Source: util/url-path.ts

/**
 * @fileoverview URL Path Builder
 */

// ------------------------------------------------------------------------------
// Private
// ------------------------------------------------------------------------------

// Pattern to check for relative paths
const PATTERN = /\/\.+/;

/**
 * remove leading & trailing slashes from some string. This is useful for
 * removing slashes from the path segments that are actually a part of the
 * path itself. Without this step, these slashes would be uri-encoded.
 *
 * @param {string} segment The path segment (ex: '/users')
 * @returns {string} The path segment with slashes trimmed (ex: 'users')
 * @private
 */
function trimSlashes(segment: string) {
  return segment.replace(/^\/|\/$/g, '');
}

// ------------------------------------------------------------------------------
// Public
// ------------------------------------------------------------------------------

/**
 * URLPath will create a full URL path from the given array of segments.
 *
 * It also provides the following features:
 * - convert all segments to strings
 * - add/remove slashes between segments, where appropriate
 * - encode each path segment to prevent path manipulation
 *
 * @name URLPath
 * @returns {string} Return a valid URL path comprised of the given path segments
 */
export = function urlPath(...args: any[]) {
  const path = args
    .map((x) => String(x))
    .map((x) => {
      var trimmedX = trimSlashes(x);
      if (PATTERN.test(trimmedX)) {
        throw new Error(
          `An invalid path parameter exists in ${trimmedX}. Relative path parameters cannot be passed.`
        );
      }
      return trimmedX;
    })
    .map((x) => encodeURIComponent(x))
    .join('/');
  return `/${path}`;
};