jest test, component test

Jest Can help you achieve painless JavaScript 单元测试支持,由 Facebook 推出.

使用命令行 npx jest 文件进行测试

test('test common matcher', () => {
    
    expect( 2 + 2 ).toBe(4)// 判断2+2是否等于4
    expect( 2 + 3 ).not.toBe(4)
})
test('test to betrue or false', () => {
    
    expect(1).toBeTruthy()//判断1是否为真
    expect(0).toBeFalsy()
})
test('test number', () => {
    
    expect(4).toBeGreaterThan(3) // 4是否比3大
    expect(2).toBeLessThan(3) // 2是否比3小
})
test('test object', () => {
    
    expect({
    name: 'roadsign'}).toEqual({
    name: 'roadsign'})
})

组件进行测试

Test cases must use the command linenpm test ,否则容易报错

import React from 'react';
import {
     render } from '@testing-library/react';
import Button from './button';

test('our first react test case', () => {
    
  const wrapper = render(<Button>nice</Button>);
  const element = wrapper.queryByText('nice');
  expect(element).toBeInTheDocument();
});