From 2e20eeb830029f58a294cf19c72502ebcf930eae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Garapich?= <michal@garapich.pl>
Date: Wed, 8 Jun 2022 00:05:18 +0200
Subject: [PATCH 1/2] feat(*): add ChannelUpdate event

---
 src/channel-manager.ts | 11 +++++++-
 src/channel.ts         | 63 +++++++++++++++++++++++++++++++-----------
 2 files changed, 57 insertions(+), 17 deletions(-)

diff --git a/src/channel-manager.ts b/src/channel-manager.ts
index dd5ea90..78126af 100644
--- a/src/channel-manager.ts
+++ b/src/channel-manager.ts
@@ -121,7 +121,16 @@ export class ChannelManager {
        */
       this.client.emit(EventNames.channelCreate, channel);
     } else {
-      channel.syncState(channelState);
+      const changes = channel.syncState(channelState);
+      if (Object.keys(changes).length > 0) {
+        /**
+         * Emitted when a channel is updated.
+         * @event Client#channelUpdate
+         * @property {Channel} channel The channel that was updated.
+         * @property {ChannelChanges} changes What changes were made to the channel.
+         */
+        this.client.emit(EventNames.channelUpdate, channel, changes);
+      }
     }
   }
 
diff --git a/src/channel.ts b/src/channel.ts
index c22d4b2..70b4a72 100644
--- a/src/channel.ts
+++ b/src/channel.ts
@@ -1,4 +1,5 @@
 import { ChannelState } from '@tf2pickup-org/mumble-protocol';
+import { Change } from './change';
 import { Client } from './client';
 import {
   createChannel,
@@ -15,6 +16,15 @@ import {
 import { Permissions } from './permissions';
 import { User } from './user';
 
+type ChannelChangeableProps = Pick<
+  Channel,
+  'name' | 'parent' | 'temporary' | 'linkedChannels'
+>;
+
+export type ChannelChanges = {
+  -readonly [P in keyof ChannelChangeableProps]?: Change<Channel[P]>;
+};
+
 /**
  * Represents a single channel.
  */
@@ -39,26 +49,31 @@ export class Channel {
   /**
    * @internal
    */
-  syncState(channelState: ChannelState) {
-    if (channelState.name !== undefined) {
-      this.name = channelState.name;
-    }
+  syncState(channelState: ChannelState): ChannelChanges {
+    const changes: ChannelChanges = {};
 
-    if (channelState.parent !== undefined) {
-      this.parent = channelState.parent;
-    }
+    this.syncProperty('name', channelState.name, changes);
+    this.syncProperty('parent', channelState.parent, changes);
+    this.syncProperty('temporary', channelState.temporary, changes);
+
+    if (channelState.linksAdd.length + channelState.linksRemove.length > 0) {
+      changes.linkedChannels = {
+        previousValue: [...this.linkedChannels],
+        currentValue: [],
+      };
+
+      this.links = [
+        ...new Set([
+          ...this.links,
+          ...channelState.links,
+          ...channelState.linksAdd,
+        ]),
+      ].filter(l => !channelState.linksRemove.includes(l));
 
-    if (channelState.temporary !== undefined) {
-      this.temporary = channelState.temporary;
+      changes.linkedChannels.currentValue = this.linkedChannels;
     }
 
-    this.links = [
-      ...new Set([
-        ...this.links,
-        ...channelState.links,
-        ...channelState.linksAdd,
-      ]),
-    ].filter(l => !channelState.linksRemove.includes(l));
+    return changes;
   }
 
   /**
@@ -199,4 +214,20 @@ export class Channel {
     await unlinkChannels(this.client.socket, this.id, targetChannel.id);
     return this;
   }
+
+  private syncProperty<R extends keyof ChannelChangeableProps>(
+    propertyName: R,
+    newValue: this[R] | undefined,
+    changes: ChannelChanges,
+  ) {
+    if (newValue === undefined) {
+      return;
+    }
+
+    (changes[propertyName] as Change<Channel[R]>) = {
+      previousValue: this[propertyName],
+      currentValue: newValue,
+    };
+    this[propertyName] = newValue;
+  }
 }

From be8ad16e15501acc8c9c13de9eee69ebd7ede2b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Garapich?= <michal@garapich.pl>
Date: Mon, 13 Jun 2022 01:44:47 +0200
Subject: [PATCH 2/2] add test

---
 src/channel.spec.ts | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/src/channel.spec.ts b/src/channel.spec.ts
index 7cbc275..1a3d841 100644
--- a/src/channel.spec.ts
+++ b/src/channel.spec.ts
@@ -48,26 +48,43 @@ describe('Channel', () => {
     expect(channel.name).toEqual('FAKE_CHANNEL_NAME');
   });
 
-  describe('sync()', () => {
+  describe('syncState()', () => {
     let channel: Channel;
 
     beforeEach(() => {
       channel = new Channel(
         client,
-        ChannelState.create({ channelId: 0 }) as ChannelState & {
+        ChannelState.create({
+          channelId: 0,
+          name: 'FAKE_CHANNEL_NAME',
+        }) as ChannelState & {
           channelId: number;
         },
       );
     });
 
     it('should update name', () => {
-      channel.syncState(ChannelState.create({ name: 'NEW_CHANNEL_NAME' }));
+      const changes = channel.syncState(
+        ChannelState.create({ name: 'NEW_CHANNEL_NAME' }),
+      );
       expect(channel.name).toEqual('NEW_CHANNEL_NAME');
+      expect(changes).toEqual({
+        name: {
+          previousValue: 'FAKE_CHANNEL_NAME',
+          currentValue: 'NEW_CHANNEL_NAME',
+        },
+      });
     });
 
     it('should update parent', () => {
-      channel.syncState(ChannelState.create({ parent: 10 }));
+      const changes = channel.syncState(ChannelState.create({ parent: 10 }));
       expect(channel.parent).toEqual(10);
+      expect(changes).toEqual({
+        parent: {
+          previousValue: undefined,
+          currentValue: 10,
+        },
+      });
     });
   });