From 2e9eba30de1a24c49feb70a9701e8e9ede5a1e86 Mon Sep 17 00:00:00 2001
From: Angus ZENG <i.am.x.fenying@gmail.com>
Date: Sun, 30 Jun 2024 19:55:41 +0800
Subject: [PATCH] feat(protocol): added feature flag properties for channel
 objects

---
 CHANGES.md                                 |  1 +
 src/examples/shared/router.ts              |  5 +++++
 src/lib/server/LegacyServerChannel.impl.ts |  4 ++++
 src/lib/shared/Channel.impl.ts             |  4 ++++
 src/lib/shared/Shared.decl.ts              | 10 ++++++++++
 5 files changed, 24 insertions(+)

diff --git a/CHANGES.md b/CHANGES.md
index 800bff3..6d67b9c 100644
--- a/CHANGES.md
+++ b/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.
diff --git a/src/examples/shared/router.ts b/src/examples/shared/router.ts
index db3926b..60cd579 100644
--- a/src/examples/shared/router.ts
+++ b/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> => {
diff --git a/src/lib/server/LegacyServerChannel.impl.ts b/src/lib/server/LegacyServerChannel.impl.ts
index 5742785..2c3f4c3 100644
--- a/src/lib/server/LegacyServerChannel.impl.ts
+++ b/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; }
diff --git a/src/lib/shared/Channel.impl.ts b/src/lib/shared/Channel.impl.ts
index a3ff500..232063a 100644
--- a/src/lib/shared/Channel.impl.ts
+++ b/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;
diff --git a/src/lib/shared/Shared.decl.ts b/src/lib/shared/Shared.decl.ts
index 540fdbd..2f16f77 100644
--- a/src/lib/shared/Shared.decl.ts
+++ b/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.
      */