stacker.news/lib/url.js

export function ensureProtocol (value) {
  if (!value) return value
  value = value.trim()
  if (!/^([a-z0-9]+:\/\/|mailto:)/.test(value)) {
    value = 'http://' + value
  }
  return value
}

export function isExternal (url) {
  return !url.startsWith(process.env.PUBLIC_URL + '/') && !url.startsWith('/')
}

export function removeTracking (value) {
  if (!value) return value
  const exprs = [
    // twitter URLs
    /^(?<url>https?:\/\/twitter\.com\/(?:#!\/)?(?<user>\w+)\/status(?:es)?\/(?<id>\d+))/
  ]
  for (const expr of exprs) {
    value = expr.exec(value)?.groups.url ?? value
  }
  return value
}

// eslint-disable-next-line
export const URL_REGEXP = /^((https?|ftp):\/\/)?(www.)?(((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:)*@)?(((\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5]))|((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.?)(:\d*)?)(\/((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)+(\/(([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)*)*)?)?(\?((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)|[\uE000-\uF8FF]|\/|\?)*)?(\#((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)|\/|\?)*)?$/i

// eslint-disable-next-line
export const WS_REGEXP = /^(wss?:\/\/)([0-9]{1,3}(?:\.[0-9]{1,3}){3}|(?=[^\/]{1,254}(?![^\/]))(?:(?=[a-zA-Z0-9-]{1,63}\.)(?:xn--+)?[a-zA-Z0-9]+(?:-[a-zA-Z0-9]+)*\.)+[a-zA-Z]{2,63})(:([0-9]{1,5}))?$/

export const IMGPROXY_URL_REGEXP = new RegExp(`^${process.env.NEXT_PUBLIC_IMGPROXY_URL}.*$`)
// this regex is not a bullet proof way of checking if a url points to an image. to be sure, fetch the url and check the mimetype
export const IMG_URL_REGEXP = /^(https?:\/\/.*\.(?:png|jpg|jpeg|gif))$/