text: import { expect } from 'chai';
  import { describe, it } from 'mocha';
  
  import { invariant } from '../invariant';
  
  describe('invariant', () => {
    it('throws on false conditions', () => {
      expect(() => invariant(false, 'Oops!')).to.throw('Oops!');
    });
  
    it('use default error message', () => {
      expect(() => invariant(false)).to.throw('Unexpected invariant triggered.');
    });
  });
  