const _ = require('lodash'); describe('testing that the environment is working properly', () => { it('object spread', () => { const { x, y, ...z } = { x: 1, y: 2, a: 3, b: 4 }; expect(x).toEqual(1); expect(y).toEqual(2); expect(z).toEqual({ a: 3, b: 4 }); }); it('async await', async () => { const result = await new Promise((r) => r('hello')); expect(result).toEqual('hello'); }); it('equality tests', () => { expect(_.eq('hello', 'hello')).toBe(true); expect(_.isEqual('hello', 'hello')).toBe(true); expect(_.eq('hello', Object('hello'))).toBe(false); expect(_.isEqual('hello', Object('hello'))).toBe(true); const a = {}; const b = {}; expect(_.eq(a, b)).toBe(false); expect(_.isEqual(a, b)).toBe(true); }); });