Support the "Clear Reactions" endpoint

src/Discord.Net.Core/API/DiscordRestApiClient.cs

@@ -536,6 +536,17 @@ namespace Discord.API
 
             await SendAsync("DELETE", () => $"channels/{channelId}/messages/{messageId}/reactions/{emoji}/{userId}", ids, options: options).ConfigureAwait(false);
         }
+        public async Task RemoveAllReactionsAsync(ulong channelId, ulong messageId, RequestOptions options = null)
+        {
+            Preconditions.NotEqual(channelId, 0, nameof(channelId));
+            Preconditions.NotEqual(messageId, 0, nameof(messageId));
+
+            options = RequestOptions.CreateOrClone(options);
+
+            var ids = new BucketIds(channelId: channelId);
+
+            await SendAsync("DELETE", () => $"channels/{channelId}/messages/{messageId}/reactions", ids, options: options).ConfigureAwait(false);
+        }
         public async Task<IReadOnlyCollection<User>> GetReactionUsersAsync(ulong channelId, ulong messageId, string emoji, GetReactionUsersParams args, RequestOptions options = null)
         {
             Preconditions.NotEqual(channelId, 0, nameof(channelId));

src/Discord.Net.Core/Entities/Messages/IUserMessage.cs

@@ -25,6 +25,8 @@ namespace Discord
         Task RemoveReactionAsync(Emoji emoji, IUser user, RequestOptions options = null);
         /// <summary> Removes a reaction from this message. </summary>
         Task RemoveReactionAsync(string emoji, IUser user, RequestOptions options = null);
+        /// <summary> Removes all reactions from this message. </summary>
+        Task RemoveAllReactionsAsync(RequestOptions options = null);
         Task<IReadOnlyCollection<IUser>> GetReactionUsersAsync(string emoji, int limit = 100, ulong? afterUserId = null, RequestOptions options = null);
 
         /// <summary> Transforms this message's text into a human readable form by resolving its tags. </summary>

src/Discord.Net.Rest/Entities/Messages/MessageHelper.cs

@@ -38,6 +38,11 @@ namespace Discord.Rest
             await client.ApiClient.RemoveReactionAsync(msg.Channel.Id, msg.Id, user.Id, emoji, options).ConfigureAwait(false);
         }
 
+        public static async Task RemoveAllReactionsAsync(IMessage msg, BaseDiscordClient client, RequestOptions options)
+        {
+            await client.ApiClient.RemoveAllReactionsAsync(msg.Channel.Id, msg.Id, options);
+        }
+
         public static async Task<IReadOnlyCollection<IUser>> GetReactionUsersAsync(IMessage msg, string emoji,
             Action<GetReactionUsersParams> func, BaseDiscordClient client, RequestOptions options)
         {

src/Discord.Net.Rest/Entities/Messages/RestUserMessage.cs

@@ -142,6 +142,9 @@ namespace Discord.Rest
             => MessageHelper.RemoveReactionAsync(this, user, emoji, Discord, options);
         public Task RemoveReactionAsync(string emoji, IUser user, RequestOptions options = null)
             => MessageHelper.RemoveReactionAsync(this, user, emoji, Discord, options);
+
+        public Task RemoveAllReactionsAsync(RequestOptions options = null)
+            => MessageHelper.RemoveAllReactionsAsync(this, Discord, options);
         
         public Task<IReadOnlyCollection<IUser>> GetReactionUsersAsync(string emoji, int limit = 100, ulong? afterUserId = null, RequestOptions options = null)
             => MessageHelper.GetReactionUsersAsync(this, emoji, x => { x.Limit = limit; x.AfterUserId = afterUserId.HasValue ? afterUserId.Value : Optional.Create<ulong>(); }, Discord, options);

src/Discord.Net.Rpc/Entities/Messages/RpcUserMessage.cs

@@ -111,6 +111,9 @@ namespace Discord.Rpc
             => MessageHelper.RemoveReactionAsync(this, user, emoji, Discord, options);
         public Task RemoveReactionAsync(string emoji, IUser user, RequestOptions options = null)
             => MessageHelper.RemoveReactionAsync(this, user, emoji, Discord, options);
+
+        public Task RemoveAllReactionsAsync(RequestOptions options = null)
+            => MessageHelper.RemoveAllReactionsAsync(this, Discord, options);
         
         public Task<IReadOnlyCollection<IUser>> GetReactionUsersAsync(string emoji, int limit, ulong? afterUserId, RequestOptions options = null)
             => MessageHelper.GetReactionUsersAsync(this, emoji, x => { x.Limit = limit; x.AfterUserId = afterUserId.HasValue ? afterUserId.Value : Optional.Create<ulong>(); }, Discord, options);

src/Discord.Net.WebSocket/Entities/Messages/SocketUserMessage.cs

@@ -136,6 +136,9 @@ namespace Discord.WebSocket
         public Task RemoveReactionAsync(string emoji, IUser user, RequestOptions options = null)
             => MessageHelper.RemoveReactionAsync(this, user, emoji, Discord, options);
 
+        public Task RemoveAllReactionsAsync(RequestOptions options = null)
+            => MessageHelper.RemoveAllReactionsAsync(this, Discord, options);
+
         public Task<IReadOnlyCollection<IUser>> GetReactionUsersAsync(string emoji, int limit = 100, ulong? afterUserId = null, RequestOptions options = null)
             => MessageHelper.GetReactionUsersAsync(this, emoji, x => { x.Limit = limit; x.AfterUserId = afterUserId.HasValue ? afterUserId.Value : Optional.Create<ulong>(); }, Discord, options);