openmct/platform/entanglement/test/ControlledPromise.js

99 lines
3.6 KiB
JavaScript

/*****************************************************************************
* Open MCT, Copyright (c) 2014-2016, United States Government
* as represented by the Administrator of the National Aeronautics and Space
* Administration. All rights reserved.
*
* Open MCT is 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.
*
* Open MCT includes source code licensed under additional open source
* licenses. See the Open Source Licenses file (LICENSES.md) included with
* this source code distribution or the Licensing information page available
* at runtime from the About dialog for additional information.
*****************************************************************************/
/*global spyOn*/
define(
function () {
/**
* An instrumented promise implementation for better control of promises
* during tests.
*
*/
function ControlledPromise() {
this.resolveHandlers = [];
this.rejectHandlers = [];
spyOn(this, 'then').andCallThrough();
}
/**
* Resolve the promise, passing the supplied value to all resolve
* handlers.
*/
ControlledPromise.prototype.resolve = function (value) {
this.resolveHandlers.forEach(function (handler) {
handler(value);
});
};
/**
* Reject the promise, passing the supplied value to all rejection
* handlers.
*/
ControlledPromise.prototype.reject = function (value) {
this.rejectHandlers.forEach(function (handler) {
handler(value);
});
};
/**
* Standard promise.then, returns a promise that support chaining.
* TODO: Need to support resolve/reject handlers that return promises.
*/
ControlledPromise.prototype.then = function (onResolve, onReject) {
var returnPromise = new ControlledPromise();
if (onResolve) {
this.resolveHandlers.push(function (resolveWith) {
var chainResult = onResolve(resolveWith);
if (chainResult && chainResult.then) {
// chainResult is a promise, resolve when it resolves.
chainResult.then(function (pipedResult) {
return returnPromise.resolve(pipedResult);
});
} else {
returnPromise.resolve(chainResult);
}
});
}
if (onReject) {
this.rejectHandlers.push(function (rejectWith) {
var chainResult = onReject(rejectWith);
if (chainResult && chainResult.then) {
chainResult.then(function (pipedResult) {
returnPromise.reject(pipedResult);
});
} else {
returnPromise.reject(chainResult);
}
});
}
return returnPromise;
};
return ControlledPromise;
}
);