source: frontend/node_modules/normalize-path/index.js

/*!
 * normalize-path <https://github.com/jonschlinkert/normalize-path>
 *
 * Copyright (c) 2014-2018, Jon Schlinkert.
 * Released under the MIT License.
 */

module.exports = function(path, stripTrailing) {
  if (typeof path !== 'string') {
    throw new TypeError('expected path to be a string');
  }

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

  var 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
  var prefix = '';
  if (len > 4 && path[3] === '\\') {
    var ch = path[2];
    if ((ch === '?' || ch === '.') && path.slice(0, 2) === '\\\\') {
      path = path.slice(2);
      prefix = '//';
    }
  }

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