feat: integration with vsnip

feat: integration with vsnip

Author: haorenW1025

README.md

@@ -101,10 +101,20 @@ inoremap <silent><expr> <TAB>
 - By default other snippets source support are disabled, turn them on by
 
 ```vim
+" possible value: 'UltiSnips', 'Neosnippet'
 let g:completion_enable_snippet = 'UltiSnips'
 ```
 - Support `UltiSnips` and `Neosnippet`
 
+### LSP Based Snippet parsing
+
+- Some language server have snippet support but neovim couldn't handle that for now, `completion-nvim` can integrate
+with other LSP snippet parsing plugin for this support.
+
+- Right now only support `vim-vsnip`(require `vim-vsnip-integ`), it should
+work out of the box if you have ![vim-vsnip](https://github.com/hrsh7th/vim-vsnip) and
+![vim-vsnip-integ](https://github.com/hrsh7th/vim-vsnip-integ) installed.
+
 ### Chain Completion Support
 
 - completion-nvim supports chain completion, which use other completion sources

lua/completion.lua

@@ -3,9 +3,6 @@ local api = vim.api
 local source = require 'source'
 local signature = require'completion.signature_help'
 local hover = require'completion.hover'
-if vim.env.SNIPPETS then
-  vim.snippet = require 'snippet'
-end
 local M = {}
 
 ------------------------------------------------------------------------
@@ -65,14 +62,15 @@ function M.confirmCompletion()
         )
         vim.lsp.util.apply_text_edits(edits, bufnr)
       end
+      if vim.fn.exists('g:loaded_vsnip_integ') then
+        api.nvim_call_function('vsnip_integ#on_complete_done_for_lsp',
+          { { completed_item = complete_item, completion_item = item } })
+      end
     end
 
     if vim.g.completion_enable_auto_paren == 1 then
       M.autoAddParens(complete_item)
     end
-    if complete_item.kind == 'Snippet' and vim.snippet ~= nil then
-      vim.snippet.expand_at_cursor(complete_item.word)
-    end
     if complete_item.kind == 'UltiSnips' then
       api.nvim_call_function('UltiSnips#ExpandSnippet', {})
     elseif complete_item.kind == 'Neosnippet' then

lua/completion/util.lua

@@ -53,7 +53,7 @@ function M.text_document_completion_list_to_complete_items(result, prefix, score
 
   for _, completion_item in ipairs(items) do
     -- skip snippets items if snippet source are enabled
-    if vim.g.completion_enable_snippet == nil or
+    if vim.fn.exists('g:loaded_vsnip_integ') or
       protocol.CompletionItemKind[completion_item.kind] ~= 'Snippet' then
       local info = ' '
       local documentation = completion_item.documentation