         listenOnce(grid, 'filter-changed', e => {
            done();
          });
          filter.path = '';
        });

        it('should warn about invalid path with undefined parent property', done => {
          const _warn = console.warn;
          const spy = console.warn = sinon.spy();

          listenOnce(filter, 'filter-changed', e => {
            setTimeout(() => {
              console.warn = _warn;
              expect(spy.called).to.be.true;
              done();
            });
       