Absolutely minimalistic, incredibly fast and fine looking neovim statusline, using only neovim API

statusline_neovim.md

It will give something like this, depending on file:

n packages/ecs-registry/src/enums.ts  [null-ls, ts_ls]     [E: 1 W: 0 I: 0 H: 0]  [typescript] 1% 1:1
n src/main.rs  [rust_analyzer]                                                          [rust] 0% 1:1
n init.lua  [lua_ls]                                           [E: 0 W: 2 I: 2 H: 1]  [lua] 78% 241:1
n main.cpp  [clangd]                                          [E: 4 W: 37 I: 0 H: 0]  [cpp] 42% 326:5

source:

function get_lsp_client()
   local msg = "No LSP"
   local buf_ft = vim.api.nvim_get_option_value("filetype", { buf = 0 })
   local clients = vim.lsp.get_clients { bufnr = 0 }
   if next(clients) == nil then return msg end
   local client_names = {}
   for _, client in pairs(clients) do
      table.insert(client_names, client.name)
   end
   return "[" .. table.concat(client_names, ", ") .. "]"
end

_G.lsp_msg = "" -- Initialize globally

vim.api.nvim_create_autocmd("LspProgress", {
   callback = function(ev)
      local value = ev.data.params.value
      if not value then return end

      if value.kind == "end" then
         _G.lsp_msg = ""
      else
         local map = {
            title = value.title,
            message = value.message,
            percentage = value.percentage,
         }
         local parts = {}
         if map.title then table.insert(parts, map.title) end
         if map.message then table.insert(parts, map.message) end
         if map.percentage then table.insert(parts, map.percentage .. "%") end

         _G.lsp_msg = table.concat(parts, " ")
      end
      vim.cmd "redrawstatus"
   end,
})
function _G.get_lsp_status() return _G.lsp_msg end

function get_lint_status()
   local diagnostics = vim.diagnostic.get(0)
   local counts = { E = 0, W = 0, I = 0, H = 0 }

   for _, d in ipairs(diagnostics) do
      if d.severity == vim.diagnostic.severity.ERROR then
         counts.E = counts.E + 1
      elseif d.severity == vim.diagnostic.severity.WARN then
         counts.W = counts.W + 1
      elseif d.severity == vim.diagnostic.severity.INFO then
         counts.I = counts.I + 1
      elseif d.severity == vim.diagnostic.severity.HINT then
         counts.H = counts.H + 1
      end
   end

   if (counts.E + counts.W + counts.I + counts.H) == 0 then return "" end

   return string.format(
      "[E: %d W: %d I: %d H: %d]",
      counts.E,
      counts.W,
      counts.I,
      counts.H
   )
end
vim.opt.statusline =
   "%{mode()} %f %m %{v:lua.get_lsp_client()} %{v:lua.get_lsp_status()} %= %{v:lua.get_lint_status()}  %y %p%% %l:%c"