Question / recipe: How to use cmp-buffer as a replacement for Vim's builtin `<C-n>/<C-p>` keyword completion?

[jfly]

I'd like to use cmp-buffer as a completion source for nvim-cmp, but only when I explicitly request completion via <C-n>/<C-p>.

I've hacked this together locally:

1. I created a new nvim-cmp source that wraps cmp-buffer. The only difference is that my complete method doesn't do anything if params.context:get_reason() == types.cmp.ContextReason.Manual.
   • I found this feature request to nvim-cmp asking about this: Create a source which is only available when completion is manually triggered? nvim-cmp#803. AFAICT, there isn't a better way to do this right now other than creating a "wrapper source".
2. I added <C-n>/<C-p> mappings to invoke require("cmp").complete.
   • This probably isn't all the relevant mappings.
   • This triggers nvim-cmp to look for completions from all sources. Ideally this would only trigger cmp-buffer. I don't see any mechanism to filter sources when invoking complete, the code seems to just unconditionally loop over all sources.