Link: https://github.com/whatever555/vim-code-checker
It should work on recent versions of vim, and also neovim. It does require the installation of an npm package (details in the README) so a recent version of node is required.
It is a simple barebones project that I have been using locally, but I thought it might be a good idea to share it with the world, and get some feedback. So any suggestions on how to improve it, or if there are better options already available, please let me know. Thanks for reading!