Nvim: Conditional linter settings based on buffer filetype?

[tom-gora]

Hi! So I am trying to dynamically toggle linters based on filetype. For now trying in markdown and the notification confirms that when I switch to markdown buffer the table is modified and I get no errors. Are values of server settings static set once per runtime and not possible to dynamically toggled?

vim.api.nvim_create_autocmd({ "BufEnter", "LspAttach" }, {
    group = lsp_hacks,
    once = true,
    callback = function(e)
        local buf_ft = api.nvim_get_option_value("filetype", { buf = e.buf })
        local buf_clients = vim.lsp.get_clients({ bufnr = e.buf })
        if buf_ft ~= "markdown" or #buf_clients < 1 then
            return
        end
        for _, c in pairs(buf_clients) do
            if c.config.name == "harper-ls" and c.config.settings then
                c.config.settings["harper-ls"].linters.SentenceCapitalization = true
                c.config.settings["harper-ls"].linters.SpellCheck = true
                vim.notify("this runs!")
                break
            end
        end
    end,
})

Am I missing something? Anyone was able to achieve dynamic behavior setting for linters?

BTW: Just as a note. I'm trying autocmd because I already tried to place the logic inside of on_attach function and it similarly did not work.

[mcecode]

Hi, I'm not a Neovim user so others might be able to help you better. However, as for your question of

Are values of server settings static set once per runtime and not possible to dynamically toggled?

The answer is that harper-ls does support updating your settings since it implements the DidChangeConfiguration Notification in the LSP spec. I'm not sure if Neovim's built-in LSP client supports it out of the box or if what you're trying to do already tries to do it, but you can try sending an RPC request to workspace/didChangeConfiguration with your updated config to achieve this. It needs to be in the following shape:

{
  "settings": {
    "harper-ls": {
      // your settings here
    }
  }
}

[tom-gora]

that is exactly the structure I am accessing with dot notation here settings["harper-ls"].linters.SentenceCapitalization = true but that I realize might be set once at server start and just changing config might be not enough to toggle this at runtime. I need to read up on how to interact with server methods from lua though as I have no clue yet. Thank you for pointing me into the direction of workspace/didChangeConfiguration :)

[tom-gora]

Again, big thanksfor your suggestions! Made it work owed to your help :)

If anyone is interested in a working solution:

vim.api.nvim_create_autocmd({ "BufEnter", "LspAttach" }, {
	group = api.nvim_create_augroup("lspHacks", { clear = true }),
	callback = function(e)
		local plain_text_filetypes =
			{ "markdown", "markdown.mdx", "markdown.rmd", "markdown.pandoc", "tex", "txt", "log" }
		local buf_ft = api.nvim_get_option_value("filetype", { buf = e.buf })
		local buf_clients = vim.lsp.get_clients({ bufnr = e.buf })
		if not vim.tbl_contains(plain_text_filetypes, buf_ft) or #buf_clients < 1 then
			return
		end
		for _, c in pairs(buf_clients) do
			if
				c.config.name ~= "harper-ls"
				-- early return if change has already been toggled
				---@diagnostic disable-next-line: need-check-nil, inject-field, undefined-field
				or c.config.settings["harper-ls"].linters.SentenceCapitalization == true
			then
				return
			end
			local new_linters = {
				SpellCheck = true,
				SpelledNumbers = false,
				AnA = true,
				SentenceCapitalization = true,
				UnclosedQuotes = true,
				WrongQuotes = false,
				LongSentences = true,
				RepeatedWords = true,
				Spaces = true,
				Matcher = true,
				CorrectNumberSuffix = true,
			}
			---@diagnostic disable-next-line: need-check-nil, inject-field
			c.config.settings["harper-ls"].linters = new_linters
			---@diagnostic disable-next-line: param-type-not-match
			local ok, _ = pcall(c.notify, "workspace/didChangeConfiguration", { settings = c.config.settings })
			if ok then
				vim.notify("Harper LSP settings adjusted to plain text linting levels. ", vim.log.levels.INFO)
			else
				vim.notify("Harper LSP failed to register settings for plain text linting. 󰇸", vim.log.levels.ERROR)
			end
			break
		end
	end,
})

BTW. Not sure why using pattern key in autocmd opts does not work, but I do a manual check of buffer filetype and this way it does work! :)