From 18181260e7b0e19181fc499a8dbfc91891d50fd5 Mon Sep 17 00:00:00 2001
From: Baris Usakli <barisusakli@gmail.com>
Date: Tue, 18 Jul 2017 13:36:21 -0400
Subject: [PATCH] closes #5836

---
 src/groups/membership.js |  4 ++++
 test/groups.js           | 26 ++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/src/groups/membership.js b/src/groups/membership.js
index 1fc06cb5a5..8ffd845443 100644
--- a/src/groups/membership.js
+++ b/src/groups/membership.js
@@ -28,6 +28,10 @@ module.exports = function (Groups) {
 			return callback(new Error('[[error:invalid-data]]'));
 		}
 
+		if (!uid) {
+			return callback(new Error('[[error:invalid-uid]]'));
+		}
+
 		async.waterfall([
 			function (next) {
 				Groups.isMember(uid, groupName, next);
diff --git a/test/groups.js b/test/groups.js
index e914953e10..d245f5744d 100644
--- a/test/groups.js
+++ b/test/groups.js
@@ -411,6 +411,32 @@ describe('Groups', function () {
 				});
 			});
 		});
+
+		it('should fail to add user to group if group name is invalid', function (done) {
+			Groups.join(0, 1, function (err) {
+				assert.equal(err.message, '[[error:invalid-data]]');
+				Groups.join(null, 1, function (err) {
+					assert.equal(err.message, '[[error:invalid-data]]');
+					Groups.join(undefined, 1, function (err) {
+						assert.equal(err.message, '[[error:invalid-data]]');
+						done();
+					});
+				});
+			});
+		});
+
+		it('should fail to add user to group if uid is invalid', function (done) {
+			Groups.join('Test', 0, function (err) {
+				assert.equal(err.message, '[[error:invalid-uid]]');
+				Groups.join('Test', null, function (err) {
+					assert.equal(err.message, '[[error:invalid-uid]]');
+					Groups.join('Test', undefined, function (err) {
+						assert.equal(err.message, '[[error:invalid-uid]]');
+						done();
+					});
+				});
+			});
+		});
 	});
 
 	describe('.leave()', function () {