1.初始化package包

npm init -y

{
  "name": "common-cjs-tools",
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "description": "常用工具方法"
}

2.新建index.js文件

3.写两个工具方法

function addFn(...args) {
  return args.reduce((acc, curr) => acc + curr, 0);
}

function multiplyFn(...args) {
  return args.reduce((acc, curr) => acc * curr, 1);
}

module.exports = { addFn, multiplyFn };

4. 本地测试下（node环境用cjs）

5.登录npm账号

npm adduser

回车跳转到浏览器登录

6发布到npm官网

npm publish

7.到npm查看官网 

8.使用npm

npm i common-cjs-tools

const { addFn, multiplyFn } = require("common-cjs-tools");

console.log(addFn(1, 2, 3, 4, 5));
console.log(multiplyFn(1 * 2 * 3 * 4));