firebase/superstatic

/**
 * Copyright (c) 2022 Google LLC
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

const fs = require("fs");

const DEFAULT_ERROR_PAGE = __dirname + "/../../templates/not_found.html";

module.exports = function (spec) {
  const content = fs.readFileSync(spec.errorPage || DEFAULT_ERROR_PAGE);

  return function (req, res) {
    // NOTE: provider isn't used to serve the pages
    // because this middleware should only serve local
    // static pages around the same directory as the
    // superstatic middleware

    res.statusCode = 404;
    res.setHeader("Content-Type", "text/html; charset=utf-8");
    res.setHeader("Cache-Control", "public, max-age=3600");
    res.end(content);
  };
};