Is there a way to prevent Neovim from editing another file?

Question

When I'm using Neovim in conjunction to firenvim to edit a text box in the browser, I typically have the need to open another file.

I'd like to disable Neovim's ability to read from and write to other files besides the one in the current buffer.

This is to be used in conjunction with some other settings and features of firenvim in order to lock down Neovim inside the browser for security.

Is there a way to block Neovim from opening another file?

Answer 1

Not sure if it can close all the holes, but I'd probably start with something like:

augroup test | au!
    autocmd BufLeave * throw 'Not allowed!'
augroup end

No doubt, you also should at least have :set secure.