feat: Note deletion logic and refactoring, #12551

src/activitypub/inbox.js

@@ -114,6 +114,51 @@ inbox.update = async (req) => {
 	}
 };
 
+inbox.delete = async (req) => {
+	const { actor, object } = req.body;
+
+	// Deletes don't have their objects resolved automatically
+	let method = 'purge';
+	try {
+		const { type } = await activitypub.get('uid', 0, object);
+		if (type === 'Tombstone') {
+			method = 'delete';
+		}
+	} catch (e) {
+		// probably 410/404
+	}
+
+	// Origin checking
+	const actorHostname = new URL(actor).hostname;
+	const objectHostname = new URL(object).hostname;
+	if (actorHostname !== objectHostname) {
+		throw new Error('[[error:activitypub.origin-mismatch]]');
+	}
+
+	const [isNote/* , isActor */] = await Promise.all([
+		posts.exists(object),
+		// db.isSortedSetMember('usersRemote:lastCrawled', object.id),
+	]);
+
+	switch (true) {
+		case isNote: {
+			const uid = await posts.getPostField(object, 'uid');
+			await api.posts[method]({ uid }, { pid: object });
+			break;
+		}
+
+		// case isActor: {
+		// console.log('actor');
+		// break;
+		// }
+
+		default: {
+			winston.verbose(`[activitypub/inbox.delete] Object (${object}) does not exist locally. Doing nothing.`);
+			break;
+		}
+	}
+};
+
 inbox.like = async (req) => {
 	const { actor, object } = req.body;
 	const { type, id } = await activitypub.helpers.resolveLocalId(object.id);

src/activitypub/notes.js

@@ -299,7 +299,10 @@ Notes.syncUserInboxes = async function (tid, uid) {
 	const score = await db.sortedSetScore(`cid:${cid}:tids`, tid);
 
 	winston.verbose(`[activitypub/syncUserInboxes] Syncing tid ${tid} with ${uids.size} inboxes`);
-	await db.sortedSetsAdd(keys, keys.map(() => score || Date.now()), tid);
+	await Promise.all([
+		db.sortedSetsAdd(keys, keys.map(() => score || Date.now()), tid),
+		db.setAdd(`tid:${tid}:recipients`, Array.from(uids)),
+	]);
 };
 
 Notes.getCategoryFollowers = async (cid) => {
@@ -355,3 +358,21 @@ Notes.announce.remove = async (pid, actor) => {
 Notes.announce.removeAll = async (pid) => {
 	await db.delete(`pid:${pid}:announces`);
 };
+
+Notes.delete = async (pids) => {
+	if (!Array.isArray(pids)) {
+		pids = [pids];
+	}
+
+	// Valid and remote content only
+	pids = pids.filter(pid => !utils.isNumber(pid));
+	const exists = await posts.exists(pids);
+	pids = pids.filter((_, idx) => exists[idx]);
+
+	let tids = await posts.getPostsFields(pids, ['tid']);
+	tids = new Set(tids.map(obj => obj.tid));
+
+	const recipientSets = pids.map(id => `post:${id}:recipients`);
+	await db.deleteAll(recipientSets);
+	await Promise.all(Array.from(tids).map(async tid => Notes.syncUserInboxes(tid)));
+};

src/api/activitypub.js

@@ -103,7 +103,7 @@ async function buildRecipients(object, { pid, uid }) {
 
 	// Directly address user if inReplyTo
 	const parentId = await posts.getPostField(object.inReplyTo, 'uid');
-	if (activitypub.helpers.isUri(parentId) && to.has(parentId)) {
+	if (activitypub.helpers.isUri(parentId)) {
 		to.add(parentId);
 	}
 
@@ -209,6 +209,38 @@ activitypubApi.update.note = enabledCheck(async (caller, { post }) => {
 	await activitypub.send('uid', caller.uid, Array.from(targets), payload);
 });
 
+activitypubApi.delete = {};
+
+activitypubApi.delete.note = enabledCheck(async (caller, { pid }) => {
+	// Only applies to local posts
+	if (!utils.isNumber(pid)) {
+		return;
+	}
+
+	const id = `${nconf.get('url')}/post/${pid}`;
+	const object = { id };
+	const { tid, uid } = await posts.getPostFields(pid, ['tid', 'uid']);
+	const origin = `${nconf.get('url')}/topic/${tid}`;
+	const { targets } = await buildRecipients(object, { pid, uid });
+
+	const allowed = await privileges.posts.can('topics:read', pid, activitypub._constants.uid);
+	if (!allowed) {
+		winston.verbose(`[activitypub/api] Not federating update of pid ${pid} to the fediverse due to privileges.`);
+		return;
+	}
+
+	const payload = {
+		id: `${id}#activity/delete/${Date.now()}`,
+		type: 'Delete',
+		to: [],
+		cc: [],
+		object: id,
+		origin,
+	};
+
+	await activitypub.send('uid', caller.uid, Array.from(targets), payload);
+});
+
 activitypubApi.like = {};
 
 activitypubApi.like.note = enabledCheck(async (caller, { pid }) => {

src/api/posts.js

@@ -220,12 +220,18 @@ postsAPI.purge = async function (caller, data) {
 		throw new Error('[[error:invalid-data]]');
 	}
 
-	const results = await isMainAndLastPost(data.pid);
-	if (results.isMain && !results.isLast) {
+	const [exists, { isMain, isLast }] = await Promise.all([
+		posts.exists(data.pid),
+		isMainAndLastPost(data.pid),
+	]);
+	if (!exists) {
+		throw new Error('[[error:no-post]]');
+	}
+	if (isMain && !isLast) {
 		throw new Error('[[error:cant-purge-main-post]]');
 	}
 
-	const isMainAndLast = results.isMain && results.isLast;
+	const isMainAndLast = isMain && isLast;
 	const postData = await posts.getPostFields(data.pid, ['toPid', 'tid']);
 	postData.pid = data.pid;
 
@@ -234,7 +240,10 @@ postsAPI.purge = async function (caller, data) {
 		throw new Error('[[error:no-privileges]]');
 	}
 	require('../posts/cache').del(data.pid);
-	await posts.purge(data.pid, caller.uid);
+	await Promise.all([
+		posts.purge(data.pid, caller.uid),
+		require('.').activitypub.delete.note(caller, { pid: data.pid }),
+	]);
 
 	websockets.in(`topic_${postData.tid}`).emit('event:post_purged', postData);
 	const topicData = await topics.getTopicFields(postData.tid, ['title', 'cid']);

src/middleware/activitypub.js

@@ -90,8 +90,8 @@ middleware.validate = async function (req, res, next) {
 };
 
 middleware.resolveObjects = async function (req, res, next) {
-	const { object } = req.body;
-	if (typeof object === 'string' || (Array.isArray(object) && object.every(o => typeof o === 'string'))) {
+	const { type, object } = req.body;
+	if (type !== 'Delete' && (typeof object === 'string' || (Array.isArray(object) && object.every(o => typeof o === 'string')))) {
 		winston.verbose('[middleware/activitypub] Resolving object(s)...');
 		try {
 			req.body.object = await activitypub.helpers.resolveObjects(object);

src/posts/attachments.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const winston = require('winston');
 const crypto = require('crypto');
 
 const db = require('../database');
@@ -50,5 +51,13 @@ Attachments.update = async (pid, attachments) => {
 	]);
 };
 
-// todo
-// Attachments.remove = async (pid) => { ... }
+Attachments.empty = async (pids) => {
+	winston.verbose(`[posts/attachments] Emptying attachments for ids ${pids.join(', ')}.`);
+	const zsets = pids.map(pid => `post:${pid}:attachments`);
+	const hashes = await db.getSortedSetsMembers(zsets);
+	const keys = hashes
+		.reduce((memo, hashes) => new Set([...memo, ...hashes]), new Set())
+		.map(hash => `attachment:${hash}`);
+
+	await db.deleteAll(keys.concat(zsets));
+};

src/posts/delete.js

@@ -9,6 +9,7 @@ const user = require('../user');
 const notifications = require('../notifications');
 const plugins = require('../plugins');
 const flags = require('../flags');
+const activitypub = require('../activitypub');
 
 module.exports = function (Posts) {
 	Posts.delete = async function (pid, uid) {
@@ -81,6 +82,8 @@ module.exports = function (Posts) {
 			deleteDiffs(pids),
 			deleteFromUploads(pids),
 			db.sortedSetsRemove(['posts:pid', 'posts:votes', 'posts:flagged'], pids),
+			Posts.attachments.empty(pids),
+			activitypub.notes.delete(pids),
 		]);
 
 		await resolveFlags(postData, uid);

test/activitypub.js

@@ -362,7 +362,7 @@ describe('ActivityPub integration', () => {
 	});
 
 	describe('Serving of local assets to remote clients', () => {
-		describe.only('Note', () => {
+		describe('Note', () => {
 			let cid;
 			let uid;
 
@@ -532,7 +532,7 @@ describe('ActivityPub integration', () => {
 		});
 	});
 
-	describe('ActivityPub', async () => {
+	describe.only('ActivityPub', async () => {
 		let files;
 
 		before(async () => {

test/activitypub/notes.js

@@ -0,0 +1,107 @@
+'use strict';
+
+const assert = require('assert');
+
+const db = require('../../src/database');
+const user = require('../../src/user');
+const categories = require('../../src/categories');
+const topics = require('../../src/topics');
+const activitypub = require('../../src/activitypub');
+const utils = require('../../src/utils');
+
+describe('Notes', () => {
+	describe('Inbox Synchronization', () => {
+		let cid;
+		let uid;
+		let topicData;
+
+		before(async () => {
+			({ cid } = await categories.create({ name: utils.generateUUID().slice(0, 8) }));
+		});
+
+		beforeEach(async () => {
+			uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+			({ topicData } = await topics.post({
+				cid,
+				uid,
+				title: utils.generateUUID(),
+				content: utils.generateUUID(),
+			}));
+		});
+
+		it('should add a topic to a user\'s inbox if user is a recipient in OP', async () => {
+			await db.setAdd(`post:${topicData.mainPid}:recipients`, [uid]);
+			await activitypub.notes.syncUserInboxes(topicData.tid);
+			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
+
+			assert.strictEqual(inboxed, true);
+		});
+
+		it('should add a topic to a user\'s inbox if a user is a recipient in a reply', async () => {
+			const uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+			const { pid } = await topics.reply({
+				tid: topicData.tid,
+				uid,
+				content: utils.generateUUID(),
+			});
+			await db.setAdd(`post:${pid}:recipients`, [uid]);
+			await activitypub.notes.syncUserInboxes(topicData.tid);
+			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
+
+			assert.strictEqual(inboxed, true);
+		});
+
+		it('should maintain a list of recipients at the topic level', async () => {
+			await db.setAdd(`post:${topicData.mainPid}:recipients`, [uid]);
+			await activitypub.notes.syncUserInboxes(topicData.tid);
+			const [isRecipient, count] = await Promise.all([
+				db.isSetMember(`tid:${topicData.tid}:recipients`, uid),
+				db.setCount(`tid:${topicData.tid}:recipients`),
+			]);
+
+			assert(isRecipient);
+			assert.strictEqual(count, 1);
+		});
+
+		it('should add topic to a user\'s inbox if it is explicitly passed in as an argument', async () => {
+			await activitypub.notes.syncUserInboxes(topicData.tid, uid);
+			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
+
+			assert.strictEqual(inboxed, true);
+		});
+	});
+
+	describe('Deletion', () => {
+		let cid;
+		let uid;
+		let topicData;
+
+		before(async () => {
+			({ cid } = await categories.create({ name: utils.generateUUID().slice(0, 8) }));
+		});
+
+		beforeEach(async () => {
+			uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+			({ topicData } = await topics.post({
+				cid,
+				uid,
+				title: utils.generateUUID(),
+				content: utils.generateUUID(),
+			}));
+		});
+
+		it('should clean up recipient sets for the post', async () => {
+			const { pid } = await topics.reply({
+				pid: `https://example.org/${utils.generateUUID().slice(0, 8)}`,
+				tid: topicData.tid,
+				uid,
+				content: utils.generateUUID(),
+			});
+			await db.setAdd(`post:${pid}:recipients`, [uid]);
+			await activitypub.notes.delete([pid]);
+
+			const inboxed = await db.isSetMember(`post:${pid}:recipients`, uid);
+			assert(!inboxed);
+		});
+	});
+});