Add TypeScript interfaces for all exported classes

## Details

- `mediasoup.types` namespace no longer exports `Worker`, `Router`, `Producer`, etc classes in `types` but instead it exports `WorkerInterface`, `RouterInterface`, `ProducerInterface`, etc.
  - NOTE: This is a breaking change somehow, but just at TS level.
- Use the new interfaces everywhere.
- This makes it easier for applications to create mediasoup mocks.

## TODO

- How to export as interface/types the functions and consts exposed by `index.ts` such as `createWorker()`, `setLogEventListeners()`, `getSupportedRtpCapabilities()`, `observer`, etc?
- In the future we may want to move those interfaces/types to another separate package so a Node application that only depends on mediasoup types doesn't need to install mediaosup. Even if we don't do that, we should change things so `types.ts` doesn't export **anything** that depends on compiled FBS types.

node/src/ActiveSpeakerObserver.ts

@@ -1,57 +1,33 @@
 import { Logger } from './Logger';
 import { EnhancedEventEmitter } from './enhancedEvents';
 import {
-	RtpObserver,
-	RtpObserverEvents,
-	RtpObserverObserverEvents,
-	RtpObserverConstructorOptions,
-} from './RtpObserver';
-import { Producer } from './Producer';
+	ActiveSpeakerObserverInterface,
+	ActiveSpeakerObserverDominantSpeaker,
+	ActiveSpeakerObserverEvents,
+	ActiveSpeakerObserverObserver,
+	ActiveSpeakerObserverObserverEvents,
+} from './ActiveSpeakerObserverInterface';
+import { RtpObserverInterface } from './RtpObserverInterface';
+import { RtpObserver, RtpObserverConstructorOptions } from './RtpObserver';
 import { AppData } from './types';
 import { Event, Notification } from './fbs/notification';
 import * as FbsActiveSpeakerObserver from './fbs/active-speaker-observer';
 
-export type ActiveSpeakerObserverOptions<
-	ActiveSpeakerObserverAppData extends AppData = AppData,
-> = {
-	interval?: number;
-
-	/**
-	 * Custom application data.
-	 */
-	appData?: ActiveSpeakerObserverAppData;
-};
-
-export type ActiveSpeakerObserverDominantSpeaker = {
-	/**
-	 * The audio Producer instance.
-	 */
-	producer: Producer;
-};
-
-export type ActiveSpeakerObserverEvents = RtpObserverEvents & {
-	dominantspeaker: [ActiveSpeakerObserverDominantSpeaker];
-};
-
-export type ActiveSpeakerObserverObserver =
-	EnhancedEventEmitter<ActiveSpeakerObserverObserverEvents>;
-
-export type ActiveSpeakerObserverObserverEvents = RtpObserverObserverEvents & {
-	dominantspeaker: [ActiveSpeakerObserverDominantSpeaker];
-};
-
 type RtpObserverObserverConstructorOptions<ActiveSpeakerObserverAppData> =
 	RtpObserverConstructorOptions<ActiveSpeakerObserverAppData>;
 
 const logger = new Logger('ActiveSpeakerObserver');
 
 export class ActiveSpeakerObserver<
-	ActiveSpeakerObserverAppData extends AppData = AppData,
-> extends RtpObserver<
-	ActiveSpeakerObserverAppData,
-	ActiveSpeakerObserverEvents,
-	ActiveSpeakerObserverObserver
-> {
+		ActiveSpeakerObserverAppData extends AppData = AppData,
+	>
+	extends RtpObserver<
+		ActiveSpeakerObserverAppData,
+		ActiveSpeakerObserverEvents,
+		ActiveSpeakerObserverObserver
+	>
+	implements RtpObserverInterface, ActiveSpeakerObserverInterface
+{
 	/**
 	 * @private
 	 */

node/src/ActiveSpeakerObserverInterface.ts

@@ -0,0 +1,47 @@
+import { EnhancedEventEmitter } from './enhancedEvents';
+import {
+	RtpObserverInterface,
+	RtpObserverEvents,
+	RtpObserverObserverEvents,
+} from './RtpObserverInterface';
+import { ProducerInterface } from './ProducerInterface';
+import { AppData } from './types';
+
+export type ActiveSpeakerObserverOptions<
+	ActiveSpeakerObserverAppData extends AppData = AppData,
+> = {
+	interval?: number;
+
+	/**
+	 * Custom application data.
+	 */
+	appData?: ActiveSpeakerObserverAppData;
+};
+
+export type ActiveSpeakerObserverDominantSpeaker = {
+	/**
+	 * The audio Producer instance.
+	 */
+	producer: ProducerInterface;
+};
+
+export type ActiveSpeakerObserverEvents = RtpObserverEvents & {
+	dominantspeaker: [ActiveSpeakerObserverDominantSpeaker];
+};
+
+export type ActiveSpeakerObserverObserver =
+	EnhancedEventEmitter<ActiveSpeakerObserverObserverEvents>;
+
+export type ActiveSpeakerObserverObserverEvents = RtpObserverObserverEvents & {
+	dominantspeaker: [ActiveSpeakerObserverDominantSpeaker];
+};
+
+export interface ActiveSpeakerObserverInterface<
+	ActiveSpeakerObserverAppData extends AppData = AppData,
+> extends RtpObserverInterface<
+		ActiveSpeakerObserverAppData,
+		ActiveSpeakerObserverEvents,
+		ActiveSpeakerObserverObserver
+	> {
+	get observer(): ActiveSpeakerObserverObserver;
+}

node/src/AudioLevelObserver.ts

@@ -1,80 +1,35 @@
 import { Logger } from './Logger';
 import { EnhancedEventEmitter } from './enhancedEvents';
 import {
-	RtpObserver,
-	RtpObserverEvents,
-	RtpObserverObserverEvents,
-	RtpObserverConstructorOptions,
-} from './RtpObserver';
-import { Producer } from './Producer';
+	AudioLevelObserverInterface,
+	AudioLevelObserverVolume,
+	AudioLevelObserverEvents,
+	AudioLevelObserverObserver,
+	AudioLevelObserverObserverEvents,
+} from './AudioLevelObserverInterface';
+import { RtpObserverInterface } from './RtpObserverInterface';
+import { RtpObserver, RtpObserverConstructorOptions } from './RtpObserver';
+import { ProducerInterface } from './ProducerInterface';
 import { AppData } from './types';
 import * as utils from './utils';
 import { Event, Notification } from './fbs/notification';
 import * as FbsAudioLevelObserver from './fbs/audio-level-observer';
 
-export type AudioLevelObserverOptions<
-	AudioLevelObserverAppData extends AppData = AppData,
-> = {
-	/**
-	 * Maximum number of entries in the 'volumes”' event. Default 1.
-	 */
-	maxEntries?: number;
-
-	/**
-	 * Minimum average volume (in dBvo from -127 to 0) for entries in the
-	 * 'volumes' event.	Default -80.
-	 */
-	threshold?: number;
-
-	/**
-	 * Interval in ms for checking audio volumes. Default 1000.
-	 */
-	interval?: number;
-
-	/**
-	 * Custom application data.
-	 */
-	appData?: AudioLevelObserverAppData;
-};
-
-export type AudioLevelObserverVolume = {
-	/**
-	 * The audio Producer instance.
-	 */
-	producer: Producer;
-
-	/**
-	 * The average volume (in dBvo from -127 to 0) of the audio Producer in the
-	 * last interval.
-	 */
-	volume: number;
-};
-
-export type AudioLevelObserverEvents = RtpObserverEvents & {
-	volumes: [AudioLevelObserverVolume[]];
-	silence: [];
-};
-
-export type AudioLevelObserverObserver =
-	EnhancedEventEmitter<AudioLevelObserverObserverEvents>;
-
-export type AudioLevelObserverObserverEvents = RtpObserverObserverEvents & {
-	volumes: [AudioLevelObserverVolume[]];
-	silence: [];
-};
-
 type AudioLevelObserverConstructorOptions<AudioLevelObserverAppData> =
 	RtpObserverConstructorOptions<AudioLevelObserverAppData>;
 
 const logger = new Logger('AudioLevelObserver');
 
 export class AudioLevelObserver<
-	AudioLevelObserverAppData extends AppData = AppData,
-> extends RtpObserver<
-	AudioLevelObserverAppData,
-	AudioLevelObserverEvents,
-	AudioLevelObserverObserver
-> {
+		AudioLevelObserverAppData extends AppData = AppData,
+	>
+	extends RtpObserver<
+		AudioLevelObserverAppData,
+		AudioLevelObserverEvents,
+		AudioLevelObserverObserver
+	>
+	implements RtpObserverInterface, AudioLevelObserverInterface
+{
 	/**
 	 * @private
 	 */
@@ -125,7 +80,9 @@ export class AudioLevelObserver<
 									volume,
 								})
 							)
-							.filter(({ producer }: { producer: Producer }) => producer);
+							.filter(
+								({ producer }: { producer: ProducerInterface }) => producer
+							);
 
 						if (volumes.length > 0) {
 							this.safeEmit('volumes', volumes);

node/src/AudioLevelObserverInterface.ts

@@ -0,0 +1,69 @@
+import { EnhancedEventEmitter } from './enhancedEvents';
+import {
+	RtpObserverInterface,
+	RtpObserverEvents,
+	RtpObserverObserverEvents,
+} from './RtpObserverInterface';
+import { ProducerInterface } from './ProducerInterface';
+import { AppData } from './types';
+
+export type AudioLevelObserverOptions<
+	AudioLevelObserverAppData extends AppData = AppData,
+> = {
+	/**
+	 * Maximum number of entries in the 'volumes”' event. Default 1.
+	 */
+	maxEntries?: number;
+
+	/**
+	 * Minimum average volume (in dBvo from -127 to 0) for entries in the
+	 * 'volumes' event.	Default -80.
+	 */
+	threshold?: number;
+
+	/**
+	 * Interval in ms for checking audio volumes. Default 1000.
+	 */
+	interval?: number;
+
+	/**
+	 * Custom application data.
+	 */
+	appData?: AudioLevelObserverAppData;
+};
+
+export type AudioLevelObserverVolume = {
+	/**
+	 * The audio Producer instance.
+	 */
+	producer: ProducerInterface;
+
+	/**
+	 * The average volume (in dBvo from -127 to 0) of the audio Producer in the
+	 * last interval.
+	 */
+	volume: number;
+};
+
+export type AudioLevelObserverEvents = RtpObserverEvents & {
+	volumes: [AudioLevelObserverVolume[]];
+	silence: [];
+};
+
+export type AudioLevelObserverObserver =
+	EnhancedEventEmitter<AudioLevelObserverObserverEvents>;
+
+export type AudioLevelObserverObserverEvents = RtpObserverObserverEvents & {
+	volumes: [AudioLevelObserverVolume[]];
+	silence: [];
+};
+
+export interface AudioLevelObserverInterface<
+	AudioLevelObserverAppData extends AppData = AppData,
+> extends RtpObserverInterface<
+		AudioLevelObserverAppData,
+		AudioLevelObserverEvents,
+		AudioLevelObserverObserver
+	> {
+	get observer(): AudioLevelObserverObserver;
+}