nvim/lua/config/barbar.lua

require("bufferline").setup ({
    options = {
        diagnostics = "nvim_lsp",
        always_show_bufferline = true,
        diagnostics_indicator = function(_, _, diag)
            local icons = LazyVim.config.icons.diagnostics
            local ret = (diag.error and icons.Error .. diag.error .. " " or "")
            .. (diag.warning and icons.Warn .. diag.warning or "")
            return vim.trim(ret)
        end,
        offsets = {
            {
                filetype = "neo-tree",
                text = "Neo-tree",
                highlight = "Directory",
                text_align = "left",
            },
            {
                filetype = "snacks_layout_box",
            },
        },
        vim.api.nvim_create_autocmd({ "BufAdd", "BufDelete" }, {
            callback = function()
                vim.schedule(function()
                    pcall(nvim_bufferline)
                end)
            end,
        })
    },
})