server/commands/announce.ts

@@ -6,7 +6,7 @@ import { Maybe } from '../interfaces'
 import { logger } from '../logger'
 import { Command } from '../structures/command'
 import { RunOptions } from '../types/commandTypes'
-import { messageIsInitialAnnouncement } from '../helper/messageIdentifiers'
+import { isInitialAnnouncement } from '../helper/messageIdentifiers'
 
 export default new Command({
 	name: 'announce',
@@ -62,7 +62,7 @@ async function sendInitialAnnouncement(guildId: string, requestId: string): Prom
 		return
 	}
 
-	const currentPinnedAnnouncementMessages = (await announcementChannel.messages.fetchPinned()).filter(message => messageIsInitialAnnouncement(message))
+	const currentPinnedAnnouncementMessages = (await announcementChannel.messages.fetchPinned()).filter(message => isInitialAnnouncement(message))
 	currentPinnedAnnouncementMessages.forEach(async (message) => await message.unpin())
 	currentPinnedAnnouncementMessages.forEach(message => message.delete())
 

server/events/deleteAnnouncementsWhenWPEnds.ts

@@ -2,7 +2,7 @@ import { Collection, GuildScheduledEvent, GuildScheduledEventStatus, Message } f
 import { v4 as uuid } from "uuid";
 import { client } from "../..";
 import { logger } from "../logger";
-import { messageIsInitialAnnouncement } from "../helper/messageIdentifiers";
+import { isInitialAnnouncement } from "../helper/messageIdentifiers";
 
 
 export const name = 'guildScheduledEventUpdate'
@@ -26,7 +26,7 @@ export async function execute(oldEvent: GuildScheduledEvent, newEvent: GuildSche
 
 			const events = await newEvent.guild.scheduledEvents.fetch()
 
-			const wpAnnouncements = (await announcementChannel.messages.fetch()).filter(message => !messageIsInitialAnnouncement(message))
+			const wpAnnouncements = (await announcementChannel.messages.fetch()).filter(message => !isInitialAnnouncement(message))
 			const announcementsWithoutEvent = filterAnnouncementsByPendingWPs(wpAnnouncements, events)
 			logger.info(`Deleting ${announcementsWithoutEvent.length} announcements.`, { guildId, requestId })
 			announcementsWithoutEvent.forEach(message => message.delete())

server/helper/messageIdentifiers.ts

@@ -1,11 +1,20 @@
 import { Message } from "discord.js";
 
-export function messageIsVoteMessage(msg: Message): boolean {
+
+// branded types to differentiate objects of identical Type but different contents
+export type VoteEndMessage = Message & { readonly __brand: 'vote' }
+export type AnnouncementMessage = Message & { readonly __brand: 'announcement' }
+export type VoteMessage = Message & { readonly __brand: 'voteend' }
+
+export type DiscordMessage = VoteMessage | VoteEndMessage | AnnouncementMessage
+
+export function isVoteMessage(msg: Message): msg is VoteMessage {
 	return msg.cleanContent.includes('[Abstimmung]')
 }
-export function messageIsInitialAnnouncement(msg: Message): boolean {
+export function isInitialAnnouncement(msg: Message): msg is AnnouncementMessage {
 	return msg.cleanContent.includes("[initial]")
 }
-export function messageIsVoteEndedMessage(msg: Message): boolean {
+export function isVoteEndedMessage(msg: Message): msg is VoteEndMessage {
 	return msg.cleanContent.includes("[Abstimmung beendet]")
 }
+

server/structures/client.ts

@@ -9,7 +9,7 @@ import { JellyfinHandler } from "../jellyfin/handler";
 import { logger } from "../logger";
 import { CommandType } from "../types/commandTypes";
 import { checkForPollsToClose } from "../commands/closepoll";
-import { messageIsInitialAnnouncement } from "../helper/messageIdentifiers";
+import { isInitialAnnouncement } from "../helper/messageIdentifiers";
 import VoteController from "../helper/vote.controller";
 
 
@@ -155,7 +155,7 @@ export class ExtendedClient extends Client {
 			}
 			this.announcementRoleHandlerTask.set(guild.id, schedule("*/10 * * * * *", async () => {
 				const requestId = uuid()
-				const messages = (await textChannel.messages.fetchPinned()).filter(message => messageIsInitialAnnouncement(message))
+				const messages = (await textChannel.messages.fetchPinned()).filter(message => isInitialAnnouncement(message))
 
 				if (messages.size > 1) {
 					logger.error("More than one pinned announcement Messages found. Unable to know which one people react to. Please fix!", { guildId: guild.id, requestId })