Modify ConnectAsync API and add DisconnectAsync to IAudioChannel

src/Discord.Net.Core/Entities/Channels/IAudioChannel.cs

@@ -10,6 +10,9 @@ namespace Discord
         Task<IAudioClient> ConnectAsync(Action<IAudioClient> configAction = null);
 
         /// <summary> Connects to this audio channel but can specify if client is handled externally. </summary>
-        Task<IAudioClient> ConnectAsync(bool external, Action<IAudioClient> configAction = null);
+        Task<IAudioClient> ConnectAsync(Action<IAudioClient> configAction = null, bool external = false);
+
+        /// <summary> Disconnects from this audio channel if applicable. </summary>
+        Task DisconnectAsync();
     }
 }

src/Discord.Net.Rest/Entities/Channels/RestGroupChannel.cs

@@ -144,7 +144,8 @@ namespace Discord.Rest
 
         //IAudioChannel
         Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction) { throw new NotSupportedException(); }
-        Task<IAudioClient> IAudioChannel.ConnectAsync(bool external, Action<IAudioClient> configAction) { throw new NotSupportedException(); }
+        Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction, bool external) { throw new NotSupportedException(); }
+        Task IAudioChannel.DisconnectAsync() { throw new NotSupportedException(); }
 
         //IChannel        
         Task<IUser> IChannel.GetUserAsync(ulong id, CacheMode mode, RequestOptions options)

src/Discord.Net.Rest/Entities/Channels/RestVoiceChannel.cs

@@ -42,7 +42,8 @@ namespace Discord.Rest
 
         //IAudioChannel
         Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction) { throw new NotSupportedException(); }
-        Task<IAudioClient> IAudioChannel.ConnectAsync(bool external, Action<IAudioClient> configAction) { throw new NotSupportedException(); }
+        Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction, bool external) { throw new NotSupportedException(); }
+        Task IAudioChannel.DisconnectAsync() { throw new NotSupportedException(); }
 
         //IGuildChannel
         Task<IGuildUser> IGuildChannel.GetUserAsync(ulong id, CacheMode mode, RequestOptions options)

src/Discord.Net.WebSocket/Entities/Channels/SocketGroupChannel.cs

@@ -207,7 +207,8 @@ namespace Discord.WebSocket
 
         //IAudioChannel
         Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction) { throw new NotSupportedException(); }
-        Task<IAudioClient> IAudioChannel.ConnectAsync(bool external, Action<IAudioClient> configAction) { throw new NotSupportedException(); }
+        Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction, bool external) { throw new NotSupportedException(); }
+        Task IAudioChannel.DisconnectAsync() { throw new NotSupportedException(); }
 
         //IChannel        
         Task<IUser> IChannel.GetUserAsync(ulong id, CacheMode mode, RequestOptions options)

src/Discord.Net.WebSocket/Entities/Channels/SocketVoiceChannel.cs

@@ -45,11 +45,14 @@ namespace Discord.WebSocket
             return await Guild.ConnectAudioAsync(Id, false, false, configAction, false).ConfigureAwait(false);
         }
 
-        public async Task<IAudioClient> ConnectAsync(bool external, Action<IAudioClient> configAction = null)
+        public async Task<IAudioClient> ConnectAsync(Action<IAudioClient> configAction = null, bool external = false)
         {
             return await Guild.ConnectAudioAsync(Id, false, false, configAction, external).ConfigureAwait(false);
         }
 
+        public async Task DisconnectAsync()
+            => await Guild.DisconnectAudioAsync();
+
         public override SocketGuildUser GetUser(ulong id)
         {
             var user = Guild.GetUser(id);

src/Discord.Net.WebSocket/Entities/Guilds/SocketGuild.cs

@@ -606,8 +606,11 @@ namespace Discord.WebSocket
             await _audioLock.WaitAsync().ConfigureAwait(false);
             try
             {
-                await RepopulateAudioStreamsAsync().ConfigureAwait(false);
-                await _audioClient.StartAsync(url, Discord.CurrentUser.Id, voiceState.VoiceSessionId, token).ConfigureAwait(false);
+                if (_audioClient != null)
+                {
+                    await RepopulateAudioStreamsAsync().ConfigureAwait(false);
+                    await _audioClient.StartAsync(url, Discord.CurrentUser.Id, voiceState.VoiceSessionId, token).ConfigureAwait(false);
+                }
             }
             catch (OperationCanceledException)
             {