The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 "use strict";

 module.metadata = {

   "stability": "unstable"

 };

 const { validateOptions: valid } = require("../deprecated/api-utils");

 // Function takes property validation rules and returns function that given

 // an `options` object will return validated / normalized options back. If

 // option(s) are invalid validator will throw exception described by rules.

 // Returned will also have contain `rules` property with a given validation

 // rules and `properties` function that can be used to generate validated

 // property getter and setters can be mixed into prototype. For more details

 // see `properties` function below.

 function contract(rules) {

   function validator(options) {

     return valid(options || {}, rules);

   }

   validator.rules = rules

   validator.properties = function(modelFor) {

     return properties(modelFor, rules);

   }

   return validator;

 }

 exports.contract = contract

 // Function takes `modelFor` instance state model accessor functions and

 // a property validation rules and generates object with getters and setters

 // that can be mixed into prototype. Property accessors update model for the

 // given instance. If you wish to react to property updates you can always

 // override setters to put specific logic.

 function properties(modelFor, rules) {

   let descriptor = Object.keys(rules).reduce(function(descriptor, name) {

     descriptor[name] = {

       get: function() { return modelFor(this)[name] },

       set: function(value) {

         let change = {};

         change[name] = value;

         modelFor(this)[name] = valid(change, rules)[name];

       }

     }

     return descriptor

   }, {});

   return Object.create(Object.prototype, descriptor);

 }

 exports.properties = properties