1. 安装

npm install --save-dev jest
npm install babel-jest babel-core@^7.0.0-bridge.0 @babel/core regenerator-runtime babel-preset-env

编辑package.json

{
  "scripts": {
    "test": "jest"
  }
}

编辑.babelrc

{
  "presets": ["env", "react"]
}

2. 创建js文件

function sum(a, b) {
  return a + b;
}
export default sum;

import sum from './index'

test('adds 1 + 2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3);
});

3. 启动测试

npm test

4. 工具安装

• IDE：VSCode