TypeError: Descriptor for property round is non-configurable and non-writable - smart contracts

Question

I have multiple cloud functions for my contracts and I am trying to create some unit tests using sinon. However, I have issues when trying to simulate some of the cloud of the functions. I want just to stub them and inside the methods I have called some properties of the smart contracts and want it to return a specified value. In order to understand what am I doing, here is a code snippet of the contract (partial):

contract RoundOracle is Ownable, AccessControl, Pausable {
    uint8 public round; // Starts from 1. Updated after each round has finished.

    uint8 public constant START = 0;
    uint8 public constant END = 1;

    event LogSetRoundBounds(uint8 round, uint256 startRound, uint256 endRound);

    constructor() {
        round = 1;
    }
}

Then I want to stub this property round and assert that its value is equal to 2, it gives me the aforementioned error. Here is the code:

describe("NFT Rounds Test", () => {
    context("NFT Rounds positive testing", () => {
        before(function () {
            initializeENV();
        });
    
        after(function () {
            sandbox.restore();
        });

        it.only("Test the web3 calls", async() => {
            console.log("hit b4 web3");
            var web = Web3.getInstance();
            console.log("hit after web3")

            var newSandbox = sinon.createSandbox();
            newSandbox.stub(web.roundOracle, "round").value(2);
            expect(web.roundOracle.round).to.equal(2, "not equal to 2");
            
            console.log("finally passed this stubbing ---");
        });
    });
});

I understand that it is because the property is non-writable, but is it possible somehow to test such scenarios even if they are not writable or configurable?

Answer 1

I figured out how can I make a workaround. First, I removed the objects (cleared them) and then defined new properties and when mocking then, just return the value that is desired.

// remove the desired objects (properties/functions)
removeRef(name, object) {
    for (let i = 0; i < this[name].length; i++) {
      delete object[this[name][i]];
    }

    for (let i = 0; i < this[name].length; i++) {
      object[this[name][i]] = {};
    }
  }

  // setting the function callback and the properties that I want to be true
  mockFunction(o, k, cb) {
    Object.defineProperty(o, k, {
      enumerable: true,
      value: cb,
      writable: true,
      configurable: true,
    });
  }

Afterwards, I am just calling the removeRef in the before() hook and then in the test functions calling it like this:

prerequisites.mockFunction(<object-instance>, "<method/property-name>", () => "hash");

the object-instance = the class where the properties and the functions are declared.