F.A.Q

Here are some common problems that you may need to understand when working with coc.nvim.

Can't get keywords completion items from other buffer.

The buffer source only provide keywords from buffers meet these conditions:

• Use bufloaded() function to check if a buffer is loaded.
• The buftype option should be empty, check it by :echo getbufvar(bufnr, "&buftype").

Environment node doesn't meet the requirement.

Use let g:coc_node_path = '/path/to/node' to make coc.nvim use custom node executable.

Bad background highlight of floating window

The background used for floating window is CocFloating which linked to NormalFloat on neovim or Pmenu on vim8. Reset the highlight in your vimrc if it's not suitable, or use colorscheme that works fine by default, for example: https://github.com/morhetz/gruvbox

Floating window position is wrong after scroll the screen.

It's expected since the float windows/popups are absolutely positioned.

How could I use omnifunc option to trigger completion of coc.nvim?

You can't, there's no such function provided for omnifunc option, because vim's omnifunc always block and LSP features like triggerCharacters and incomplete response can't work.

If you want to manually trigger completion add "suggest.autoTrigger": "none", to coc-settings.json and bind a trigger key like:

  inoremap <silent><expr> <c-space> coc#refresh()

Note that some terminals send <NUL> when you press <c-space>, so you could use instead:

  inoremap <silent><expr> <NUL> coc#refresh()

How could I disable floating window?

• For documentation of completion, use "suggest.floatEnable": false in settings.json.
• For diagnostic messages, use "diagnostic.messageTarget": "echo" in settings.json.
• For signature help, use "signature.target": "echo" in settings.json.
• For documentation on hover, use "hover.target": "echo" in settings.json.

Highlight of background seems wrong with floating window.

The default highlight group linked by CocFloating could have reverse attribute, you will have colored background for some texts on that case, define your own CocFloating highlight group on that case.

hi link CocFloating Normal

How to make preview window shown aside with pum?

For vim, make sure echo has('textprop') && has('patch-8.1.1719') echo 1. For neovim, make sure :echo exists('##CompleteChanged') && exists('*nvim_open_win') echo 1.

To preview expanded snippet body, you can use coc-snippets.

My pum flickers when typing.

Use latest neovim/vim which support equal field of completion item, checkout :h complete-items to see if it's supported.

My vim is blocked sometimes.

• Make sure you have set hidden in your .vimrc.
• Use CocActionAsync instead of CocAction in your autocmd, except for BufWritePre.
• Use CocRequestAsync instead of CocRequest when possible.

Language server doesn't work with unsaved buffer.

Some language servers don't work when the buffer not saved to disk. This is because they only tested on VSCode which always create file before create buffer.

Save the buffer to disk and restart coc.nvim server by :CocRestart to make the language server work.

Function parameter/auto import not work on complete done.

• Make sure the language server your're using have support for function snippet/auto import.
• You must use confirm completion to make coc.nvim does extra edit after complete done, which is <C-y> by default.
• Some language servers are known to have issues with responded textEdit on completion.
• Some language servers doesn't have support for textEdit on completion but coc extension does, so it's better to use extension when it exists.

Linting is slow.

By default, coc doesn't show diagnostics in UI when you're in insert mode, add "diagnostic.refreshOnInsertMode": true in settings file to enable refresh on insert mode.

Sign of diagnostics not shown.

If there are other signs that have higher offset, sign of coc.nvim can't be shown. You can change the offset of coc.nvim's signs by add "diagnostic.signOffset": 9999999 to your coc-settings.json to make it higher priority. The default value is 1000. You can also change the signcolumn option (available with latest neovim) like: set signcolumn=auto:2.

Not working after upgrade node.

Run command :CocRebuild to rebuild coc extensions. Some of them could be using C++ add-ons, which require a rebuild after upgrade.

If it's still not working, you can force coc to start with a specified node executable. In your .vimrc add a line like let g:coc_node_path = '/usr/local/opt/node@10/bin/node'

No completion triggered after type trigger character sometimes.

Some language servers can be slow for receiving document change before trigger completion. You can change the wait time for language server to finish the document change process before completion by changing suggest.triggerCompletionWait in your coc-settings.json, it's default to 50 in milliseconds.

My custom key-mapping is not working.

Some plugins like Ultisnips and vim-closer would remap your <tab> or <cr> without configuration. You can check out your key-mapping by command like :verbose imap <tab>.

How could I profile vim.

• Enter these commands:

  :profile start profile.log
  :profile func *
  :profile file *

• Make issue happen.
• Run command :profile stop (neovim only).
• Exit vim, and open the newly generated profile.log file in your current directory.

How could I profile coc.nvim.

To get the communication between vim and coc.nvim

• Add let g:node_client_debug = 1 in your vimrc.
• Restart vim and make issue happen.
• Use command :call coc#client#open_log() to open log file, or use :echo $NODE_CLIENT_LOG_FILE to get file path of log.

How to change highlight of diagnostic signs?

The sign highlight groups are CocErrorSign CocWarningSign CocInfoSign CocHintSign

You can customize the highlight by adding something like:

highlight link CocErrorSign GruvboxRed

In your .vimrc.

See :h coc-highlights for all highlight groups.

How to get log of coc.nvim?

Enable debug mode for coc in your terminal:

export NVIM_COC_LOG_LEVEL=debug

Open log file by command:

:CocOpenLog

How to show documentation of symbol under cursor, also known as cursor hover?

This is done by the doHover action. Configure a mapping like, e.g.:

nnoremap <silent> <leader>h :call CocActionAsync('doHover')<cr>

Cursor disappeared after exit CocList

Possible bug with guicursor option on your terminal, you can disable transparent cursor by let g:coc_disable_transparent_cursor = 1 in your .vimrc.