merge: Clone note when adding myReaction to streamed notes. (!854)

View MR for information: https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/854

Approved-by: dakkar <dakkar@thenautilus.net>
Approved-by: Marie <github@yuugi.dev>

1 files changed, 35 insertions, 4 deletions

diff --git a/packages/backend/src/server/api/stream/channel.ts b/packages/backend/src/server/api/stream/channel.ts
index 93d5046902..047dedd5ce 100644
--- a/packages/backend/src/server/api/stream/channel.ts
+++ b/packages/backend/src/server/api/stream/channel.ts
@@ -103,11 +103,42 @@ export default abstract class Channel {
 
 	public onMessage?(type: string, body: JsonValue): void;
 
-	public async assignMyReaction(note: Packed<'Note'>, noteEntityService: NoteEntityService) {
-		if (this.user && Object.keys(note.reactions).length > 0) {
-			const myReaction = await noteEntityService.populateMyReaction(note, this.user.id);
-			note.myReaction = myReaction;
+	public async assignMyReaction(note: Packed<'Note'>, noteEntityService: NoteEntityService): Promise<Packed<'Note'>> {
+		let changed = false;
+		// StreamingApiServerService creates a single EventEmitter per server process,
+		// so a new note arriving from redis gets de-serialised once per server process,
+		// and then that single object is passed to all active channels on each connection.
+		// If we didn't clone the notes here, different connections would asynchronously write
+		// different values to the same object, resulting in a random value being sent to each frontend. -- Dakkar
+		const clonedNote = { ...note };
+		if (this.user && isRenotePacked(note) && !isQuotePacked(note)) {
+			if (note.renote && Object.keys(note.renote.reactions).length > 0) {
+				const myReaction = await noteEntityService.populateMyReaction(note.renote, this.user.id);
+				if (myReaction) {
+					changed = true;
+					clonedNote.renote = { ...note.renote };
+					clonedNote.renote.myReaction = myReaction;
+				}
+			}
+			if (note.renote?.reply && Object.keys(note.renote.reply.reactions).length > 0) {
+				const myReaction = await noteEntityService.populateMyReaction(note.renote.reply, this.user.id);
+				if (myReaction) {
+					changed = true;
+					clonedNote.renote = { ...note.renote };
+					clonedNote.renote.reply = { ...note.renote.reply };
+					clonedNote.renote.reply.myReaction = myReaction;
+				}
+			}
 		}
+		if (this.user && note.reply && Object.keys(note.reply.reactions).length > 0) {
+			const myReaction = await noteEntityService.populateMyReaction(note.reply, this.user.id);
+			if (myReaction) {
+				changed = true;
+				clonedNote.reply = { ...note.reply };
+				clonedNote.reply.myReaction = myReaction;
+			}
+		}
+		return changed ? clonedNote : note;
 	}
 }