测试契约时的错误处理- TypeError:无法读取未定义属性的“长度”

Question

在尝试测试FundMe合同时，我得到了以下错误。

以下是我的看法：

学习Blockchain，Solidity和Stack Web3 Development JavaScript -32小时课程，由Patrick在FreeCodeCamp YT频道上

我是在11:18在上面的课程中犯了这个错误。我几乎什么都试过了，但什么也帮不了我，我找到了问题所在。

问题:我在哪里发现测试文件中的问题？

对我来说，我不知道如何修复它，因为这个错误几乎和我在部署时遇到的问题相同，我只是在hardhat.config.js文件中添加了一些代码。但在测试中，我遇到了同样的问题，但不起作用。

namedAccounts: {
    deployer: {
        default: 0, // here this will by default take the first account as deployer
    },
},

为了我的FundMe.test.js

const { assert, expect } = require("chai")
const { deployments, network, ethers } = require("hardhat")

describe("FundMe", function () {
    let fundMe
    let mockV3Aggregator
    let deployer
    beforeEach(async () => {
        // const accounts = await ethers.getSigners()
        // deployer = accounts[0]
        deployer = (await getNamedAccounts()).deployer
        await deployments.fixture(["all"])
        fundMe = await ethers.getContract("FundMe", deployer)
        mockV3Aggregator = await ethers.getContract(
            "MockV3Aggregator",
            deployer
        )
    })

    describe("constructor", function () {
        it("sets the aggregator addresses correctly", async () => {
            const response = await fundMe.getPriceFeed()
            assert.equal(response, mockV3Aggregator.address)
        })
    })
})

这里是错误：

  FundMe
    constructor

      1) "before each" hook for "sets the aggregator addresses correctly"


  0 passing (1s)
  1 failing

  1) FundMe
       "before each" hook for "sets the aggregator addresses correctly":
   
   ERROR processing /Users/namnguyen/Workspace/blockchain/smart-contract-programming/hardhat-fund-me/deploy/01-deploy-fund-me.js:
TypeError: Cannot read property 'length' of undefined
    at getFrom (/Users/namnguyen/Workspace/blockchain/smart-contract-programming/hardhat-fund-me/node_modules/hardhat-deploy/src/helpers.ts:1713:14)
    at fetchIfDifferent (/Users/namnguyen/Workspace/blockchain/smart-contract-programming/hardhat-fund-me/node_modules/hardhat-deploy/src/helpers.ts:939:38)
    at processTicksAndRejections (internal/process/task_queues.js:95:5)
    at runNextTicks (internal/process/task_queues.js:64:3)
    at listOnTimeout (internal/timers.js:526:9)
    at processTimers (internal/timers.js:500:7)
    at _deployOne (/Users/namnguyen/Workspace/blockchain/smart-contract-programming/hardhat-fund-me/node_modules/hardhat-deploy/src/helpers.ts:1002:24)
    at Object.module.exports [as func] (/Users/namnguyen/Workspace/blockchain/smart-contract-programming/hardhat-fund-me/deploy/01-deploy-fund-me.js:13:34)
    at DeploymentsManager.executeDeployScripts (/Users/namnguyen/Workspace/blockchain/smart-contract-programming/hardhat-fund-me/node_modules/hardhat-deploy/src/DeploymentsManager.ts:1219:22)
    at DeploymentsManager.runDeploy (/Users/namnguyen/Workspace/blockchain/smart-contract-programming/hardhat-fund-me/node_modules/hardhat-deploy/src/DeploymentsManager.ts:1052:5)
  Error: ERROR processing /Users/namnguyen/Workspace/blockchain/smart-contract-programming/hardhat-fund-me/deploy/01-deploy-fund-me.js:
  TypeError: Cannot read property 'length' of undefined
      at getFrom (node_modules/hardhat-deploy/src/helpers.ts:1713:14)
      at fetchIfDifferent (node_modules/hardhat-deploy/src/helpers.ts:939:38)
      at processTicksAndRejections (internal/process/task_queues.js:95:5)
      at runNextTicks (internal/process/task_queues.js:64:3)
      at listOnTimeout (internal/timers.js:526:9)
      at processTimers (internal/timers.js:500:7)
      at _deployOne (node_modules/hardhat-deploy/src/helpers.ts:1002:24)
      at Object.module.exports [as func] (deploy/01-deploy-fund-me.js:13:34)
      at DeploymentsManager.executeDeployScripts (node_modules/hardhat-deploy/src/DeploymentsManager.ts:1219:22)
      at DeploymentsManager.runDeploy (node_modules/hardhat-deploy/src/DeploymentsManager.ts:1052:5)
      at DeploymentsManager.executeDeployScripts (node_modules/hardhat-deploy/src/DeploymentsManager.ts:1222:19)
      at processTicksAndRejections (internal/process/task_queues.js:95:5)
      at runNextTicks (internal/process/task_queues.js:64:3)
      at listOnTimeout (internal/timers.js:526:9)
      at processTimers (internal/timers.js:500:7)
      at DeploymentsManager.runDeploy (node_modules/hardhat-deploy/src/DeploymentsManager.ts:1052:5)
      at Object.fixture (node_modules/hardhat-deploy/src/DeploymentsManager.ts:315:9)
      at Context.<anonymous> (test/unit/FundMe.test.js:12:9)

谢谢你的帮忙!

Answer 1

通常，这是因为文件namedAccount中缺少hardhat.config.js的配置。配置告诉插件hardhat-deploy它应该使用哪个帐户来部署合同。

检查hardhat.config.js，并将下面的代码片段添加到文件中：

  namedAccounts: {
    deployer: {
      default: 0, 
      1: 0, 
    },