Connection was forcibly closed by the remote host on receive - unit-testing

Question

Hello i am trying to understand why i am getting this exception:
Message: System.Net.Sockets.SocketException : An existing connection was forcibly closed by the remote host
I am performing unit tests using NUnit and i am using the same redis-server instance for all of the tests (hosted on local).
The first unit test set works like a charm - i can send and receive data from the Redis server.
On the second test i can send but on receive i get the exception thrown.Do i have to close the socket between tests (given it is not disposed when out of test-scope) or is there something i must be aware of when switching from a unit test to another?
Test that works
class RedisTests
{
[TestCase("*2\r\n$3\r\nget\r\n$1\r\na\r\n","$1\r\n3\r\n")]
[TestCase("*3\r\n$3\r\nset\r\n$1\r\na\r\n$1\r\n3\r\n", "+OK\r\n",Description ="Cmd:Set a 3 Result: +OK\r\n")]
public async Task RedisSetTest(string command, string expectedResult)
{
Socket socket = TConstants.MakeSocket();
IPEndPoint redisPoint = TConstants.MakeEndpoint(TConstants.DEFAULT_ADDRESS,TConstants.REDIS_PORT);
await socket.ConnectAsync(redisPoint);
Provider provider = Provider.Create(socket, 30);
await socket.SendAsync(TConstants.UTF8Encode(command), SocketFlags.None);
try
{
SmartMemory memory = await provider.ReceiveAsync();
var payload = Extensions.Map(x => (char)x,
memory.Iterator.Slice(0, memory.Message.Length).ToEnumerable()
);
string result = string.Concat(payload);
Assert.AreEqual(expectedResult, result);
}
catch (Exception exception)
{
Debug.WriteLine(exception.Message);
throw;
}
}
}
P.S The Provider's method ReceiveAsync is just a wrapper and performs the Socket.ReceiveAsync at its core the same way.
Test that throws exception
class STMTests
{
[TestCase(2)]
public async Task FillIntegerNode(int value)
{
Socket socket = TConstants.MakeSocket();
IPEndPoint redisPoint=TConstants.MakeEndpoint(TConstants.DEFAULT_ADDRESS, TConstants.REDIS_PORT);
//port = 6379
//address="127.0.0.1"
await socket.ConnectAsync(redisPoint);
Memory<byte>data=BitConverter.GetBytes(injectableNode.Value);
int sent=await socket.SendAsync(data, SocketFlags.None);
Memory<byte> dt = new byte[33];
var mem = await socket.ReceiveAsync(dt, SocketFlags.None);
Assert.IsTrue(true);
}
}
I added a picture with the test hierachy :

Answer 1

It's a general rule that if you create something disposable, then you are the one responsible for disposing of it. In this case, you are creating the socket in each test, right in the test method itself. So you have to dispose it in the test method or in a TearDown, which is run immediately after each test method.
Generally, the simplest way to dispose of something created in a test is via using.
OTOH, if you wanted all the methods in the test fixture class to use the same socket, you should open it in a OneTimeSetUp method and dispose it in a OneTimeTearDown.