test that multiple clients can connect

[Augry2]

Problem Description

create a unit test for making sure that multiple clients can connect to the server simultaneously.

[kappsegla]

Testing connections from multiple clients means that we will have to start threads and also involve handling incoming connections on a server socket. That might be a bit problematic to implement as unit tests and are more of type integration tests.

[Rishad11]

We could, perhaps, simulate client connections and avoid the complexities of actual network interactions.