feat: utility functions to get local followers/counts given a remote actor uri, plumb cid into notes.assert via inbox.announce if a local cid is following the sending actor

src/activitypub/actors.js

@@ -163,3 +163,34 @@ Actors.assert = async (ids, options = {}) => {
 
 	return actors;
 };
+
+Actors.getLocalFollowers = async (id) => {
+	const response = {
+		uids: new Set(),
+		cids: new Set(),
+	};
+
+	if (!activitypub.helpers.isUri(id)) {
+		return response;
+	}
+
+	const members = await db.getSortedSetMembers(`followersRemote:${id}`);
+
+	members.forEach((id) => {
+		if (utils.isNumber(id)) {
+			response.uids.add(parseInt(id, 10));
+		} else if (id.startsWith('cid|') && utils.isNumber(id.slice(4))) {
+			response.cids.add(parseInt(id.slice(4), 10));
+		}
+	});
+
+	return response;
+};
+
+Actors.getLocalFollowersCount = async (id) => {
+	if (!activitypub.helpers.isUri(id)) {
+		return false;
+	}
+
+	return await db.sortedSetCard(`followersRemote:${id}`);
+};

src/activitypub/inbox.js

@@ -122,8 +122,8 @@ inbox.announce = async (req) => {
 		socketHelpers.sendNotificationToPostOwner(pid, actor, 'announce', 'notifications:activitypub.announce');
 	} else {
 		// Remote object
-		const isFollowed = await db.sortedSetCard(`followersRemote:${actor}`);
-		if (!isFollowed) {
+		const numFollowers = await activitypub.actors.getLocalFollowersCount(actor);
+		if (!numFollowers) {
 			winston.info(`[activitypub/inbox.announce] Rejecting ${object.id} via ${actor} due to no followers`);
 			reject('Announce', object, actor);
 			return;
@@ -135,7 +135,13 @@ inbox.announce = async (req) => {
 			return;
 		}
 
-		({ tid } = await activitypub.notes.assert(0, pid, { skipChecks: true })); // checks skipped; done above.
+		const { cids } = await activitypub.actors.getLocalFollowers(actor);
+		let cid = null;
+		if (cids.size > 0) {
+			cid = Array.from(cids)[0];
+		}
+
+		({ tid } = await activitypub.notes.assert(0, pid, { cid, skipChecks: true })); // checks skipped; done above.
 		if (!tid) {
 			return;
 		}

src/activitypub/notes.js

@@ -65,7 +65,7 @@ Notes.assert = async (uid, input, options = { skipChecks: false }) => {
 		({ cid, mainPid } = await topics.getTopicFields(tid, ['tid', 'cid', 'mainPid']));
 	} else {
 		// mainPid ok to leave as-is
-		cid = -1;
+		cid = options.cid || -1;
 		title = name || utils.decodeHTMLEntities(utils.stripHTMLTags(content));
 		if (title.length > meta.config.maximumTitleLength) {
 			title = `${title.slice(0, meta.config.maximumTitleLength - 3)}...`;
@@ -179,7 +179,7 @@ async function assertRelation(post) {
 	 */
 
 	// Is followed by at least one local user
-	const isFollowed = await db.sortedSetCard(`followersRemote:${post.uid}`);
+	const numFollowers = await activitypub.actors.getLocalFollowersCount(post.uid);
 
 	// Local user is mentioned
 	const { tag } = post._activitypub;
@@ -199,7 +199,7 @@ async function assertRelation(post) {
 		uids = uids.filter(Boolean);
 	}
 
-	return isFollowed || uids.length;
+	return numFollowers > 0 || uids.length;
 }
 
 Notes.updateLocalRecipients = async (id, { to, cc }) => {
@@ -214,11 +214,12 @@ Notes.updateLocalRecipients = async (id, { to, cc }) => {
 
 		const followedUid = await db.getObjectField('followersUrl:uid', recipient);
 		if (followedUid) {
-			const followers = await db.getSortedSetMembers(`followersRemote:${followedUid}`);
-			if (followers.length) {
-				uids.add(...followers.map(uid => parseInt(uid, 10)));
+			const { uids: followers } = await activitypub.actors.getLocalFollowers(followedUid);
+			if (followers.size > 0) {
+				followers.forEach((uid) => {
+					uids.add(uid);
+				});
 			}
-			// return;
 		}
 	}));