Testing the safeMint function

Question

I am trying to successfully write a unit test for my safeMint function below.

Here is my current test:

const assert = require("assert");
const { accounts } = require("@openzeppelin/test-environment");
const ComNFT = artifacts.require("ComNFT");
const { expect } = require("chai");

// describe('ComNFT', () => {
// let accounts;
let comNFT;

beforeEach(async () => {
  accounts = await web3.eth.getAccounts();
  comNFT = await ComNFT.new({ from: accounts[0] });
  //comNFT = await ComNFT.at("");
  // console.log(comNFT.address);
});


  it('should fail when called by a non-owner account', async () => {
    try {
      await web3.eth.sendTransaction({
        from: accounts[1], // The non-owner account
        to: comNFT.address, // The contract address
        data: comNFT.methods.safeMint(accounts[1], 'token URI').encodeABI() // The function call and arguments, encoded as ABI
      });
      assert.fail('Expected error not thrown');
    } catch (error) {
      assert(error.message.includes('onlyOwner'), 'Expected "onlyOwner" error message not found');
    }
  });

  it('should be able to mint a new token', async () => {
    await web3.eth.sendTransaction({
      from: accounts[0], // The owner account
      to: comNFT.address, // The contract address
      data: comNFT.methods.safeMint(accounts[1], 'token URI').encodeABI() // The function call and arguments, encoded as ABI
    });

    const tokenURI = await comNFT.tokenURI(1); // Assume the token ID is 1
    assert.equal(tokenURI, 'token URI');
  });

    function safeMint(address to, string memory uri) public onlyOwner {
        uint256 tokenId = _tokenIdCounter.current();
        _tokenIdCounter.increment();
        _safeMint(to, tokenId);
        _setTokenURI(tokenId, uri);
    }

I am getting a failure message after i run npx truffle test " 1) "before each" hook for "should fail when called by a non-owner account"

0 passing (3s) 1 failing

1. "before each" hook for "should fail when called by a non-owner account": TypeError: Assignment to constant variable. at Context. (test/ComNFT.js:11:12)"

Can someone suggest a way of me successfully writing a test that calls safeMint?

The other test "itshould fail when called by a non-owner account" is also not running?

Thanks

Answer 1

safeMint function has onlyowner modifir, you should call safeMint function with the owner address that is accounts[0] (not accounts[1])