Neovim + cmp duplicate elements

Plugins
1

Снимок экрана 2022-01-05 в 15.23.31
Снимок экрана 2022-01-05 в 15.23.31495×522 24.7 KB

can you tell me this is the normal behavior of the plugin?

2

You can try with this setting

require("cmp").setup({
   formatting = {
      format = function (entry, vim_item)
			vim_item.dup = { buffer = 1, path = 1, nvim_lsp = 0 }
      end
   }
})
3 
Error executing vim.schedule lua callback: ...e/nvim/site/pack/packer/start/nvim-cmp/lua/cmp/entry.lua:290: attempt to index local 'vim_item' (a nil value)                                                                                     
stack traceback:                                                                                                                                                                                                                                
        ...e/nvim/site/pack/packer/start/nvim-cmp/lua/cmp/entry.lua:290: in function 'callback'                                                                                                                                                 
        .../site/pack/packer/start/nvim-cmp/lua/cmp/utils/cache.lua:36: in function 'get_vim_item'                                                                                                                                              
        ...e/nvim/site/pack/packer/start/nvim-cmp/lua/cmp/entry.lua:205: in function 'get_view'                                                                                                                                                 
        ...cker/start/nvim-cmp/lua/cmp/view/custom_entries_view.lua:121: in function 'open'                                                                                                                                                     
        ...re/nvim/site/pack/packer/start/nvim-cmp/lua/cmp/view.lua:107: in function 'open'                                                                                                                                                     
        ...re/nvim/site/pack/packer/start/nvim-cmp/lua/cmp/core.lua:284: in function 'cb'                                                                                                                                                       
        vim.lua:285: in function <vim.lua:285>
4

my config

local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities = require('cmp_nvim_lsp').update_capabilities(capabilities)
vim.o.completeopt = 'menuone,noselect'
-- luasnip setup
local luasnip = require 'luasnip'
-- nvim-cmp setup
local cmp = require 'cmp'
cmp.setup {
    snippet = {
        expand = function(args)
            luasnip.lsp_expand(args.body)
        end,
    },
    formatting = {
      format = function (entry, vim_item)
			vim_item.dup = { buffer = 1, path = 1, nvim_lsp = 0 }
      end,
   },
    sources = {
        { name = 'nvim_lsp' },
        { name = 'luasnip' },
        { name = 'path' },
        { name = 'buffer', option = {
            get_bufnrs = function()
                return vim.api.nvim_list_bufs()
            end
        },
      },
    },
}