Truffle test fails while checking if the contract instance has the owner address

Question

As I was going through the truffle test for the smart contract below to check if it has the owner address:

pragma solidity >=0.4.21 <0.7.0;


contract Owner {
    address public owner;
    address public nextOwner;
    constructor () public {
        owner = msg.sender;
    }
}

it fails with the message below: after running the truffle test.

Using network 'development'.


Compiling your contracts...
===========================
> Compiling ./contracts/Owner.sol
> Artifacts written to /tmp/test-2020319-8538-1ih1ur3.6ijj
> Compiled successfully using:
   - solc: 0.5.16+commit.9c3226ce.Emscripten.clang



  Contract: Owner
    The attributes
0x7C94D330943a4a6CC1c25eF043446dA1898F4688
      ✓ has the address
      1) has the owner
    > No events were emitted


  1 passing (406ms)
  1 failing

  1) Contract: Owner
       The attributes
         has the owner:

      has owner address
      + expected - actual

      -0x0000000000000000000000000000000000000000
      +0xBcB8563A1f9707BDa6bb020222b664Ddc100e5a4

      at Context.it (test/DIce.js:21:20)
      at <anonymous>
      at process._tickCallback (internal/process/next_tick.js:189:7)

It is clear that the actual and the expected was not equal.

The test script I was using is below:

const Owner = artifacts.require('./Owner.sol');

contract('Owner', accounts => {
    const owner = accounts[0];
    const nextOwner = accounts[1];

      describe('The attributes', () => {
        let ownerInstance;
        beforeEach(async () => {
            ownerInstance = await Owner.new();
        });

        it('has the address', () => {
            const address = ownerInstance.address;
            assert.notEqual(address, '0x0', 'has contract address');
            console.log(address);
        });

        it('has the owner', async () => {
            const address = await ownerInstance.nextOwner();
            assert.equal(address, owner, 'has owner address');
        });

});

});

Could you please advice? I would appreciate discussions over this. Thanks.

Answer 1

Change this:

ownerInstance.nextOwner()

To this:

ownerInstance.owner()

The nextOwner variable becomes non-zero only when the contract's ownership is transferred.