text: const chai = require('chai');
  const expect = chai.expect;
  
  describe('chai test', () => {
    it('should compare some values', () => {
      expect(1).to.equal(1);
    });
  
    it('should test the object data', () => {
      expect({ name: 'foo' }).to.deep.equal({ name: 'foo' });
      expect({ name: 'foo' }).to.have.property('name').to.equal('foo');
      expect(5 > 8).to.be.false;
      expect({}).to.be.a('object');
      expect('foo').to.be.a('string');
      expect(3).to.be.a('number');
      expect('bar').to.be.a('string').with.lengthOf(3);
      expect([1,2,3].length).to.equal(3);
      expect(null).to.be.null;
      expect(undefined).to.not.exist;
      expect(1).to.exist;
    });
  });
  