Insert `rubocop:disable`/`rubocop:enable` comments

rubocop_disable.lua

RD = RD or {}

function RD.join(tbl, sep)
  local ret = ''
  for i, v in pairs(tbl) do
    ret = ret .. v .. sep
  end
  return ret:sub(1, -#sep - 1)
end

function RD.map(tbl, f)
  local t = {}
  for k,v in pairs(tbl) do
    t[k] = f(v)
  end
  return t
end

function RD.rubocop_disable()
  local current_lnum = vim.api.nvim_win_get_cursor(0)[1]
  local current_line = vim.api.nvim_get_current_line()

  local diagnostics = vim.diagnostic.get(0, { lnum = current_lnum - 1 })
  local diagnostic = diagnostics[1]

  if diagnostic and diagnostic.source == 'rubocop' then
    local code = RD.join(RD.map(diagnostics, function(d) return d.code end), ', ')

    if diagnostic.lnum == diagnostic.end_lnum then
      local new_text = current_line .. ' # rubocop:disable ' .. code
      vim.api.nvim_set_current_line(new_text)
    else
      local indent = tonumber(vim.call('indent', current_lnum))
      local padding = string.rep(' ', indent)

      local enable_text = padding .. '# rubocop:enable ' .. code
      vim.api.nvim_buf_set_lines(0, diagnostic.end_lnum + 1, diagnostic.end_lnum + 1, false, {enable_text})

      local disable_text = padding .. '# rubocop:disable ' .. code
      vim.api.nvim_buf_set_lines(0, diagnostic.lnum, diagnostic.lnum, false, {disable_text})
    end
  end
end

vim.api.nvim_set_keymap('n', '<space>x', '<cmd>lua RD.rubocop_disable()<CR>', {})

This works when rubocop messages are coming via https://github.com/jose-elias-alvarez/null-ls.nvim