michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: module.metadata = {
michael@0:   "stability": "unstable"
michael@0: };
michael@0: 
michael@0: const { validateOptions: valid } = require("../deprecated/api-utils");
michael@0: 
michael@0: // Function takes property validation rules and returns function that given
michael@0: // an `options` object will return validated / normalized options back. If
michael@0: // option(s) are invalid validator will throw exception described by rules.
michael@0: // Returned will also have contain `rules` property with a given validation
michael@0: // rules and `properties` function that can be used to generate validated
michael@0: // property getter and setters can be mixed into prototype. For more details
michael@0: // see `properties` function below.
michael@0: function contract(rules) {
michael@0:   function validator(options) {
michael@0:     return valid(options || {}, rules);
michael@0:   }
michael@0:   validator.rules = rules
michael@0:   validator.properties = function(modelFor) {
michael@0:     return properties(modelFor, rules);
michael@0:   }
michael@0:   return validator;
michael@0: }
michael@0: exports.contract = contract
michael@0: 
michael@0: // Function takes `modelFor` instance state model accessor functions and
michael@0: // a property validation rules and generates object with getters and setters
michael@0: // that can be mixed into prototype. Property accessors update model for the
michael@0: // given instance. If you wish to react to property updates you can always
michael@0: // override setters to put specific logic.
michael@0: function properties(modelFor, rules) {
michael@0:   let descriptor = Object.keys(rules).reduce(function(descriptor, name) {
michael@0:     descriptor[name] = {
michael@0:       get: function() { return modelFor(this)[name] },
michael@0:       set: function(value) {
michael@0:         let change = {};
michael@0:         change[name] = value;
michael@0:         modelFor(this)[name] = valid(change, rules)[name];
michael@0:       }
michael@0:     }
michael@0:     return descriptor
michael@0:   }, {});
michael@0:   return Object.create(Object.prototype, descriptor);
michael@0: }
michael@0: exports.properties = properties