Resolve Matrix room aliases to Discord channels

src/d2m/actions/create-room.js

@@ -39,26 +39,6 @@ const DEFAULT_PRIVACY_LEVEL = 0
 /** @type {Map<string, Promise<string>>} channel ID -> Promise<room ID> */
 const inflightRoomCreate = new Map()
 
-/**
- * Async because it gets all room state from the homeserver.
- * @param {string} roomID
- */
-async function roomToKState(roomID) {
-	const root = await api.getAllState(roomID)
-	return ks.stateToKState(root)
-}
-
-/**
- * @param {string} roomID
- * @param {any} kstate
- */
-async function applyKStateDiffToRoom(roomID, kstate) {
-	const events = await ks.kstateToState(kstate)
-	return Promise.all(events.map(({type, state_key, content}) =>
-		api.sendState(roomID, type, state_key, content)
-	))
-}
-
 /**
  * @param {{id: string, name: string, topic?: string?, type: number, parent_id?: string?}} channel
  * @param {{id: string}} guild
@@ -253,9 +233,9 @@ async function postApplyPowerLevels(kstate, callback) {
 
 	// Now *really* apply the power level overrides on top of what Synapse *really* set
 	if (powerLevelContent) {
-		const newRoomKState = await roomToKState(roomID)
+		const newRoomKState = await ks.roomToKState(roomID)
 		const newRoomPowerLevelsDiff = ks.diffKState(newRoomKState, {"m.room.power_levels/": powerLevelContent})
-		await applyKStateDiffToRoom(roomID, newRoomPowerLevelsDiff)
+		await ks.applyKStateDiffToRoom(roomID, newRoomPowerLevelsDiff)
 	}
 
 	return roomID
@@ -384,7 +364,7 @@ async function _syncRoom(channelID, shouldActuallySync) {
 	const {spaceID, channelKState} = await channelToKState(channel, guild, {api}) // calling this in both branches because we don't want to calculate this if not syncing
 
 	// sync channel state to room
-	const roomKState = await roomToKState(roomID)
+	const roomKState = await ks.roomToKState(roomID)
 	if (+roomKState["m.room.create/"].room_version <= 8) {
 		// join_rule `restricted` is not available in room version < 8 and not working properly in version == 8
 		// read more: https://spec.matrix.org/v1.8/rooms/v9/
@@ -392,7 +372,7 @@ async function _syncRoom(channelID, shouldActuallySync) {
 		channelKState["m.room.join_rules/"] = {join_rule: "public"}
 	}
 	const roomDiff = ks.diffKState(roomKState, channelKState)
-	const roomApply = applyKStateDiffToRoom(roomID, roomDiff)
+	const roomApply = ks.applyKStateDiffToRoom(roomID, roomDiff)
 	db.prepare("UPDATE channel_room SET name = ? WHERE room_id = ?").run(channel.name, roomID)
 
 	// sync room as space member
@@ -462,7 +442,7 @@ async function unbridgeDeletedChannel(channel, guildID) {
  * @returns {Promise<string[]>}
  */
 async function _syncSpaceMember(channel, spaceID, roomID) {
-	const spaceKState = await roomToKState(spaceID)
+	const spaceKState = await ks.roomToKState(spaceID)
 	let spaceEventContent = {}
 	if (
 		channel.type !== DiscordTypes.ChannelType.PrivateThread // private threads do not belong in the space (don't offer people something they can't join)
@@ -475,7 +455,7 @@ async function _syncSpaceMember(channel, spaceID, roomID) {
 	const spaceDiff = ks.diffKState(spaceKState, {
 		[`m.space.child/${roomID}`]: spaceEventContent
 	})
-	return applyKStateDiffToRoom(spaceID, spaceDiff)
+	return ks.applyKStateDiffToRoom(spaceID, spaceDiff)
 }
 
 async function createAllForGuild(guildID) {
@@ -498,8 +478,6 @@ module.exports.ensureRoom = ensureRoom
 module.exports.syncRoom = syncRoom
 module.exports.createAllForGuild = createAllForGuild
 module.exports.channelToKState = channelToKState
-module.exports.roomToKState = roomToKState
-module.exports.applyKStateDiffToRoom = applyKStateDiffToRoom
 module.exports.postApplyPowerLevels = postApplyPowerLevels
 module.exports._convertNameAndTopic = convertNameAndTopic
 module.exports._unbridgeRoom = _unbridgeRoom

src/d2m/actions/create-space.js

@@ -116,9 +116,9 @@ async function _syncSpace(guild, shouldActuallySync) {
 	const guildKState = await guildToKState(guild, privacy_level) // calling this in both branches because we don't want to calculate this if not syncing
 
 	// sync guild state to space
-	const spaceKState = await createRoom.roomToKState(spaceID)
+	const spaceKState = await ks.roomToKState(spaceID)
 	const spaceDiff = ks.diffKState(spaceKState, guildKState)
-	await createRoom.applyKStateDiffToRoom(spaceID, spaceDiff)
+	await ks.applyKStateDiffToRoom(spaceID, spaceDiff)
 
 	// guild icon was changed, so room avatars need to be updated as well as the space ones
 	// doing it this way rather than calling syncRoom for great efficiency gains
@@ -183,9 +183,9 @@ async function syncSpaceFully(guildID) {
 	const guildKState = await guildToKState(guild, privacy_level)
 
 	// sync guild state to space
-	const spaceKState = await createRoom.roomToKState(spaceID)
+	const spaceKState = await ks.roomToKState(spaceID)
 	const spaceDiff = ks.diffKState(spaceKState, guildKState)
-	await createRoom.applyKStateDiffToRoom(spaceID, spaceDiff)
+	await ks.applyKStateDiffToRoom(spaceID, spaceDiff)
 
 	const childRooms = await api.getFullHierarchy(spaceID)
 

src/d2m/actions/update-pins.js

@@ -6,6 +6,8 @@ const {discord, sync, db} = passthrough
 const pinsToList = sync.require("../converters/pins-to-list")
 /** @type {import("../../matrix/api")} */
 const api = sync.require("../../matrix/api")
+/** @type {import("../../matrix/kstate")} */
+const ks = sync.require("../../matrix/kstate")
 
 /**
  * @template {string | null | undefined} T
@@ -23,13 +25,13 @@ function convertTimestamp(timestamp) {
  * @param {number?} convertedTimestamp
  */
 async function updatePins(channelID, roomID, convertedTimestamp) {
-	const pins = await discord.snow.channel.getChannelPinnedMessages(channelID)
-	const eventIDs = pinsToList.pinsToList(pins)
-	if (pins.length === eventIDs.length || eventIDs.length) {
-		await api.sendState(roomID, "m.room.pinned_events", "", {
-			pinned: eventIDs
-		})
-	}
+	const discordPins = await discord.snow.channel.getChannelPinnedMessages(channelID)
+	const pinned = pinsToList.pinsToList(discordPins)
+
+	const kstate = await ks.roomToKState(roomID)
+	const diff = ks.diffKState(kstate, {"m.room.pinned_events/": {pinned}})
+	await ks.applyKStateDiffToRoom(roomID, diff)
+
 	db.prepare("UPDATE channel_room SET last_bridged_pin_timestamp = ? WHERE channel_id = ?").run(convertedTimestamp || 0, channelID)
 }
 

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

@@ -330,9 +330,9 @@ async function uploadEndOfMessageSpriteSheet(content, attachments, pendingFiles,
  */
 async function handleRoomOrMessageLinks(input, di) {
 	let offset = 0
-	for (const match of [...input.matchAll(/("?https:\/\/matrix.to\/#\/(![^"/, ?)]+)(?:\/(\$[^"/ ?)]+))?(?:\?[^",:!? )]*?)?)(">|[,<\n )]|$)/g)]) {
+	for (const match of [...input.matchAll(/("?https:\/\/matrix.to\/#\/((?:#|%23|!)[^"/, ?)]+)(?:\/(\$[^"/ ?)]+))?(?:\?[^",:!? )]*?)?)(">|[,<\n )]|$)/g)]) {
 		assert(typeof match.index === "number")
-		const [_, attributeValue, roomID, eventID, endMarker] = match
+		let [_, attributeValue, roomID, eventID, endMarker] = match
 		let result
 
 		const resultType = endMarker === '">' ? "html" : "plain"
@@ -350,6 +350,16 @@ async function handleRoomOrMessageLinks(input, di) {
 		// Don't process links that are part of the reply fallback, they'll be removed entirely by turndown
 		if (input.slice(match.index + match[0].length + offset).startsWith("In reply to")) continue
 
+		// Resolve room alias to room ID if needed
+		roomID = decodeURIComponent(roomID)
+		if (roomID[0] === "#") {
+			try {
+				roomID = await di.api.getAlias(roomID)
+			} catch (e) {
+				continue // Room alias is unresolvable, so it can't be converted
+			}
+		}
+
 		const channelID = select("channel_room", "channel_id", {room_id: roomID}).pluck().get()
 		if (!channelID) continue
 		if (!eventID) {

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

@@ -2957,6 +2957,133 @@ test("event2message: mentioning bridged rooms works (plaintext body)", async t =
 	)
 })
 
+test("event2message: mentioning bridged rooms by alias works", async t => {
+	let called = 0
+	t.deepEqual(
+		await eventToMessage({
+			content: {
+				msgtype: "m.text",
+				body: "wrong body",
+				format: "org.matrix.custom.html",
+				formatted_body: `I'm just <a href="https://matrix.to/#/%23worm-farm%3Acadence.moe?via=cadence.moe">worm-farm</a> testing channel mentions`
+			},
+			event_id: "$g07oYSZFWBkxohNEfywldwgcWj1hbhDzQ1sBAKvqOOU",
+			origin_server_ts: 1688301929913,
+			room_id: "!kLRqKKUQXcibIMtOpl:cadence.moe",
+			sender: "@cadence:cadence.moe",
+			type: "m.room.message",
+			unsigned: {
+				age: 405299
+			}
+		}, {}, {
+			api: {
+				async getAlias(alias) {
+					called++
+					t.equal(alias, "#worm-farm:cadence.moe")
+					return "!BnKuBPCvyfOkhcUjEu:cadence.moe"
+				}
+			}
+		}),
+		{
+			ensureJoined: [],
+			messagesToDelete: [],
+			messagesToEdit: [],
+			messagesToSend: [{
+				username: "cadence [they]",
+				content: "I'm just <#1100319550446252084> testing channel mentions",
+				avatar_url: undefined,
+				allowed_mentions: {
+					parse: ["users", "roles"]
+				}
+			}]
+		}
+	)
+	t.equal(called, 1)
+})
+
+test("event2message: mentioning bridged rooms by alias works (plaintext body)", async t => {
+	let called = 0
+	t.deepEqual(
+		await eventToMessage({
+			content: {
+				msgtype: "m.text",
+				body: `I'm just https://matrix.to/#/#worm-farm:cadence.moe?via=cadence.moe testing channel mentions`
+			},
+			event_id: "$g07oYSZFWBkxohNEfywldwgcWj1hbhDzQ1sBAKvqOOU",
+			origin_server_ts: 1688301929913,
+			room_id: "!kLRqKKUQXcibIMtOpl:cadence.moe",
+			sender: "@cadence:cadence.moe",
+			type: "m.room.message",
+			unsigned: {
+				age: 405299
+			}
+		}, {}, {
+			api: {
+				async getAlias(alias) {
+					called++
+					t.equal(alias, "#worm-farm:cadence.moe")
+					return "!BnKuBPCvyfOkhcUjEu:cadence.moe"
+				}
+			}
+		}),
+		{
+			ensureJoined: [],
+			messagesToDelete: [],
+			messagesToEdit: [],
+			messagesToSend: [{
+				username: "cadence [they]",
+				content: "I'm just <#1100319550446252084> testing channel mentions",
+				avatar_url: undefined,
+				allowed_mentions: {
+					parse: ["users", "roles"]
+				}
+			}]
+		}
+	)
+	t.equal(called, 1)
+})
+
+test("event2message: mentioning bridged rooms by alias skips the link when alias is unresolvable", async t => {
+	let called = 0
+	t.deepEqual(
+		await eventToMessage({
+			content: {
+				msgtype: "m.text",
+				body: `I'm just https://matrix.to/#/#worm-farm:cadence.moe?via=cadence.moe and https://matrix.to/#/!BnKuBPCvyfOkhcUjEu:cadence.moe?via=cadence.moe testing channel mentions`
+			},
+			event_id: "$g07oYSZFWBkxohNEfywldwgcWj1hbhDzQ1sBAKvqOOU",
+			origin_server_ts: 1688301929913,
+			room_id: "!kLRqKKUQXcibIMtOpl:cadence.moe",
+			sender: "@cadence:cadence.moe",
+			type: "m.room.message",
+			unsigned: {
+				age: 405299
+			}
+		}, {}, {
+			api: {
+				async getAlias(alias) {
+					called++
+					throw new MatrixServerError("Alias doesn't exist or something")
+				}
+			}
+		}),
+		{
+			ensureJoined: [],
+			messagesToDelete: [],
+			messagesToEdit: [],
+			messagesToSend: [{
+				username: "cadence [they]",
+				content: "I'm just <https://matrix.to/#/#worm-farm:cadence.moe?via=cadence.moe> and <#1100319550446252084> testing channel mentions",
+				avatar_url: undefined,
+				allowed_mentions: {
+					parse: ["users", "roles"]
+				}
+			}]
+		}
+	)
+	t.equal(called, 1)
+})
+
 test("event2message: mentioning known bridged events works (plaintext body)", async t => {
 	t.deepEqual(
 		await eventToMessage({

src/m2d/event-dispatcher.js

@@ -189,6 +189,7 @@ async event => {
 	}
 
 	await updatePins.updatePins(pins, prev)
+	await api.ackEvent(event)
 }))
 
 sync.addTemporaryListener(as, "type:m.room.member", guard("m.room.member",

src/matrix/api.js

@@ -6,7 +6,7 @@ const assert = require("assert").strict
 const fetch = require("node-fetch").default
 
 const passthrough = require("../passthrough")
-const { discord, sync, db } = passthrough
+const {sync} = passthrough
 /** @type {import("./mreq")} */
 const mreq = sync.require("./mreq")
 /** @type {import("./txnid")} */
@@ -367,6 +367,16 @@ async function ackEvent(event, mxid) {
 	await sendReadReceipt(event.room_id, event.event_id, mxid)
 }
 
+/**
+ * Resolve a room alias to a room ID.
+ * @param {string} alias
+ */
+async function getAlias(alias) {
+	/** @type {Ty.R.ResolvedRoom} */
+	const root = await mreq.mreq("GET", `/client/v3/directory/room/${encodeURIComponent(alias)}`)
+	return root.room_id
+}
+
 module.exports.path = path
 module.exports.register = register
 module.exports.createRoom = createRoom
@@ -395,3 +405,4 @@ module.exports.ping = ping
 module.exports.getMedia = getMedia
 module.exports.sendReadReceipt = sendReadReceipt
 module.exports.ackEvent = ackEvent
+module.exports.getAlias = getAlias

src/matrix/kstate.js

@@ -8,6 +8,8 @@ const passthrough = require("../passthrough")
 const {sync} = passthrough
 /** @type {import("./file")} */
 const file = sync.require("./file")
+/** @type {import("./api")} */
+const api = sync.require("./api")
 
 /** Mutates the input. Not recursive - can only include or exclude entire state events. */
 function kstateStripConditionals(kstate) {
@@ -102,8 +104,32 @@ function diffKState(actual, target) {
 	return diff
 }
 
+/* c8 ignore start */
+
+/**
+ * Async because it gets all room state from the homeserver.
+ * @param {string} roomID
+ */
+async function roomToKState(roomID) {
+	const root = await api.getAllState(roomID)
+	return stateToKState(root)
+}
+
+/**
+ * @param {string} roomID
+ * @param {any} kstate
+ */
+async function applyKStateDiffToRoom(roomID, kstate) {
+	const events = await kstateToState(kstate)
+	return Promise.all(events.map(({type, state_key, content}) =>
+		api.sendState(roomID, type, state_key, content)
+	))
+}
+
 module.exports.kstateStripConditionals = kstateStripConditionals
 module.exports.kstateUploadMxc = kstateUploadMxc
 module.exports.kstateToState = kstateToState
 module.exports.stateToKState = stateToKState
 module.exports.diffKState = diffKState
+module.exports.roomToKState = roomToKState
+module.exports.applyKStateDiffToRoom = applyKStateDiffToRoom

src/matrix/power.js

@@ -3,7 +3,6 @@
 const {db, from} = require("../passthrough")
 const {reg} = require("./read-registration")
 const ks = require("./kstate")
-const {applyKStateDiffToRoom, roomToKState} = require("../d2m/actions/create-room")
 
 /** Apply global power level requests across ALL rooms where the member cache entry exists but the power level has not been applied yet. */
 function _getAffectedRooms() {
@@ -23,9 +22,9 @@ async function applyPower() {
 
 	const rows = _getAffectedRooms()
 	for (const row of rows) {
-		const kstate = await roomToKState(row.room_id)
+		const kstate = await ks.roomToKState(row.room_id)
 		const diff = ks.diffKState(kstate, {"m.room.power_levels/": {users: {[row.mxid]: row.power_level}}})
-		await applyKStateDiffToRoom(row.room_id, diff)
+		await ks.applyKStateDiffToRoom(row.room_id, diff)
 		// There is a listener on m.room.power_levels to do this same update,
 		// but we update it here anyway since the homeserver does not always deliver the event round-trip.
 		db.prepare("UPDATE member_cache SET power_level = ? WHERE room_id = ? AND mxid = ?").run(row.power_level, row.room_id, row.mxid)

src/types.d.ts

@@ -336,6 +336,11 @@ export namespace R {
 		room_id: string
 		room_type?: string
 	}
+
+	export type ResolvedRoom = {
+		room_id: string
+		servers: string[]
+	}
 }
 
 export type Pagination<T> = {

src/web/pug/guild.pug

@@ -11,7 +11,7 @@ mixin badge-private
     | Private
 
 mixin discord(channel, radio=false)
-  - let permissions = dUtils.getPermissions([], discord.guilds.get(channel.guild_id).roles, null, channel.permission_overwrites)
+  - let permissions = dUtils.getPermissions([], guild.roles, null, channel.permission_overwrites)
   .s-user-card.s-user-card__small
     if !dUtils.hasPermission(permissions, DiscordTypes.PermissionFlagsBits.ViewChannel)
       != icons.Icons.IconLock