docusaurus/lib/core/toSlug.js

/**
 * Copyright (c) 2017-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

module.exports = string => {
  //  var accents = "àáäâèéëêìíïîòóöôùúüûñç";
  const accents =
    "\u00e0\u00e1\u00e4\u00e2\u00e8" +
    "\u00e9\u00eb\u00ea\u00ec\u00ed\u00ef" +
    "\u00ee\u00f2\u00f3\u00f6\u00f4\u00f9" +
    "\u00fa\u00fc\u00fb\u00f1\u00e7";

  const without = "aaaaeeeeiiiioooouuuunc";

  let slug = string
    .toString()
    // Handle uppercase characters
    .toLowerCase()
    // Handle accentuated characters
    .replace(new RegExp("[" + accents + "]", "g"), c => {
      return without.charAt(accents.indexOf(c));
    })
    // Replace `.`, `(` and `?` with blank string like Github does
    .replace(/\.|\(|\?/g, "")
    // Dash special characters
    .replace(/[^a-z0-9]/g, "-")
    // Compress multiple dash
    .replace(/-+/g, "-")
    // Trim dashes
    .replace(/^-|-$/g, "");

  // Add trailing `-` if string contains ` ...` in the end like Github does
  if (/\s[.]{1,}/.test(string)) {
    slug += "-";
  }

  return slug;
};