fix snippet (#1051)

* fix snippet
* add snippet test

Author: prabirshrestha

autoload/lsp/omni.vim

@@ -299,6 +299,7 @@ function! lsp#omni#get_vim_completion_items(options) abort
         endif
 
         if l:expandable
+            let l:vim_complete_item['word'] = lsp#utils#make_valid_word(substitute(l:vim_complete_item['word'], '\$[0-9]\+\|\${\%(\\.\|[^}]\)\+}', '', 'g'))
             let l:vim_complete_item['abbr'] = l:completion_item['label'] . '~'
         else
             let l:vim_complete_item['abbr'] = l:completion_item['label']

test/lsp/omni.vimspec

@@ -140,5 +140,47 @@ Describe lsp#omni
             let got = lsp#omni#get_vim_completion_items(options)
             Assert Equals(got, want)
         End
+
+        It should return correct items for snippets
+            if !has('patch-8.0.1493')
+                Skip This test requires 'patch-8.0.1493'
+            endif
+
+            let item = {
+                \ "label": "sysout",
+                \ "insertText": "System.out.println(${0});",
+                \ "kind": 15,
+                \ "insertTextFormat": 2,
+                \ "documentation": "System.out.println();",
+                \ "detail": "print to standard out"
+                \ }
+
+            let options = {
+            \ 'server': { 'name': 'dummy-server' },
+            \ 'position': { 'line': 1, 'character': 1 },
+            \ 'response': { 'result': [item] },
+            \}
+
+            let want = {
+            \ 'items': [{
+            \  'word': 'System.out.println',
+            \  'abbr': 'sysout~',
+            \  'icase': 1,
+            \  'dup': 1,
+            \  'empty': 1,
+            \  'kind': 'snippet',
+            \  'user_data': '{"vim-lsp/key":"0"}',
+            \  }],
+            \  'incomplete': 0,
+            \}
+
+            let got = lsp#omni#get_vim_completion_items(options)
+            Assert Equals(got, want)
+            Assert Equals(lsp#omni#get_managed_user_data_from_completed_item(got['items'][0]), {
+                        \   'server_name': 'dummy-server',
+                        \   'completion_item': item,
+                        \   'complete_position': { 'line': 1, 'character': 1 }
+                        \ })
+        End
     End
 End