git.squeep.com Git - squeep-api-dingus/blob - lib/router/path-parameter.js

   1 'use strict';
   2
   3 const parameters = new Map();
   4 /**
   5  * De-duplicating factory of minimal-objects to track the named-parameter parts of path definitions.
   6  */
   7 class PathParameter extends null {
   8   static #parameters = parameters;
   9
  10   /**
  11    *
  12    * @param {string} parameter name
  13    * @returns {PathParameter} frozen parameter object
  14    */
  15   constructor(parameter) {
  16     if (!parameter || typeof(parameter) !== 'string') {
  17       throw new RangeError('parameter must be string');
  18     }
  19
  20     if (PathParameter.#parameters.has(parameter)) {
  21       return PathParameter.#parameters.get(parameter); // NOSONAR
  22     }
  23
  24     const pathParameter = Object.create(PathParameter.prototype);
  25     pathParameter.parameter = parameter;
  26     Object.freeze(pathParameter);
  27     PathParameter.#parameters.set(parameter, pathParameter);
  28     return pathParameter; // NOSONAR
  29   }
  30
  31   /**
  32    * @returns {string} parameter string
  33    */
  34   toString() {
  35     return this.parameter;
  36   }
  37
  38   /**
  39    * @returns {string} parameter string
  40    */
  41   toJSON() {
  42     return this.parameter;
  43   }
  44
  45   /**
  46    * Clear the de-duplication table, for tests.
  47    */
  48   static _flush() {
  49     PathParameter.#parameters.clear();
  50   }
  51 }
  52
  53 module.exports = PathParameter;