Fix a few more compiler warnings

Signed-off-by: Ske <voltasalt@gmail.com>

Myriad/Cache/MemoryDiscordCache.cs

@@ -151,10 +151,11 @@ namespace Myriad.Cache
         public bool TryGetRole(ulong roleId, out Role role) =>
             _roles.TryGetValue(roleId, out role!);
 
-        public async IAsyncEnumerable<Guild> GetAllGuilds()
+        public IAsyncEnumerable<Guild> GetAllGuilds()
         {
-            foreach (var guild in _guilds.Values)
-                yield return guild.Guild;
+            return _guilds.Values
+                .Select(g => g.Guild)
+                .ToAsyncEnumerable();
         }
 
         public IEnumerable<Channel> GetGuildChannels(ulong guildId)

Myriad/Myriad.csproj

@@ -19,6 +19,7 @@
       <PackageReference Include="Polly" Version="7.2.1" />
       <PackageReference Include="Polly.Contrib.WaitAndRetry" Version="1.1.1" />
       <PackageReference Include="Serilog" Version="2.10.0" />
+      <PackageReference Include="System.Linq.Async" Version="5.0.0" />
     </ItemGroup>
 
 </Project>

PluralKit.Bot/CommandSystem/ContextEntityArgumentsExt.cs

@@ -155,19 +155,19 @@ namespace PluralKit.Bot
             return $"Group not found. Note that a group ID is 5 characters long.";
         }
         
-        public static async Task<Channel> MatchChannel(this Context ctx)
+        public static Task<Channel> MatchChannel(this Context ctx)
         {
             if (!MentionUtils.TryParseChannel(ctx.PeekArgument(), out var id)) 
-                return null;
+                return Task.FromResult<Channel>(null);
 
             if (!ctx.Cache.TryGetChannel(id, out var channel))
-                return null;
+                return Task.FromResult<Channel>(null);
             
-            if (!(channel.Type == Channel.ChannelType.GuildText || channel.Type == Channel.ChannelType.GuildText)) 
-                return null;
+            if (!(channel.Type == Channel.ChannelType.GuildText || channel.Type == Channel.ChannelType.GuildNews)) 
+                return Task.FromResult<Channel>(null);
             
             ctx.PopArgument();
-            return channel;
+            return Task.FromResult(channel);
         }
 
         public static Guild MatchGuild(this Context ctx)

PluralKit.Core/Database/Wrappers/IPKCommand.cs

@@ -10,7 +10,7 @@ namespace PluralKit.Core
     {
         public Task PrepareAsync(CancellationToken ct = default);
         public Task<int> ExecuteNonQueryAsync(CancellationToken ct = default);
-        public Task<object> ExecuteScalarAsync(CancellationToken ct = default);
+        public Task<object?> ExecuteScalarAsync(CancellationToken ct = default);
         public Task<DbDataReader> ExecuteReaderAsync(CancellationToken ct = default);
         public Task<DbDataReader> ExecuteReaderAsync(CommandBehavior behavior, CancellationToken ct = default);
     }

PluralKit.Core/Database/Wrappers/PKCommand.cs

@@ -2,6 +2,7 @@
 using System;
 using System.Data;
 using System.Data.Common;
+using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -32,13 +33,14 @@ namespace PluralKit.Core
         }
 
         public override Task<int> ExecuteNonQueryAsync(CancellationToken ct) => LogQuery(Inner.ExecuteNonQueryAsync(ct));
-        public override Task<object> ExecuteScalarAsync(CancellationToken ct) => LogQuery(Inner.ExecuteScalarAsync(ct));
+        public override Task<object?> ExecuteScalarAsync(CancellationToken ct) => LogQuery(Inner.ExecuteScalarAsync(ct));
         protected override async Task<DbDataReader> ExecuteDbDataReaderAsync(CommandBehavior behavior, CancellationToken ct) => await LogQuery(Inner.ExecuteReaderAsync(behavior, ct));
 
         public override Task PrepareAsync(CancellationToken ct = default) => Inner.PrepareAsync(ct);
         public override void Cancel() => Inner.Cancel();
         protected override DbParameter CreateDbParameter() => Inner.CreateParameter();
 
+        [AllowNull]
         public override string CommandText
         {
             get => Inner.CommandText;

PluralKit.Core/Database/Wrappers/PKConnection.cs

@@ -2,6 +2,7 @@
 using System;
 using System.Data;
 using System.Data.Common;
+using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -73,13 +74,14 @@ namespace PluralKit.Core
         IDbTransaction IPKConnection.BeginTransaction() => throw SyncError(nameof(BeginTransaction));
         IDbTransaction IPKConnection.BeginTransaction(IsolationLevel level) => throw SyncError(nameof(BeginTransaction));
 
+        [AllowNull]
         public override string ConnectionString
         {
             get => Inner.ConnectionString;
             set => Inner.ConnectionString = value;
         }
 
-        public override string? Database => Inner.Database;
+        public override string Database => Inner.Database!;
         public override ConnectionState State => Inner.State;
         public override string DataSource => Inner.DataSource;
         public override string ServerVersion => Inner.ServerVersion;