sku-pg
Version:
Skulpt is a Javascript implementation of Python 2.x. Python that runs in your browser!
84 lines (72 loc) • 2.64 kB
JavaScript
// Copyright 2009 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview This module simplifies testing code which uses many stateful
* singletons. The {@link goog.testing.singleton.addSingletonGetter} function
* adds a static {@code getInstance} method to the class, which in addition to
* creating and returning a singleton instance, registers it in a global
* repository. This way the effect of all {@code getInstance} calls can be
* simply reset in {@code tearDown} without knowing what singletons were
* instantiated in the tests.
*
* Usage:
* <ol>
* <li>Load {@code base.js}.
* <li>Load {@code goog.testing.singleton}. It overrides
* {@link goog.addSingletonGetter} by
* {@link goog.testing.addSingletonGetter}.
* <li>Load the code to test.
* <li>Call {@link goog.testing.singleton.reset} in the {@code tearDown}.
* </ol>
*
*
*/
goog.provide('goog.testing.singleton');
goog.require('goog.array');
/**
* List of all singleton classes for which the instance has been created.
* @type {Array.<!Function>}
* @private
*/
goog.testing.singletons_ = [];
/**
* Adds a {@code getInstance} static method to the given class which in addition
* to always returning the same instance object, registers the constructor in a
* global array.
* @param {!Function} ctor The constructor for the class to add the static
* method to.
*/
goog.testing.singleton.addSingletonGetter = function(ctor) {
ctor.getInstance = function() {
if (!ctor.instance_) {
ctor.instance_ = new ctor();
goog.testing.singletons_.push(ctor);
}
return ctor.instance_;
};
};
/**
* Deletes all singleton instances, so {@code getInstance} will return a new
* instance on next call.
*/
goog.testing.singleton.reset = function() {
goog.array.forEach(goog.testing.singletons_, function(ctor) {
delete ctor.instance_;
});
goog.array.clear(goog.testing.singletons_);
};
/**
* Overrides {@code goog.addSingletonGetter} in {@code base.js}.
*/
goog.addSingletonGetter = goog.testing.singleton.addSingletonGetter;