Move reaction_part to new events when possible

d2m/actions/edit-message.js

@@ -53,7 +53,7 @@ async function editMessage(message, guild, row) {
 	const sendNewEventParts = new Set()
 	for (const promotion of promotions) {
 		if ("eventID" in promotion) {
-			db.prepare(`UPDATE event_message SET ${promotion.column} = 0 WHERE event_id = ?`).run(promotion.eventID)
+			db.prepare(`UPDATE event_message SET ${promotion.column} = ? WHERE event_id = ?`).run(promotion.value ?? 0, promotion.eventID)
 		} else if ("nextEvent" in promotion) {
 			sendNewEventParts.add(promotion.column)
 		}

d2m/converters/edit-to-changes.js

@@ -122,7 +122,7 @@ async function editToChanges(message, guild, api) {
 	eventsToReplace = eventsToReplace.filter(eventCanBeEdited)
 
 	// We want to maintain exactly one part = 0 and one reaction_part = 0 database row at all times.
-	/** @type {({column: string, eventID: string} | {column: string, nextEvent: true})[]} */
+	/** @type {({column: string, eventID: string, value?: number} | {column: string, nextEvent: true})[]} */
 	const promotions = []
 	for (const column of ["part", "reaction_part"]) {
 		const candidatesForParts = unchangedEvents.concat(eventsToReplace)
@@ -142,6 +142,16 @@ async function editToChanges(message, guild, api) {
 				promotions.push({column, nextEvent: true})
 			}
 		}
+		// If adding events, try to keep reactions attached to the bottom of the group (unless reactions have already been added)
+		if (eventsToSend.length && !promotions.length) {
+			const existingReaction = select("reaction", "message_id", {message_id: message.id}).pluck().get()
+			if (!existingReaction) {
+				const existingPartZero = candidatesForParts.find(p => p.old.reaction_part === 0)
+				assert(existingPartZero) // will exist because a reaction_part=0 always exists and no events are being removed
+				promotions.push({column: "reaction_part", eventID: existingPartZero.old.event_id, value: 1}) // update the current reaction_part to 1
+				promotions.push({column: "reaction_part", nextEvent: true}) // the newly created event will have reaction_part = 0
+			}
+		}
 	}
 
 	// Removing unnecessary properties before returning

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

@@ -109,7 +109,7 @@ test("edit2changes: change file type", async t => {
 	t.deepEqual(promotions, [{column: "part", nextEvent: true}, {column: "reaction_part", nextEvent: true}])
 })
 
-test("edit2changes: add caption back to that image", async t => {
+test("edit2changes: add caption back to that image (due to it having a reaction, the reaction_part will not be moved)", async t => {
 	const {eventsToRedact, eventsToReplace, eventsToSend, promotions} = await editToChanges(data.message_update.added_caption_to_image, data.guild.general, {})
 	t.deepEqual(eventsToRedact, [])
 	t.deepEqual(eventsToSend, [{
@@ -266,7 +266,14 @@ test("edit2changes: generated embed", async t => {
 			+ `</li><li>Both players present their best five-or-less-card pok...</li></ul></p></blockquote>`,
 		"m.mentions": {}
 	}])
-	t.deepEqual(promotions, []) // TODO: it would be ideal to promote this to reaction_part = 0. this is OK to do because the main message won't have had any reactions yet.
+	t.deepEqual(promotions, [{
+		"column": "reaction_part",
+		"eventID": "$mPSzglkCu-6cZHbYro0RW2u5mHvbH9aXDjO5FCzosc0",
+		"value": 1,
+	}, {
+		"column": "reaction_part",
+		"nextEvent": true,
+	}])
 	t.equal(senderMxid, "@_ooye_cadence:cadence.moe")
 	t.equal(called, 1)
 })
@@ -308,6 +315,13 @@ test("edit2changes: generated embed on a reply", async t => {
 			+ `</p><p>You're invited to talk on Matrix. If you don't already have a client this link will help you pick one, and join the conversation. If you already have one, this link will help you join the conversation</p></blockquote>`,
 		"m.mentions": {}
 	}])
-	t.deepEqual(promotions, []) // TODO: it would be ideal to promote this to reaction_part = 0. this is OK to do because the main message won't have had any reactions yet.
+	t.deepEqual(promotions, [{
+		"column": "reaction_part",
+		"eventID": "$UTqiL3Zj3FC4qldxRLggN1fhygpKl8sZ7XGY5f9MNbF",
+		"value": 1,
+	}, {
+		"column": "reaction_part",
+		"nextEvent": true,
+	}])
 	t.equal(senderMxid, "@_ooye_cadence:cadence.moe")
 })

test/ooye-test-data.sql

@@ -148,6 +148,9 @@ INSERT INTO member_cache (room_id, mxid, displayname, avatar_url, power_level) V
 ('!kLRqKKUQXcibIMtOpl:cadence.moe', '@test_auto_invite:example.org', NULL, NULL, 0),
 ('!BpMdOUkWWhFxmTrENV:cadence.moe', '@test_auto_invite:example.org', NULL, NULL, 100);
 
+INSERT INTO reaction (hashed_event_id, message_id, encoded_emoji) VALUES
+(5162930312280790092, '1141501302736695317', '%F0%9F%90%88');
+
 INSERT INTO member_power (mxid, room_id, power_level) VALUES
 ('@test_auto_invite:example.org', '*', 100);