Refactor Sentry scope enrichment

PluralKit.Bot/Bot.cs

@@ -47,6 +47,8 @@ namespace PluralKit.Bot
             _client.DebugLogger.LogMessageReceived += FrameworkLog;
             
             // HandleEvent takes a type parameter, automatically inferred by the event type
+            // It will then look up an IEventHandler<TypeOfEvent> in the DI container and call that object's handler method
+            // For registering new ones, see Modules.cs 
             _client.MessageCreated += HandleEvent;
             _client.MessageDeleted += HandleEvent;
             _client.MessageUpdated += HandleEvent;
@@ -69,8 +71,14 @@ namespace PluralKit.Bot
             async Task HandleEventInner()
             {
                 var serviceScope = _services.BeginLifetimeScope();
+                
+                // Find an event handler that can handle the type of event (<T>) we're given
                 var handler = serviceScope.Resolve<IEventHandler<T>>();
-
+                
+                // Also, find a Sentry enricher for the event type (if one is present), and ask it to put some event data in the Sentry scope
+                var sentryEnricher = serviceScope.ResolveOptional<ISentryEnricher<T>>();
+                sentryEnricher?.Enrich(serviceScope.Resolve<Scope>(), evt);
+                
                 try
                 {
                     await handler.Handle(evt);

PluralKit.Bot/Handlers/MessageCreated.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 using System.Threading.Tasks;
 
 using App.Metrics;
@@ -129,21 +128,6 @@ namespace PluralKit.Bot
         {
             _metrics.Measure.Meter.Mark(BotMetrics.MessagesReceived);
             _lastMessageCache.AddMessage(evt.Channel.Id, evt.Message.Id);
-            
-            // Add message info as Sentry breadcrumb
-            _sentryScope.AddBreadcrumb(evt.Message.Content, "event.message", data: new Dictionary<string, string>
-            {
-                {"user", evt.Author.Id.ToString()},
-                {"channel", evt.Channel.Id.ToString()},
-                {"guild", evt.Channel.GuildId.ToString()},
-                {"message", evt.Message.Id.ToString()},
-            });
-            _sentryScope.SetTag("shard", evt.Client.ShardId.ToString());
-            
-            // Also report information about the bot's permissions in the channel
-            // We get a lot of permission errors so this'll be useful for determining problems
-            var perms = evt.Channel.BotPermissions();
-            _sentryScope.AddBreadcrumb(perms.ToPermissionString(), "permissions");
         }
     }
 }

PluralKit.Bot/Handlers/MessageDeleted.cs

@@ -12,37 +12,19 @@ namespace PluralKit.Bot
     public class MessageDeleted: IEventHandler<MessageDeleteEventArgs>, IEventHandler<MessageBulkDeleteEventArgs>
     {
         private readonly ProxyService _proxy;
-        private readonly Scope _sentryScope;
 
-        public MessageDeleted(Scope sentryScope, ProxyService proxy)
+        public MessageDeleted(ProxyService proxy)
         {
-            _sentryScope = sentryScope;
             _proxy = proxy;
         }
         
         public Task Handle(MessageDeleteEventArgs evt)
         {
-            _sentryScope.AddBreadcrumb("", "event.messageDelete", data: new Dictionary<string, string>()
-            {
-                {"channel", evt.Channel.Id.ToString()},
-                {"guild", evt.Channel.GuildId.ToString()},
-                {"message", evt.Message.Id.ToString()},
-            });
-            _sentryScope.SetTag("shard", evt.Client.ShardId.ToString());
-
             return _proxy.HandleMessageDeletedAsync(evt);
         }
 
         public Task Handle(MessageBulkDeleteEventArgs evt)
         {
-            _sentryScope.AddBreadcrumb("", "event.messageDelete", data: new Dictionary<string, string>()
-            {
-                {"channel", evt.Channel.Id.ToString()},
-                {"guild", evt.Channel.Id.ToString()},
-                {"messages", string.Join(",", evt.Messages.Select(m => m.Id))},
-            });
-            _sentryScope.SetTag("shard", evt.Client.ShardId.ToString());
-
             return _proxy.HandleMessageBulkDeleteAsync(evt);
         }
     }

PluralKit.Bot/Handlers/MessageEdited.cs

@@ -35,14 +35,6 @@ namespace PluralKit.Bot
             
             // Also, if this is in DMs don't bother either
             if (evt.Channel.Guild == null) return;
-            
-            _sentryScope.AddBreadcrumb(evt.Message.Content ?? "<unknown>", "event.messageEdit", data: new Dictionary<string, string>()
-            {
-                {"channel", evt.Channel.Id.ToString()},
-                {"guild", evt.Channel.GuildId.ToString()},
-                {"message", evt.Message.Id.ToString()}
-            });
-            _sentryScope.SetTag("shard", evt.Client.ShardId.ToString());
 
             // If this isn't the last message in the channel, don't do anything
             if (_lastMessageCache.GetLastMessage(evt.Channel.Id) != evt.Message.Id) return;

PluralKit.Bot/Handlers/ReactionAdded.cs

@@ -10,25 +10,14 @@ namespace PluralKit.Bot
     public class ReactionAdded: IEventHandler<MessageReactionAddEventArgs>
     {
         private readonly ProxyService _proxy;
-        private readonly Scope _sentryScope;
 
-        public ReactionAdded(ProxyService proxy, Scope sentryScope)
+        public ReactionAdded(ProxyService proxy)
         {
             _proxy = proxy;
-            _sentryScope = sentryScope;
         }
 
         public Task Handle(MessageReactionAddEventArgs evt)
         {
-            _sentryScope.AddBreadcrumb("", "event.reaction", data: new Dictionary<string, string>()
-            {
-                {"user", evt.User.Id.ToString()},
-                {"channel", (evt.Channel?.Id ?? 0).ToString()},
-                {"guild", (evt.Channel?.GuildId ?? 0).ToString()},
-                {"message", evt.Message.Id.ToString()},
-                {"reaction", evt.Emoji.Name}
-            });
-            _sentryScope.SetTag("shard", evt.Client.ShardId.ToString());
             return _proxy.HandleReactionAddedAsync(evt);
         }
     }

PluralKit.Bot/Modules.cs

@@ -69,6 +69,13 @@ namespace PluralKit.Bot
             
             // Sentry stuff
             builder.Register(_ => new Scope(null)).AsSelf().InstancePerLifetimeScope();
+            builder.RegisterType<SentryEnricher>()
+                .As<ISentryEnricher<MessageCreateEventArgs>>()
+                .As<ISentryEnricher<MessageDeleteEventArgs>>()
+                .As<ISentryEnricher<MessageUpdateEventArgs>>()
+                .As<ISentryEnricher<MessageBulkDeleteEventArgs>>()
+                .As<ISentryEnricher<MessageReactionAddEventArgs>>()
+                .SingleInstance();
 
             // Utils
             builder.Register(c => new HttpClient

PluralKit.Bot/Utils/SentryUtils.cs

@@ -0,0 +1,93 @@
+using System.Collections.Generic;
+using System.Linq;
+
+using DSharpPlus;
+using DSharpPlus.EventArgs;
+
+using Sentry;
+
+namespace PluralKit.Bot
+{
+    public interface ISentryEnricher<T> where T: DiscordEventArgs
+    {
+        void Enrich(Scope scope, T evt);
+    }
+
+    public class SentryEnricher:
+        ISentryEnricher<MessageCreateEventArgs>,
+        ISentryEnricher<MessageDeleteEventArgs>,
+        ISentryEnricher<MessageUpdateEventArgs>,
+        ISentryEnricher<MessageBulkDeleteEventArgs>,
+        ISentryEnricher<MessageReactionAddEventArgs>
+    {
+        // TODO: should this class take the Scope by dependency injection instead?
+        // Would allow us to create a centralized "chain of handlers" where this class could just be registered as an entry in
+        
+        public void Enrich(Scope scope, MessageCreateEventArgs evt)
+        {
+            scope.AddBreadcrumb(evt.Message.Content, "event.message", data: new Dictionary<string, string>
+            {
+                {"user", evt.Author.Id.ToString()},
+                {"channel", evt.Channel.Id.ToString()},
+                {"guild", evt.Channel.GuildId.ToString()},
+                {"message", evt.Message.Id.ToString()},
+            });
+            scope.SetTag("shard", evt.Client.ShardId.ToString());
+
+            // Also report information about the bot's permissions in the channel
+            // We get a lot of permission errors so this'll be useful for determining problems
+            var perms = evt.Channel.BotPermissions();
+            scope.AddBreadcrumb(perms.ToPermissionString(), "permissions");
+        }
+
+        public void Enrich(Scope scope, MessageDeleteEventArgs evt)
+        {
+            scope.AddBreadcrumb("", "event.messageDelete",
+                data: new Dictionary<string, string>()
+                {
+                    {"channel", evt.Channel.Id.ToString()},
+                    {"guild", evt.Channel.GuildId.ToString()},
+                    {"message", evt.Message.Id.ToString()},
+                });
+            scope.SetTag("shard", evt.Client.ShardId.ToString());
+        }
+
+        public void Enrich(Scope scope, MessageUpdateEventArgs evt)
+        {
+            scope.AddBreadcrumb(evt.Message.Content ?? "<unknown>", "event.messageEdit",
+                data: new Dictionary<string, string>()
+                {
+                    {"channel", evt.Channel.Id.ToString()},
+                    {"guild", evt.Channel.GuildId.ToString()},
+                    {"message", evt.Message.Id.ToString()}
+                });
+            scope.SetTag("shard", evt.Client.ShardId.ToString());
+        }
+
+        public void Enrich(Scope scope, MessageBulkDeleteEventArgs evt)
+        {
+            scope.AddBreadcrumb("", "event.messageDelete",
+                data: new Dictionary<string, string>()
+                {
+                    {"channel", evt.Channel.Id.ToString()},
+                    {"guild", evt.Channel.Id.ToString()},
+                    {"messages", string.Join(",", evt.Messages.Select(m => m.Id))},
+                });
+            scope.SetTag("shard", evt.Client.ShardId.ToString());
+        }
+
+        public void Enrich(Scope scope, MessageReactionAddEventArgs evt)
+        {
+            scope.AddBreadcrumb("", "event.reaction",
+                data: new Dictionary<string, string>()
+                {
+                    {"user", evt.User.Id.ToString()},
+                    {"channel", (evt.Channel?.Id ?? 0).ToString()},
+                    {"guild", (evt.Channel?.GuildId ?? 0).ToString()},
+                    {"message", evt.Message.Id.ToString()},
+                    {"reaction", evt.Emoji.Name}
+                });
+            scope.SetTag("shard", evt.Client.ShardId.ToString());
+        }
+    }
+}