feat(on_message): audit messages

- Provide advise for certain message content
- When messages contain links to X, advise to use xcancel for better previews

Author: theetrain

src/events/on_message/_advise.ts

@@ -0,0 +1,59 @@
+import { ChannelType, Message } from 'discord.js';
+import { has_link } from './_common.js';
+import urlRegex from 'url-regex';
+
+const replacementMap = [
+	{ test: 'https://x.com', replace: 'https://xcancel.com' },
+];
+
+export default async function mutate_content(message: Message) {
+	if (
+		message.channel.type != ChannelType.GuildText ||
+		(!has_link(message) && !message.content.includes('x.com'))
+	)
+		return;
+
+	// Get links
+	const caughtLinks: string[] | undefined = message.content
+		.match(urlRegex())
+		?.filter(
+			(link) =>
+				replacementMap.findIndex((item) =>
+					link.startsWith(item.test),
+				) !== -1,
+		);
+	if (!caughtLinks) return;
+	const hasXLinks: boolean = caughtLinks.some((item) =>
+		item.startsWith('https://x.com'),
+	);
+	if (!hasXLinks) return;
+
+	const updatedPhrase: string =
+		caughtLinks.length > 1
+			? 'Here are the updated links:'
+			: 'Here is the updated link:';
+	const updatedLinks = caughtLinks
+		.map((link) => {
+			const replaceIdx = replacementMap.findIndex((item) =>
+				link.startsWith(item.test),
+			);
+			return link.replace(
+				replacementMap[replaceIdx].test,
+				replacementMap[replaceIdx].replace,
+			);
+		})
+		.join('\n');
+
+	const updatedMessage: string = (function () {
+		let newContent = message.content;
+		replacementMap.forEach(
+			(item) =>
+				(newContent = newContent.replace(item.test, item.replace)),
+		);
+		return newContent;
+	})();
+
+	await message.author.send(
+		`Re: ${message.url}\n\nI see you've provided a link to \`x.com\`. Please consider posting a new message having \`x.com\` replaced with \`xcancel.com\`, that way server members may view the message and thread without requiring an account.\n\n${updatedPhrase}\`\`\`${updatedLinks}\`\`\`\n\nHere is your entire message with adjusted links:\n\`\`\`${updatedMessage}\`\`\``,
+	);
+}

src/events/on_message/on_message.ts

@@ -2,6 +2,7 @@ import check_links from './_check_links.js';
 import spam_filter from './_spam_filter.js';
 import autothread from './_autothread.js';
 import slow_mode from './_slow_mode.js';
+import advise from './_advise.js';
 import { event } from 'jellycommands';
 import { STOP } from './_common.js';
 
@@ -16,6 +17,7 @@ export default event({
 			check_links,
 			autothread,
 			slow_mode,
+			advise,
 		]) {
 			try {
 				await handler(message);