Add ircPreventMention (#502)

* Add ircPreventMention

(This adds a zero-width character to nicknames to prevent IRC-side pings.)

Original commits:

- Add ircPreventMention code

- Document ircPreventMention

- Make ircNickColor wrap the displayUsername

- Fix build errors

- Default ircPreventMention to false

* Correct that ircPreventMention is off by default

* Test ircPreventMention

Only tests turning it on; extant tests ensure it's off by default.

README.md

@@ -88,6 +88,7 @@ First you need to create a Discord bot user, which you can do by following the i
       "webhookAvatarURL": "https://robohash.org/{$nickname}" // Default avatar to use for webhook messages
     },
     "ircNickColor": false, // Gives usernames a color in IRC for better readability (on by default)
+    "ircPreventMention": true, // Prevents users of both IRC and Discord from being mentioned in IRC when they speak in Discord (off by default)
     // Makes the bot hide the username prefix for messages that start
     // with one of these characters (commands):
     "commandCharacters": ["!", "."],

lib/bot.js

@@ -37,6 +37,7 @@ class Bot {
     this.discordToken = options.discordToken;
     this.commandCharacters = options.commandCharacters || [];
     this.ircNickColor = options.ircNickColor !== false; // default to true
+    this.ircPreventMention = options.ircPreventMention === true; // default: false
     this.channels = _.values(options.channelMapping);
     this.ircStatusNotices = options.ircStatusNotices;
     this.announceSelfJoin = options.announceSelfJoin;
@@ -325,9 +326,16 @@ class Bot {
       const nickname = Bot.getDiscordNicknameOnServer(author, fromGuild);
       let text = this.parseText(message);
       let displayUsername = nickname;
+
+      if (this.ircPreventMention) {
+        // Prevent users of both IRC and Discord from
+        // being mentioned in IRC when they talk in Discord.
+        displayUsername = `${displayUsername.slice(0, 1)}\u200B${displayUsername.slice(1)}`;
+      }
+
       if (this.ircNickColor) {
         const colorIndex = (nickname.charCodeAt(0) + nickname.length) % NICK_COLORS.length;
-        displayUsername = irc.colors.wrap(NICK_COLORS[colorIndex], nickname);
+        displayUsername = irc.colors.wrap(NICK_COLORS[colorIndex], displayUsername);
       }
 
       const patternMap = {

test/bot.test.js

@@ -336,6 +336,33 @@ describe('Bot', function () {
     }
   );
 
+  it('should break mentions when ircPreventMention is enabled', function () {
+    const newConfig = { ...config, ircPreventMention: true };
+    this.bot = new Bot(newConfig);
+    this.bot.connect();
+
+    const text = 'testmessage';
+    const username = 'otherauthor';
+    const brokenNickname = 'o\u200Btherauthor';
+    const message = {
+      content: text,
+      mentions: { users: [] },
+      channel: {
+        name: 'discord'
+      },
+      author: {
+        username,
+        id: 'not bot id'
+      },
+      guild: this.guild
+    };
+
+    this.bot.sendToIRC(message);
+    // Wrap in colors:
+    const expected = `<\u000304${brokenNickname}\u000f> ${text}`;
+    ClientStub.prototype.say.should.have.been.calledWith('#irc', expected);
+  });
+
   it('should parse text from discord when sending messages', function () {
     const text = '<#1234>';
     const message = {