Fix IRC quit messages sending to all channels by tracking users

Keep a list of users in each channel, using the names event
in addition to the join/part events, so as to prevent spamming
unnecessary channels when the quit event is raised with all
channels from a server.

Fixes #213.

lib/bot.js

@@ -57,6 +57,9 @@ class Bot {
     // ircChannel: IRC channel (e.g. #irc)
     this.formatDiscord = this.format.discord || '**<{$author}>** {$withMentions}';
 
+    // Keep track of { channel => [list, of, usernames] } for ircStatusNotices
+    this.channelUsers = {};
+
     this.channelMapping = {};
 
     // Remove channel passwords from the mapping and lowercase IRC channel names
@@ -125,21 +128,38 @@ class Bot {
     this.ircClient.on('join', (channel, nick) => {
       if (!this.ircStatusNotices) return;
       if (nick === this.nickname && !this.announceSelfJoin) return;
+      // self-join is announced before names (which includes own nick)
+      // so don't add nick to channelUsers
+      if (nick !== this.nickname) this.channelUsers[channel].push(nick);
       this.sendExactToDiscord(channel, `*${nick}* has joined the channel`);
     });
 
     this.ircClient.on('part', (channel, nick, reason) => {
-      if (!this.ircStatusNotices || nick === this.nickname) return;
+      if (!this.ircStatusNotices) return;
+      // remove list of users when no longer in channel (as it will become out of date)
+      if (nick === this.nickname) {
+        delete this.channelUsers[channel];
+        return;
+      }
+      this.channelUsers[channel].splice(this.channelUsers[channel].indexOf(nick), 1);
       this.sendExactToDiscord(channel, `*${nick}* has left the channel (${reason})`);
     });
 
     this.ircClient.on('quit', (nick, reason, channels) => {
       if (!this.ircStatusNotices || nick === this.nickname) return;
       channels.forEach((channel) => {
+        const index = this.channelUsers[channel].indexOf(nick);
+        if (index === -1) return;
+        this.channelUsers[channel].splice(index, 1);
         this.sendExactToDiscord(channel, `*${nick}* has quit (${reason})`);
       });
     });
 
+    this.ircClient.on('names', (channel, nicks) => {
+      if (!this.ircStatusNotices) return;
+      this.channelUsers[channel] = Object.keys(nicks);
+    });
+
     this.ircClient.on('action', (author, to, text) => {
       this.sendToDiscord(author, to, `_${text}_`);
     });

test/bot-events.test.js

@@ -123,26 +123,43 @@ describe('Bot Events', function () {
     this.bot.sendToDiscord.should.have.been.calledWithExactly(author, channel, formattedText);
   });
 
+  it('should keep track of users through names event when irc status notices enabled', function () {
+    const bot = createBot({ ...config, ircStatusNotices: true });
+    bot.connect();
+    bot.channelUsers.should.be.an('object');
+    const channel = '#channel';
+    // nick => '' means the user is not a special user
+    const nicks = { [bot.nickname]: '', user: '', user2: '@', user3: '+' };
+    bot.ircClient.emit('names', channel, nicks);
+    bot.channelUsers.should.deep.equal({ '#channel': [bot.nickname, 'user', 'user2', 'user3'] });
+  });
+
   it('should send join messages to discord when config enabled', function () {
     const bot = createBot({ ...config, ircStatusNotices: true });
     bot.connect();
     const channel = '#channel';
+    bot.ircClient.emit('names', channel, { [bot.nickname]: '' });
     const nick = 'user';
     const text = `*${nick}* has joined the channel`;
     bot.ircClient.emit('join', channel, nick);
     bot.sendExactToDiscord.should.have.been.calledWithExactly(channel, text);
+    bot.channelUsers.should.deep.equal({ '#channel': [bot.nickname, nick] });
   });
 
   it('should not announce itself joining by default', function () {
     const bot = createBot({ ...config, ircStatusNotices: true });
     bot.connect();
     const channel = '#channel';
+    bot.ircClient.emit('names', channel, { [bot.nickname]: '' });
     const nick = bot.nickname;
     bot.ircClient.emit('join', channel, nick);
     bot.sendExactToDiscord.should.not.have.been.called;
+    bot.channelUsers.should.deep.equal({ '#channel': [bot.nickname] });
   });
 
-  it('should be possible to get the bot to announce itself joining', function () {
+  it('should announce the bot itself when config enabled', function () {
+    // self-join is announced before names (which includes own nick)
+    // hence don't trigger a names and don't expect anything of bot.channelUsers
     const bot = createBot({ ...config, ircStatusNotices: true, announceSelfJoin: true });
     bot.connect();
     const channel = '#channel';
@@ -157,23 +174,46 @@ describe('Bot Events', function () {
     bot.connect();
     const channel = '#channel';
     const nick = 'user';
+    bot.ircClient.emit('names', channel, { [bot.nickname]: '', [nick]: '' });
+    bot.channelUsers.should.deep.equal({ '#channel': [bot.nickname, nick] });
     const reason = 'Leaving';
     const text = `*${nick}* has left the channel (${reason})`;
     bot.ircClient.emit('part', channel, nick, reason);
     bot.sendExactToDiscord.should.have.been.calledWithExactly(channel, text);
+    // it should remove the nickname from the channelUsers list
+    bot.channelUsers.should.deep.equal({ '#channel': [bot.nickname] });
+  });
+
+  it('should not announce itself leaving a channel', function () {
+    const bot = createBot({ ...config, ircStatusNotices: true });
+    bot.connect();
+    const channel = '#channel';
+    bot.ircClient.emit('names', channel, { [bot.nickname]: '', user: '' });
+    bot.channelUsers.should.deep.equal({ '#channel': [bot.nickname, 'user'] });
+    const reason = 'Leaving';
+    bot.ircClient.emit('part', channel, bot.nickname, reason);
+    bot.sendExactToDiscord.should.not.have.been.called;
+    // it should remove the nickname from the channelUsers list
+    bot.channelUsers.should.deep.equal({});
   });
 
-  it('should send quit messages to discord when config enabled', function () {
+  it('should only send quit messages to discord for channels the user is tracked in', function () {
     const bot = createBot({ ...config, ircStatusNotices: true });
     bot.connect();
     const channel1 = '#channel1';
     const channel2 = '#channel2';
+    const channel3 = '#channel3';
     const nick = 'user';
+    bot.ircClient.emit('names', channel1, { [bot.nickname]: '', [nick]: '' });
+    bot.ircClient.emit('names', channel2, { [bot.nickname]: '' });
+    bot.ircClient.emit('names', channel3, { [bot.nickname]: '', [nick]: '' });
     const reason = 'Quit: Leaving';
     const text = `*${nick}* has quit (${reason})`;
-    bot.ircClient.emit('quit', nick, reason, [channel1, channel2]);
+    // send quit message for all channels on server, as the node-irc library does
+    bot.ircClient.emit('quit', nick, reason, [channel1, channel2, channel3]);
+    bot.sendExactToDiscord.should.have.been.calledTwice;
     bot.sendExactToDiscord.getCall(0).args.should.deep.equal([channel1, text]);
-    bot.sendExactToDiscord.getCall(1).args.should.deep.equal([channel2, text]);
+    bot.sendExactToDiscord.getCall(1).args.should.deep.equal([channel3, text]);
   });
 
   it('should be possible to disable join/part/quit messages', function () {
@@ -183,6 +223,7 @@ describe('Bot Events', function () {
     const nick = 'user';
     const reason = 'Leaving';
 
+    bot.ircClient.emit('names', channel, { [bot.nickname]: '' });
     bot.ircClient.emit('join', channel, nick);
     bot.ircClient.emit('part', channel, nick, reason);
     bot.ircClient.emit('join', channel, nick);