fix guild member fetching edge cases (#1115)

* thx4tipprogrammixluvubye

* consistancy

* make this loop for some reason

* so impatient

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

@@ -1,7 +1,7 @@
-// ##untested##
-
 const AbstractHandler = require('./AbstractHandler');
 const Constants = require('../../../../util/Constants');
+// uncomment in v12
+// const Collection = require('../../../../util/Collection');
 
 class GuildMembersChunkHandler extends AbstractHandler {
   handle(packet) {
@@ -10,9 +10,13 @@ class GuildMembersChunkHandler extends AbstractHandler {
     const guild = client.guilds.get(data.guild_id);
     if (!guild) return;
 
+    // uncomment in v12
+    // const members = new Collection();
+    //
+    // for (const member of data.members) members.set(member.id, guild._addMember(member, false));
+
     const members = data.members.map(member => guild._addMember(member, false));
 
-    guild._checkChunks();
     client.emit(Constants.Events.GUILD_MEMBERS_CHUNK, members);
 
     client.ws.lastHeartbeatAck = true;
@@ -22,7 +26,7 @@ class GuildMembersChunkHandler extends AbstractHandler {
 /**
  * Emitted whenever a chunk of guild members is received (all members come from the same guild)
  * @event Client#guildMembersChunk
- * @param {GuildMember[]} members The members in the chunk
+ * @param {Collection<GuildMember>} members The members in the chunk
  */
 
 module.exports = GuildMembersChunkHandler;

src/structures/Guild.js

@@ -337,7 +337,6 @@ class Guild {
    * @returns {Promise<GuildMember>}
    */
   fetchMember(user, cache = true) {
-    if (this._fetchWaiter) return Promise.reject(new Error('Already fetching guild members.'));
     user = this.client.resolver.resolveUser(user);
     if (!user) return Promise.reject(new Error('User is not cached. Use Client.fetchUser first.'));
     if (this.members.has(user.id)) return Promise.resolve(this.members.get(user.id));
@@ -347,17 +346,17 @@ class Guild {
   /**
    * Fetches all the members in the guild, even if they are offline. If the guild has less than 250 members,
    * this should not be necessary.
-   * @param {string} [query=''] An optional query to provide when fetching members
+   * @param {string} [query=''] Limit fetch to members with similar usernames
    * @returns {Promise<Guild>}
    */
   fetchMembers(query = '') {
     return new Promise((resolve, reject) => {
-      if (this._fetchWaiter) throw new Error(`Already fetching guild members in ${this.id}.`);
       if (this.memberCount === this.members.size) {
+        // uncomment in v12
+        // resolve(this.members)
         resolve(this);
         return;
       }
-      this._fetchWaiter = resolve;
       this.client.ws.send({
         op: Constants.OPCodes.REQUEST_GUILD_MEMBERS,
         d: {
@@ -366,7 +365,17 @@ class Guild {
           limit: 0,
         },
       });
-      this._checkChunks();
+      const handler = (members, guild) => {
+        if (guild.id !== this.id) return;
+        if (this.memberCount === this.members.size) {
+          this.client.removeListener(Constants.Events.GUILD_MEMBERS_CHUNK, handler);
+          // uncomment in v12
+          // resolve(this.members)
+          resolve(this);
+          return;
+        }
+      };
+      this.client.on(Constants.Events.GUILD_MEMBERS_CHUNK, handler);
       this.client.setTimeout(() => reject(new Error('Members didn\'t arrive in time.')), 120 * 1000);
     });
   }
@@ -812,7 +821,6 @@ class Guild {
       this.client.emit(Constants.Events.GUILD_MEMBER_ADD, member);
     }
 
-    this._checkChunks();
     return member;
   }
 
@@ -842,7 +850,6 @@ class Guild {
 
   _removeMember(guildMember) {
     this.members.delete(guildMember.id);
-    this._checkChunks();
   }
 
   _memberSpeakUpdate(user, speaking) {
@@ -866,15 +873,6 @@ class Guild {
     }
     this.presences.set(id, new Presence(presence));
   }
-
-  _checkChunks() {
-    if (this._fetchWaiter) {
-      if (this.members.size === this.memberCount) {
-        this._fetchWaiter(this);
-        this._fetchWaiter = null;
-      }
-    }
-  }
 }
 
 module.exports = Guild;