[TOC] > [github](https://github.com/facebook/jest) > [文档](https://jestjs.io/docs/en/using-matchers#arrays-and-iterables) > [Jest 实践指南](http://github.yanhaixiang.com/jest-tutorial/basic/config-react/#%E9%85%8D%E7%BD%AE-webpack) ## 安装 ``` yarn add --dev jest npm install --save-dev jest // or 全局安装 npm install -g jest ``` ## idea 添加库 文件 | 设置 | 语言和框架 | JavaScript | 库 的下载按钮中添加 jest ## 示例 ### hello world <details> <summary>sum.js</summary> ``` function sum(a, b) { return a + b; } module.exports = sum; // or // export {Status,}; ``` </details> <br /> <details> <summary>sum.test.js</summary> ``` const sum = require('./sum'); // or const {sum} = require('./sum'); test('adds 1 + 2 to equal 3', () => { expect(sum(1, 2)).toBe(3); }); ``` </details> <br /> <details> <summary>package.json</summary> ``` { "scripts": { "test": "jest" } } ``` </details> <br /> 执行 ``` npm run test // or jest sum.test.js ```