write logs to log channel

Author: tjjfvi

.env.example

@@ -21,3 +21,5 @@ GENERAL_HELP_CHANNEL=
 TIME_BEFORE_HELPER_PING=
 
 SUGGESTIONS_CHANNEL=
+
+LOG_CHANNEL=

src/env.ts

@@ -34,3 +34,5 @@ export const timeBeforeHelperPing = parseInt(
 );
 
 export const suggestionsChannelId = process.env.SUGGESTIONS_CHANNEL!;
+
+export const logChannelId = process.env.LOG_CHANNEL!;

src/index.ts

@@ -2,6 +2,7 @@ import { token, botAdmins } from './env';
 import CookiecordClient from 'cookiecord';
 import { Intents } from 'discord.js';
 import { getDB } from './db';
+import { hookLog } from './log';
 
 import { AutoroleModule } from './modules/autorole';
 import { EtcModule } from './modules/etc';
@@ -51,7 +52,10 @@ for (const mod of [
 getDB(); // prepare the db for later
 
 client.login(token);
-client.on('ready', () => console.log(`Logged in as ${client.user?.tag}`));
+client.on('ready', () => {
+	console.log(`Logged in as ${client.user?.tag}`);
+	hookLog(client);
+});
 
 process.on('unhandledRejection', e => {
 	console.error('Unhandled rejection', e);

src/log.ts

@@ -0,0 +1,73 @@
+import CookiecordClient from 'cookiecord';
+import { Channel, GuildMember, TextChannel, User } from 'discord.js';
+import { inspect } from 'util';
+import { logChannelId } from './env';
+
+const logDebounceTime = 5000;
+const logMaxLength = 2000;
+
+export async function hookLog(client: CookiecordClient) {
+	const guild = client.guilds.cache.get(
+		(await client.guilds.fetch()).first()!.id,
+	)!;
+	const channel = (await guild.channels.fetch(logChannelId)) as TextChannel;
+	let curLogText = '';
+	let timeout: NodeJS.Timeout | null = null;
+	const origLog = console.log;
+	console.log = (...args) => {
+		origLog(...args);
+		postLog(args);
+	};
+	const origError = console.error;
+	console.error = (...args) => {
+		origError(...args);
+		postLog(['[ERROR]', ...args]);
+	};
+	console.log('Writing logs to', channel);
+	function argToString(arg: unknown) {
+		if (typeof arg === 'string') return arg;
+		return inspect(arg);
+	}
+	function postLog(args: unknown[]) {
+		curLogText += `[${new Date().toISOString()}] ${args
+			.map(argToString)
+			.join(' ')}\n`;
+		if (timeout) clearTimeout(timeout);
+		while (curLogText.length > logMaxLength) {
+			const initial =
+				curLogText.match(/^[^]{0,2000}\n/g)?.[0] ??
+				curLogText.slice(0, 2000);
+			curLogText = curLogText.slice(initial.length);
+			postCodeblock(initial);
+		}
+		if (curLogText.trim().length)
+			timeout = setTimeout(() => {
+				postCodeblock(curLogText);
+				curLogText = '';
+			}, logDebounceTime);
+	}
+	async function postCodeblock(content: string) {
+		channel.send(`\`\`\`ts\n${content}\n\`\`\``);
+	}
+}
+
+function defineCustomUtilInspect<T>(
+	Cls: { new (...args: any): T; prototype: T },
+	cb: (value: T) => string,
+) {
+	// @ts-ignore
+	Cls.prototype[inspect.custom] = function () {
+		return cb(this);
+	};
+}
+
+const inspectUser = (user: User) =>
+	`@${user.username}#${user.discriminator}/${user.id}`;
+defineCustomUtilInspect(User, inspectUser);
+defineCustomUtilInspect(GuildMember, member => inspectUser(member.user));
+
+defineCustomUtilInspect(Channel, channel =>
+	'name' in channel
+		? `#${(channel as any).name}/${(channel as Channel).id}`
+		: `#${channel.id}`,
+);