option to dump gw payloads on errors (#2999)

* option to dump gw payloads on errors

* w a r n i n g

src/Discord.Net.WebSocket/DiscordSocketClient.cs

@@ -83,6 +83,7 @@ namespace Discord.WebSocket
         internal bool AlwaysResolveStickers { get; private set; }
         internal bool LogGatewayIntentWarnings { get; private set; }
         internal bool SuppressUnknownDispatchWarnings { get; private set; }
+        internal bool IncludeRawPayloadOnGatewayErrors { get; private set; }
         internal int AuditLogCacheSize { get; private set; }
 
         internal new DiscordSocketApiClient ApiClient => base.ApiClient;
@@ -158,6 +159,7 @@ namespace Discord.WebSocket
             AlwaysResolveStickers = config.AlwaysResolveStickers;
             LogGatewayIntentWarnings = config.LogGatewayIntentWarnings;
             SuppressUnknownDispatchWarnings = config.SuppressUnknownDispatchWarnings;
+            IncludeRawPayloadOnGatewayErrors = config.IncludeRawPayloadOnGatewayErrors;
             HandlerTimeout = config.HandlerTimeout;
             State = new ClientState(0, 0);
             Rest = new DiscordSocketRestClient(config, ApiClient);
@@ -3342,6 +3344,13 @@ namespace Discord.WebSocket
             }
             catch (Exception ex)
             {
+                if (IncludeRawPayloadOnGatewayErrors)
+                {
+                    ex.Data["opcode"] = opCode;
+                    ex.Data["type"] = type;
+                    ex.Data["payload_data"] = (payload as JToken).ToString();
+                }
+
                 await _gatewayLogger.ErrorAsync($"Error handling {opCode}{(type != null ? $" ({type})" : "")}", ex).ConfigureAwait(false);
             }
         }

src/Discord.Net.WebSocket/DiscordSocketConfig.cs

@@ -176,6 +176,15 @@ namespace Discord.WebSocket
             }
         }
 
+        /// <summary>
+        ///     Gets or sets whether or not to include the raw payload on gateway errors.
+        /// </summary>
+        /// <remarks>
+        ///     Note that this may expose sensitive information to logs. It is recommended to only enable this in
+        ///     cases where you are actively debugging an issue.
+        /// </remarks>
+        public bool IncludeRawPayloadOnGatewayErrors { get; set; } = false;
+
         private int maxWaitForGuildAvailable = 10000;
 
         /// <summary>