Merge branch 'release/3.x' into dnet-staging

src/Discord.Net.Rest/API/Rest/CreateWebhookMessageParams.cs

@@ -13,7 +13,7 @@ namespace Discord.API.Rest
         private static JsonSerializer _serializer = new JsonSerializer { ContractResolver = new DiscordContractResolver() };
 
         [JsonProperty("content")]
-        public string Content { get; set;  }
+        public Optional<string> Content { get; set;  }
 
         [JsonProperty("nonce")]
         public Optional<string> Nonce { get; set; }

src/Discord.Net.Rest/DiscordRestApiClient.cs

@@ -786,8 +786,9 @@ namespace Discord.API
             if (!args.Embeds.IsSpecified || args.Embeds.Value == null || args.Embeds.Value.Length == 0)
                 Preconditions.NotNullOrEmpty(args.Content, nameof(args.Content));
 
-            if (args.Content?.Length > DiscordConfig.MaxMessageSize)
+            if (args.Content.IsSpecified && args.Content.Value?.Length > DiscordConfig.MaxMessageSize)
                 throw new ArgumentException(message: $"Message content is too long, length must be less or equal to {DiscordConfig.MaxMessageSize}.", paramName: nameof(args.Content));
+
             options = RequestOptions.CreateOrClone(options);
 
             var ids = new BucketIds(webhookId: webhookId);
@@ -1336,7 +1337,7 @@ namespace Discord.API
             if ((!args.Embeds.IsSpecified || args.Embeds.Value == null || args.Embeds.Value.Length == 0) && !args.File.IsSpecified)
                 Preconditions.NotNullOrEmpty(args.Content, nameof(args.Content));
 
-            if (args.Content?.Length > DiscordConfig.MaxMessageSize)
+            if(args.Content.IsSpecified && args.Content.Value?.Length > DiscordConfig.MaxMessageSize)
                 throw new ArgumentException(message: $"Message content is too long, length must be less or equal to {DiscordConfig.MaxMessageSize}.", paramName: nameof(args.Content));
 
             options = RequestOptions.CreateOrClone(options);

src/Discord.Net.Rest/Entities/Interactions/CommandBase/RestCommandBase.cs

@@ -115,7 +115,7 @@ namespace Discord.Rest
                 Type = InteractionResponseType.ChannelMessageWithSource,
                 Data = new API.InteractionCallbackData
                 {
-                    Content = text,
+                    Content = text ?? Optional<string>.Unspecified,
                     AllowedMentions = allowedMentions?.ToModel() ?? Optional<API.AllowedMentions>.Unspecified,
                     Embeds = embeds.Select(x => x.ToModel()).ToArray(),
                     TTS = isTTS,

src/Discord.Net.WebSocket/Entities/Interaction/SocketBaseCommand/SocketCommandBase.cs

@@ -114,7 +114,7 @@ namespace Discord.WebSocket
                 Type = InteractionResponseType.ChannelMessageWithSource,
                 Data = new API.InteractionCallbackData
                 {
-                    Content = text,
+                    Content = text ?? Optional<string>.Unspecified,
                     AllowedMentions = allowedMentions?.ToModel() ?? Optional<API.AllowedMentions>.Unspecified,
                     Embeds = embeds.Select(x => x.ToModel()).ToArray(),
                     TTS = isTTS,
@@ -168,7 +168,7 @@ namespace Discord.WebSocket
 
             var args = new API.Rest.CreateWebhookMessageParams
             {
-                Content = text,
+                Content = text ?? Optional<string>.Unspecified,
                 AllowedMentions = allowedMentions?.ToModel() ?? Optional<API.AllowedMentions>.Unspecified,
                 IsTTS = isTTS,
                 Embeds = embeds.Select(x => x.ToModel()).ToArray(),