Implement remote account unfollow

src/processor/http/index.ts

@@ -3,6 +3,7 @@ import follow from './follow';
 import performActivityPub from './perform-activitypub';
 import processInbox from './process-inbox';
 import reportGitHubFailure from './report-github-failure';
+import unfollow from './unfollow';
 
 const handlers = {
   deliverPost,
@@ -10,6 +11,7 @@ const handlers = {
   performActivityPub,
   processInbox,
   reportGitHubFailure,
+  unfollow
 };
 
 export default (job, done) => handlers[job.data.type](job).then(() => done(), done);

src/processor/http/unfollow.ts

@@ -0,0 +1,54 @@
+import FollowedLog from '../../models/followed-log';
+import Following from '../../models/following';
+import FollowingLog from '../../models/following-log';
+import User, { isRemoteUser, pack as packUser } from '../../models/user';
+import stream from '../../publishers/stream';
+import renderFollow from '../../remote/activitypub/renderer/follow';
+import renderUndo from '../../remote/activitypub/renderer/undo';
+import context from '../../remote/activitypub/renderer/context';
+import request from '../../remote/request';
+
+export default async ({ data }) => {
+	// Delete following
+	const following = await Following.findOneAndDelete({ _id: data.id });
+	if (following === null) {
+		return;
+	}
+
+	const promisedFollower = User.findOne({ _id: following.followerId });
+	const promisedFollowee = User.findOne({ _id: following.followeeId });
+
+	await Promise.all([
+		// Decrement following count
+		User.update({ _id: following.followerId }, { $inc: { followingCount: -1 } }),
+		promisedFollower.then(({ followingCount }) => FollowingLog.insert({
+			userId: following.followerId,
+			count: followingCount - 1
+		})),
+
+		// Decrement followers count
+		User.update({ _id: following.followeeId }, { $inc: { followersCount: -1 } }),
+		promisedFollowee.then(({ followersCount }) => FollowedLog.insert({
+			userId: following.followeeId,
+			count: followersCount - 1
+		})),
+
+		// Publish follow event
+		Promise.all([promisedFollower, promisedFollowee]).then(async ([follower, followee]) => {
+			if (isRemoteUser(follower)) {
+				return;
+			}
+
+			const promisedPackedUser = packUser(followee, follower);
+
+			if (isRemoteUser(followee)) {
+				const undo = renderUndo(renderFollow(follower, followee));
+				undo['@context'] = context;
+
+				await request(follower, followee.account.inbox, undo);
+			}
+
+			stream(follower._id, 'unfollow', promisedPackedUser);
+		})
+	]);
+};