material-motion-testing-utils/src/createMockObserver.ts

Utilities for testing the Material Motion framework

/** @license
 *  Copyright 2016 - present The Material Motion 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.
 */

import {
  Observer,
} from 'indefinite-observable';

import {
  stub,
} from 'sinon';

export default function createMockObserver<T>() {
  return new MockObserver<T>();
}

export class MockObserver<T> {
  next?: Function;
  disconnect = stub();

  connect = (observer: Observer<T>) => {
    this.next = observer.next.bind(observer);

    return this.disconnect;
  }
}