@mpxjs/webpack-plugin/lib/utils/is-url-request.js

mpx compile core

const isUrlRequestRaw = require('loader-utils').isUrlRequest
const tagRE = /\{\{((?:.|\n|\r)+?)\}\}(?!})/

module.exports = function isUrlRequest (url, root, externals) {
  // 对于非字符串或空字符串url直接返回false
  if (!url || typeof url !== 'string') return false
  // 对于@开头且后续字符串为合法标识符的情况也返回false，识别为theme变量
  if (/^@[A-Za-z_$][A-Za-z0-9_$]*$/.test(url)) return false
  if (/^.+:\/\//.test(url)) return false
  // 对于url中存在Mustache插值的情况也返回false
  if (tagRE.test(url)) return false
  // url存在于externals中也返回false
  if (externals && externals.some((external) => {
    if (typeof external === 'string') {
      return external === url
    } else if (external instanceof RegExp) {
      return external.test(url)
    }
    return false
  })) return false
  return isUrlRequestRaw(url, root)
}