Jest 是一个令人愉快的 JavaScript 测试框架,专注于 简洁明快。

基本环境

安装依赖

npm install

备注:安装babel 为了让jest 支持ES6语法 ​​import/export​

package.json

{
"type": "module",
"scripts": {
"test": "jest --verbose"
},
"devDependencies": {
"babel-core": "^6.26.3",
"babel-jest": "^28.1.3",
"babel-preset-env": "^1.7.0",
"jest": "^28.1.3",
"regenerator-runtime": "^0.13.9"
}
}

babel 配置文件 .babelrc

{
"presets": ["env"]
}

测试示例

src/functions.js

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

tests/functions.test.js

import functions from '../src/functions'

test('sum(2 + 2) 等于 4', () => {
expect(functions.sum(2, 2)).toBe(4)
})

运行测试

$ npx jest
PASS tests/functions.test.js
✓ sum(2 + 2) 等于 4 (1 ms)

Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 1.141 s
Ran all test

参考
​​​使用Jest测试JavaScript (入门篇)​