Clean up Message#mentions and message updates

src/structures/MessageMentions.js

@@ -0,0 +1,145 @@
+const Collection = require('../util/Collection');
+
+/**
+ * Keeps track of mentions in a {@link Message}
+ */
+class MessageMentions {
+  /**
+   * @param {Message} message Message to read mentions from
+   * @param {?Array<Object>} users Raw user objects from Discord
+   * @param {?Array<Object>} roles Raw role objects from Discord
+   * @param {?boolean} everyone Whether @everyone or @here were mentioned
+   * @private
+   */
+  constructor(message, users, roles, everyone) {
+    /**
+     * Whether `@everyone` or ``@here` were mentioned
+     * @type {boolean}
+     */
+    this.everyone = Boolean(everyone);
+
+    if (users) {
+      if (users instanceof Collection) {
+        /**
+         * Any users that were mentioned
+         * @type {Collection<Snowflake, User>}
+         */
+        this.users = new Collection(users);
+      } else {
+        this.users = new Collection();
+        for (const mention of users) {
+          let user = message.client.users.get(mention.id);
+          if (!user) user = message.client.dataManager.newUser(mention);
+          this.users.set(user.id, user);
+        }
+      }
+    } else {
+      this.users = new Collection();
+    }
+
+    if (roles) {
+      if (roles instanceof Collection) {
+        /**
+         * Any roles that were mentioned
+         * @type {Collection<Snowflake, Role>}
+         */
+        this.roles = new Collection(roles);
+      } else {
+        this.roles = new Collection();
+        for (const mention of roles) {
+          const role = message.channel.guild.roles.get(mention);
+          if (role) this.roles.set(role.id, role);
+        }
+      }
+    } else {
+      this.roles = new Collection();
+    }
+
+    /**
+     * Content of the message
+     * @type {Message}
+     * @private
+     */
+    this._content = message.content;
+
+    /**
+     * Guild the message is in
+     * @type {?Guild}
+     * @private
+     */
+    this._guild = message.channel.guild;
+
+    /**
+     * Cached members for {@MessageMention#members}
+     * @type {?Collection<Snowflake, GuildMember>}
+     * @private
+     */
+    this._members = null;
+
+    /**
+     * Cached channels for {@MessageMention#channels}
+     * @type {?Collection<Snowflake, GuildChannel>}
+     * @private
+     */
+    this._channels = null;
+  }
+
+  /**
+   * Any members that were mentioned (only in {@link TextChannel}s)
+   * @type {?Collection<Snowflake, GuildMember>}
+   * @readonly
+   */
+  get members() {
+    if (this._members) return this._members;
+    if (!this.guild) return null;
+    this._members = new Collection();
+    this.users.forEach(user => {
+      const member = this._guild.member(user);
+      if (member) this._members.set(member.user.id, member);
+    });
+    return this._members;
+  }
+
+  /**
+   * Any channels that were mentioned (only in {@link TextChannel}s)
+   * @type {?Collection<Snowflake, GuildChannel>}
+   * @readonly
+   */
+  get channels() {
+    if (this._channels) return this._channels;
+    if (!this.guild) return null;
+    this._channels = new Collection();
+    let matches;
+    while ((matches = this.constructor.CHANNELS_PATTERN.exec(this._content)) !== null) {
+      const chan = this._guild.channels.get(matches[1]);
+      if (chan) this._channels.set(chan.id, chan);
+    }
+    return this._channels;
+  }
+}
+
+/**
+ * Regular expression that globally matches `@everyone` and `@here`
+ * @type {RegExp}
+ */
+MessageMentions.EVERYONE_PATTERN = /@(everyone|here)/g;
+
+/**
+ * Regular expression that globally matches user mentions like `<#81440962496172032>`
+ * @type {RegExp}
+ */
+MessageMentions.USERS_PATTERN = /<@!?[0-9]+>/g;
+
+/**
+ * Regular expression that globally matches role mentions like `<@&297577916114403338>`
+ * @type {RegExp}
+ */
+MessageMentions.ROLES_PATTERN = /<@&[0-9]+>/g;
+
+/**
+ * Regular expression that globally matches channel mentions like `<#222079895583457280>`
+ * @type {RegExp}
+ */
+MessageMentions.CHANNELS_PATTERN = /<#([0-9]+)>/g;
+
+module.exports = MessageMentions;