Handle replies to state events with no body

src/m2d/converters/event-to-message.js

@@ -476,7 +476,7 @@ async function eventToMessage(event, guild, di) {
 	// Try to extract an accurate display name and avatar URL from the member event
 	const member = await getMemberFromCacheOrHomeserver(event.room_id, event.sender, di?.api)
 	if (member.displayname) displayName = member.displayname
-	if (member.avatar_url) avatarURL = mxUtils.getPublicUrlForMxc(member.avatar_url) || undefined
+	if (member.avatar_url) avatarURL = mxUtils.getPublicUrlForMxc(member.avatar_url)
 	// If the display name is too long to be put into the webhook (80 characters is the maximum),
 	// put the excess characters into displayNameRunoff, later to be put at the top of the message
 	let [displayNameShortened, displayNameRunoff] = splitDisplayName(displayName)
@@ -512,8 +512,7 @@ async function eventToMessage(event, guild, di) {
 			// Is it editing a reply? We need special handling if it is.
 			// Get the original event, then check if it was a reply
 			const originalEvent = await di.api.getEvent(event.room_id, originalEventId)
-			if (!originalEvent) return
+			const repliedToEventId = originalEvent?.content?.["m.relates_to"]?.["m.in_reply_to"]?.event_id
-			const repliedToEventId = originalEvent.content["m.relates_to"]?.["m.in_reply_to"]?.event_id
 			if (!repliedToEventId) return
 
 			// After all that, it's an edit of a reply.
@@ -576,34 +575,27 @@ async function eventToMessage(event, guild, di) {
 			if (row) {
 				replyLine += `https://discord.com/channels/${guild.id}/${row.channel_id}/${row.message_id} `
 			}
-			const sender = repliedToEvent.sender
-			const authorID = getUserOrProxyOwnerID(sender)
-			if (authorID) {
-				replyLine += `<@${authorID}>`
-			} else {
-				let senderName = select("member_cache", "displayname", {mxid: sender}).pluck().get()
-				if (!senderName) {
-					const match = sender.match(/@([^:]*)/)
-					assert(match)
-					senderName = match[1]
-				}
-				replyLine += `**Ⓜ${senderName}**`
-			}
 			// If the event has been edited, the homeserver will include the relation in `unsigned`.
 			if (repliedToEvent.unsigned?.["m.relations"]?.["m.replace"]?.content?.["m.new_content"]) {
 				repliedToEvent = repliedToEvent.unsigned["m.relations"]["m.replace"] // Note: this changes which event_id is in repliedToEvent.
 				repliedToEvent.content = repliedToEvent.content["m.new_content"]
 			}
-			let contentPreview
+			/** @type {string} */
+			let repliedToContent = repliedToEvent.content.formatted_body || repliedToEvent.content.body
 			const fileReplyContentAlternative = attachmentEmojis.get(repliedToEvent.content.msgtype)
+			let contentPreview
 			if (fileReplyContentAlternative) {
 				contentPreview = " " + fileReplyContentAlternative
 			} else if (repliedToEvent.unsigned?.redacted_because) {
 				contentPreview = " (in reply to a deleted message)"
+			} else if (typeof repliedToContent !== "string") {
+				// in reply to a weird metadata event like m.room.name, m.room.member...
+				// I'm not implementing text fallbacks for arbitrary room events. this should cover most cases
+				// this has never ever happened in the wild anyway
+				repliedToEvent.sender = ""
+				contentPreview = " (channel details edited)"
 			} else {
 				// Generate a reply preview for a standard message
-				/** @type {string} */
-				let repliedToContent = repliedToEvent.content.formatted_body || repliedToEvent.content.body
 				repliedToContent = repliedToContent.replace(/.*<\/mx-reply>/s, "") // Remove everything before replies, so just use the actual message body
 				repliedToContent = repliedToContent.replace(/^\s*<blockquote>.*?<\/blockquote>(.....)/s, "$1") // If the message starts with a blockquote, don't count it and use the message body afterwards
 				repliedToContent = repliedToContent.replace(/(?:\n|<br>)+/g, " ") // Should all be on one line
@@ -624,6 +616,15 @@ async function eventToMessage(event, guild, di) {
 					contentPreview = ""
 				}
 			}
+			const sender = repliedToEvent.sender
+			const authorID = getUserOrProxyOwnerID(sender)
+			if (authorID) {
+				replyLine += `<@${authorID}>`
+			} else {
+				let senderName = select("member_cache", "displayname", {mxid: sender}).pluck().get()
+				if (!senderName) senderName = sender.match(/@([^:]*)/)?.[1]
+				if (senderName) replyLine += `**Ⓜ${senderName}**`
+			}
 			replyLine = `-# > ${replyLine}${contentPreview}\n`
 		})()
 

src/m2d/converters/event-to-message.test.js

@@ -2625,6 +2625,52 @@ test("event2message: rich reply to a deleted event", async t => {
 	)
 })
 
+test("event2message: rich reply to a state event with no body", async t => {
+	t.deepEqual(
+		await eventToMessage({
+			type: "m.room.message",
+			sender: "@ampflower:matrix.org",
+			content: {
+				msgtype: "m.text",
+				body: "> <@ampflower:matrix.org> changed the room topic\n\nnice room topic",
+				format: "org.matrix.custom.html",
+				formatted_body: "<mx-reply><blockquote><a href=\"https://matrix.to/#/!TqlyQmifxGUggEmdBN:cadence.moe/$f-noT-d-Eo_Xgpc05Ww89ErUXku4NwKWYGHLzWKo1kU?via=cadence.moe\">In reply to</a> <a href=\"https://matrix.to/#/@ampflower:matrix.org\">@ampflower:matrix.org</a> changed the room topic<br></blockquote></mx-reply>nice room topic",
+				"m.relates_to": {
+					"m.in_reply_to": {
+						event_id: "$f-noT-d-Eo_Xgpc05Ww89ErUXku4NwKWYGHLzWKo1kU"
+					}
+				}
+			},
+			event_id: "$v_Gtr-bzv9IVlSLBO5DstzwmiDd-GSFaNfHX66IupV8",
+			room_id: "!TqlyQmifxGUggEmdBN:cadence.moe"
+		 }, data.guild.general, {
+			api: {
+				getEvent: mockGetEvent(t, "!TqlyQmifxGUggEmdBN:cadence.moe", "$f-noT-d-Eo_Xgpc05Ww89ErUXku4NwKWYGHLzWKo1kU", {
+					type: "m.room.topic",
+					sender: "@ampflower:matrix.org",
+					content: {
+						topic: "you're cute"
+					},
+					user_id: "@ampflower:matrix.org"
+				})
+			}
+		}),
+		{
+			ensureJoined: [],
+			messagesToDelete: [],
+			messagesToEdit: [],
+			messagesToSend: [{
+				username: "Ampflower 🌺",
+				content: "-# > <:L1:1144820033948762203><:L2:1144820084079087647> (channel details edited)\nnice room topic",
+				avatar_url: "https://bridge.example.org/download/matrix/cadence.moe/PRfhXYBTOalvgQYtmCLeUXko",
+				allowed_mentions: {
+					parse: ["users", "roles"]
+				}
+			}]
+		}
+	)
+})
+
 test("event2message: raw mentioning discord users in plaintext body works", async t => {
 	t.deepEqual(
 		await eventToMessage({