摘要：如何選擇就如果上面所有，需要打包進生產環境就保存到，只是在開發或者打包的時候使用的就保存到即可。提示不能發布當前版本解決方案不能發布已經發布的版本，修改一下版本號就可以了想不到了，想到了再寫資源項目

本篇文章承接上文，記錄的是一些使用過程中的疑惑

解決方案：使用淘寶cnpm，推薦使用cnpm，因為如果修改npm倉庫，將會導致無法發布包。

$ npm install -g cnpm --registry=https://registry.npm.taobao.org
/usr/local/bin/cnpm -> /usr/local/lib/node_modules/cnpm/bin/cnpm
+ cnpm@5.1.1
updated 4 packages in 10.035s

$ cnpm install lodash

解決方案：推薦第一種，簡單！

第一種：給全局包安裝路徑權限

$ npm config get prefix
/usr/local
$ sudo chown -R $(whoami) $(npm config get prefix)/{lib/node_modules,bin,share}

第二種：修改全局包安裝路徑到有權限的地方

 $ mkdir ~/.npm-global
 $ npm config set prefix "~/.npm-global"
 $ export PATH=~/.npm-global/bin:$PATH
 $ source ~/.profile

本質上是沒有差別的，只是一個裝在了全局文件夾，一個裝在了項目文件夾。全局文件夾中的包到處都可以引用，而裝在項目文件夾中的包只有該項目才可以引用（其實都可以引用），以下做實驗來演示

新建文件夾0x007-local-global-diff1,0x008-local-global-diff2,0x009-local-global-diff3,0x010-local-global-diff4,并且使用命名空間做包名

$ mkdir 0x007-local-global-diff1
$ mkdir 0x008-local-global-diff2
$ mkdir 0x009-local-global-diff3
$ mkdir 0x010-local-global-diff4

編寫并發布@followwinter/0x007-local-global-diff1@1.0.0

$ cd 0x007-local-global-diff1
$ npm init
This utility will walk you through creating a package.json file.
It only covers the most common items, and tries to guess sensible defaults.

See `npm help json` for definitive documentation on these fields
and exactly what they do.

Use `npm install ` afterwards to install a package and
save it as a dependency in the package.json file.

Press ^C at any time to quit.
package name: (0x007-local-global-diff1) @followwinter/0x007-local-global-diff1
version: (1.0.0) 
description: 
entry point: (index.js) 
test command: 
git repository: 
keywords: 
author: 
license: (ISC) 
About to write to /MY_PROJECT/PROJECT_OWN/NodeJS/npm/0x007-local-global-diff1/package.json:

{
  "name": "@followwinter/0x007-local-global-diff1",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo "Error: no test specified" && exit 1"
  },
  "author": "",
  "license": "ISC"
}


Is this ok? (yes) 

$ vim index.js
// index.js
exports.printMsg = function() {
  console.log("This is a message from the @followwinter/0x007-local-global-diff1@1.0.0 package");
}
$ npm publish --access public
+ @followwinter/0x007-local-global-diff1@1.0.0

安裝并引用@followwinter/0x007-local-global-diff1@1.0.0

$ cd  0x008-local-global-diff2
$ vim index.js
$ npm install @followwinter/0x007-local-global-diff1
npm WARN saveError ENOENT: no such file or directory, open "/MY_PROJECT/PROJECT_OWN/NodeJS/npm/0x008-local-global-diff2/package.json"
npm notice created a lockfile as package-lock.json. You should commit this file.
npm WARN enoent ENOENT: no such file or directory, open "/MY_PROJECT/PROJECT_OWN/NodeJS/npm/0x008-local-global-diff2/package.json"
npm WARN 0x008-local-global-diff2 No description
npm WARN 0x008-local-global-diff2 No repository field.
npm WARN 0x008-local-global-diff2 No README data
npm WARN 0x008-local-global-diff2 No license field.

+ @followwinter/0x007-local-global-diff1@1.0.0
added 1 package in 2.361s

$ vim index.js
// index.js
var myModule = require("@followwinter/0x007-local-global-diff1");
console.log(myModule);
myModule.printMsg();

$ node index.js
{ printMsg: [Function] }
This is a message from the @followwinter/0x007-local-global-diff1@1.0.0 package

更新@followwinter/0x007-local-global-diff1@1.0.0版本

$ cd 0x007-local-global-diff1/
$  vim index.js

// index.js
exports.printMsg = function() {
  console.log("This is a message from the @followwinter/0x007-local-global-diff1@1.0.2 package");
}

$ vim package.js
// package.js
{
  "name": "@followwinter/0x007-local-global-diff1",
  "version": "1.0.2",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo "Error: no test specified" && exit 1"
  },
  "author": "",
  "license": "ISC"
}

$ npm publish --access public
+ @followwinter/0x007-local-global-diff1@1.0.2

全局安裝新版本并引用

$ cd 0x009-local-global-diff3/
$ npm install @followwinter/0x007-local-global-diff1 -g
+ @followwinter/0x007-local-global-diff1@1.0.2
$ vim index.js
// index.js
var myModule = require("@followwinter/0x007-local-global-diff1");
console.log(myModule);
myModule.printMsg();

$ node index.js
{ printMsg: [Function] }
This is a message from the @followwinter/0x007-local-global-diff1@1.0.2 package

運行0x008-local-global-diff2，驗證全局和本地的引用順序

$ cd 0x008-local-global-diff2
$ node index.js
This is a message from the @followwinter/0x007-local-global-diff1@1.0.0 package

0x010引用0x008中的node_modules中的0x007

$ cd 0x010-local-global-diff4/
$ vim index.js

// index.js
var myModule = require("/MY_PROJECT/PROJECT_OWN/NodeJS/npm/0x008-local-global-diff2/node_modules/@followwinter/0x007-local-global-diff1");
console.log(myModule);
myModule.printMsg();

$ node index.js 
{ printMsg: [Function] }
This is a message from the @followwinter/0x007-local-global-diff1@1.0.0 package

所以包的查找順序是

- 項目的`node_modules`文件夾
- 全局的`node_modules`文件夾

但是都可以找到就是,主要是查找路徑和順序的問題，而關于如何抉擇存在哪呢？考慮的問題有一下幾點

是否在意全局文件的占用問題，全局文件不手動刪除會一直存在，占用磁盤空間

是否在多個項目使用不同版本？版本之間還有沖突？如果是這樣，推薦還是保存在本地

是否有命令行功能？如果有推薦安裝在全局，因為安裝本地調用需要調整調用路徑，很麻煩

區別：沒有啥區別，只有語義上的區別，dependencies一般說的是項目運行需要的包，或者說需要打包進生產環境的包，比如jQuery、lodash之類，而dependencies-dev一般說的是開發需要用的包，比如webpack、gulp之類，在生產環境中不需要打包。
如何選擇就如果上面所有，需要打包進生產環境就保存到dependencies，只是在開發或者打包的時候使用的就保存到dependencies-dev即可。

npm ERR! publish Failed PUT 403
npm ERR! code E403
npm ERR! You cannot publish over the previously published version 1.0.2. : @followwinter/0x007-local-global-diff1

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/FollowWinter/.npm/_logs/2017-09-10T14_01_59_753Z-debug.log

解決方案：不能發布已經發布的版本，修改一下版本號就可以了

項目github