I use vim for editing code for some time now, At first I'd edit solutions at vim and to run tests I'd open shell and type in the command to run and check the solution. That was quit a pain. Main objective of this plugin was not to go back and forth between my shell and vim.

I've written and been using this plugin for a while. you can check on the details on Github. Main feature of this plugin is that, you can give the input test case in a buffer and it'll show the output in another buffer. Also it saves the i/o history so that you can run all the cases at once!