Update bot.ts

src/bot.ts

@@ -9,6 +9,7 @@ import * as Bluebird from "bluebird";
 import * as mime from "mime";
 import * as marked from "marked";
 import * as path from "path";
+import * as escapeStringRegexp from "escape-string-regexp";
 
 // Due to messages often arriving before we get a response from the send call,
 // messages get delayed from discord.
@@ -239,7 +240,7 @@ export class DiscordBot {
 
   private HandleMentions(body: string, members: Discord.GuildMember[]): string {
     for (const member of members) {
-      body = body.replace(new RegExp(member.displayName, "g"), `<@!${member.id}>`);
+      body = body.replace(new RegExp(escapeStringRegexp(member.displayName), "g"), `<@!${member.id}>`);
     }
     return body;
   }