text: import BrowserFeatures from 'util/BrowserFeatures';
  
  describe('util/BrowserFeatures', () => {
    describe('getUserLanguages', () => {
      it('returns a non-read-only array on Chrome/Firefox', () => {
        jest.spyOn(navigator, 'languages', 'get').mockImplementation(() => Object.freeze(['en_US', 'en']));
        let errorThrown = false;
        let result = null;
        try {
          result = BrowserFeatures.getUserLanguages();
          result[0] = 'foo';
        }
        catch (err) {
          errorThrown = true;
        }
        expect(errorThrown).toBe(false);
        expect(result[0]).toBe('foo');
      });
    });
  });