fix: check if unread_tids are followed

src/database/mongo/sorted.js

@@ -318,6 +318,9 @@ module.exports = function (module) {
 		if (!key) {
 			return;
 		}
+		if (!values.length) {
+			return [];
+		}
 		values = values.map(helpers.valueToString);
 		const results = await module.client.collection('objects').find({
 			_key: key, value: { $in: values },

src/database/postgres/sorted.js

@@ -410,6 +410,9 @@ SELECT 1
 			return;
 		}
 
+		if (!values.length) {
+			return [];
+		}
 		values = values.map(helpers.valueToString);
 
 		const res = await module.pool.query({

src/database/redis/sorted.js

@@ -203,6 +203,9 @@ module.exports = function (module) {
 	};
 
 	module.isSortedSetMembers = async function (key, values) {
+		if (!values.length) {
+			return [];
+		}
 		const batch = module.client.batch();
 		values.forEach(v => batch.zscore(key, String(v)));
 		const results = await helpers.execBatch(batch);