Signal-Desktop/ts/util/attachments.ts

// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only

import { isString } from 'lodash';
import { join, normalize } from 'path';
import fse from 'fs-extra';

import { isPathInside } from './isPathInside';

const PATH = 'attachments.noindex';
const AVATAR_PATH = 'avatars.noindex';
const BADGES_PATH = 'badges.noindex';
const STICKER_PATH = 'stickers.noindex';
const TEMP_PATH = 'temp';
const UPDATE_CACHE_PATH = 'update-cache';
const DRAFT_PATH = 'drafts.noindex';

const CACHED_PATHS = new Map<string, string>();

const createPathGetter =
  (subpath: string) =>
  (userDataPath: string): string => {
    if (!isString(userDataPath)) {
      throw new TypeError("'userDataPath' must be a string");
    }

    const naivePath = join(userDataPath, subpath);

    const cached = CACHED_PATHS.get(naivePath);
    if (cached) {
      return cached;
    }

    let result = naivePath;
    if (fse.pathExistsSync(naivePath)) {
      result = fse.realpathSync(naivePath);
    }

    CACHED_PATHS.set(naivePath, result);

    return result;
  };

export const getAvatarsPath = createPathGetter(AVATAR_PATH);
export const getBadgesPath = createPathGetter(BADGES_PATH);
export const getDraftPath = createPathGetter(DRAFT_PATH);
export const getPath = createPathGetter(PATH);
export const getStickersPath = createPathGetter(STICKER_PATH);
export const getTempPath = createPathGetter(TEMP_PATH);
export const getUpdateCachePath = createPathGetter(UPDATE_CACHE_PATH);

export const createDeleter = (
  root: string
): ((relativePath: string) => Promise<void>) => {
  if (!isString(root)) {
    throw new TypeError("'root' must be a path");
  }

  return async (relativePath: string): Promise<void> => {
    if (!isString(relativePath)) {
      throw new TypeError("'relativePath' must be a string");
    }

    const absolutePath = join(root, relativePath);
    const normalized = normalize(absolutePath);
    if (!isPathInside(normalized, root)) {
      throw new Error('Invalid relative path');
    }
    await fse.remove(absolutePath);
  };
};