feat(protocol): added feature flag properties for channel objects

CHANGES.md

@@ -3,6 +3,7 @@
 ## v1.1.0
 
 - feat(protocol): added experimental supports for transports between worker thread.
+- feat(protocol): added feature flag properties for channel objects.
 - fix(protocol): simplified the ITransporter.end method.
 - fix(decoder): should decode protocol error as special error.
 - fix(protocol): put protocol-error code in server_internal_server data.

src/examples/shared/router.ts

@@ -51,6 +51,11 @@ export const router: Tv.Servers.IRouter = new Tv.Servers.SimpleJsonApiRouter()
 
         serverLogs.ok(`Channel#${ctx.channel.id} invoked sendMeMessage with message: ${msg}`);
 
+        if (!ctx.channel.isMessageSupported) {
+
+            throw new Tv.errors.cmd_not_impl();
+        }
+
         ctx.channel.sendMessage(msg).catch(e => serverLogs.error(`Failed while sending message, error: ${e}`));
     })
     .registerApi('sendMeMessageAsync', async (ctx, msg: string): Promise<void> => {

src/lib/server/LegacyServerChannel.impl.ts

@@ -32,6 +32,10 @@ export class TvLegacyServerChannelV1 extends EventEmitter implements Shared.ICha
 
     public get writable(): boolean { return false; }
 
+    public get isMessageSupported(): boolean { return false; }
+
+    public get isBinaryStreamSupported(): boolean { return false; }
+
     public get id(): number { return 0; }
 
     public get timeout(): number { return 30_000; }

src/lib/shared/Channel.impl.ts

@@ -88,6 +88,10 @@ export abstract class AbstractTvChannelV2
 
     public ended: boolean = false;
 
+    public get isMessageSupported(): boolean { return true; }
+
+    public get isBinaryStreamSupported(): boolean { return this.streams.maxStreams !== 0; }
+
     public get finished(): boolean {
 
         return this._state === EState.ENDED;

src/lib/shared/Shared.decl.ts

@@ -303,6 +303,16 @@ export interface IChannelBase<TEvents extends IDefaultEvents> extends IEventList
      */
     readonly transporter: ITransporter;
 
+    /**
+     * Whether this channel supports server-push messages or not.
+     */
+    readonly isMessageSupported: boolean;
+
+    /**
+     * Whether this channel supports binary streams or not.
+     */
+    readonly isBinaryStreamSupported: boolean;
+
     /**
      * Tells whether this channel is closed on the local side or not.
      */