From 2a080b737cbb1f949314e177359bdf92fc5b91ea Mon Sep 17 00:00:00 2001
From: Cadence Ember <cadence@disroot.org>
Date: Tue, 20 Aug 2024 03:15:33 +1200
Subject: [PATCH] Parsing HTML with regular expressions (GONE WRONG)

---
 m2d/converters/event-to-message.js      |  6 ++---
 m2d/converters/event-to-message.test.js | 34 +++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/m2d/converters/event-to-message.js b/m2d/converters/event-to-message.js
index 2a32dde..2984e8e 100644
--- a/m2d/converters/event-to-message.js
+++ b/m2d/converters/event-to-message.js
@@ -329,7 +329,7 @@ async function uploadEndOfMessageSpriteSheet(content, attachments, pendingFiles,
  */
 async function handleRoomOrMessageLinks(input, di) {
 	let offset = 0
-	for (const match of [...input.matchAll(/("?https:\/\/matrix.to\/#\/(![^"/, ?)]+)(?:\/(\$[^"/ ?)]+))?(?:\?[^",:!? )]*)?)(">|[, )]|$)/g)]) {
+	for (const match of [...input.matchAll(/("?https:\/\/matrix.to\/#\/(![^"/, ?)]+)(?:\/(\$[^"/ ?)]+))?(?:\?[^",:!? )]*?)?)(">|[,<\n )]|$)/g)]) {
 		assert(typeof match.index === "number")
 		const [_, attributeValue, roomID, eventID, endMarker] = match
 		let result
@@ -726,7 +726,7 @@ async function eventToMessage(event, guild, di) {
 			content = turndownService.turndown(root)
 
 			// Put < > around any surviving matrix.to links to hide the URL previews
-			content = content.replace(/\bhttps?:\/\/matrix\.to\/[^ )]*/g, "<$&>")
+			content = content.replace(/\bhttps?:\/\/matrix\.to\/[^<>\n )]*/g, "<$&>")
 
 			// It's designed for commonmark, we need to replace the space-space-newline with just newline
 			content = content.replace(/  \n/g, "\n")
@@ -745,7 +745,7 @@ async function eventToMessage(event, guild, di) {
 			}
 
 			content = await handleRoomOrMessageLinks(content, di) // Replace matrix.to links with discord.com equivalents where possible
-			content = content.replace(/\bhttps?:\/\/matrix\.to\/[^ )]*/, "<$&>") // Put < > around any surviving matrix.to links to hide the URL previews
+			content = content.replace(/\bhttps?:\/\/matrix\.to\/[^<>\n )]*/, "<$&>") // Put < > around any surviving matrix.to links to hide the URL previews
 
 			const result = await checkWrittenMentions(content, event.sender, event.room_id, guild, di)
 			if (result) {
diff --git a/m2d/converters/event-to-message.test.js b/m2d/converters/event-to-message.test.js
index f997b44..b404e59 100644
--- a/m2d/converters/event-to-message.test.js
+++ b/m2d/converters/event-to-message.test.js
@@ -3025,6 +3025,40 @@ test("event2message: mentioning known bridged events works (formatted body)", as
 	)
 })
 
+test("event2message: mentioning known bridged events followed by line break and user mention works (partially formatted body)", async t => {
+	t.deepEqual(
+		await eventToMessage({
+			content: {
+				msgtype: "m.text",
+				body: "wrong body",
+				format: "org.matrix.custom.html",
+				formatted_body: `https://matrix.to/#/!CzvdIdUQXgUjDVKxeU:cadence.moe/$zXSlyI78DQqQwwfPUSzZ1b-nXzbUrCDljJgnGDdoI10?via=cadence.moe<a href="https://matrix.to/#/@_ooye_extremity:cadence.moe">extremity</a>`
+			},
+			event_id: "$g07oYSZFWBkxohNEfywldwgcWj1hbhDzQ1sBAKvqOOU",
+			origin_server_ts: 1688301929913,
+			room_id: "!kLRqKKUQXcibIMtOpl:cadence.moe",
+			sender: "@cadence:cadence.moe",
+			type: "m.room.message",
+			unsigned: {
+				age: 405299
+			}
+		}),
+		{
+			ensureJoined: [],
+			messagesToDelete: [],
+			messagesToEdit: [],
+			messagesToSend: [{
+				username: "cadence [they]",
+				content: "https://discord.com/channels/497159726455455754/497161350934560778/1141619794500649020<@114147806469554185>",
+				avatar_url: undefined,
+				allowed_mentions: {
+					parse: ["users", "roles"]
+				}
+			}]
+		}
+	)
+})
+
 test("event2message: mentioning unknown bridged events can approximate with timestamps", async t => {
 	let called = 0
 	t.deepEqual(