fix: change owner missing await

src/posts/user.js

@@ -123,7 +123,7 @@ module.exports = function (Posts) {
 	};
 
 	Posts.changeOwner = async function (pids, toUid) {
-		const exists = user.exists(toUid);
+		const exists = await user.exists(toUid);
 		if (!exists) {
 			throw new Error('[[error:no-user]]');
 		}

test/posts.js

@@ -134,6 +134,14 @@ describe('Post\'s', function () {
 		assert.strictEqual(await topics.isOwner(postResult.topicData.tid, newUid), true);
 	});
 
+	it('should fail to change owner if new owner does not exist', async function () {
+		try {
+			await posts.changeOwner([1], '9999999');
+		} catch (err) {
+			assert.strictEqual(err.message, '[[error:no-user]]');
+		}
+	});
+
 	it('should return falsy if post does not exist', function (done) {
 		posts.getPostData(9999, function (err, postData) {
 			assert.ifError(err);