Update should maintain TTL

[zulander1]

When adding an object with a TTL then updating the object causes the TTL to disappear. I think we should change this behaviors so the object TTL is maintained during the update.

        var james = new Customer
        {
            Id = 1,
            FirstName = "James",
            LastName = "Bond",
            Email = "[email protected]",
            Age = 68
        };

        // Insert Object
        customers.Insert(james, TimeSpan.FromMinutes(1));

        james.FirstName = "James1";
        customers.Update(james);

This results in:

1679760370.742888 [0 172.17.0.1:37810] "JSON.SET" "Redis.OM.Test.ConsoleApp.Program+Customer:1" "." "{\"Id\":1,\"FirstName\":\"James\",\"LastName\":\"Bond\",\"Email\":\"[email protected]\",\"Age\":68,\"Home\":\"0,0\"}"
1679760370.742923 [0 172.17.0.1:37810] "SELECT" "0"
1679760370.742932 [0 172.17.0.1:37810] "PEXPIRE" "Redis.OM.Test.ConsoleApp.Program+Customer:1" "60000"
1679760370.742942 [0 172.17.0.1:37810] "SELECT" "0"
1679760370.742946 [0 172.17.0.1:37810] "EXEC"
1679760370.807542 [0 172.17.0.1:37810] "SELECT" "0"
1679760370.807566 [0 172.17.0.1:37810] "SCRIPT" "LOAD" "\\r\\nredis.call('UNLINK', KEYS[1])\\r\\nredis.call('JSON.SET', KEYS[1], '.', ARGV[1])\\r\\nreturn 0\\r\\n"
1679760370.810061 [0 172.17.0.1:37810] "SELECT" "0"
1679760370.810109 [0 172.17.0.1:37810] "EVALSHA" "662066e89db469f8f9a8a7409b603b218bc4eac8" "1" "Redis.OM.Test.ConsoleApp.Program+Customer:1" "{\"Id\":1,\"FirstName\":\"James1\",\"LastName\":\"Bond\",\"Email\":\"[email protected]\",\"Age\":68,\"Home\":\"0,0\"}"
1679760370.810221 [0 lua] "UNLINK" "Redis.OM.Test.ConsoleApp.Program+Customer:1"
1679760370.810365 [0 lua] "JSON.SET" "Redis.OM.Test.ConsoleApp.Program+Customer:1" "." "{\"Id\":1,\"FirstName\":\"James1\",\"LastName\":\"Bond\",\"Email\":\"[email protected]\",\"Age\":68,\"Home\":\"0,0\"}"

[zulander1]

I think we should combine #251 and #216 to this:

Update (T item) - update and maintain the current TTL
Update (T item, Timespan ttl) - update and when timespan is 0 then remove any TTL otherwise update to new TTL

looking at the code, its already implemented, we just implement it in the update portion !

[slorello89]

Completed in #340