Voice Broadcast playback (#9372)

* Implement actual voice broadcast playback

* Move PublicInterface type to test

* Implement pausing a voice broadcast playback

* Implement PR feedback

* Remove unnecessary early return

test/test-utils/audio.ts

@@ -0,0 +1,81 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+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 EventEmitter from "events";
+import { SimpleObservable } from "matrix-widget-api";
+
+import { Playback, PlaybackState } from "../../src/audio/Playback";
+import { PlaybackClock } from "../../src/audio/PlaybackClock";
+import { UPDATE_EVENT } from "../../src/stores/AsyncStore";
+
+type PublicInterface<T> = {
+    [P in keyof T]: T[P];
+};
+
+export const createTestPlayback = (): Playback => {
+    const eventEmitter = new EventEmitter();
+
+    return {
+        thumbnailWaveform: [1, 2, 3],
+        sizeBytes: 23,
+        waveform: [4, 5, 6],
+        waveformData: new SimpleObservable<number[]>(),
+        destroy: jest.fn(),
+        play: jest.fn(),
+        prepare: jest.fn(),
+        pause: jest.fn(),
+        stop: jest.fn(),
+        toggle: jest.fn(),
+        skipTo: jest.fn(),
+        isPlaying: false,
+        clockInfo: createTestPlaybackClock(),
+        currentState: PlaybackState.Stopped,
+        emit: (event: PlaybackState, ...args: any[]): boolean => {
+            eventEmitter.emit(event, ...args);
+            eventEmitter.emit(UPDATE_EVENT, event, ...args);
+            return true;
+        },
+        // EventEmitter
+        on: eventEmitter.on.bind(eventEmitter),
+        once: eventEmitter.once.bind(eventEmitter),
+        off: eventEmitter.off.bind(eventEmitter),
+        addListener: eventEmitter.addListener.bind(eventEmitter),
+        removeListener: eventEmitter.removeListener.bind(eventEmitter),
+        removeAllListeners: eventEmitter.removeAllListeners.bind(eventEmitter),
+        getMaxListeners: eventEmitter.getMaxListeners.bind(eventEmitter),
+        setMaxListeners: eventEmitter.setMaxListeners.bind(eventEmitter),
+        listeners: eventEmitter.listeners.bind(eventEmitter),
+        rawListeners: eventEmitter.rawListeners.bind(eventEmitter),
+        listenerCount: eventEmitter.listenerCount.bind(eventEmitter),
+        eventNames: eventEmitter.eventNames.bind(eventEmitter),
+        prependListener: eventEmitter.prependListener.bind(eventEmitter),
+        prependOnceListener: eventEmitter.prependOnceListener.bind(eventEmitter),
+    } as PublicInterface<Playback> as Playback;
+};
+
+export const createTestPlaybackClock = (): PlaybackClock => {
+    return {
+        durationSeconds: 31,
+        timeSeconds: 41,
+        liveData: new SimpleObservable<number[]>(),
+        populatePlaceholdersFrom: jest.fn(),
+        flagLoadTime: jest.fn(),
+        flagStart: jest.fn(),
+        flagStop: jest.fn(),
+        syncTo: jest.fn(),
+        destroy: jest.fn(),
+    } as PublicInterface<PlaybackClock> as PlaybackClock;
+};