Optionally use lsp as default formatter

[erikzaadi]

If the setup flag lsp_as_default_formatter is passed, then instead of failing when a filetype is missing a formatter, it'll default to lsp

Partially resolves #8

[glepnir]

maybe there need create a new file ?

[erikzaadi]

You mean like a state file? Or no need to create a new file and chuck that into formatters or something?

[glepnir]

aha sry i mean no need create a file. actually I don't understand there. for use default lsp .how to register filetype ? I think something need to do in filetype module when fmt_default_lsp is true ?

[erikzaadi]

well that's the thing, you don't need to explicitly configure per file type with this change (when enabled).
The lsp format just work ™️ for whatever lsp server that's loaded for the current file type.
E.g if I'm editing a Python file and I've installed jedi or anakin, then they'll be used by the native lsp buf format function.
Regarding the config file, just wanted a in memory state for the plugin that can be set in the init file and later accessed by the formatter when invoked, thinking that this might be the first of many.
I'm quite sure I can move the config to something exposed by the formatter for the init to set if that's something you'd prefer.

[glepnir]

I think something should be like . when LspAttach register this filetype and default is lsp if you config some other tools then make lsp to the first in filetype.[this filetype]. but this mean if someone have au BufWritePre ft vim.lsp.buf.format he must remove this in his config .

[erikzaadi]

@glepnir not sure I understand the wanted changes..
if you're using nvim-lspconfig or something similar, then the filetypes are already setup automagically.
If someone has the BufWritePre thingy before using guard then it'll be the same issue before and after this pr.
Could you elaborate a bit more of the changes you want for this PR? I'll be glad to apply them!

[barrett-ruth]

@erikzaadi is this ready for merge? Having an LSP fallback is one of the last things guard.nvim needs to be to replace the majority of null-ls formatting functionality.

[erikzaadi]

@barrett-ruth IMHO Yes, still waiting for @glepnir 's reply to my comment (and approval)

[glepnir]

Sorry for the late reply. I'm confused about the implementation here. guard supports multiple tools to format a language. In fact, the filetype module creates a formatting or lint configuration table (queue) for each file type. What we should do when using lsp as default is to register filetype to filetype module in LspAttach or insert lsp into the first like

if opt.lsp_as_default then
  vim.api.nvim_create_autocmd('LspAttach', {
      calback = function(args)
              local client = vim.lsp.get_client_by_id(args.data.client_id)
              if not client:support_methods('textDoucment/format') then
                   return
              end
              local  fthandler = require('guard.filetype')
              if fthandler[vim.bo[args.buf].filetype] and  fthandler[vim.bo[args.buf].filetype].fmt  then
                          table.insert(fthandler[vim.bo[args.buf]], 1, require('guard.tool.formatter').lsp)
              else
                     fthandler(vim.bo[args.buf].filetype):fmt(require('guard.tool.formatter').lsp)
               end
      end
  })
end

typing on github. so the code just example

[erikzaadi]

@glepnir Used your reference to add the functionality , verified that it works locally.
Removed the config file, will squash the last commit before merging.

[erikzaadi]

@barrett-ruth FYI #16 (comment)