Added "When" parameter to SortedSetAdd to support NX and XX options

StackExchange.Redis.Tests/DatabaseWrapperTests.cs

@@ -638,16 +638,16 @@ public void SortAndStore()
         [Test]
         public void SortedSetAdd_1()
         {
-            wrapper.SortedSetAdd("key", "member", 1.23, CommandFlags.HighPriority);
-            mock.Verify(_ => _.SortedSetAdd("prefix:key", "member", 1.23, CommandFlags.HighPriority));
+            wrapper.SortedSetAdd("key", "member", 1.23, When.Exists, CommandFlags.HighPriority);
+            mock.Verify(_ => _.SortedSetAdd("prefix:key", "member", 1.23, When.Exists, CommandFlags.HighPriority));
         }
 
         [Test]
         public void SortedSetAdd_2()
         {
             SortedSetEntry[] values = new SortedSetEntry[0];
-            wrapper.SortedSetAdd("key", values, CommandFlags.HighPriority);
-            mock.Verify(_ => _.SortedSetAdd("prefix:key", values, CommandFlags.HighPriority));
+            wrapper.SortedSetAdd("key", values, When.Exists, CommandFlags.HighPriority);
+            mock.Verify(_ => _.SortedSetAdd("prefix:key", values, When.Exists, CommandFlags.HighPriority));
         }
 
         [Test]

StackExchange.Redis.Tests/Issues/SO23949477.cs

@@ -13,14 +13,16 @@ public void Execute()
                 var db = conn.GetDatabase(0);
                 RedisKey key = Me();
                 db.KeyDelete(key, CommandFlags.FireAndForget);
-                db.SortedSetAdd(key, "c", 3, CommandFlags.FireAndForget);
+                db.SortedSetAdd(key, "c", 3, When.Always, CommandFlags.FireAndForget);
                 db.SortedSetAdd(key,
                     new[] {
                         new SortedSetEntry("a", 1),
                         new SortedSetEntry("b", 2),
                         new SortedSetEntry("d", 4),
                         new SortedSetEntry("e", 5)
-                    }, CommandFlags.FireAndForget);
+                    },
+                    When.Always,
+                    CommandFlags.FireAndForget);
                 var pairs = db.SortedSetRangeByScoreWithScores(
                     key, order: Order.Descending, take: 3);
                 Assert.AreEqual(3, pairs.Length);

StackExchange.Redis.Tests/WrapperBaseTests.cs

@@ -601,16 +601,16 @@ public void SortAsync()
         [Test]
         public void SortedSetAddAsync_1()
         {
-            wrapper.SortedSetAddAsync("key", "member", 1.23, CommandFlags.HighPriority);
-            mock.Verify(_ => _.SortedSetAddAsync("prefix:key", "member", 1.23, CommandFlags.HighPriority));
+            wrapper.SortedSetAddAsync("key", "member", 1.23, When.Exists, CommandFlags.HighPriority);
+            mock.Verify(_ => _.SortedSetAddAsync("prefix:key", "member", 1.23, When.Exists, CommandFlags.HighPriority));
         }
 
         [Test]
         public void SortedSetAddAsync_2()
         {
             SortedSetEntry[] values = new SortedSetEntry[0];
-            wrapper.SortedSetAddAsync("key", values, CommandFlags.HighPriority);
-            mock.Verify(_ => _.SortedSetAddAsync("prefix:key", values, CommandFlags.HighPriority));
+            wrapper.SortedSetAddAsync("key", values, When.Exists, CommandFlags.HighPriority);
+            mock.Verify(_ => _.SortedSetAddAsync("prefix:key", values, When.Exists, CommandFlags.HighPriority));
         }
 
         [Test]

StackExchange.Redis/StackExchange/Redis/IDatabase.cs

@@ -638,14 +638,14 @@ public interface IDatabase : IRedis, IDatabaseAsync
         /// </summary>
         /// <returns>True if the value was added, False if it already existed (the score is still updated)</returns>
         /// <remarks>http://redis.io/commands/zadd</remarks>
-        bool SortedSetAdd(RedisKey key, RedisValue member, double score, CommandFlags flags = CommandFlags.None);
+        bool SortedSetAdd(RedisKey key, RedisValue member, double score, When when = When.Always, CommandFlags flags = CommandFlags.None);
 
         /// <summary>
         /// Adds all the specified members with the specified scores to the sorted set stored at key. If a specified member is already a member of the sorted set, the score is updated and the element reinserted at the right position to ensure the correct ordering.
         /// </summary>
         /// <returns>The number of elements added to the sorted sets, not including elements already existing for which the score was updated.</returns>
         /// <remarks>http://redis.io/commands/zadd</remarks>
-        long SortedSetAdd(RedisKey key, SortedSetEntry[] values, CommandFlags flags = CommandFlags.None);
+        long SortedSetAdd(RedisKey key, SortedSetEntry[] values, When when = When.Always, CommandFlags flags = CommandFlags.None);
 
         /// <summary>
         /// Computes a set operation over two sorted sets, and stores the result in destination, optionally performing 

StackExchange.Redis/StackExchange/Redis/IDatabaseAsync.cs

@@ -596,14 +596,14 @@ public interface IDatabaseAsync : IRedisAsync
         /// </summary>
         /// <returns>True if the value was added, False if it already existed (the score is still updated)</returns>
         /// <remarks>http://redis.io/commands/zadd</remarks>
-        Task<bool> SortedSetAddAsync(RedisKey key, RedisValue member, double score, CommandFlags flags = CommandFlags.None);
+        Task<bool> SortedSetAddAsync(RedisKey key, RedisValue member, double score, When when = When.Always, CommandFlags flags = CommandFlags.None);
 
         /// <summary>
         /// Adds all the specified members with the specified scores to the sorted set stored at key. If a specified member is already a member of the sorted set, the score is updated and the element reinserted at the right position to ensure the correct ordering.
         /// </summary>
         /// <returns>The number of elements added to the sorted sets, not including elements already existing for which the score was updated.</returns>
         /// <remarks>http://redis.io/commands/zadd</remarks>
-        Task<long> SortedSetAddAsync(RedisKey key, SortedSetEntry[] values, CommandFlags flags = CommandFlags.None);
+        Task<long> SortedSetAddAsync(RedisKey key, SortedSetEntry[] values, When when = When.Always, CommandFlags flags = CommandFlags.None);
 
         /// <summary>
         /// Computes a set operation over two sorted sets, and stores the result in destination, optionally performing 

StackExchange.Redis/StackExchange/Redis/KeyspaceIsolation/DatabaseWrapper.cs

@@ -416,14 +416,14 @@ public RedisValue[] Sort(RedisKey key, long skip = 0, long take = -1, Order orde
             return Inner.Sort(ToInner(key), skip, take, order, sortType, SortByToInner(by), SortGetToInner(get), flags);
         }
 
-        public long SortedSetAdd(RedisKey key, SortedSetEntry[] values, CommandFlags flags = CommandFlags.None)
+        public long SortedSetAdd(RedisKey key, SortedSetEntry[] values, When when = When.Always, CommandFlags flags = CommandFlags.None)
         {
-            return Inner.SortedSetAdd(ToInner(key), values, flags);
+            return Inner.SortedSetAdd(ToInner(key), values, when, flags);
         }
 
-        public bool SortedSetAdd(RedisKey key, RedisValue member, double score, CommandFlags flags = CommandFlags.None)
+        public bool SortedSetAdd(RedisKey key, RedisValue member, double score, When when = When.Always, CommandFlags flags = CommandFlags.None)
         {
-            return Inner.SortedSetAdd(ToInner(key), member, score, flags);
+            return Inner.SortedSetAdd(ToInner(key), member, score, when, flags);
         }
 
         public long SortedSetCombineAndStore(SetOperation operation, RedisKey destination, RedisKey[] keys, double[] weights = null, Aggregate aggregate = Aggregate.Sum, CommandFlags flags = CommandFlags.None)

StackExchange.Redis/StackExchange/Redis/KeyspaceIsolation/WrapperBase.cs

@@ -416,14 +416,14 @@ public Task<RedisValue[]> SortAsync(RedisKey key, long skip = 0, long take = -1,
             return Inner.SortAsync(ToInner(key), skip, take, order, sortType, SortByToInner(by), SortGetToInner(get), flags);
         }
 
-        public Task<long> SortedSetAddAsync(RedisKey key, SortedSetEntry[] values, CommandFlags flags = CommandFlags.None)
+        public Task<long> SortedSetAddAsync(RedisKey key, SortedSetEntry[] values, When when = When.Always, CommandFlags flags = CommandFlags.None)
         {
-            return Inner.SortedSetAddAsync(ToInner(key), values, flags);
+            return Inner.SortedSetAddAsync(ToInner(key), values, when, flags);
         }
 
-        public Task<bool> SortedSetAddAsync(RedisKey key, RedisValue member, double score, CommandFlags flags = CommandFlags.None)
+        public Task<bool> SortedSetAddAsync(RedisKey key, RedisValue member, double score, When when = When.Always, CommandFlags flags = CommandFlags.None)
         {
-            return Inner.SortedSetAddAsync(ToInner(key), member, score, flags);
+            return Inner.SortedSetAddAsync(ToInner(key), member, score, when, flags);
         }
 
         public Task<long> SortedSetCombineAndStoreAsync(SetOperation operation, RedisKey destination, RedisKey[] keys, double[] weights = null, Aggregate aggregate = Aggregate.Sum, CommandFlags flags = CommandFlags.None)

StackExchange.Redis/StackExchange/Redis/RedisDatabase.cs

@@ -1146,27 +1146,27 @@ public Task<RedisValue[]> SortAsync(RedisKey key, long skip = 0, long take = -1,
             return ExecuteAsync(msg, ResultProcessor.RedisValueArray);
         }
 
-        public bool SortedSetAdd(RedisKey key, RedisValue member, double score, CommandFlags flags = CommandFlags.None)
+        public bool SortedSetAdd(RedisKey key, RedisValue member, double score, When when = When.Always, CommandFlags flags = CommandFlags.None)
         {
-            var msg = Message.Create(Database, flags, RedisCommand.ZADD, key, score, member);
+            var msg = GetSortedSetAddMessage(key, member, score, when, flags);
             return ExecuteSync(msg, ResultProcessor.Boolean);
         }
 
-        public long SortedSetAdd(RedisKey key, SortedSetEntry[] values, CommandFlags flags = CommandFlags.None)
+        public long SortedSetAdd(RedisKey key, SortedSetEntry[] values, When when = When.Always, CommandFlags flags = CommandFlags.None)
         {
-            var msg = GetSortedSetAddMessage(key, values, flags);
+            var msg = GetSortedSetAddMessage(key, values, when, flags);
             return ExecuteSync(msg, ResultProcessor.Int64);
         }
 
-        public Task<bool> SortedSetAddAsync(RedisKey key, RedisValue member, double score, CommandFlags flags = CommandFlags.None)
+        public Task<bool> SortedSetAddAsync(RedisKey key, RedisValue member, double score, When when = When.Always, CommandFlags flags = CommandFlags.None)
         {
-            var msg = Message.Create(Database, flags, RedisCommand.ZADD, key, score, member);
+            var msg = GetSortedSetAddMessage(key, member, score, when, flags);
             return ExecuteAsync(msg, ResultProcessor.Boolean);
         }
 
-        public Task<long> SortedSetAddAsync(RedisKey key, SortedSetEntry[] values, CommandFlags flags = CommandFlags.None)
+        public Task<long> SortedSetAddAsync(RedisKey key, SortedSetEntry[] values, When when = When.Always, CommandFlags flags = CommandFlags.None)
         {
-            var msg = GetSortedSetAddMessage(key, values, flags);
+            var msg = GetSortedSetAddMessage(key, values, when, flags);
             return ExecuteAsync(msg, ResultProcessor.Int64);
         }
 
@@ -1741,22 +1741,45 @@ Message GetRestoreMessage(RedisKey key, byte[] value, TimeSpan? expiry, CommandF
             return Message.Create(Database, flags, RedisCommand.RESTORE, key, pttl, value);
         }
 
-        private Message GetSortedSetAddMessage(RedisKey key, SortedSetEntry[] values, CommandFlags flags)
+        private Message GetSortedSetAddMessage(RedisKey key, RedisValue member, double score, When when, CommandFlags flags)
         {
+            WhenAlwaysOrExistsOrNotExists(when);
+            switch (when)
+            {
+                case When.Always: return Message.Create(Database, flags, RedisCommand.ZADD, key, score, member);
+                case When.NotExists: return Message.Create(Database, flags, RedisCommand.ZADD, key, RedisLiterals.NX, score, member);
+                case When.Exists: return Message.Create(Database, flags, RedisCommand.ZADD, key, RedisLiterals.XX, score, member);
+                default: throw new ArgumentOutOfRangeException(nameof(when));
+            }
+        }
+
+        private Message GetSortedSetAddMessage(RedisKey key, SortedSetEntry[] values, When when, CommandFlags flags)
+        {
+            WhenAlwaysOrExistsOrNotExists(when);
             if (values == null) throw new ArgumentNullException(nameof(values));
             switch (values.Length)
             {
                 case 0: return null;
                 case 1:
-                    return Message.Create(Database, flags, RedisCommand.ZADD, key,
-                        values[0].score, values[0].element);
-                case 2:
-                    return Message.Create(Database, flags, RedisCommand.ZADD, key,
-                        values[0].score, values[0].element,
-                        values[1].score, values[1].element);
+                    return GetSortedSetAddMessage(key, values[0].element, values[0].score, when, flags);
                 default:
-                    var arr = new RedisValue[values.Length * 2];
+                    RedisValue[] arr;
                     int index = 0;
+                    switch (when)
+                    {
+                        case When.Always:
+                            arr = new RedisValue[values.Length * 2];
+                            break;
+                        case When.NotExists:
+                            arr = new RedisValue[values.Length * 2 + 1];
+                            arr[index++] = RedisLiterals.NX;
+                            break;
+                        case When.Exists:
+                            arr = new RedisValue[values.Length * 2 + 1];
+                            arr[index++] = RedisLiterals.XX;
+                            break;
+                        default: throw new ArgumentOutOfRangeException(nameof(when));
+                    }
                     for (int i = 0; i < values.Length; i++)
                     {
                         arr[index++] = values[i].score;