should_attach - what to disable on?

[gegoune]

Hey, have recently realised that I null-ls runs on some buffers that make no sense, for example those of diffview, so I have disabled it with:

  should_attach = function(bufnr)
    return not vim.api.nvim_buf_get_name(bufnr):match '^diffview://'
  end,

Got two questions:

1. what are some other common windows/buffers worth disabling? Should they perhaps be added to null-ls by default, which brings me to Q2
2. Documentation states:

To cut down potentially expensive calls, null-ls will call should_attach after its own internal checks pass, so it's not guaranteed to run on each new buffer.

What are those checks?

Thanks!

[jose-elias-alvarez]

I've erred on the side of not disabling things just because I didn't want to limit the kinds of sources people could make (for example, buffers that operate on Git commit buffers). You can see the default check logic here - the basic idea is to attach only to named file buffers. Even this may be too strict, since in #819 we found that acwrite buffers may also be valid targets.

[gegoune]

Thank you for an answer. It makes sense not to add anything to the plugin, I understand it now. Still, would be nice to have a list (maybe on wiki?) for commonly disabled buffers, for example on packer's window, which builtin check returns true for at the moment.

[jose-elias-alvarez]

That's strange that it's running in Packer's window, since that should be marked as a non-file buffer. I'll look into it a bit more, I also think we can be a bit more aggressive about disabling things like diffview until we specifically run into a problem.