Add tests for ClientHandler

[Vimbayinashe]

ClientHandler currently has a code coverage of 0% in the existing tests.

[LordRekishi]

It might be difficult to make functional tests for the ClientHandler and Server since their functionality is tied to connecting clients and sending questions and receiving responses through the network.

[Vimbayinashe]

Yes, I agree 😅! Martin mentioned that it is possible to mock a socket byte stream as an argument for ClientHandler's constructor and test its run method when I was working on issue #11 so I want to give it a try.

[LordRekishi]

Yes, I agree 😅! Martin mentioned that it is possible to mock a socket byte stream as an argument for ClientHandler's constructor and test its run method when I was working on issue #11 so I want to give it a try.

Go for it! You might also be able to use my Client stub class found in the test folder, together with what I did in @BeforeAll in my ServerTest