closes #4814

src/groups/delete.js

@@ -39,7 +39,9 @@ module.exports = function(Groups) {
 						}, next);
 					});
 				}
-			], callback);
+			], function(err) {
+				callback(err);
+			});
 		});
 	};
 };

src/groups/membership.js

@@ -13,13 +13,38 @@ var db = require('./../database');
 module.exports = function(Groups) {
 
 	Groups.join = function(groupName, uid, callback) {
-		function join() {
+		callback = callback || function() {};
-			var tasks = [
+
-				async.apply(db.sortedSetAdd, 'group:' + groupName + ':members', Date.now(), uid),
+		if (!groupName) {
-				async.apply(db.incrObjectField, 'group:' + groupName, 'memberCount')
+			return callback(new Error('[[error:invalid-data]]'));
-			];
+		}
 
 		async.waterfall([
+			function(next) {
+				Groups.isMember(uid, groupName, next);
+			},
+			function(isMember, next) {
+				if (isMember) {
+					return callback();
+				}
+				Groups.exists(groupName, next);
+			},
+			function(exists, next) {
+				if (exists) {
+					return next();
+				}
+				Groups.create({
+					name: groupName,
+					description: '',
+					hidden: 1
+				}, function(err) {
+					if (err && err.message !== '[[error:group-already-exists]]') {
+						winston.error('[groups.join] Could not create new hidden group: ' + err.message);
+						return callback(err);
+					}
+					next();
+				});
+			},
 			function(next) {
 				async.parallel({
 					isAdmin: function(next) {
@@ -31,6 +56,10 @@ module.exports = function(Groups) {
 				}, next);
 			},
 			function(results, next) {
+				var tasks = [
+					async.apply(db.sortedSetAdd, 'group:' + groupName + ':members', Date.now(), uid),
+					async.apply(db.incrObjectField, 'group:' + groupName, 'memberCount')
+				];
 				if (results.isAdmin) {
 					tasks.push(async.apply(db.setAdd, 'group:' + groupName + ':owners', uid));
 				}
@@ -50,35 +79,6 @@ module.exports = function(Groups) {
 				next();
 			}
 		], callback);
-		}
-
-		callback = callback || function() {};
-
-		if (!groupName) {
-			return callback(new Error('[[error:invalid-data]]'));
-		}
-
-		Groups.exists(groupName, function(err, exists) {
-			if (err) {
-				return callback(err);
-			}
-
-			if (exists) {
-				return join();
-			}
-
-			Groups.create({
-				name: groupName,
-				description: '',
-				hidden: 1
-			}, function(err) {
-				if (err && err.message !== '[[error:group-already-exists]]') {
-					winston.error('[groups.join] Could not create new hidden group: ' + err.message);
-					return callback(err);
-				}
-				join();
-			});
-		});
 	};
 
 	function setGroupTitleIfNotSet(groupName, uid, callback) {
@@ -204,38 +204,52 @@ module.exports = function(Groups) {
 	Groups.leave = function(groupName, uid, callback) {
 		callback = callback || function() {};
 
-		var tasks = [
+		async.waterfall([
+			function(next) {
+				Groups.isMember(uid, groupName, next);
+			},
+			function(isMember, next) {
+				if (!isMember) {
+					return callback();
+				}
+
+				Groups.exists(groupName, next);
+			},
+			function(exists, next) {
+				if (!exists) {
+					return callback();
+				}
+				async.parallel([
 					async.apply(db.sortedSetRemove, 'group:' + groupName + ':members', uid),
 					async.apply(db.setRemove, 'group:' + groupName + ':owners', uid),
 					async.apply(db.decrObjectField, 'group:' + groupName, 'memberCount')
-		];
+				], next);
-
+			},
-		async.parallel(tasks, function(err) {
+			function(results, next) {
-			if (err) {
+				Groups.getGroupFields(groupName, ['hidden', 'memberCount'], next);
-				return callback(err);
+			},
+			function(groupData, next) {
+				if (!groupData) {
+					return callback();
 				}
-
+				if (parseInt(groupData.hidden, 10) === 1 && parseInt(groupData.memberCount, 10) === 0) {
+					Groups.destroy(groupName, next);
+				} else {
+					if (parseInt(groupData.hidden, 10) !== 1) {
+						db.sortedSetAdd('groups:visible:memberCount', groupData.memberCount, groupName, next);
+					} else {
+						next();
+					}
+				}
+			},
+			function(next) {
 				plugins.fireHook('action:group.leave', {
 					groupName: groupName,
 					uid: uid
 				});
-
+				next();
-			Groups.getGroupFields(groupName, ['hidden', 'memberCount'], function(err, groupData) {
-				if (err || !groupData) {
-					return callback(err);
 			}
-
+		], callback);
-				if (parseInt(groupData.hidden, 10) === 1 && parseInt(groupData.memberCount, 10) === 0) {
-					Groups.destroy(groupName, callback);
-				} else {
-					if (parseInt(groupData.hidden, 10) !== 1) {
-						db.sortedSetAdd('groups:visible:memberCount', groupData.memberCount, groupName, callback);
-					} else {
-						callback();
-					}
-				}
-			});
-		});
 	};
 
 	Groups.leaveAllGroups = function(uid, callback) {