text: import { isNotNull, isNotEmpty, isPresent, getMentionsAndTags } from './util';
  
  describe('#isNotNull', () => {
    it('handles nullables', () => {
      expect(isNotNull(undefined)).toEqual(false);
      expect(isNotNull(null)).toEqual(false);
    });
    it('handles empty objects', () => {
      expect(isNotNull('')).toEqual(true);
      expect(isNotNull([])).toEqual(true);
    });
  });
  
  describe('#isNotEmpty', () => {
    it('handles nullables', () => {
      expect(isNotEmpty(undefined)).toEqual(true);
      expect(isNotEmpty(null)).toEqual(true);
    });
    it('handles empty objects', () => {
      expect(isNotEmpty('')).toEqual(false);
      expect(isNotEmpty([])).toEqual(false);
    });
  });
  
  describe('#isPresent', () => {
    it('handles nullables', () => {
      expect(isPresent(undefined)).toEqual(false);
      expect(isPresent(null)).toEqual(false);
    });
    it('handles empty objects', () => {
      expect(isPresent('')).toEqual(false);
      expect(isPresent([])).toEqual(false);
    });
  });
  
  describe('getMentionsAndTags', () => {
    it('handles empty objects', () => {
      expect(getMentionsAndTags('')).toEqual([]);
      expect(getMentionsAndTags('The quick brown fox')).toEqual([]);
    });
    it('handles tags', () => {
      expect(getMentionsAndTags('The quick #brown fox')).toEqual(['#brown']);
      expect(getMentionsAndTags('The quick bro#wn fox')).toEqual([]);
      expect(getMentionsAndTags('The quick brown# fox')).toEqual([]);
    });
    it('handles mentions', () => {
      expect(getMentionsAndTags('The quick brown @fox')).toEqual(['@fox']);
      expect(getMentionsAndTags('The quick brown fox@')).toEqual([]);
      expect(getMentionsAndTags('The quick brown fo@x')).toEqual([]);
    });
    it('handles a combination', () => {
      expect(getMentionsAndTags('The quick #brown @fox')).toEqual([
        '#brown',
        '@fox',
      ]);
      expect(getMentionsAndTags('The quick br#own fox@')).toEqual([]);
      expect(getMentionsAndTags('The quick #brown fo@x')).toEqual(['#brown']);
    });
  });
  