hub-server

Simple TCP-based chat server. Client can be found: https://github.com/alankritjoshi/hub-client

Setup

1. go run server.go 1234

How it works

1. Use SyncMap for maintaining concurrent access to different clients
2. Use Go Routines for handling connection
3. Use handlers for input:
   1. "whoami" -> returns clientID of the requesting client
   2. "whoelse" -> returns space-separated clientIDs connected to server apart from requesting client
   3. "send [message] [clientID 1] [clientID 2] ... [clientID 3]" -> sends [message] to specified space-separated clientIDs

Checks in place

1. Hard limit of 255 simultaneous connections
2. Rejection of commands other than described above

Testing

Manual Testing

1. Tested basic functionality
2. Spun up 100 chat connections using a script and applied a sequence of 1. whoelse and 2. send [random_word] [list of clientIDs from 1.]

Unit Testing

1. Unable to make connection mocking work in interest of time so added a unit test outline once connection mocking is available

To Improve

1. Use structs to simplify data sharing for handlers
2. Use better error handling structs/package for consistent error to the client
3. Figure out how to mock connections for unit tests
4. Find an optimal way of making the "whoelse" handler work. I forgot that there's no concept of sets in GoLang but the Map can be utilized better instead of printing each clientID on the fly