Lesson 7 FundMe dot test dot js - Error when running unit test

[x-gee]

Following with the tutorial at time stamp 11:18:00, when I run the yarn hardhat test, I am facing with the following error

  1 failing

  1) FundMe
       "before each" hook for "Sets the Aggregator address correctly":
     ERROR processing /home/x/sol/hh/fundme/deploy/00-deploy-mock.js:
TypeError: Cannot read properties of undefined (reading 'length')
    at getFrom (/home/x/sol/hh/fundme/node_modules/hardhat-deploy/src/helpers.ts:1713:14)

Its not the full error code but it continues in the helper.ts file..
Following the error code in first two lines " error processing - 00-deploy-mock.js "

I am not able to understand what is wrong here. As it says TypeError : cannot read properties of undefined (reading 'length'), following all the errors line by line is getting a bit confusing for me. Below is the fundme.test.js code for your reference.

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

describe("FundMe", async function () {
    let fundMe
    let deployer
    let mockV3Aggregator
    beforeEach(async function () {
        //deploy our fundMe contract
        // using hardhat-deploy it will deploy with mock script
        // fixture helps to run entire deploy folder with as many tags as we want.
        // const accounts = await ethers.getSigners()
        // get.Signers is gonna return whatever is in the accounts section of your network.
        // const accountZero = accounts[0]
        deployer = (await getNamedAccounts()).deployer
        await deployments.fixture(["all"])
        fundMe = await ethers.getContract("FundMe", deployer)
        mockV3Aggregator = await ethers.getContract("MockV3Aggregator", deployer)
    })

    describe("constructor", async function () {
        it("Sets the Aggregator address correctly", async function () {
            const response = await fundMe.priceFeed()
            assert.equal(response, mockV3Aggregator.address)

        })
    })
})

[tuhindasv0]

hi @x-gee

i think your code is failing here

deployer = (await getNamedAccounts()).deployer

did you added below config in hardhat.config.js

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

if not ..could you please try running the test after adding those lines

[x-gee]

I already had that in the hardhat.config.js, however I commented it out because I was I was getting following network based error

 Error HH8: There's one or more errors in your config file:

  * Invalid account: #0 for network: ropsten - private key too short, expected 32 bytes
  * Invalid value undefined for HardhatConfig.networks.rinkeby.url - Expected a value of type string.
  * Invalid account: #0 for network: rinkeby - private key too short, expected 32 bytes
  * Invalid value undefined for HardhatConfig.networks.gasReporter.url - Expected a value of type string.
  * Invalid value undefined for HardhatConfig.networks.etherscan.url - Expected a value of type string.
  * Invalid value undefined for HardhatConfig.networks.namedAccounts.url - Expected a value of type string

After Uncommenting the namedAccounts section led me to the following error .

Error HH8: There's one or more errors in your config file:

  * Invalid value undefined for HardhatConfig.networks.namedAccounts.url - Expected a value of type string.

Here I realized namedAccounts does not need to be in the network config section (THIS WAS MY MAJOR MISTAKE RIGHT FROM THE BEGINNING WHICH I FAILED TO NOTICE). Pasting it outside network {} , gave me the solution I was looking for.

FundMe
    constructor
      ✓ sets the aggregator address correctly

·-----------------------|----------------------------|-------------|-----------------------------·
|  Solc version: 0.8.8  ·  Optimizer enabled: false  ·  Runs: 200  ·  Block limit: 30000000 gas  │
························|····························|·············|······························
|  Methods                                                                                       │
·············|··········|··············|·············|·············|···············|··············
|  Contract  ·  Method  ·  Min         ·  Max        ·  Avg        ·  # calls      ·  eur (avg)  │
·············|··········|··············|·············|·············|···············|··············
|  Deployments          ·                                          ·  % of limit   ·             │
························|··············|·············|·············|···············|··············
|  FundMe               ·           -  ·          -  ·     874943  ·        2.9 %  ·          -  │
························|··············|·············|·············|···············|··············
|  MockV3Aggregator     ·           -  ·          -  ·     569635  ·        1.9 %  ·          -  │
·-----------------------|--------------|-------------|-------------|---------------|-------------·

  1 passing (1s)

Done in 3.52s.

Thank you @tuhindasv0 for guiding me to the solution.

However I have a question.
Based on the error code and the fundme.test.js code that I gave in the first place, what was the information that made you look at the deployer await getnamedAccounts statement might have a problem?

Because now after I have the solution, when I read my initial question again I still have no idea why to look for getnamedAccount deployer statement..??

[tuhindasv0]

I have faced the similar issue, when i was trying to test and deploy, and for me the error message reads something like this

  TypeError: Cannot read properties of undefined (reading 'length')
      at getFrom (node_modules\hardhat-deploy\src\helpers.ts:1713:14)
      at _deploy (node_modules\hardhat-deploy\src\helpers.ts:533:9)
      at processTicksAndRejections (node:internal/process/task_queues:96:5)
      at _deployOne (node_modules\hardhat-deploy\src\helpers.ts:1004:16)
      at Object.module.exports [as func] (deploy\00-mock-priceFeed.js:12:38)
      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 Object.fixture (node_modules\hardhat-deploy\src\DeploymentsManager.ts:315:9)
      at Context.<anonymous> (test\unit\Fundme.test.js:15:9)
      at DeploymentsManager.executeDeployScripts (node_modules\hardhat-deploy\src\DeploymentsManager.ts:1222:19)
      at processTicksAndRejections (node:internal/process/task_queues:96:5)
      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:15:9)

I got the clue from the last line

at Context.<anonymous> (test\unit\Fundme.test.js:15:9)

[harshuo2]

@x-gee What I have understood is when you get the TypeError: Cannot read properties of undefined (reading 'length'), it means that something in your program is undefined. So in such cases, try to log as many places as you think would give the undefined. And when you find the problematic piece, investigate further over it...