enable typechecking, expose types to users

replicates:
medooze/audio-codecs-node#4
medooze/media-server-node#229

plus these followups:

medooze/audio-codecs-node@9f1de91
medooze/audio-codecs-node@ea62f68
medooze/audio-codecs-node@beed5bd

the following files were nearly identical to
audio-codecs and were simply copied from there,
thus do NOT require manual review:

- Properties.js (completely identical)
- VideoEncoderIncomingStreamTrack.js (only difference
  is replacing "audio" with "video" preserving case)

index.d.ts

@@ -0,0 +1,11 @@
+export * from "./build/types/VideoCodecs";
+
+export type VideoDecoder = import("./build/types/VideoDecoder");
+export type VideoEncoder = import("./build/types/VideoEncoder");
+export type { CodecParams } from "./build/types/VideoEncoder";
+export type VideoEncoderIncomingStreamTrack = import("./build/types/VideoEncoderIncomingStreamTrack");
+
+export type {
+	ActiveEncodingInfo, ActiveLayersInfo,
+	EncodingStats, LayerStats, MediaStats, PacketWaitTime, TrackStats,
+} from "./build/types/VideoEncoderIncomingStreamTrack";

lib/Native.js

@@ -5,10 +5,11 @@ const SharedPointer = require("./SharedPointer");
 try 
 {
 	//We try first to load it via dlopen on Node 9
+	//@ts-expect-error
 	process.dlopen(module,path.resolve(path.dirname(module.filename), "../build/Release/medooze-video-codecs.node"), os.constants.dlopen.RTLD_NOW )//| os.constants.dlopen.RTLD_DEEPBIND);
 } catch (e) {
 	//old one
-	module.exports = require("../build/Release/medooze-video-codecs");
+	module.exports = require(/** @type {any} */ ("../build/Release/medooze-video-codecs"));
 }
 
 SharedPointer.wrapNativeModule(module);

lib/Properties.js

@@ -1,8 +1,17 @@
 const Native		= require("./Native");
 
-function fromObject(object)
+/**
+ * @typedef {unknown} Properties
+ * Plain JSON object representing codec properties.
+ * See Properties C++ class and fromObject below.
+ */
+
+function fromObject(/** @type {Properties} */ object)
 {
-	function convert(properties, object, preffix = "")
+	function convert(
+		/** @type {Native.Properties} */ properties,
+		/** @type {Properties} */ object,
+		preffix = "")
 	{
 		if (object)
 			//For each pro
@@ -34,4 +43,3 @@ function fromObject(object)
 module.exports = {
 	fromObject
 }
-

lib/VideoCodecs.js

@@ -8,11 +8,13 @@ const LFSR	  = require('lfsr');
 const defaultSeed = new LFSR(8, 92914);
 
 //Replace default seeed
-LFSR.prototype._defaultSeed = function(n) {
+LFSR.prototype._defaultSeed = function(/** @type {number} */ n) {
 	if (!n) throw new Error('n is required');
 	return defaultSeed.seq(n);
 };
 
+/** @typedef {import("./Properties").Properties} Properties */
+
 /** @namespace */
 const VideoCodecs = {};
 
@@ -29,15 +31,8 @@ VideoCodecs.terminate = function()
 /**
  * Create a new VideoEnocder
  * @memberof VideoCodecs
- * @param {String} codec		Codec name
- * @param {Object} params		Codec params
- * @param {Number} params.width 
- * @param {Number} params.height
- * @param {Number} params.fps
- * @param {Number} params.bitrate
- * @param {Number} params.intraPeriod
- * @param {Object} params.properties	Codec specific properties 
- * @returns {VideoEnocder} The new created encoder
+ * @param {String} codec Codec name
+ * @param {VideoEncoder.CodecParams} params Codec params
  */
 VideoCodecs.createVideoEncoder = function(codec,params)
 {
@@ -55,23 +50,20 @@ VideoCodecs.createVideoDecoder = function()
 	return new VideoDecoder();
 };
 
+/**
+ * @param {string} encoderCodec encoder name
+ * @param {string} codec decoder name
+ * @param {Uint8Array} buffer input buffer
+ * @returns {Promise<Buffer>} output buffer
+ */
 VideoCodecs.generateThumbnail = function(encoderCodec, codec, buffer)
 {
-	return new Promise((resolve, reject) =>
-	{
-
+	return new Promise((resolve, reject) => {
 		//New task
-		const task = new Native.ThumbnailGeneratorTask({
-			resolve : (a)=>{
-				resolve(a)
-			}, 
-			reject : (e)=>{
-				reject(new Error(e));
-			}
-		});
+		const task = new Native.ThumbnailGeneratorTask({ resolve, reject });
 		//Execute it
 		task.Run(encoderCodec, codec, buffer);
-	});
+	}).catch(e => Promise.reject(new Error(e)));
 };
 
 

lib/VideoDecoder.js

@@ -1,6 +1,13 @@
 const Native		= require("./Native");
+const SharedPointer	= require("./SharedPointer");
 const Emitter		= require("medooze-event-emitter");
 
+/**
+ * @typedef {Object} VideoDecoderEvents
+ * @property {(self: VideoDecoder) => void} stopped
+ */
+
+/** @extends {Emitter<VideoDecoderEvents>} */
 class VideoDecoder extends Emitter
 {
 	/**
@@ -14,7 +21,7 @@ class VideoDecoder extends Emitter
 		super();
 
 		//Create decoder
-		this.decoder = new Native.VideoDecoderWorkerShared();
+		this.decoder = SharedPointer(new Native.VideoDecoderWorkerShared());
 
 		//Start decoder
 		this.decoder.Start();
@@ -71,7 +78,7 @@ class VideoDecoder extends Emitter
 		this.attached = null;
 	}
 
-	attachTo(track)
+	attachTo(/** @type {import("./VideoEncoderIncomingStreamTrack") | undefined} */ track)
 	{
 		//Detach first
 		this.detach();
@@ -99,20 +106,13 @@ class VideoDecoder extends Emitter
 		//Stop decoder
 		this.decoder.Stop();
 
-		/**
-		* VideoDecoder stopped event
-		*
-		* @name stopped
-		* @memberof VideoDecoder
-		* @kind event
-		* @argument {VideoDecoder} decoder
-		*/
 		this.emit("stopped", this);
 
 		//Stop emitter
 		super.stop();
 
 		//Remove native refs
+		//@ts-expect-error
 		this.decoder = null;
 	}
 };

lib/VideoEncoder.js

@@ -5,14 +5,40 @@ const Properties	= require("./Properties")
 const LFSR		= require("lfsr");
 const VideoEncoderIncomingStreamTrack = require("./VideoEncoderIncomingStreamTrack");
 
+//@ts-expect-error
+const parseInt = /** @type {(x: number) => number} */ (global.parseInt);
+//@ts-expect-error
+const parseFloat = /** @type {(x: number) => number} */ (global.parseFloat);
+
+/**
+ * @typedef {Object} CodecParams
+ * @property {number} [width] (integer)
+ * @property {number} [height] (integer)
+ * @property {number} fps (integer)
+ * @property {number} bitrate (integer)
+ * @property {number} [intraPeriod] (integer)
+ * @property {number} [scaleResolutionDownBy] (float)
+ * @property {number} [scaleResolutionToHeight] (integer)
+ * @property {boolean} [allowSameHeight]
+ * @property {Properties} properties
+ */
+
+/**
+ * @typedef {Object} VideoEncoderEvents
+ * @property {(self: VideoEncoder) => void} stopped
+ */
+
+/** @extends {Emitter<VideoEncoderEvents>} */
 class VideoEncoder extends Emitter
 {
 	/**
 	 * @ignore
 	 * @hideconstructor
 	 * private constructor
 	 */
-	constructor(codec,params)
+	constructor(
+		/** @type {string} */ codec,
+		/** @type {CodecParams} */ params)
 	{
 		//Init emitter
 		super();
@@ -37,7 +63,7 @@ class VideoEncoder extends Emitter
 		//And audio pipe
 		this.pipe = new Native.VideoPipe();
 		//Init pipe
-		this.pipe.Init(scaleResolutionDownBy, scaleResolutionToHeight, allowedDownScaling);
+		this.pipe.Init(scaleResolutionDownBy, scaleResolutionToHeight, /** @type {Native.VideoPipeAllowedDownScaling} */ (allowedDownScaling));
 		//Set it in encoder
 		this.encoder.Init(this.pipe);
 		//Start encoding
@@ -50,6 +76,9 @@ class VideoEncoder extends Emitter
 		this.tracks = new Map();
 	}
 
+	/**
+	 * @param {number} delayms delay in milliseconds
+	 */
 	setMaxDelay(delayms) 
 	{
 		this.pipe.SetMaxDelay(delayms);
@@ -82,10 +111,15 @@ class VideoEncoder extends Emitter
 		};
 	}
 
+	/**
+	 * @param {string} trackId (unused. FIXME: please remove)
+	 * @param {Native.FrameDispatchCoordinatorShared} frameDispatchCoordinator
+	 * @returns 
+	 */
 	createIncomingStreamTrack(trackId, frameDispatchCoordinator)
 	{
 		//Create the source
-		const bridge = new Native.MediaFrameListenerBridgeShared(this.encoder.GetTimeService(), this.lfsr.seq(31));
+		const bridge = SharedPointer(new Native.MediaFrameListenerBridgeShared(this.encoder.GetTimeService(), this.lfsr.seq(31)));
 		if (frameDispatchCoordinator)
 			bridge.SetFrameDispatchCoordinator(frameDispatchCoordinator);
 
@@ -118,7 +152,7 @@ class VideoEncoder extends Emitter
 	}
 
 
-	attachTo(decoder)
+	attachTo(/** @type {import("./VideoDecoder") | undefined} */decoder)
 	{
 		//Detach first
 		this.detach();
@@ -157,14 +191,6 @@ class VideoEncoder extends Emitter
 			//Stop it
 			track.stop();
 
-		/**
-		* VideoEncoder stopped event
-		*
-		* @name stopped
-		* @memberof VideoEncoder
-		* @kind event
-		* @argument {VideoEncoder} encoder
-		*/
 		this.emit("stopped", this);
 
 		//Stop emitter
@@ -176,7 +202,9 @@ class VideoEncoder extends Emitter
 		this.pipe.End();
 
 		//Remove brdige reference, so destructor is called on GC
+		//@ts-expect-error
 		this.pipe = null;
+		//@ts-expect-error
 		this.encoder = null;
 	}
 };