Using pattern matching for nulls where applicable, discarded unused lambda parameters, cleaned up some classes. Unignored ServerLog commands which was mistakenly ignored due to a .gitignore rule

src/NadekoBot/Services/CommandHandler.cs

@@ -61,7 +61,7 @@ public class CommandHandler : INService
             GLOBAL_COMMANDS_COOLDOWN,
             GLOBAL_COMMANDS_COOLDOWN);
 
-        _prefixes = bot.AllGuildConfigs.Where(x => x.Prefix != null)
+        _prefixes = bot.AllGuildConfigs.Where(x => x.Prefix is not null)
                        .ToDictionary(x => x.GuildId, x => x.Prefix)
                        .ToConcurrent();
     }
@@ -111,7 +111,7 @@ public class CommandHandler : INService
 
     public async Task ExecuteExternal(ulong? guildId, ulong channelId, string commandText)
     {
-        if (guildId != null)
+        if (guildId is not null)
         {
             var guild = _client.GetGuild(guildId.Value);
             if (guild?.GetChannel(channelId) is not SocketTextChannel channel)
@@ -210,7 +210,7 @@ public class CommandHandler : INService
             {
 #if !GLOBAL_NADEKO
                 // track how many messagges each user is sending
-                UserMessagesSent.AddOrUpdate(usrMsg.Author.Id, 1, (key, old) => ++old);
+                UserMessagesSent.AddOrUpdate(usrMsg.Author.Id, 1, (_, old) => ++old);
 #endif
 
                 var channel = msg.Channel;
@@ -221,7 +221,7 @@ public class CommandHandler : INService
             catch (Exception ex)
             {
                 Log.Warning(ex, "Error in CommandHandler");
-                if (ex.InnerException != null)
+                if (ex.InnerException is not null)
                     Log.Warning(ex.InnerException, "Inner Exception of the error in CommandHandler");
             }
         });
@@ -260,10 +260,10 @@ public class CommandHandler : INService
                 return;
             }
 
-            if (error != null)
+            if (error is not null)
             {
                 LogErroredExecution(error, usrMsg, channel as ITextChannel, blockTime, startTime);
-                if (guild != null)
+                if (guild is not null)
                     await CommandErrored(info, channel as ITextChannel, error);
             }
         }
@@ -384,7 +384,7 @@ public class CommandHandler : INService
         var chosenOverload = successfulParses[0];
         var execResult = (ExecuteResult)await chosenOverload.Key.ExecuteAsync(context, chosenOverload.Value, services);
 
-        if (execResult.Exception != null
+        if (execResult.Exception is not null
             && (execResult.Exception is not HttpException he
                 || he.DiscordCode != DiscordErrorCode.InsufficientPermissions))
             Log.Warning(execResult.Exception, "Command Error");

src/NadekoBot/Services/Impl/Localization.cs

@@ -40,7 +40,7 @@ public class Localization : ILocalization, INService
 
                                                         return cultureInfo;
                                                     })
-                                                .Where(x => x.Value != null));
+                                                .Where(x => x.Value is not null));
     }
 
     public void SetGuildCulture(IGuild guild, CultureInfo ci)
@@ -61,7 +61,7 @@ public class Localization : ILocalization, INService
             uow.SaveChanges();
         }
 
-        GuildCultureInfos.AddOrUpdate(guildId, ci, (id, old) => ci);
+        GuildCultureInfos.AddOrUpdate(guildId, ci, (_, _) => ci);
     }
 
     public void RemoveGuildCulture(IGuild guild)

src/NadekoBot/Services/Impl/RedisCache.cs

@@ -38,7 +38,7 @@ public class RedisCache : IDataCache
     {
         var _db = Redis.GetDatabase();
         byte[] x = await _db.StringGetAsync("image_" + key);
-        return (x != null, x);
+        return (x is not null, x);
     }
 
     public Task SetImageDataAsync(Uri key, byte[] data)
@@ -51,7 +51,7 @@ public class RedisCache : IDataCache
     {
         var _db = Redis.GetDatabase();
         string x = await _db.StringGetAsync("anime_" + key);
-        return (x != null, x);
+        return (x is not null, x);
     }
 
     public Task SetAnimeDataAsync(string key, string data)
@@ -64,7 +64,7 @@ public class RedisCache : IDataCache
     {
         var _db = Redis.GetDatabase();
         string x = await _db.StringGetAsync("novel_" + key);
-        return (x != null, x);
+        return (x is not null, x);
     }
 
     public Task SetNovelDataAsync(string key, string data)
@@ -156,7 +156,7 @@ public class RedisCache : IDataCache
     public bool TryGetEconomy(out string data)
     {
         var _db = Redis.GetDatabase();
-        if ((data = _db.StringGet($"{_redisKey}_economy")) != null) return true;
+        if ((data = _db.StringGet($"{_redisKey}_economy")) is not null) return true;
 
         return false;
     }

src/NadekoBot/Services/Impl/StatsService.cs

@@ -132,7 +132,7 @@ public class StatsService : IStatsService, IReadyExecutor, INService, IDisposabl
             return Task.CompletedTask;
         };
 
-        _botlistTimer = new(async state =>
+        _botlistTimer = new(async _ =>
             {
                 if (string.IsNullOrWhiteSpace(_creds.BotListToken))
                     return;

src/NadekoBot/Services/Impl/YtdlOperation.cs

@@ -67,7 +67,7 @@ public class YtdlOperation
         process.Start();
 
         string line;
-        while ((line = await process.StandardOutput.ReadLineAsync()) != null)
+        while ((line = await process.StandardOutput.ReadLineAsync()) is not null)
             yield return line;
     }
 }