istanbul generates empty report - testing

Question

I wanted to launch istanbul in my project, however no matter what I do reports shows only zeros. like below :
----------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
----------|---------|----------|---------|---------|-------------------
All files | 0 | 0 | 0 | 0 |
----------|---------|----------|---------|---------|-------------------
Even though it shows above the coverage report list of the test that passed. For simplicity I created super simple project for replication where I have only one function in indentity.js file :
export const identity = (x) => x;
and one simple test licated in test.js file
import { identity } from "./identity.js";
import assert from "assert";
describe("identity", function () {
it("should return passed argument", () => {
assert.equal(identity(1), 1);
assert.equal(identity("string"), "string");
assert.deepEqual(identity({ a: 1 }), { a: 1 });
});
});
and after I run nyc mocha I expect to see 100% coverage but what I have is the same table with zeros.
Is there some settings I missed to see proper coverage report ?
Thx in advance.