validate-npm-package-name源码阅读笔记

作用

校验npm包的名称是否符合规则

使用方法

引入

const validate = require("validate-npm-package-name");

具体使用方法

let res = validate("package-name");

如果通过，会打印出以下信息

res { validForNewPackages: true, validForOldPackages: true

如果不通过，会显示以下信息

{
  validForNewPackages: false,
  validForOldPackages: true,
  warnings: [ 'name can no longer contain capital letters' ]
}

源码分析

// 输出的校验函数
var validate = module.exports = function (name) {

	// 包名不能为null
	if (name === null) {
    errors.push('name cannot be null')
    return done(warnings, errors)
  }
  // 包名不能为undefined
  if (name === undefined) {
    errors.push('name cannot be undefined')
    return done(warnings, errors)
  }
	// 包名只能是字符串
  if (typeof name !== 'string') {
    errors.push('name must be a string')
    return done(warnings, errors)
  }
	//包名必须具有长度，不能是空字符串
  if (!name.length) {
    errors.push('name length must be greater than zero')
  }
	// 包名不能以‘.’开头
  if (name.match(/^./)) {
    errors.push('name cannot start with a period')
  }
	包名不能以‘_’开头
  if (name.match(/^_/)) {
    errors.push('name cannot start with an underscore')
  }
	// 包名前后不能有空格
  if (name.trim() !== name) {
    errors.push('name cannot contain leading or trailing spaces')
  }

  // No funny business
  var blacklist = [ 'node_modules','favicon.ico']
  blacklist.forEach(function (blacklistedName) {
    if (name.toLowerCase() === blacklistedName) {
      errors.push(blacklistedName + ' is a blacklisted name')
    }
  })

  // Generate warnings for stuff that used to be allowed

  // core module names like http, events, util, etc
  builtins.forEach(function (builtin) {
    if (name.toLowerCase() === builtin) {
      warnings.push(builtin + ' is a core module name')
    }
  })
  // 包名不能包含大写字母
  if (name.toLowerCase() !== name) {
    warnings.push('name can no longer contain capital letters')
  }
  // 特殊字符的校验
  if (/[~'!()*]/.test(name.split('/').slice(-1)[0])) {
    warnings.push('name can no longer contain special characters ("~'!()*")')
  }
  // 只能含有url中能识别的字符
  if (encodeURIComponent(name) !== name) {
    // Maybe it's a scoped package name, like @user/package
    var nameMatch = name.match(scopedPackagePattern)
    if (nameMatch) {
      var user = nameMatch[1]
      var pkg = nameMatch[2]
      if (encodeURIComponent(user) === user && encodeURIComponent(pkg) === pkg) {
        return done(warnings, errors)
      }
    }

    errors.push('name can only contain URL-friendly characters')
  }
  return done(warnings, errors)
}

注意这个scopedPackagePattern，这个正则赋值给了函数，暴露的validate函数具有这个属性并可以修改，以便于用户自定义校验规则

validate.scopedPackagePattern = scopedPackagePattern

其中builtins最终只是一个json，里面有各种包名，是node的内置模块

[  "assert",  "buffer",  "child_process",  "cluster",  "console",  "constants",  "crypto",  "dgram",  "dns",  "domain",  "events",  "fs",  "http",  "https",  "module",  "net",  "os",  "path",  "process",  "punycode",  "querystring",  "readline",  "repl",  "stream",  "string_decoder",  "timers",  "tls",  "tty",  "url",  "util",  "v8",  "vm",  "zlib"]

done函数就是上方的返回值

var done = function (warnings, errors) {
	// 这个result就是返回的result
  var result = {
    validForNewPackages: errors.length === 0 && warnings.length === 0,
    validForOldPackages: errors.length === 0,
    warnings: warnings,
    errors: errors
  }
  if (!result.warnings.length) delete result.warnings
  if (!result.errors.length) delete result.errors
  return result
}

总结

内容不多而且很简单，就是各个类型的校验