feat(MessageReaction): backport removeAll and MessageReactionRemoveEmoji event (#3741)

* Add new action and websocket handler

* Add REST method for removing reaction emoji

* Update Message#_removeReaction to handle removing whole emoji

* Add MessageReaction#removeAll and update typings

* Apply uncached user fix

src/client/actions/ActionsManager.js

@@ -8,6 +8,7 @@ class ActionsManager {
     this.register(require('./MessageUpdate'));
     this.register(require('./MessageReactionAdd'));
     this.register(require('./MessageReactionRemove'));
+    this.register(require('./MessageReactionRemoveEmoji'));
     this.register(require('./MessageReactionRemoveAll'));
     this.register(require('./ChannelCreate'));
     this.register(require('./ChannelDelete'));

src/client/actions/MessageReactionRemoveEmoji.js

@@ -0,0 +1,27 @@
+const Action = require('./Action');
+const Constants = require('../../util/Constants');
+
+class MessageReactionRemoveEmoji extends Action {
+  handle(data) {
+    // Verify channel
+    const channel = this.client.channels.get(data.channel_id);
+    if (!channel || channel.type === 'voice') return false;
+    // Verify message
+    const message = channel.messages.get(data.message_id);
+    if (!message) return false;
+    if (!data.emoji) return false;
+    // Verify reaction
+    const reaction = message._removeReaction(data.emoji);
+    if (reaction) this.client.emit(Constants.Events.MESSAGE_REACTION_REMOVE_EMOJI, reaction);
+
+    return { message, reaction };
+  }
+}
+
+/**
+ * Emitted whenever a reaction emoji is removed from a cached message.
+ * @event Client#messageReactionRemoveEmoji
+ * @param {MessageReaction} messageReaction The reaction object
+ */
+
+module.exports = MessageReactionRemoveEmoji;

src/client/rest/RESTMethods.js

@@ -945,6 +945,17 @@ class RESTMethods {
     );
   }
 
+  removeMessageReactionEmoji(message, emoji) {
+    const endpoint = Endpoints.Message(message).Reaction(emoji);
+    return this.rest.makeRequest('delete', endpoint, true).then(() =>
+      this.client.actions.MessageReactionRemoveEmoji.handle({
+        message_id: message.id,
+        emoji: Util.parseEmoji(emoji),
+        channel_id: message.channel.id,
+      }).reaction
+    );
+  }
+
   removeMessageReactions(message) {
     return this.rest.makeRequest('delete', Endpoints.Message(message).reactions, true)
       .then(() => message);

src/client/websocket/packets/WebSocketPacketManager.js

@@ -55,6 +55,7 @@ class WebSocketPacketManager {
     this.register(Constants.WSEvents.RELATIONSHIP_REMOVE, require('./handlers/RelationshipRemove'));
     this.register(Constants.WSEvents.MESSAGE_REACTION_ADD, require('./handlers/MessageReactionAdd'));
     this.register(Constants.WSEvents.MESSAGE_REACTION_REMOVE, require('./handlers/MessageReactionRemove'));
+    this.register(Constants.WSEvents.MESSAGE_REACTION_REMOVE, require('./handlers/MessageReactionRemoveEmoji'));
     this.register(Constants.WSEvents.MESSAGE_REACTION_REMOVE_ALL, require('./handlers/MessageReactionRemoveAll'));
     this.register(Constants.WSEvents.WEBHOOKS_UPDATE, require('./handlers/WebhooksUpdate'));
   }

src/client/websocket/packets/handlers/MessageReactionRemoveEmoji.js

@@ -0,0 +1,11 @@
+const AbstractHandler = require('./AbstractHandler');
+
+class MessageReactionRemoveEmoji extends AbstractHandler {
+  handle(packet) {
+    const client = this.packetManager.client;
+    const data = packet.d;
+    client.actions.MessageReactionRemoveEmoji.handle(data);
+  }
+}
+
+module.exports = MessageReactionRemoveEmoji;

src/structures/Message.js

@@ -590,6 +590,10 @@ class Message {
     const emojiID = emoji.id ? `${emoji.name}:${emoji.id}` : emoji.name;
     if (this.reactions.has(emojiID)) {
       const reaction = this.reactions.get(emojiID);
+      if (!user) {
+        this.reactions.delete(emojiID);
+        return reaction;
+      }
       if (reaction.users.has(user.id)) {
         reaction.users.delete(user.id);
         reaction.count--;

src/structures/MessageReaction.js

@@ -69,6 +69,17 @@ class MessageReaction {
     );
   }
 
+  /**
+   * Removes this reaction from the message
+   * @returns {Promise<MessageReaction>}
+   */
+  removeAll() {
+    const message = this.message;
+    return message.client.rest.methods.removeMessageReactionEmoji(
+      message, this.emoji.identifier
+    );
+  }
+
   /**
    * Fetch all the users that gave this reaction. Resolves with a collection of users, mapped by their IDs.
    * @param {number} [limit=100] The maximum amount of users to fetch, defaults to 100

src/util/Constants.js

@@ -349,6 +349,7 @@ exports.Events = {
   MESSAGE_BULK_DELETE: 'messageDeleteBulk',
   MESSAGE_REACTION_ADD: 'messageReactionAdd',
   MESSAGE_REACTION_REMOVE: 'messageReactionRemove',
+  MESSAGE_REACTION_REMOVE_EMOJI: 'messageReactionRemoveEmoji',
   MESSAGE_REACTION_REMOVE_ALL: 'messageReactionRemoveAll',
   USER_UPDATE: 'userUpdate',
   USER_NOTE_UPDATE: 'userNoteUpdate',
@@ -418,6 +419,7 @@ exports.ActivityFlags = {
  * * MESSAGE_DELETE_BULK
  * * MESSAGE_REACTION_ADD
  * * MESSAGE_REACTION_REMOVE
+ * * MESSAGE_REACTION_REMOVE_EMOJI
  * * MESSAGE_REACTION_REMOVE_ALL
  * * USER_UPDATE
  * * USER_NOTE_UPDATE
@@ -461,6 +463,7 @@ exports.WSEvents = {
   MESSAGE_DELETE_BULK: 'MESSAGE_DELETE_BULK',
   MESSAGE_REACTION_ADD: 'MESSAGE_REACTION_ADD',
   MESSAGE_REACTION_REMOVE: 'MESSAGE_REACTION_REMOVE',
+  MESSAGE_REACTION_RMEOVE_EMOJI: 'MESSAGE_REACTION_REMOVE_EMOJI',
   MESSAGE_REACTION_REMOVE_ALL: 'MESSAGE_REACTION_REMOVE_ALL',
   USER_UPDATE: 'USER_UPDATE',
   USER_NOTE_UPDATE: 'USER_NOTE_UPDATE',

typings/index.d.ts

@@ -138,6 +138,7 @@ declare module 'discord.js' {
 		public on(event: 'messageDeleteBulk', listener: (messages: Collection<Snowflake, Message>) => void): this;
 		public on(event: 'messageReactionAdd', listener: (messageReaction: MessageReaction, user: User) => void): this;
 		public on(event: 'messageReactionRemove', listener: (messageReaction: MessageReaction, user: User) => void): this;
+		public on(event: 'messageReactionRemoveEmoji', listener: (messageReaction: MessageReaction) => void): this;
 		public on(event: 'messageReactionRemoveAll', listener: (message: Message) => void): this;
 		public on(event: 'messageUpdate', listener: (oldMessage: Message, newMessage: Message) => void): this;
 		public on(event: 'presenceUpdate', listener: (oldMember: GuildMember, newMember: GuildMember) => void): this;
@@ -187,6 +188,7 @@ declare module 'discord.js' {
 		public once(event: 'messageDeleteBulk', listener: (messages: Collection<Snowflake, Message>) => void): this;
 		public once(event: 'messageReactionAdd', listener: (messageReaction: MessageReaction, user: User) => void): this;
 		public once(event: 'messageReactionRemove', listener: (messageReaction: MessageReaction, user: User) => void): this;
+		public once(event: 'messageReactionRemoveEmoji', listener: (messageReaction: MessageReaction) => void): this;
 		public once(event: 'messageReactionRemoveAll', listener: (message: Message) => void): this;
 		public once(event: 'messageUpdate', listener: (oldMessage: Message, newMessage: Message) => void): this;
 		public once(event: 'presenceUpdate', listener: (oldMember: GuildMember, newMember: GuildMember) => void): this;
@@ -919,6 +921,7 @@ declare module 'discord.js' {
 		public users: Collection<string, User>;
 		public fetchUsers(limit?: number, options?: { after?: number; before?: number }): Promise<Collection<Snowflake, User>>;
 		public remove(user?: UserResolvable): Promise<MessageReaction>;
+		public removeAll(): Promise<MessageReaction>;
 	}
 
 	export class NewsChannel extends TextChannel {