Error: invalid contract address or ENS name (argument="addressOrName", value=undefined, code=INVALID_ARGUMENT, version=contracts/5.7.0)

Question

I am trying to test the contract but getting error:

  Basic NFT Unit Tests
    Constructor

      1) "before each" hook for "Initializes the NFT Correctly."


  0 passing (2s)
  1 failing

  1) Basic NFT Unit Tests
       "before each" hook for "Initializes the NFT Correctly.":
     Error: invalid contract address or ENS name (argument="addressOrName", value=undefined, code=INVALID_ARGUMENT, version=contracts/5.7.0)
      at Logger.makeError (node_modules\@ethersproject\logger\src.ts\index.ts:269:28)
      at Logger.throwError (node_modules\@ethersproject\logger\src.ts\index.ts:281:20)
      at Logger.throwArgumentError (node_modules\@ethersproject\logger\src.ts\index.ts:285:21)
      at Contract.BaseContract (node_modules\@ethersproject\contracts\src.ts\index.ts:712:20)
      at new Contract (node_modules\@ethersproject\contracts\lib\index.js:1053:42)
      at Function.ContractFactory.getContract (node_modules\@ethersproject\contracts\src.ts\index.ts:1297:16)
      at ContractFactory.attach (node_modules\@ethersproject\contracts\src.ts\index.ts:1260:42)
      at getContractAtFromArtifact (node_modules\@nomiclabs\hardhat-ethers\src\internal\helpers.ts:377:26)
      at processTicksAndRejections (node:internal/process/task_queues:95:5)
      at Context.<anonymous> (test\basicNft.test.js:15:26)`

Here, my code

const { assert } = require("chai")
const { network, deployments, ethers } = require("hardhat")
const { developmentChains } = require("../helper-hardhat-config")


!developmentChains.includes(network.name)
    ? describe.skip
    : describe("Basic NFT Unit Tests", function () {
          let basicNft, deployer

          beforeEach(async () => {
              accounts = await ethers.getSigners()
              deployer = accounts[0]
              await deployments.fixture(["basicNft"])
              basicNft = await ethers.getContractAt("BasicNFT")
          })
        
        describe("Constructor", () => {
            it("Initializes the NFT Correctly.", async () => {
                const name = await basicNft.name()
                const symbol = await basicNft.symbol()
                const tokenCounter=await basicNft.getTokenCounter()
                assert.equal(name, "Dogie")
                assert.equal(symbol, "DOG")
                assert.equal(tokenCounter.toString(),"0")
            })
        })

        describe("Mint NFT", () => {
          beforeEach(async () => {
              const txResponse = await basicNft.mintNft()
              await txResponse.wait(1)
          })
          it("Allows users to mint an NFT, and updates appropriately", async function () {
              const tokenURI = await basicNft.tokenURI(0)
              const tokenCounter = await basicNft.getTokenCounter()

              assert.equal(tokenCounter.toString(), "1")
              assert.equal(tokenURI, await basicNft.TOKEN_URI())
          })
          it("Show the correct balance and owner of an NFT", async function () {
              const deployerAddress = deployer.address;
              const deployerBalance = await basicNft.balanceOf(deployerAddress)
              const owner = await basicNft.ownerOf("0")

              assert.equal(deployerBalance.toString(), "1")
              assert.equal(owner, deployerAddress)
          })
        })
    })

Answer 1

You are passing a faulty parameter in the getContractAt() function. It takes the contract name and address.

What you are trying to do here is connect to a deployed contract, but to achieve that, you need to provide the contract address.

Read more about it here.