Promote another event if part = 0 is redacted

d2m/actions/edit-message.js

@@ -1,7 +1,7 @@
 // @ts-check
 
 const passthrough = require("../../passthrough")
-const { sync, db } = passthrough
+const {sync, db, select} = passthrough
 /** @type {import("../converters/edit-to-changes")} */
 const editToChanges = sync.require("../converters/edit-to-changes")
 /** @type {import("../../matrix/api")} */
@@ -12,7 +12,7 @@ const api = sync.require("../../matrix/api")
  * @param {import("discord-api-types/v10").APIGuild} guild
  */
 async function editMessage(message, guild) {
-	const {roomID, eventsToRedact, eventsToReplace, eventsToSend, senderMxid} = await editToChanges.editToChanges(message, guild, api)
+	const {roomID, eventsToRedact, eventsToReplace, eventsToSend, senderMxid, promoteEvent, promoteNextEvent} = await editToChanges.editToChanges(message, guild, api)
 
 	// 1. Replace all the things.
 	for (const {oldID, newContent} of eventsToReplace) {
@@ -33,10 +33,17 @@ async function editMessage(message, guild) {
 	for (const eventID of eventsToRedact) {
 		await api.redactEvent(roomID, eventID, senderMxid)
 		db.prepare("DELETE FROM event_message WHERE event_id = ?").run(eventID)
-		// TODO: If I just redacted part = 0, I should update one of the other events to make it the new part = 0, right?
 	}
 
-	// 3. Send all the things.
+	// 3. Consistency: Ensure there is exactly one part = 0
+	let eventPart = 1
+	if (promoteEvent) {
+		db.prepare("UPDATE event_message SET part = 0 WHERE event_id = ?").run(promoteEvent)
+	} else if (promoteNextEvent) {
+		eventPart = 0
+	}
+
+	// 4. Send all the things.
 	for (const content of eventsToSend) {
 		const eventType = content.$type
 		/** @type {Pick<typeof content, Exclude<keyof content, "$type">> & { $type?: string }} */
@@ -44,7 +51,9 @@ async function editMessage(message, guild) {
 		delete contentWithoutType.$type
 
 		const eventID = await api.sendEvent(roomID, eventType, contentWithoutType, senderMxid)
-		db.prepare("INSERT INTO event_message (event_id, event_type, event_subtype, message_id, part, source) VALUES (?, ?, ?, ?, 1, 1)").run(eventID, eventType, content.msgtype || null, message.id) // part 1 = supporting; source 1 = discord
+		db.prepare("INSERT INTO event_message (event_id, event_type, event_subtype, message_id, part, source) VALUES (?, ?, ?, ?, ?, 1)").run(eventID, eventType, content.msgtype || null, message.id, eventPart) // part 1 = supporting; source 1 = discord
+
+		eventPart = 1
 	}
 }
 

d2m/converters/edit-to-changes.js

@@ -83,6 +83,20 @@ async function editToChanges(message, guild, api) {
 	// Anything remaining in oldEventRows is present in the old version only and should be redacted.
 	eventsToRedact = oldEventRows
 
+	// If events are being deleted, we might be deleting the part = 0. But we want to have a part = 0 at all times. In this case we choose an existing event to promote.
+	let promoteEvent = null, promoteNextEvent = false
+	if (eventsToRedact.some(e => e.part === 0)) {
+		if (eventsToReplace.length) {
+			// We can choose an existing event to promote. Bigger order is better.
+			const order = e => 2*+(e.event_type === "m.room.message") + 1*+(e.event_subtype === "m.text")
+			eventsToReplace.sort((a, b) => order(b) - order(a))
+			promoteEvent = eventsToReplace[0].old.event_id
+		} else {
+			// Everything is being deleted. Whatever gets sent in their place will be the new part = 0.
+			promoteNextEvent = true
+		}
+	}
+
 	// Now, everything in eventsToSend and eventsToRedact is a real change, but everything in eventsToReplace might not have actually changed!
 	// (Example: a MESSAGE_UPDATE for a text+image message - Discord does not allow the image to be changed, but the text might have been.)
 	// So we'll remove entries from eventsToReplace that *definitely* cannot have changed. (This is category 4 mentioned above.) Everything remaining *may* have changed.
@@ -103,7 +117,7 @@ async function editToChanges(message, guild, api) {
 	eventsToRedact = eventsToRedact.map(e => e.event_id)
 	eventsToReplace = eventsToReplace.map(e => ({oldID: e.old.event_id, newContent: makeReplacementEventContent(e.old.event_id, e.newFallbackContent, e.newInnerContent)}))
 
-	return {roomID, eventsToReplace, eventsToRedact, eventsToSend, senderMxid}
+	return {roomID, eventsToReplace, eventsToRedact, eventsToSend, senderMxid, promoteEvent, promoteNextEvent}
 }
 
 /**

d2m/converters/edit-to-changes.test.js

@@ -4,7 +4,7 @@ const data = require("../../test/data")
 const Ty = require("../../types")
 
 test("edit2changes: edit by webhook", async t => {
-	const {senderMxid, eventsToRedact, eventsToReplace, eventsToSend} = await editToChanges(data.message_update.edit_by_webhook, data.guild.general, {})
+	const {senderMxid, eventsToRedact, eventsToReplace, eventsToSend, promoteEvent, promoteNextEvent} = await editToChanges(data.message_update.edit_by_webhook, data.guild.general, {})
 	t.deepEqual(eventsToRedact, [])
 	t.deepEqual(eventsToSend, [])
 	t.deepEqual(eventsToReplace, [{
@@ -27,10 +27,12 @@ test("edit2changes: edit by webhook", async t => {
 		}
 	}])
 	t.equal(senderMxid, null)
+	t.equal(promoteEvent, null)
+	t.equal(promoteNextEvent, false)
 })
 
 test("edit2changes: bot response", async t => {
-	const {senderMxid, eventsToRedact, eventsToReplace, eventsToSend} = await editToChanges(data.message_update.bot_response, data.guild.general, {
+	const {senderMxid, eventsToRedact, eventsToReplace, eventsToSend, promoteEvent, promoteNextEvent} = await editToChanges(data.message_update.bot_response, data.guild.general, {
 		async getJoinedMembers(roomID) {
 			t.equal(roomID, "!hYnGGlPHlbujVVfktC:cadence.moe")
 			return new Promise(resolve => {
@@ -82,17 +84,21 @@ test("edit2changes: bot response", async t => {
 		}
 	}])
 	t.equal(senderMxid, "@_ooye_bojack_horseman:cadence.moe")
+	t.equal(promoteEvent, null)
+	t.equal(promoteNextEvent, false)
 })
 
 test("edit2changes: remove caption from image", async t => {
-	const {eventsToRedact, eventsToReplace, eventsToSend} = await editToChanges(data.message_update.removed_caption_from_image, data.guild.general, {})
+	const {eventsToRedact, eventsToReplace, eventsToSend, promoteEvent, promoteNextEvent} = await editToChanges(data.message_update.removed_caption_from_image, data.guild.general, {})
 	t.deepEqual(eventsToRedact, ["$mtR8cJqM4fKno1bVsm8F4wUVqSntt2sq6jav1lyavuA"])
 	t.deepEqual(eventsToSend, [])
 	t.deepEqual(eventsToReplace, [])
+	t.equal(promoteEvent, "$51f4yqHinwnSbPEQ9dCgoyy4qiIJSX0QYYVUnvwyTCI")
+	t.equal(promoteNextEvent, false)
 })
 
 test("edit2changes: add caption back to that image", async t => {
-	const {eventsToRedact, eventsToReplace, eventsToSend} = await editToChanges(data.message_update.added_caption_to_image, data.guild.general, {})
+	const {eventsToRedact, eventsToReplace, eventsToSend, promoteEvent, promoteNextEvent} = await editToChanges(data.message_update.added_caption_to_image, data.guild.general, {})
 	t.deepEqual(eventsToRedact, [])
 	t.deepEqual(eventsToSend, [{
 		$type: "m.room.message",
@@ -101,6 +107,8 @@ test("edit2changes: add caption back to that image", async t => {
 		"m.mentions": {}
 	}])
 	t.deepEqual(eventsToReplace, [])
+	t.equal(promoteEvent, null)
+	t.equal(promoteNextEvent, false)
 })
 
 test("edit2changes: stickers and attachments are not changed, only the content can be edited", async t => {