README.md

Simple chat

Implements test assignment from a company I was interviewing for.

Running

1. Build, test and publish

   dotnet build
   dotnet test
   dotnet publish

2. Navigate to published server

   pushd ./examples/published/server
   ./chat-server
   # Something happening, Ctrl-C when finished

   same for client (in another terminal, maybe run several of them)

   pushd ./examples/published/server
   ./chat-server
   # Something happening, Ctrl-C when finished

3. Some interaction in client terminal

   Victor entered the chat
   :l
   Barrens-General
   LFG
   :c NewRoom
   :j LFG
   [room=LFG][user=Victor]: HEllo
   Joined ChatRoom[Id=2,Name=LFG]
   :s LFG Hello from another window
   [room=LFG][user=Antti]: Hello from another window
   [room=LFG][user=Victor]: Well, hello there
   

Some notes

• The chat library itself relies on the underlying transport (implementation of IChatTransport) to throw an error from Receive call on disconnection. Unfortunately, with plain TCP implementation that is bundled in examples one can wait for quite a while until OS closes the socket and Receive errors out. One possible workaround is to have a transport-level keepalive but I didn't implement it.
  • In tests this is achieved by closing writing part of the Channel-based transport, which is instantaneous.
• The API provided is centered around proxy-like objects (especially on the client - IRoom there is a proxy), so some scenarios like "listen to any message in any room" will required something like Task.WhenAny(rooms.Select(room => room.GetMessage())) polling.
• Polling - the API doesn't use callbacks as it's simpler to use polling on Tasks and it gives more control. But implementing callback-based API on top of Task is entirely possible, just like it's possible to do the other way round.
• ! First build after dotnet clean fails: see non-reproducible issue on GitHub that reproduces all-right on my machine.
• Short description of client (admittedly poor) commands (found in examples/console-interaction):
  • :l - list available rooms
  • :c <RoomNameSingleWord> - create room
  • :j <RoomNameSingleWord> - join room
  • :s <RoomNameSingleWord> Message any number of words - send message to the room