old_contents: import Router from 'src/router';
  
  //set initial url to /
  window.history.replaceState(null, null, '/');
  
  describe("Base functionality", () => {
    const router = new Router();
    it('returns root correctly', () => {
      expect(router.root).to.be.equal('');
    });
    it('returns query params correctly', () => {
      expect(router.params).to.deep.equal({});
    });
  });
  
new_contents: import Router from 'src/router';
  
  //set initial url to /
  window.history.replaceState(null, null, '/');
  
  describe("Base functionality", () => {
    const router = new Router();
    it('returns root correctly', () => {
      assert.equal(router.root, '');
    });
    it('returns query params correctly', () => {
      assert.deepEqual(router.params, {});
    });
  });
  
subject: change assertion