Overleaf/services/web/frontend/js/ide/directives/SafePath.js

/* eslint-disable
    max-len,
    no-return-assign,
*/
// TODO: This file was created by bulk-decaffeinate.
// Fix any style issues and re-enable lint.
/*
 * decaffeinate suggestions:
 * DS102: Remove unnecessary code created because of implicit returns
 * DS207: Consider shorter variations of null checks
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
 */
// This file is shared between the frontend and server code of web, so that
// filename validation is the same in both implementations.
// Both copies must be kept in sync:
//   app/coffee/Features/Project/SafePath.coffee
//   public/coffee/ide/directives/SafePath.coffee

let SafePath
const BADCHAR_RX = new RegExp(
  `\
[\
\\/\
\\\\\
\\*\
\\u0000-\\u001F\
\\u007F\
\\u0080-\\u009F\
\\uD800-\\uDFFF\
]\
`,
  'g'
)

const BADFILE_RX = new RegExp(
  `\
(^\\.$)\
|(^\\.\\.$)\
|(^\\s+)\
|(\\s+$)\
`,
  'g'
)

// Put a block on filenames which match javascript property names, as they
// can cause exceptions where the code puts filenames into a hash. This is a
// temporary workaround until the code in other places is made safe against
// property names.
//
// The list of property names is taken from
//   ['prototype'].concat(Object.getOwnPropertyNames(Object.prototype))
const BLOCKEDFILE_RX = new RegExp(`\
^(\
prototype\
|constructor\
|toString\
|toLocaleString\
|valueOf\
|hasOwnProperty\
|isPrototypeOf\
|propertyIsEnumerable\
|__defineGetter__\
|__lookupGetter__\
|__defineSetter__\
|__lookupSetter__\
|__proto__\
)$\
`)

const MAX_PATH = 1024 // Maximum path length, in characters. This is fairly arbitrary.

export default (SafePath = {
  clean(filename) {
    filename = filename.replace(BADCHAR_RX, '_')
    // for BADFILE_RX replace any matches with an equal number of underscores
    filename = filename.replace(BADFILE_RX, match =>
      new Array(match.length + 1).join('_')
    )
    // replace blocked filenames 'prototype' with '@prototype'
    filename = filename.replace(BLOCKEDFILE_RX, '@$1')
    return filename
  },

  isCleanFilename(filename) {
    return (
      SafePath.isAllowedLength(filename) &&
      !filename.match(BADCHAR_RX) &&
      !filename.match(BADFILE_RX)
    )
  },

  isAllowedLength(pathname) {
    return pathname.length > 0 && pathname.length <= MAX_PATH
  }
})