somefile.unit.test.js //jest unit test file

import pageData from '../__mocks__/somefile.mock.json';
...
describe('My component', () => {
  it('Test 1', async () => {
    const page = Object.assign({}, pageData);
    page.someprop = 'baboon';
  });
  it('Test 2', async () => {
    const page = Object.assign({}, pageData);
    console.log(page.someprop); //baboon
  });
});

I want imported objects will be immutable. Trying to clone it with "Object.assign", but for some reason, pageData does not clone and by changing "page" i do change "pageData" at the same time.

Why Object.assign does not work in Jest? ( I've tried jest.unmock('object-assign') )