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05 npm scripts ​

简介 ​

package.json 中的 scripts 字段可以定义快捷命令：

  • npm run start 相当于 node app
  • npm run dev 可以用 nodemon 自动重启
  • npm test 运行测试
json
{
  "name": "5-npm-scripts",
  "version": "1.0.0",
  "dependencies": {},
  "devDependencies": {
    "nodemon": "^1.9.2"
  },
  "scripts": {
    "start": "node app",
    "dev": "nodemon app",
    "test": "node test",
    "test-watch": "nodemon test"
  }
}

nodemon ​

nodemon 可以监控 JS 文件变化，自动重启 Node.js 进程。

bash
npm install nodemon -D

示例：模块 + 测试 ​

app.js

javascript
'use strict';
var math = require('./math');
var value = math.add(5, 6);
console.log(value);

math.js

javascript
exports.add = function(a, b) {
  return a + b;
}

exports.subtract = function(a, b) {
  return a - b;
}

exports.multiply = function(a, b) {
  return a * b;
}

test.js

javascript
'use strict';
var assert = require('assert');
var math = require('./math');

assert(math.add(3, 4) === 7);
assert(math.subtract(3, 4) === -1);
assert(math.multiply(3, 4) === 12);

console.log('all tests passed!');

扩展阅读：npm scripts 使用指南 - 阮一峰