fix: avoid overwrting user defined mapping

autoload/completion.vim

@@ -5,8 +5,14 @@ function! completion#completion_confirm() abort
 endfunction
 
 function! completion#wrap_completion() abort
- if pumvisible() != 0 && complete_info()["selected"] != "-1"
- call completion#completion_confirm()
+ if pumvisible() != 0
+ if complete_info()["selected"] != "-1"
+ call completion#completion_confirm()
+ else
+ call nvim_feedkeys("\<c-e>", "n", v:true)
+ let key = g:completion_confirm_key
+ call nvim_feedkeys(key, "n", v:true)
+ endif
  else
  call nvim_feedkeys("\<c-g>\<c-g>", "n", v:true)
  let key = g:completion_confirm_key

lua/completion.lua

@@ -33,6 +33,7 @@ M.triggerCompletion = function()
  source.triggerCompletion(true, manager)
 end
 
+
 M.completionToggle = function()
  local enable = api.nvim_call_function('completion#get_buffer_variable', {'completion_enable'})
  if enable == nil then
@@ -110,6 +111,17 @@ local function hasConfirmedCompletion()
  end
 end
 
+-- make sure we didn't overwrite user defined mapping
+local function checkMapping(map, key)
+ for _, m in ipairs(map) do
+ if api.nvim_replace_termcodes(m.lhs, true, false, true) == api.nvim_replace_termcodes(key, true, false, true) then
+ if not m.rhs:find("completion_confirm_completion") then
+ return false
+ end
+ end
+ end
+ return true
+end
 ------------------------------------------------------------------------
 -- autocommands --
 ------------------------------------------------------------------------
@@ -213,11 +225,19 @@ M.on_attach = function(option)
  api.nvim_command("autocmd InsertCharPre <buffer> lua require'completion'.on_InsertCharPre()")
  api.nvim_command("autocmd CompleteDone <buffer> lua require'completion'.on_CompleteDone()")
  api.nvim_command("augroup end")
- if string.len(opt.get_option('confirm_key')) ~= 0 then
- api.nvim_buf_set_keymap(0, 'i', opt.get_option('confirm_key'),
- 'pumvisible() ? complete_info()["selected"] != "-1" ? "\\<Plug>(completion_confirm_completion)" :'..
- ' "\\<c-e>\\<CR>" : "\\<CR>"',
- {silent=false, noremap=false, expr=true})
+ local confirm_key = opt.get_option('confirm_key')
+ if string.len(confirm_key) ~= 0 then
+ if checkMapping(api.nvim_buf_get_keymap(0, "i"), confirm_key) and 
+ (manager.checkGlobalMapping or checkMapping(api.nvim_get_keymap("i"), confirm_key)) then
+ manager.checkGlobalMapping = true
+ api.nvim_buf_set_keymap(0, 'i', confirm_key, '<Plug>(completion_confirm_completion)',
+ {silent=false, noremap=false})
+ else
+ api.nvim_err_writeln(string.format(
+ "completion-nvim: mapping conflict! you've already mapped your confirm key to something else in insert mode. ".. 
+ " Consider changing g:completion_confirm_key"
+ ))
+ end
  end
  -- overwrite vsnip_integ autocmd since we handle it on ourself in confirmCompletion
  if vim.fn.exists("#vsnip_integ") then

lua/completion/manager.lua

@@ -19,6 +19,7 @@ manager = {
  confirmedCompletion = false, -- flag for manual confirmation of completion
  forceCompletion = false, -- flag for forced manual completion/source change
  chainIndex = 1, -- current index in loaded chain
+ checkGlobalMapping = false -- indication of global mapping is checked or not
 }
 
 -- reset manager