validate-npm-package-name 源码解析

还是老方式拿到一个包

• 先到 npm 去看下使用文档，看下事例，api 啥的有个大体了解

• 到 git 看源码，对项目目录整体有个了解

• 看看 package.json，对项目依赖有个大体了解

• 看看 test 测试用例，了解使用方法

• clone 到本地断点调试下，看下主体流程，不用太细

• 然后再去关注局部或者每个方法

看了 npm 的 api 和使用例子如下

var validate = require('validate-npm-package-name')

validate('some-package')
validate('example.com')
validate('under_score')
validate('123numeric')
validate('excited!')
validate('@npm/thingy')
validate('@jane/foo.js')

由此可以看出，这个包的作用是检测 npm 包名是否符合规范，由于功能也比较简单就直接上源码注释

'use strict'

var scopedPackagePattern = new RegExp('^(?:@([^/]+?)[/])?([^/]+?)$')
// node的内部核心包
var builtins = require('builtins')
var blacklist = ['node_modules', 'favicon.ico']
// 定义导出函数
var validate = (module.exports = function (name) {
  var warnings = []
  var errors = []
  // 不能为null
  if (name === null) {
    errors.push('name cannot be null')
    return done(warnings, errors)
  }
  // 不能为undefined
  if (name === undefined) {
    errors.push('name cannot be undefined')
    return done(warnings, errors)
  }
  // 必须是字符串
  if (typeof name !== 'string') {
    errors.push('name must be a string')
    return done(warnings, errors)
  }
  // 长度不能为0
  if (!name.length) {
    errors.push('name length must be greater than zero')
  }
  // 不能以.开头
  if (name.match(/^\./)) {
    errors.push('name cannot start with a period')
  }
  // 不能以下滑线开头
  if (name.match(/^_/)) {
    errors.push('name cannot start with an underscore')
  }
  // 不能空格
  if (name.trim() !== name) {
    errors.push('name cannot contain leading or trailing spaces')
  }

  // No funny business
  blacklist.forEach(function (blacklistedName) {
    if (name.toLowerCase() === blacklistedName) {
      errors.push(blacklistedName + ' is a blacklisted name')
    }
  })

  // Generate warnings for stuff that used to be allowed

  // 不能是内部node包
  builtins.forEach(function (builtin) {
    if (name.toLowerCase() === builtin) {
      warnings.push(builtin + ' is a core module name')
    }
  })

  // really-long-package-names-------------------------------such--length-----many---wow
  // 长度不能大于214
  if (name.length > 214) {
    warnings.push('name can no longer contain more than 214 characters')
  }

  // 不能大小混合
  if (name.toLowerCase() !== name) {
    warnings.push('name can no longer contain capital letters')
  }
  // 这些符合不能有
  if (/[~'!()*]/.test(name.split('/').slice(-1)[0])) {
    warnings.push('name can no longer contain special characters ("~\'!()*")')
  }

  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)
})

validate.scopedPackagePattern = scopedPackagePattern

var done = function (warnings, errors) {
  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
}

小结

整体而言就是对包名的一个规则校验