Clean up nearly all promises to utilise chaining, other small fixes

src/structures/MessageReaction.js

@@ -1,54 +1,6 @@
 const Collection = require('../util/Collection');
 const Emoji = require('./Emoji');
 
-/**
- * Represents a limited emoji set used for both custom and unicode emojis. Custom emojis
- * will use this class opposed to the Emoji class when the client doesn't know enough
- * information about them.
- */
-class ReactionEmoji {
-  constructor(reaction, name, id) {
-    /**
-     * The message reaction this emoji refers to
-     * @type {MessageReaction}
-     */
-    this.reaction = reaction;
-    /**
-     * The name of this reaction emoji.
-     * @type {string}
-     */
-    this.name = name;
-    /**
-     * The ID of this reaction emoji.
-     * @type {string}
-     */
-    this.id = id;
-  }
-
-  /**
-   * The identifier of this emoji, used for message reactions
-   * @readonly
-   * @type {string}
-   */
-  get identifier() {
-    if (this.id) {
-      return `${this.name}:${this.id}`;
-    }
-    return encodeURIComponent(this.name);
-  }
-
-  /**
-   * Creates the text required to form a graphical emoji on Discord.
-   * @example
-   * // send the emoji used in a reaction to the channel the reaction is part of
-   * reaction.message.channel.sendMessage(`The emoji used is ${reaction.emoji}`);
-   * @returns {string}
-   */
-  toString() {
-    return this.id ? `<:${this.name}:${this.id}>` : this.name;
-  }
-}
-
 /**
  * Represents a reaction to a message
  */
@@ -59,22 +11,26 @@ class MessageReaction {
      * @type {Message}
      */
     this.message = message;
+
     /**
      * Whether the client has given this reaction
      * @type {boolean}
      */
     this.me = me;
-    this._emoji = new ReactionEmoji(this, emoji.name, emoji.id);
+
     /**
      * The number of people that have given the same reaction.
      * @type {number}
      */
     this.count = count || 0;
+
     /**
      * The users that have given this reaction, mapped by their ID.
      * @type {Collection<string, User>}
      */
     this.users = new Collection();
+
+    this._emoji = new ReactionEmoji(this, emoji.name, emoji.id);
   }
 
   /**
@@ -83,9 +39,7 @@ class MessageReaction {
    * @type {Emoji|ReactionEmoji}
    */
   get emoji() {
-    if (this._emoji instanceof Emoji) {
-      return this._emoji;
-    }
+    if (this._emoji instanceof Emoji) return this._emoji;
     // check to see if the emoji has become known to the client
     if (this._emoji.id) {
       const emojis = this.message.client.emojis;
@@ -106,11 +60,10 @@ class MessageReaction {
   remove(user = this.message.client.user) {
     const message = this.message;
     user = this.message.client.resolver.resolveUserID(user);
-
-    if (!user) return Promise.reject('A UserIDResolvable is required (string, user, member, message, guild)');
-
+    if (!user) return Promise.reject('Couldn\'t resolve the user ID to remove from the reaction.');
     return message.client.rest.methods.removeMessageReaction(
-      message.channel.id, message.id, this.emoji.identifier, user);
+      message.channel.id, message.id, this.emoji.identifier, user
+    );
   }
 
   /**
@@ -121,19 +74,66 @@ class MessageReaction {
    */
   fetchUsers(limit = 100) {
     const message = this.message;
-    return new Promise((resolve, reject) => {
-      message.client.rest.methods.getMessageReactionUsers(message.channel.id, message.id, this.emoji.identifier, limit)
-        .then(users => {
-          this.users = new Collection();
-          for (const rawUser of users) {
-            const user = this.message.client.dataManager.newUser(rawUser);
-            this.users.set(user.id, user);
-          }
-          this.count = this.users.size;
-          resolve(this.users);
-        }, reject);
+    return message.client.rest.methods.getMessageReactionUsers(
+      message.channel.id, message.id, this.emoji.identifier, limit
+    ).then(users => {
+      this.users = new Collection();
+      for (const rawUser of users) {
+        const user = this.message.client.dataManager.newUser(rawUser);
+        this.users.set(user.id, user);
+      }
+      this.count = this.users.size;
+      return users;
     });
   }
 }
 
+/**
+ * Represents a limited emoji set used for both custom and unicode emojis. Custom emojis
+ * will use this class opposed to the Emoji class when the client doesn't know enough
+ * information about them.
+ */
+class ReactionEmoji {
+  constructor(reaction, name, id) {
+    /**
+     * The message reaction this emoji refers to
+     * @type {MessageReaction}
+     */
+    this.reaction = reaction;
+
+    /**
+     * The name of this reaction emoji.
+     * @type {string}
+     */
+    this.name = name;
+
+    /**
+     * The ID of this reaction emoji.
+     * @type {string}
+     */
+    this.id = id;
+  }
+
+  /**
+   * The identifier of this emoji, used for message reactions
+   * @readonly
+   * @type {string}
+   */
+  get identifier() {
+    if (this.id) return `${this.name}:${this.id}`;
+    return encodeURIComponent(this.name);
+  }
+
+  /**
+   * Creates the text required to form a graphical emoji on Discord.
+   * @example
+   * // send the emoji used in a reaction to the channel the reaction is part of
+   * reaction.message.channel.sendMessage(`The emoji used is ${reaction.emoji}`);
+   * @returns {string}
+   */
+  toString() {
+    return this.id ? `<:${this.name}:${this.id}>` : this.name;
+  }
+}
+
 module.exports = MessageReaction;