feat: ability to query remote users by webfinger handle

src/activitypub/actors.js

@@ -31,10 +31,8 @@ Actors.assert = async (ids, options = {}) => {
 	// Translate webfinger handles to uris
 	ids = (await Promise.all(ids.map(async (id) => {
 		const originalId = id;
-		const isUri = activitypub.helpers.isUri(id);
-		// only look up webfinger if the id is not a supported URI
-		if (id.includes('@') && !isUri) {
-			const host = isUri ? new URL(id).host : id.split('@')[1];
+		if (activitypub.helpers.isWebfinger(id)) {
+			const host = id.split('@')[1];
 			if (host === nconf.get('url_parsed').host) { // do not assert loopback ids
 				return 'loopback';
 			}

src/activitypub/helpers.js

@@ -15,6 +15,7 @@ const ttl = require('../cache/ttl');
 const user = require('../user');
 const activitypub = require('.');
 
+const webfingerRegex = /^(@|acct:)?\w+@.+$/;
 const webfingerCache = ttl({ ttl: 1000 * 60 * 60 * 24 }); // 24 hours
 
 const Helpers = module.exports;
@@ -33,6 +34,21 @@ Helpers.isUri = (value) => {
 	});
 };
 
+Helpers.isWebfinger = (value) => {
+	// N.B. returns normalized handle, so truthy check!
+	if (webfingerRegex.test(value) && !Helpers.isUri(value)) {
+		if (value.startsWith('@')) {
+			return value.slice(1);
+		} else if (value.startsWith('acct:')) {
+			return value.slice(5);
+		}
+
+		return value;
+	}
+
+	return false;
+};
+
 Helpers.query = async (id) => {
 	const isUri = Helpers.isUri(id);
 	// username@host ids use acct: URI schema

src/user/search.js

@@ -41,14 +41,17 @@ module.exports = function (User) {
 		} else if (searchBy === 'uid') {
 			uids = [query];
 		} else {
-			if (!data.findUids && data.uid && activitypub.helpers.isUri(data.query)) {
-				const assertion = await activitypub.actors.assert([data.query]);
+			if (!data.findUids && data.uid) {
+				const handle = activitypub.helpers.isWebfinger(data.query);
+				if (handle || activitypub.helpers.isUri(data.query)) {
+					const assertion = await activitypub.actors.assert([handle || data.query]);
 					if (assertion === true) {
-					uids = [query];
+						uids = [handle ? await User.getUidByUserslug(handle) : query];
 					} else if (Array.isArray(assertion) && assertion.length) {
 						uids = assertion.map(u => u.id);
 					}
 				}
+			}
 
 			if (!uids.length) {
 				const searchMethod = data.findUids || findUids;