Lualine config for LSP clients, formatters and linters

lualine.lua

-- Returns a string with a list of attached LSP clients, including 
-- formatters and linters from null-ls, nvim-lint and formatter.nvim

local function get_attached_clients()
	local buf_clients = vim.lsp.get_active_clients({ bufnr = 0 })
	if #buf_clients == 0 then
		return "LSP Inactive"
	end

	local buf_ft = vim.bo.filetype
	local buf_client_names = {}

	-- add client
	for _, client in pairs(buf_clients) do
		if client.name ~= "copilot" and client.name ~= "null-ls" then
			table.insert(buf_client_names, client.name)
		end
	end

	-- Generally, you should use either null-ls or nvim-lint + formatter.nvim, not both.
    
	-- Add sources (from null-ls)
	-- null-ls registers each source as a separate attached client, so we need to filter for unique names down below.
	local null_ls_s, null_ls = pcall(require, "null-ls")
	if null_ls_s then
		local sources = null_ls.get_sources()
		for _, source in ipairs(sources) do
			if source._validated then
				for ft_name, ft_active in pairs(source.filetypes) do
					if ft_name == buf_ft and ft_active then
						table.insert(buf_client_names, source.name)
					end
				end
			end
		end
	end

	-- Add linters (from nvim-lint)
	local lint_s, lint = pcall(require, "lint")
	if lint_s then
		for ft_k, ft_v in pairs(lint.linters_by_ft) do
			if type(ft_v) == "table" then
				for _, linter in ipairs(ft_v) do
					if buf_ft == ft_k then
						table.insert(buf_client_names, linter)
					end
				end
			elseif type(ft_v) == "string" then
				if buf_ft == ft_k then
					table.insert(buf_client_names, ft_v)
				end
			end
		end
	end

	-- Add formatters (from formatter.nvim)
	local formatter_s, _ = pcall(require, "formatter")
	if formatter_s then
		local formatter_util = require("formatter.util")
		for _, formatter in ipairs(formatter_util.get_available_formatters_for_ft(buf_ft)) do
			if formatter then
				table.insert(buf_client_names, formatter)
			end
		end
	end

	-- This needs to be a string only table so we can use concat below
	local unique_client_names = {}
	for _, client_name_target in ipairs(buf_client_names) do
		local is_duplicate = false
		for _, client_name_compare in ipairs(unique_client_names) do
			if client_name_target == client_name_compare then
				is_duplicate = true
			end
		end
		if not is_duplicate then
			table.insert(unique_client_names, client_name_target)
		end
	end

	local client_names_str = table.concat(unique_client_names, ", ")
	local language_servers = string.format("[%s]", client_names_str)

	return language_servers
end


return {
    "nvim-lualine/lualine.nvim",
    event = { "VimEnter", "BufReadPost", "BufNewFile" },
    config = function()
        local attached_clients = {
            get_attached_clients,
            color = {
                gui = "bold"
            }
        }
        -- Example lualine setup
        require("lualine").setup({
            options = {
                theme = "auto",
                globalstatus = true,
                component_separators = { left = "|", right = "|" },
            },

            
            sections = {
                lualine_b = { "branch", "diff" },
                lualine_x = { "diagnostics", attached_clients, "filetype" },

            }
        })
    end,
}