text: import Feature from 'ol/Feature';
  import findAllLevels from '../src/levels';
  
  describe('findAllLevels', () => {
    it('find one level', () => {
      expect(findAllLevels([
        new Feature({ layer: 'area', level: 0 }),
        new Feature({ layer: 'area', level: 0 })
      ])).toEqual([0]);
    });
  
    it('find multiple levels', () => {
      expect(findAllLevels([
        new Feature({ layer: 'area', level: 0 }),
        new Feature({ layer: 'area', level: 1 })
      ])).toEqual([1, 0]);
    });
  
    it('sort levels', () => {
      expect(findAllLevels([
        new Feature({ layer: 'area', level: 1 }),
        new Feature({ layer: 'area', level: 0 })
      ])).toEqual([1, 0]);
    });
  
     it('sort levels with minus', () => {
      expect(findAllLevels([
        new Feature({ layer: 'area', level: 1 }),
        new Feature({ layer: 'area', level: -1 }),
        new Feature({ layer: 'area', level: -2 }),
        new Feature({ layer: 'area', level: 0  })
      ])).toEqual([1, 0, -1, -2]);
    });
  
    it('ignore levels from indoor=level', () => {
      expect(findAllLevels([
        new Feature({ layer: 'area', level: 0 }),
        new Feature({ layer: 'area', class: 'level', level: 1 })
      ])).toEqual([0]);
    });
  
    it('ignore features from non area layer', () => {
      expect(findAllLevels([
        new Feature({ layer: 'area', level: 0 }),
        new Feature({ layer: 'poi', level: 1 }),
      ])).toEqual([0]);
    });
  
    it('find zero levels', () => {
      expect(findAllLevels([])).toEqual([]);
    });
  });
  