwewanttoload.ThepurposeofthecodeistoobtainanabstractrepresentationoftheHelloWorldsmartcontractforfuturedeploymentorinteractionwiththecontract.Definedafunctionthattakesadeployerobjectasaparameter.DeployerisadeploymenttoolobjectprovidedbyTruffle.ThemaincontentofthefunctionistousethedeployerobjecttodeploythepreviouslyloadedHelloWorldsmartcontract.WhenTruffleexecutesthedeploymentscript,itcallsthisfunctionandpassesintheappropriatedeployerobjecttodeploytheHelloWorldsmartcontracttoGanach.3.6編輯部署文件在“migrations”目錄下創(chuàng)建“1_deploy_contract.js”文件（如下圖所示）。在Truffle項(xiàng)目中，artifacts是Truffle提供的全局對(duì)象，artifacts.require方法用于加載智能合約的抽象表示。此處的“HelloWorld”即我們要加載的合約。該代碼的作用是獲取“HelloWorld”智能合約的抽象表示，以便后續(xù)進(jìn)行合約部署或與合約交互。定義了一個(gè)以deployer對(duì)象為參數(shù)的函數(shù)，deployer是Truffle提供的部署工具對(duì)象。該函數(shù)的主要內(nèi)容是使用deployer對(duì)象部署之前加載的“HelloWorld”智能合約。當(dāng)Truffle執(zhí)行部署腳本時(shí)，會(huì)調(diào)用該函數(shù)并傳入相應(yīng)的deployer對(duì)象，從而將“HelloWorld”智能合約部署到Ganache中。263.7.EditTestScriptCreateHelloWorld.jsinthetestdirectory.HereisatestsuitedefinedfortheHelloWorldsmartcontract.TheaccountsparameterisanarrayprovidedbyTruffle,containingtheaddressesofEthereumaccountsinthetestingenvironment,whichcanbeusedtosimulateoperationssuchastransactionsenders.3.7編輯測(cè)試腳本在“test”目錄下創(chuàng)建“helloworld.js”文件。此處為“HelloWorld”智能合約定義了一個(gè)測(cè)試套件。accounts參數(shù)是Truffle提供的一個(gè)數(shù)組，包含測(cè)試環(huán)境中以太坊賬戶的地址，可用于模擬交易發(fā)送者等操作。284PARTtestcase第四部分：測(cè)試用例304.1.TestCase1Instancebasedcontract:First,createanewinstanceoftheHelloWorldcontract.Theawaitkeywordindicatesthatthisisanasynchronousoperation,ascreatingacontractinstanceinvolvesinteractingwiththeEthereumblockchainandtakestime.StepOneSetnewvalueandvalidateresult:CallthegetmethodintheHelloWorldcontractinstance.ThismethodshouldbedefinedintheHelloWorldcontracttoobtainthenamevalue,whichisinferredtobeastringstoredinthecontractbasedonthefollowingassertion.assert.equal(result,"Hello,World!");Thisisanassertionstatementusedtoverifywhetherthevaluereturnedbythegetmethodisequaltotheexpected"Hello,World!".Ifitisnotequal,thetestfails.StepOne4.1測(cè)試用例1第一步：基于合約創(chuàng)建實(shí)例首先，創(chuàng)建一個(gè)“HelloWorld”合約的新實(shí)例。await關(guān)鍵字表示這是一個(gè)異步操作，因?yàn)閯?chuàng)建合約實(shí)例需要與以太坊區(qū)塊鏈進(jìn)行交互，此過(guò)程需要一定時(shí)間。32第二步：設(shè)置新值并驗(yàn)證結(jié)果調(diào)用“HelloWorld”合約實(shí)例中的get方法。該方法應(yīng)在“HelloWorld”合約中定義，用于獲取name的值，根據(jù)后續(xù)的斷言可推斷其為存儲(chǔ)在合約中的字符串。assert.equal(result,"Hello,World!");這是一條斷言語(yǔ)句，用于驗(yàn)證get方法返回的值是否與預(yù)期的“Hello,World!”相等。若不相等，則測(cè)試失敗。4.2.TestCase2Similarly,firstperformcontractinstantiation.StepOneSetnewvalueandvalidateresult:CallthesetmethodintheHelloWorldcontractinstance,passing'NewName'asaparameter.Thismethodisusedtosetanewvalueinthecontract,whichmaybetoupdatethevalueofastoragevariable.Callthegetmethodagaintoobtaintheupdatedvalue.assert.equal(newResult,'NewName');Finally,verifythroughassertionswhetherthenewvaluereturnedbythegetmethodisequaltothepreviouslyset'NewName'.Ifitisequal,itindicatesthatthesetmethodhascorrectlyupdat