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

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