发布一个验证图片格式的npm包

创建npm账号

创建npm包

npm init

package name: (validate-image) 
version: (1.0.0) 
description: validate real image
entry point: (index.js) 
test command: 
git repository: 
keywords: image validate 
author: kris_zhang
license: (ISC) 
About to write to /Users/zhangjiewen/Desktop/projects/study/npm/validate-image/package.json:

{
  "name": "validate-image",
  "version": "1.0.0",
  "description": "validate real image",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [
    "image",
    "validate"
  ],
  "author": "kris_zhang",
  "license": "ISC"
}

Npm config package.json

docs.npmjs.com/cli/v8/conf…

图片格式

读取文件Hex内容

vscode插件：Hex Editor

hexInfo.json

{
    "jpg": "FF D8 FF",
    "png": "89 50 4E 47 0D 0A 1A 0A",
    "gif": ["47 49 46 38 39 61", "47 49 46 38 37 61"],
    "webp": "52 49 46 46",
    "ico": "00 00 01 00",
    "bmp": "42 4D"
}

index.js

import hexInfo from './util/hexInfo.json'

const getHexNumber = (file) => {
  return new Promise((file, callback) => {
    const reader = new FileReader();

    reader.onloadend = function (e) {
      const arr = new Uint8Array(e.target.result).subarray(0, 4);
      let hexNumber = "";
      for (let i = 0; i < arr.length; i++) {
        hexNumber += arr[i].toString(16).padStart(2, "0").toUpperCase();
      }
      callback(hexNumber);
    };

    reader.readAsArrayBuffer(file.slice(0, 4));
  });
};

const validateImage = (file, imageType) => {
  return hexInfo[imageType].includes(getHexNumber(file)) 
}

export default {
  getHexNumber,
  validateImage
}

发布npm包

zhangjiewen@zhangjiewendeMacBook-Pro validate-image % npm config set registry https://registry.npmjs.org/   
zhangjiewen@zhangjiewendeMacBook-Pro validate-image % npm login                                          
npm WARN adduser `adduser` will be split into `login` and `register` in a future version. `adduser` will become an alias of `register`. `login` (currently an alias) will become its own command.
npm notice Log in on https://registry.npmjs.org/
Username: zhangjiewen
Password: 
Email: (this IS public) 474350393@qq.com
npm notice Please check your email for a one-time password (OTP)
Enter one-time password: 91832573
Logged in as zhangjiewen on https://registry.npmjs.org/.

zhangjiewen@zhangjiewendeMacBook-Pro validate-image % npm publish
npm notice 
npm notice 📦  validate-image@1.0.0
npm notice === Tarball Contents === 
npm notice 662B index.js         
npm notice 288B package.json     
npm notice 191B util/hexInfo.json
npm notice === Tarball Details === 
npm notice name:          validate-image                          
npm notice version:       1.0.0                                   
npm notice filename:      validate-image-1.0.0.tgz                
npm notice package size:  765 B                                   
npm notice unpacked size: 1.1 kB                                  
npm notice shasum:        edf0e0b5ddd3e9e7e0eeabf319dcab33cdf96578
npm notice integrity:     sha512-Pyx6NjgFXhu4x[...]FRhqBma86GWyA==
npm notice total files:   3                                       
npm notice 
npm notice Publishing to https://registry.npmjs.org/
+ validate-image@1.0.0

验证