normalize_path.mjs

/* eslint-disable @kbn/eslint/require-license-header */
/**
 * @notice
 * This code includes a copy of the `normalize-path`
 * https://github.com/jonschlinkert/normalize-path/blob/52c3a95ebebc2d98c1ad7606cbafa7e658656899/index.js
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2014-2018, Jon Schlinkert.
 *
 * 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.
 */

/**
 * @param {string} path
 * @returns {string}
 */
export function normalizePath(path) {
  if (typeof path !== 'string') {
    throw new TypeError('expected path to be a string');
  }

  if (path === '\\' || path === '/') return '/';

  const len = path.length;
  if (len <= 1) return path;

  // ensure that win32 namespaces has two leading slashes, so that the path is
  // handled properly by the win32 version of path.parse() after being normalized
  // https://msdn.microsoft.com/library/windows/desktop/aa365247(v=vs.85).aspx#namespaces
  let prefix = '';
  if (len > 4 && path[3] === '\\') {
    const ch = path[2];
    if ((ch === '?' || ch === '.') && path.slice(0, 2) === '\\\\') {
      path = path.slice(2);
      prefix = '//';
    }
  }

  const segs = path.split(/[/\\]+/);
  if (segs[segs.length - 1] === '') {
    segs.pop();
  }
  return prefix + segs.join('/');
}